text:
Radiation astronomy/Asteroids
Asteroids in the solar system are categorized by size and number. Credit: Marco Colombo, DensityDesign Research Lab.{{free media}}
The center image is a log-log plot of frequency vs. size for asteroids in the solar system.
Theoretical asteroidsEdit
Def. a "naturally occurring solid object, [which is] smaller than a planet[1] and is not a comet,[2] that orbits a star"[3] is called an asteroid.
"The term "asteroid" has never been precisely defined. It was coined for objects which looked like stars in a telescope but moved like planets. These were known from the asteroid belt between Mars and Jupiter, and were later found co-orbiting with Jupiter (Trojan asteroids) and within the orbit of Mars. They were naturally distinguished from comets, which did not look at all starlike. Starting in the 1970s, small non-cometary bodies were found outside the orbit of Jupiter, and usage became divided as to whether to call these "asteroids" as well. Some astronomers restrict the term "asteroid" to rocky or rocky-icy bodies with orbits up to Jupiter. They may retain the term planetoid for all small bodies, and thus tend to use it for icy or rocky-icy bodies beyond Jupiter, or may use dedicated words such as centaurs, Kuiper belt objects, transneptunian objects, etc. for the latter. Other astronomers use "asteroid" for all non-cometary bodies smaller than a planet, even large ones such as Sedna and (occasionally) Pluto. However, the distinction between asteroid and comet is an artificial one; many outer "asteroids" would become comets if they ventured nearer the Sun. The official terminology since 2006 has been small Solar System body for any body that orbits the Sun directly and whose shape is not dominated by gravity."[1]
EntitiesEdit
Main articles: Radiation astronomy/Entities and Entities
"Asteroids in particularly large classes tend to be broken into subgroups with the first letter denoting the dominant group and the succeeding letters denoting less prominent spectral affinities or subgroups."[4]
"From the dominant group, the asteroids evolve to intersect the Earth's orbit on a median time scale of about 60 Myr."[5]
A asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/As and A asteroids
Spectra "of several related asteroid classes (types A, R, and V) were also analyzed for comparison to various S-subtypes."[6]
"Observing 246 Asporina and 289 Nenetta, [6] were the first to identify A-type asteroids as nearly pure olivine assemblages based on their spectral characteristics. These asteroids display a single broad absorption feature centered at 1.06 μm (Band I) without any significant pyroxene feature at ~2.0 μm (Band II)."[7]
Only "a handful of A-type objects were discovered during the taxonomic surveys, assuming that all A-type asteroids are olivine-rich. The study of A-type asteroids may help solve the "missing mantle problem" in the asteroid belt."[7]
Blue asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Blues and Blue asteroids
This is an ultraviolet image of Pallas showing its flattened shape taken by the Hubble Space Telescope. Credit: NASA.
Pallas, minor-planet designation 2 Pallas, is the second asteroid to have been discovered (after Ceres), and one of the largest in the Solar System. It is estimated to comprise 7% of the mass of the asteroid belt,[8] and its diameter of 544 kilometres (338 mi) is slightly larger than that of 4 Vesta. It is however 10–30% less massive than Vesta,[9] placing it third among the asteroids.
"Spectrally blue (B-type) asteroids are rare, with the second discovered asteroid, Pallas, being the largest and most famous example."[10]
"[T]he negative optical spectral slope of some B-type asteroids is due to the presence of a broad absorption band centered near 1.0 μm. The 1 μm band can be matched in position and shape using magnetite (Fe3O4), which is an important indicator of past aqueous alteration in the parent body. ... Observations of B-type asteroid (335) Roberta in the 3 μm region reveal an absorption feature centered at 2.9 μm, which is consistent with the absorption due to phyllosilicates (another hydration product) observed in CI chondrites. ... at least some B-type asteroids are likely to have incorporated significant amounts of water ice and to have experienced intensive aqueous alteration."[10]
"The [Sloan Digital Sky Survey] SDSS "blue" asteroids are related to the C-type (carbonaceous) asteroids, but not all of them are C-type. They are a mixture of C-, E-, M-, and P-types."[11]
Carbonaceous asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Carbonaceous and Carbonaceous asteroids
C-type asteroids are carbonaceous asteroids. They are the most common variety, forming around 75% of known asteroids,[12] and an even higher percentage in the outer part of the asteroid belt beyond 2.7 AU, which is dominated by this asteroid type. The proportion of C-types may actually be greater than this, because C-types are much darker than most other asteroid types except D-types and others common only at the extreme outer edge of the asteroid belt. Their spectra contain moderately strong ultraviolet absorption at wavelengths below about 0.4 μm to 0.5 μm, while at longer wavelengths they are largely featureless but slightly reddish. The so-called "water" absorption feature around 3 μm, which can be an indication of water content in minerals is also present.
D asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Ds and D asteroids
"Two comets observed at low activity (visible nuclei) also have properties more consistent with D asteroids than any other class (very low reported geometric albedos of 0.02 and red colors)."[13]
E asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Es and E asteroids
The "enstatite achondrite-like E-asteroids almost certainly derive from the melting and differentiation of highly reduced parent materials analogous to enstatite chondrites (e.g., Keil 1989)."[6]
F asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Fs and F asteroids
F-type asteroids have spectra generally similar to those of the B-type asteroids, but lack the "water" absorption feature around 3 μm indicative of hydrated minerals, and differ in the low wavelength part of the ultraviolet spectrum below 0.4 μm.
G asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Gs and G asteroids
"G-type asteroids are a relatively uncommon type of carbonaceous asteroid. The most notable asteroid in this class is 1 Draft:Ceres. Generally similar to the C-type objects, but containing a strong ultraviolet absorption feature below 0.5 μm.
H asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Hs and H asteroids
"Group H asteroids are apparently olivine rich. In addition, this group exhibits the lowest mean value for the bend parameter. The asteroid 7 Iris is a typical member of this group."[14]
I asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Is and I asteroids
Hardersen (2003) "started by dividing asteroids into two classes: Class I asteroids, which allow diagnostic determinations of their mineralogy, and Class II asteroids, where the determination is nondiagnostic and open to interpretation."[15]
J asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Js and J asteroids
"The remaining six are interpreted as diogenitic in composition and were designated as J asteroids (mnemonic for the Johnstown diogenite)."[16]
K asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Ks and K asteroids
"Bell (1988) distinguished a new class (K-type) from previous members of the S-class and interpreted these objects as composed of material analogous to the undifferentiated CO3 ro CV3 carbonaceous chondrites."[6]
L asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Ls and L asteroids
"Color dependent photometry calibration, or the HK solar color, might be in error by 0.1 magnitude and cause the L asteroids not to coincide with the carbonaceous chondrites, but we do not think that this is a very likely possibility."[17]
M asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Ms and M asteroids
"Exposure of compositionally distinct internal layers from within parent planetesimals may be an important source of the diversity within the S-population and is presumably the source of the M- and A-type."[6]
"M-class [...] contains both metallic objects [...] 216 Kleopatra and [...] 16 Psyche".[18]
N asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Ns and N asteroids
"Emission features attributable to fine-grained silicates are seen in the spectra of two of the M-types and at least four of the C-types. This is the first positive evidence that N-type asteroids have a silicate component on their surface similar to that of other asteroids."[19]
O asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Os and O asteroids
"O-type asteroids 3628 Boznemcová and 7472 Kumakiri have absorption bands similar to pyroxenes but with band minima that are not typically found for terrestrial pyroxenes and known pyroxene-dominated meteorite assemblages."[20]
P asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Ps and P asteroids
"Whereas most of the P-type asteroids spectrally match the Tagish Lake meteorite in the wavelength range longer than 0.9 μm, they are different in the shorter wavelength range."[21]
Q asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Qs and Q asteroids
lf "planetary encounters are important, the distribution of Q-type asteroids in the planet-crossing space should show a correlation with the perihelion distance, exactly as we have found here."[22]
R asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Rs and R asteroids
"A-type asteroids are a relatively rare taxonomic class with no more than 17 known objects [1,2,3]. They were first identified as a separate group of R-type asteroids based on broadband spectrophotometry by [4], and were later classified based on ECAS data by Tholen (1984) [1]."[7]
Siliceous asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Siliceous and Siliceous asteroids
This graph depicts carrier wavelength versus band ratios to divide or characterize the siliceous asteroids. Credit: Michael J. Gaffey, Jeffrey F. Bell, R. Hamilton Brown, Thomas H. Burbine, Jennifer L. Piatek, Kevin L. Reed, and Damon A. Chaky.
"The presence of trapped solar gas in stony meteorites places their origin in the regoliths of asteroidal-type bodies. The most plausible sources are the C (carbonaceous) and S (siliceous) asteroids, in spite of the differences between the spectra of S asteroids and ordinary chondrites."[23]
"The S-asteroid class includes a number of distinct compositional subtypes [designated S(I)-S(VII)] which exhibit surface silicate assemblages ranging from pure olivine (dunites) through olivine-pyroxene mixtures to pure pyroxene or pyroxene-feldspar mixtures (basalts)."[6] These are shown in the graph on the right.
T asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Ts and T asteroids
The "T-type asteroids appear to contain at least two mineralogically distinct types."[24]
U asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Us and U asteroids
"The SU type represents an ambiguous classification with parameters of both the S- and the [unusual] U-types but with the former more likely--Tholen 1984, 1989, Tholen and Barucci 1989."[6]
V asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Vs and V asteroids
As NASA's Dawn spacecraft takes off for its next destination, this mosaic synthesizes some of the best views the spacecraft had of the giant asteroid Vesta. Credit: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA.
Location and structure of the Vesta family are depicted. Credit: Deuar.
In the full image of Vesta at right, the rocky-object appears to have suffered from meteor damage.
Vesta, minor-planet designation 4 Vesta, is one of the largest asteroids in the Solar System. It lost some 1% of its mass less than a billion years ago in a collision that left an enormous crater occupying much of its southern hemisphere. Debris from this event has fallen to Earth as howardite–eucrite–diogenite (HED) meteorites, a rich source of information about the asteroid.[25][26]
"V-type asteroids are bodies whose surfaces are constituted of basalt. In the Main Asteroid Belt, most of these asteroids are assumed to come from the basaltic crust of Asteroid (4) Vesta."[27]
The Vestian asteroids consist "of 4 Vesta, the second-most-massive of all asteroids (mean diameter of 530 km), and many small asteroids below 10 km diameter. The brightest of these, 1929 Kollaa and 2045 Peking, have an absolute magnitude of 12.2, which would give them a radius of about 7.5 km assuming the same high albedo as 4 Vesta."[28]
"A HCM numerical analysis (by Zappala 1995) determined a large group of 'core' family members, whose proper orbital elements lie in the approximate ranges"[28]
min 2.26 AU 0.075 5.6°
max 2.48 AU 0.122 7.9°
"This gives the approximate boundaries of the family. At the present epoch, the range of osculating orbital elements of these core members is"[28]
"The Zappala 1995 analysis[29] found 235 core members. A search of a recent proper-element database (AstDys) for 96944 minor planets in 2005 yielded 6051 objects (about 6% of the total) lying within the Vesta-family region as per the first table above."[28]
W asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Ws and W asteroids
"Rivkin et al. also noted that W-type asteroids in their survey are lacking an FeO absorption band (0.4–0.5 μm), an expected feature if the hydrated minerals formed in the presence of significant free metal."[30]
"CB chondrites have only very minor amounts of phyllosilicates and may come from W-type asteroids ("wet-M" asteroids)."[31]
X asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Xs and X asteroids
"Since the composition of X-type asteroids remains unclear and their relation to mineralogical type is unknown, [87] Sylvia's bulk porosity is not well constrained."[32]
Y asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Ys and Y asteroids
Yarkovsky effect:
1. Radiation from asteroid's surface
2. Prograde rotating asteroid
2.1 Location with "Afternoon"
3. Asteroid's orbit
4. Radiation from Sun. Credit: Graevemoore.
The possible importance of the Yarkovsky effect is the movement of meteoroids about the Solar System.[33]
The diurnal effect is the dominant component for bodies with diameter greater than about 100 m.[34]
On very long timescales over which the spin axis of the body may be repeatedly changed due to collisions (and hence also the direction of the diurnal effect changes), the seasonal effect will also tend to dominate.[34]
The effect was first measured in 1991–2003 on the asteroid 6489 Golevka which drifted 15 km from its predicted position over twelve years (the orbit was established with great precision by a series of radar observations in 1991, 1995 and 1999 from the Arecibo Observatory radio telescope).[35]
The "population of asteroids in comet-like orbits using available asteroid size and albedo catalogs of data taken with the Infrared Astronomical Satellite [I], AKARI [A], and the Wide-field Infrared Survey Explorer [W] on the basis of their orbital properties (i.e., the Tisserand parameter with respect to Jupiter, TJ, and the aphelion distance, Q, [is] 123 asteroids in comet-like orbits [with] Q < 4.5 AU and TJ < 3, [including] a considerable number (i.e., 25 by our criteria) of asteroids in comet-like orbits have high albedo, pv > 0.1. [As] such high-albedo objects mostly consist of small (D < 3 km) bodies distributed in near-Earth space (with perihelion distance of q < 1.3 AU) [may be] susceptible to the Yarkovsky effect and drifted into comet-like orbits via chaotic resonances with planets."[36]
"There are 138,285 asteroids whose albedos and sizes are given in the I–A–W catalog. [...] nearly all high-albedo [asteroids in comet-like orbits] ACOs consist of small asteroids at q < 1.3 AU. This trend cannot be explained by the observational bias. Because the result is obtained based on the mid-infrared data, which, unlike optical observations, are less sensitive to albedo values, it provides reliable sets of asteroid albedo information. If there are big ACOs with high albedo beyond q = 1.3 AU, they would be detected easily. Although further dynamical study is essential to evaluate the population quantitatively, we propose that such ACOs with high albedos were injected from the domain of TJ > 3 via the Yarkovsky effect, because small objects with higher surface temperature are susceptible to the thermal drag force and gradually change their orbital elements to be observed as ACOs in our list."[36]
"Although there are uncertainties in the dynamical simulation such as the value of the Yarkovsky force and the rocket force (for active comets), we conservatively consider that these three objects (2000 SU236, 2008 UM7, and 2009 SC298) are ACOs and PDCs. ["potential dormant comet" (PDC) is one having a low albedo (pv < 0.1) among ACOs. The second term is a paronomasia associating the spectra of potential dormant comets with spectra similar to P-type, D-type, or C-type asteroids (Licandro et al. 2008; DeMeo & Binzel 2008).]"[36]
"Let us consider how the Yarkovsky effect moves an asteroid into a comet-like orbit. As shown [...], high-albedo ACOs concentrate in a range of 2 < a < 3.5 AU, similar to main-belt asteroids and [Jupiter-family comets] JFCs. The Tisserand parameter is a function of a, e, and i, [the semimajor axis, eccentricity, and inclination, respectively] while the Yarkovsky effect changes a. Due to the similarity in a between high-albedo ACOs and main-belt asteroids, we conjecture that subsequent dynamical effects may change e and i. Widely known as a standard model for orbital evolution of near-Earth asteroids, the Yarkovsky effect could move small main-belt asteroids' orbits until they are close to resonances with planets, and subsequently, these resonances can push them into terrestrial planet crossing orbits (see, e.g., Morbidelli et al. 2002). Numerical simulations demonstrated that chaotic resonances cause a significant increase in the e and i of test particles in the resonance regions (Gladman et al. 1997). Bottke et al. (2002) suggested that some objects on TJ < 3 (or even TJ < 2) can result from chaotic resonances. [...] Although there are a couple of ACOs close to resonances, their semimajor axes are not related to these major resonances. Therefore, it may be reasonable to think that encounters with terrestrial planets as well as chaotic resonances with massive planets can drift main-belt asteroids into comet-like orbits."[36]
"In particular, we stress again the significance of high-albedo ACOs. As we discussed through our ground-based observation with the Subaru Telescope, high-albedo ACOs, which may have composition similar to silicaceous asteroids, definitively exist in the I–A–W database. Considering the very low TJ as well as the small size and perihelion distance, we suggest that such high-albedo ACOs have been injected via nongravitational forces, most likely the Yarkovsky effect."[36]
Z asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Zs and Z asteroids
"There is a general increase in 'redness' with heliocentric distance in the outer belt asteroids going from the moderately red P asteroids, through the redder D asteroids, to the much redder Z asteroids."[37]
Earth crossersEdit
Main articles: Rocks/Rocky objects/Asteroids/Earth crossers and Earth crossers
The close approach of apollo asteroid 2007 VK184 was in May 2014. Credit: Osamu Ajiki (AstroArts) and Ron Baalke (JPL).
EC denotes Earth-crossing.[5]
"50 % of the MB Mars-crossers [MCs] become ECs within 59.9 Myr and [this] contribution ... dominates the production of ECs".[5]
This diagram maps the data gathered from 1994-2013 on small asteroids impacting Earth's atmosphere. Credit: NASA/Planetary Science.
"This diagram [center] maps the data gathered from 1994-2013 on small asteroids impacting Earth's atmosphere to create very bright meteors, technically called "bolides" and commonly referred to as "fireballs". Sizes of red dots (daytime impacts) and blue dots (nighttime impacts) are proportional to the optical radiated energy of impacts measured in billions of Joules (GJ) of energy, and show the location of impacts from objects about 1 meter (3 feet) to almost 20 meters (60 feet) in size."[38]
"A map released [...] by NASA's Near Earth Object (NEO) Program reveals that small asteroids frequently enter and disintegrate in the Earth's atmosphere with random distribution around the globe. Released to the scientific community, the map visualizes data gathered by U.S. government sensors from 1994 to 2013. The data indicate that Earth's atmosphere was impacted by small asteroids, resulting in a bolide (or fireball), on 556 separate occasions in a 20-year period. Almost all asteroids of this size disintegrate in the atmosphere and are usually harmless. The notable exception was the Chelyabinsk event which was the largest asteroid to hit Earth in this period."[38]
2008 TC3Edit
Estimated path and altitude of the meteor in red, with the possible location for the METEOSAT IR fireball (bolide) as orange crosshairs and the infrasound detection of the explosion in green. Credit: George William Herbert (graphic overlay) / US Government (original map).{{free media}}
An animation of 2008 TC3's excited rotation prior to entering the atmosphere is shown. Credit: Astronomical Institute of the Charles University: Josef Ďurech, Vojtěch Sidorin.
Meteosat 8/EUMETSAT infrared image is of the explosion. Credit: .
This webcam frame was shot. Credit: Webcam at kitepower, Mangroovy Beach, El Gouna, Red Sea governate, Egypt.
2008 TC3 fragment was found on February 28, 2009 by Peter Jenniskens, with help from students and staff of the University of Khartoum. Nubian Desert, Sudan. Credit: .
Meteosat 8 / EUMETSAT visual image is first light flare from 2008 TC3 with lat/long reference. Credit: .
Meteosat 8 / EUMETSAT IR image of main fireball from 2008 TC3. Credit: .
Meteosat images combined, showing offset from first light flare to main IR flare. Credit:
2008 TC3 (Catalina Sky Survey temporary designation 8TA9D69) was an 80-tonne (80-long-ton; 90-short-ton), 4.1-meter (13 ft) diameter asteroid[39] that entered Earth's atmosphere on October 7, 2008.[40] It exploded at an estimated 37 kilometers (23 mi) above the Nubian Desert in Sudan. Some 600 meteorites, weighing a total of 10.5 kilograms (23.1 lb), were recovered; many of these belonged to a rare type known as ureilites, which contain, among other minerals, nanodiamonds.[39][41][42]
It was the first time that an asteroid impact had been predicted prior to its entry into the atmosphere as a meteor.[43]
The asteroid was discovered by Richard A. Kowalski at the Catalina Sky Survey (CSS) 1.5-meter telescope at Mount Lemmon, north of Tucson, Arizona, US, on October 6, 06:39 UTC, 19 hours before the impact.[44][45][46]
It was notable as the first such body to be observed and tracked prior to reaching Earth.[43] The process of detecting and tracking a near-Earth object, an effort sometimes referred to as Spaceguard, was put to the test. In total, 586 astrometric and almost as many photometric observations were performed by 27 amateur and professional observers in less than 19 hours and reported to the Minor Planet Center, which in eleven hours issued 25 Minor Planet Electronic Circulars with new orbit solutions as observations poured in. On October 7, 01:49 UTC,[46] the asteroid entered the shadow of the Earth, which made further observations impossible.
Impact predictions were performed by University of Pisa's CLOMON 2 semi-automatic monitoring system[47][48] as well as Jet Propulsion Laboratory's Sentry system. Spectral observations that were performed by astronomers at the 4.2-meter William Herschel Telescope at La Palma, Canary Islands are consistent with either a C-type or M-type asteroid.
The meteor entered Earth's atmosphere above northern Sudan at 02:46 UTC (05:46 local time) on October 7, 2008 with a velocity of 12.8 kilometers per second (29,000 mph) at an azimuth of 281 degrees and an altitude angle of 19 degrees to the local horizon. It exploded tens of kilometers above the ground with the energy of 0.9 to 2.1 kilotons of TNT over a remote area of the Nubian Desert, causing a large fireball or bolide.[49]
The meteor's "light was so intense that it lit up the sky like a full moon and an airliner 1,400 km (870 mi) away reported seeing the bright flash."[50] A webcam captured the flash lighting up El-Gouna beach 725 kilometres north of the explosion (see this webcam frame).[51]
"Une webcam de surveillance, située sur la plage de la Mer Rouge à El Gouna en Egypte, a enregistré indirectement le flash de l'explosion qui s'est produit à environ 725 km plus au sud."[51]
A low-resolution image of the explosion was captured by the weather satellite Meteosat 8.[52] The Meteosat images place the fireball at 21°00′N 32°09′E / 21.00°N 32.15°E / 21.00; 32.15 (2008 TC3 fireball).[53] Infrasound detector arrays in Kenya also detected a sound wave from the direction of the expected impact corresponding to energy of 1.1 to 2.1 kilotons of TNT.[54] Asteroids of this size hit Earth about two or three times a year.[55]
The trajectory showed intersection with Earth's surface at roughly 20°18′N 33°30′E / 20.3°N 33.5°E / 20.3; 33.5 (2008 TC3 projected impact)[56] though the object was expected to break up perhaps 100–200 kilometers (60–120 mi) west as it descended, somewhat east of the Nile River, and about 100 kilometers (60 mi) south of the Egypt–Sudan border.
According to U.S. government sources[57][58] U.S. satellites detected the impact at 02:45:40 UT, with the initial detection at 20°54′N 31°24′E / 20.9°N 31.4°E / 20.9; 31.4 (2008 TC3 initial detection) at 65.4 kilometres (40.6 mi) altitude and final explosion at 20°48′N 32°12′E / 20.8°N 32.2°E / 20.8; 32.2 (2008 TC3 final explosion) at 37 kilometres (23 mi) altitude. These images have not been publicly released.
A search of the impact zone that began on December 6, 2008, turned up 10.5 kilograms (23 lb) of rock in some 600 fragments. These meteorites are collectively named Almahata Sitta,[59] which means "Station Six"[60] in Arabic and is a train station between Wadi Halfa and Khartoum, Sudan. This search was led by Peter Jenniskens from the SETI Institute, California and Muawia Shaddad of the University of Khartoum in Sudan and carried out with the collaboration of students and staff of the University of Khartoum. The initial 15 meteorites were found in the first three days of the search. Numerous witnesses were interviewed, and the hunt was guided with a search grid and specific target area produced by NASA's Jet Propulsion Laboratory in Pasadena, California.[61][62][63][64][65]
Samples of the Almahata Sitta meteorite were sent for analysis to a consortium of researchers led by Jenniskens, the Almahata Sitta consortium, including NASA Ames Research Center in California, the Johnson Space Center in Houston, the Carnegie Institution of Washington, and Fordham University in New York City. The first sample measured was an anomalous ultra-fine-grained porous polymict ureilite achondrite, with large carbonaceous grains. Reflectance spectra of the meteorite, combined with the astronomal observations, identified asteroid 2008 TC3 as an F-type asteroid class. These fragile anomalous dark carbon-rich ureilites are now firmly linked to the group of F-class asteroids.[39] Amino acids have been found on the meteorite.[66] The nanodiamonds found in the meteorite were shown to have grown slowly, implying that the source is another planet in the solar system.[67]
Richard Kowalski, who discovered the object, received a tiny fragment of Almahatta Sitta, a gift from friends and well-wishers on the Minor Planet Mailing List, which Kowalski founded in order to help connect professional and amateur astronomers.[68]
Apollo asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Apollos and Apollos
This a diagram showing the Apollo asteroids, compared to the orbits of the terrestrial planets of the Solar System.
Mars (M)
Venus (V) Mercury (H) Sun
Apollo asteroids
Earth (E)
Credit: AndrewBuck.
Photograph of the full disc of the asteroid 162173 Ryugu, as it appeared to the Hayabusa2 spacecraft's Optical Navigation Camera – Telescopic (ONC-T) at a distance of 20 kilometres (12 miles) at 03:50 UTC on 26 June 2018. Credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST.{{fairuse}}
Asteroid Bennu imaged by the OSIRIS-REx probe on arrival 3 December 2018. Credit: NASA/Goddard/University of Arizona.{{free media}}
Photo of 101955 Bennu was taken by the OSIRIS-REx probe on 3 December 2018. Credit: NASA/Goddard/University of Arizona.
Note that sizes and distances of bodies and orbits are not to scale in the image on the right.
As of 2015, the Apollo asteroid group includes a total of 6,923 known objects of which 991 are numbered (JPL SBDB).
Ryugu shown on the left was discovered on 10 May 1999 by astronomers with the Lincoln Near-Earth Asteroid Research at the Lincoln Laboratory's Experimental Test Site near Socorro, New Mexico, in the United States.[69]
The asteroid was officially named "Ryugu" by the Minor Planet Center on 28 September 2015.[70]
Initial images taken by the Hayabusa-2 spacecraft on approach at a distance of 700 km were released on 14 June 2018 and revealed a diamond shaped body and confirmed its retrograde rotation.[71]
Between 17 and 18 June 2018, Hayabusa 2 went from 330 km to 240 km from Ryugu and captured a series of additional images from the closer approach.[72]
On 21 September 2018, the first two of these rovers, which will hop around the surface of the asteroid, were released from Hayabusa2.[73]
On September 22, 2018, JAXA confirmed the two rovers had successfully touched down on Ryugu's surface which marks the first time a mission has completed a successful landing on a fast-moving asteroid body.[74]
"This series of images [second down on the right] taken by the OSIRIS-REx spacecraft shows Bennu in one full rotation from a distance of around 50 miles (80 km). The spacecraft's PolyCam camera obtained the 36 2.2-millisecond frames over a period of four hours and 18 minutes."[75]
101955 Bennu (provisional designation 1999 RQ36[76], a C-type carbonaceous asteroid in the Apollo group discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) Project on September 11, 1999, is a potentially hazardous object that is listed on the Sentry monitoring system, Sentry Risk Table, with the second-highest cumulative rating on the Palermo Technical Impact Hazard Scale.[77] It has a cumulative 1-in-2,700 chance of impacting Earth between 2175 and 2199.[78][79]
101955 Bennu has a mean diameter of approximately 492 m (1,614 ft; 0.306 mi) and has been observed extensively with the Arecibo Observatory planetary radar and the Goldstone Deep Space Communications Complex NASA Deep Space Network.[80][81][82]
Asteroid Bennu has a roughly spheroidal shape, resembling a spinning top, with the direction of rotation about its axis retrograde with respect to its orbit and a fairly smooth shape with one prominent 10–20 m boulder on its surface, in the southern hemisphere.[79]
There is a well-defined ridge along the equator of asteroid Bennu that suggests that fine-grained regolith particles have accumulated in this area, possibly because of its low gravity and fast rotation.[79]
Observations of this minor planet by the Spitzer Space Telescope in 2007 gave an effective diameter of 484±10 m, which is in line with other studies. It has a low visible geometric albedo of 0.046±0.005. The thermal inertia was measured and found to vary by ±19% during each rotational period suggesting that the regolith grain size is moderate, ranging from several millimeters up to a centimeter, and evenly distributed. No emission from a potential dust coma has been detected around asteroid Bennu, which puts a limit of 106 g of dust within a radius of 4750 km.[83]
Astrometric observations between 1999 and 2013 have demonstrated that 101955 Bennu is influenced by the Yarkovsky effect, causing the semimajor axis to drift on average by 284±1.5 meters/year; analysis of the gravitational and thermal effects give a bulk density of ρ = 1,260±70 kg/m3, which is only slightly denser than water, the predicted macroporosity is 40±10%, suggesting that the interior has a rubble pile structure, with an estimated mass is 7.8±0.9×1010
kg.[84]
Photometric observations of Bennu in 2005 yielded a synodic rotation period of 4.2905±0.0065 h, a B-type asteroid classification, which is a sub-category of C-type asteroid or carbonaceous asteroids. Polarimetric observations show that Bennu belongs to the rare F-type asteroid or F subclass of carbonaceous asteroids, which is usually associated with cometary features.[85] Measurements over a range of phase angles show a phase function slope of 0.040 magnitudes per degree, which is similar to other near-Earth asteroids with low albedo.[86]
Asteroid Bennu's basic mineralogy and chemical nature would have been established during the first 10 million years of the Solar System's formation, where the carbonaceous material underwent some geologic heating and chemical transformation into more complex minerals.[79] Bennu probably began in the inner asteroid belt as a fragment from a larger body with a diameter of 100 km, where simulations suggest a 70% chance it came from the Polana family and a 30% chance it derived from the 495 Eulalia (Eulalia family).[87]
Subsequently, the orbit drifted as a result of the Yarkovsky effect and mean motion resonances with the giant planets, such as Jupiter and Saturn modified the asteroid, possibly changing its spin, shape, and surface features.[88]
A possible cometary origin for Bennu, based on similarities of its spectroscopic properties with known comets, with the estimated fraction of comets in the population of Near Earth asteroids is 8±5 %.[85]
Mars crossersEdit
Main articles: Rocks/Rocky objects/Asteroids/Mars crossers and Mars crossers
"50 % of the MB Mars-crossers [MCs] become ECs within 59.9 Myr".[5]
Amor asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Amors and Amors
This is a diagram showing the general location of the Amor asteroids and Mars trojans, compared to the orbits of the terrestrial planets Mercury (H), Venus (V), Earth (E) and Mars (M).
Amor asteroids
Mars trojans
Venus (V)
Mercury (H)
Note that sizes and distances of bodies and orbits are not to scale. Credit: AndrewBuck.
Mars TrojansEdit
Main articles: Rocks/Rocky objects/Asteroids/Mars Trojans and Mars Trojans
From the diagram in the section Amor asteroids, the Mars Trojans occupy comparable positions relative to Mars that the Trojan asteroids do to Jupiter.
Asteroid beltsEdit
Main articles: Rocks/Rocky objects/Asteroids/Belts and Belts
This is a composite image, to scale, of the asteroids which have been imaged at high resolution. As of 2011 they are, from largest to smallest: 4 Vesta, 21 Lutetia, 253 Mathilde, 243 Ida and its moon Dactyl, 433 Eros, 951 Gaspra, 2867 Šteins, 25143 Itokawa. Credit: NASA/JPL-Caltech/JAXA/ESA.
The asteroid belt is shown in (white) and the Trojan asteroids (green). Credit: .
This is an approximately natural color picture of the asteroid 243 Ida on August 28, 1993. Credit: NASA/JPL.
Def. a "region of the orbital plane of the solar system located between the orbits of Mars and Jupiter which is occupied by numerous minor planets and the dwarf planet Ceres"[89] is called an asteroid belt.
"The MB group is the most numerous group of MCs. ... 50 % of the MB Mars-crossers [MCs] become ECs within 59.9 Myr and [this] contribution ... dominates the production of ECs"[5]. MB denotes the main belt of asteroids.[5]
The interplanetary medium includes interplanetary dust, cosmic rays and hot plasma from the solar wind. The temperature of the interplanetary medium varies. For dust particles within the asteroid belt, typical temperatures range from 200 K (−73 °C) at 2.2 AU down to 165 K (−108 °C) at 3.2 AU[90] The density of the interplanetary medium is very low, about 5 particles per cubic centimeter in the vicinity of the Earth; it decreases with increasing distance from the sun, in inverse proportion to the square of the distance. It is variable, and may be affected by magnetic fields and events such as coronal mass ejections. It may rise to as high as 100 particles/cm³.
"The hydromagnetic approach led to the discovery of two important observational regularities in the solar system: (1) the band structure [such as in the rings of Saturn and in the asteroid belt], and (2) the cosmogonic shadow effect (the two-thirds fall down effect)."[91]
The majority of known asteroids orbit within the asteroid belt between the orbits of Mars and Jupiter ... This belt is now estimated to contain between 1.1 and 1.9 million asteroids larger than 1 km in diameter,[92] and millions of smaller ones.[93]
At second right is an approximately natural color image of the asteroid 243 Ida. "There are brighter areas, appearing bluish in the picture, around craters on the upper left end of Ida, around the small bright crater near the center of the asteroid, and near the upper right-hand edge (the limb). This is a combination of more reflected blue light and greater absorption of near infrared light, suggesting a difference in the abundance or composition of iron-bearing minerals in these areas."[94]
Baptistina familyEdit
298 Baptistina (center) is one of the largest presumed remnants of the Baptistina family. Credit: .
The Baptistina family (Family identification number, FIN: 403) is an asteroid family of more than 2500 members that was probably produced by the breakup of an asteroid 170 km (110 mi) across 80 million years ago following an impact with a smaller body. The two largest presumed remnants of the parent asteroid are main-belt asteroids 298 Baptistina and 1696 Nurmela. The Batistina family is part of the larger Flora clan.[95][96]
The Baptistina family consists of darkly colored asteroids and meteoroids in similar orbits. Many mountain-sized fragments from the collision would have leaked into the inner solar system through orbital resonances with Mars and Jupiter, causing a prolonged series of asteroid impacts. Previously, this collision was believed to have occurred about 160 million years ago, and many impacts between 100 and 50 million years ago were attributed to it. However, in 2011, data from WISE revised the date of the proposed collision which broke up the parent asteroid to about 80 million years ago.[97]
Following the impact of the Chelyabinsk meteor in 2013, a paper published in the journal Icarus showed that shock produced during impact of a large asteroid can darken otherwise bright silicate material. Spectral analysis of the darkly-colored portions of the non-carbonaceous Chelyabinsk meteorite closely matched the color of members of the Baptistina family, showing that a low albedo does not necessarily indicate the composition of the family.[98]
Eos familyEdit
Main articles: Rocks/Rocky objects/Asteroids/Eos and Eos family
Members include 221 Eos, 339 Dorothea, 450 Brigitta, 513 Centesima, 562 Salome, 579, 633 Zelima, 639 Latona, 651 Antikleia, 653 Berenike, 661 Cloelia, 669 Kypria, 742 Edisona, 807 Ceraskia, 876 Scott, 890 Waltraut, 1075, 1199, and 1364.
Koronis familyEdit
Main articles: Rocks/Rocky objects/Asteroids/Koronis and Koronis family
These are some of the Koronis family asteroids. Credit: NASA.
Members include 158 Koronis, 167 Urda, 208 Lacrimosa, 243 Ida,[99] 311, 321, 534, 720, and 1223.
At second right is an approximately natural color image of the asteroid 243 Ida. The dot to the right is its moon Dactyl. "There are brighter areas, appearing bluish in the picture, around craters on the upper left end of Ida, around the small bright crater near the center of the asteroid, and near the upper right-hand edge (the limb). This is a combination of more reflected blue light and greater absorption of near infrared light, suggesting a difference in the abundance or composition of iron-bearing minerals in these areas."[94]
Ida was discovered on 29 September 1884 by Austrian astronomer Johann Palisa at the Vienna Observatory.[100] It was his 45th asteroid discovery.[101] Ida was named by Moriz von Kuffner, a Viennese brewer and amateur astronomer.[102][103] In Greek mythology, Ida was a nymph of Crete who raised the god Zeus.[104] Ida was recognized as a member of the Koronis family by Kiyotsugu Hirayama, who proposed in 1918 that the group comprised the remnants of a destroyed precursor body.[105]
Ida's reflection spectrum was measured on 16 September 1980 by astronomers David J. Tholen and Edward F. Tedesco as part of the eight-color asteroid survey (ECAS).[106]
"The Eos and Koronis families ... are entirely of type S, which is rare at their heliocentric distances ..."[106]
Its spectrum matched those of the asteroids in the S-type classification.[106] Many observations of Ida were made in early 1993 by the United States Naval Observatory Flagstaff Station and the Oak Ridge Observatory. These improved the measurement of Ida's orbit around the Sun and reduced the uncertainty of its position during the Galileo flyby from 78 to 60 km (48 to 37 mi).[107]
Maria familyEdit
Main articles: Rocks/Rocky objects/Asteroids/Maria and Maria family
Members include 170 Maria, 472, 660, 695, and 714.
Nysian asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Nysians and Nysians
This is a screen shot of a computer plot for the Nysian family of asteroids. Credit: EasySky.
The Nysian asteroids occur primarily between the orbits of Mars and Jupiter but some are between Earth and Mars.
Trojan asteroidsEdit
Main articles: Rocks/Rocky objects/Asteroids/Trojans and Trojan asteroids
Diagram of Lagrange points is in a system where the primary is much more massive than the secondary. Credit: Cmglee.
Def. "the L4 and L5 Lagrange points of the Sun-Jupiter orbital configuration"[108] are called the Trojan points.
Def. "an asteroid occupying the Trojan points of the Sun-Jupiter system"[109] is called a Trojan asteroid.
The Trojan asteroids orbit 60 degrees ahead of and behind Jupiter as it circles the Sun."[110]
Asteroid (514107) 2015 BZ509 may be a former interstellar object, captured some 4.5 billion years ago, as evidenced by its co-orbital motion with Jupiter and its retrograde orbit around the Sun.[111]
CentaursEdit
Main articles: Rocks/Rocky objects/Centaurs and Centaurs
Def. an "icy planetoid that orbits the Sun between Jupiter and Neptune"[112] is called a Centaur.
"The recent investigation of the orbital distribution of Centaurs (Emel'yanenko et al., 2005) showed that there are two dynamically distinct classes of Centaurs, a dominant group with semimajor axes a > 60 AU and a minority group with a < 60 AU."[113] "[T]he intrinsic number of such objects is roughly an order of magnitude greater than that for a<60 AU".[113]
RadarsEdit
Main articles: Radiation astronomy/Radars and Radar astronomy
This image is of asteroid 2012 LZ1 by the Arecibo Observatory in Puerto Rico using the Arecibo Planetary Radar. Credit: Arecibo Observatory.
Radar astronomy is used to detect and study astronomical objects that reflect radio rays.
"The advantages of radar in planetary astronomy result from (1) the observer's control of all the attributes of the coherent signal used to illuminate the target, especially the wave form's time/frequency modulation and polarization; (2) the ability of radar to resolve objects spatially via measurements of the distribution of echo power in time delay and Doppler frequency; (3) the pronounced degree to which delay-Doppler measurements constrain orbits and spin vectors; and (4) centimeter-to-meter wavelengths, which easily penetrate optically opaque planetary clouds and cometary comae, permit investigation of near-surface macrostructure and bulk density, and are sensitive to high concentrations of metal or, in certain situations, ice."[114]
514107 KaʻepaokaʻawelaEdit
Retrograde orbit of 2015 BZ509 has 100 day motion markers. Credit: Tomruen.{{free media}}
Orbital diagram is shown. Credit: Nwbeeson.
Orbit (side-view) is compared to Jupiter. Credit: Nwbeeson.
Kaʻepaokaʻawela shows apparent retrograde motion in the sky while it is on the far side of the sun, rather than at opposition with the sun. Credit: Tomruen.
514107 Kaʻepaokaʻawela, provisional designation 2015 BZ509, also nicknamed Bee-Zed,[115] is a small asteroid, approximately 3 kilometers (2 miles) in diameter,[116] in a resonant, co-orbital motion with Jupiter.[117] Its orbit is retrograde, which is opposite to the direction of most other bodies in the Solar System.[118] It was discovered on 26 November 2014, by astronomers of the Pan-STARRS survey at Haleakala Observatory on the island of Maui, United States.[119] The unusual object is the first example of an asteroid in a 1:−1 resonance with any of the planets.[120]
Kaʻepaokaʻawela orbits the Sun at a distance of 3.2–7.1 AU once every 11 years and 8 months (4,256 days; semi-major axis of 5.14 AU), has an eccentricity of 0.38 and an inclination of 163° with respect to the ecliptic.[121]
The orbit of this asteroid is shown in blue when it is above the plane of the orbit of Jupiter, and in magenta when it is below the plane of the orbit of Jupiter.[117]
The plane of the orbit of Jupiter is shown in black, but in this frame of reference Jupiter (the red dot) stays at the right end of the black line. The orbit of this asteroid is shown in blue when it is above (north of) the plane of the orbit of Jupiter, and it is shown in magenta when it is below (south of) the plane of the orbit of Jupiter.[117]
Kaʻepaokaʻawela has been in its retrograde resonance with Jupiter since the origin of the Solar System instead of it being an object that is only briefly in this orbit that was observed by chance using the Copernican principle.[122][123] Since its retrograde orbit is in the opposite direction as objects that formed in the early Solar System they posit that Kaʻepaokaʻawela has an interstellar origin.[124] If confirmed, this origin would have implications on current theories such as the detailed timing and mechanics of planet formation, and the delivery of water and organic molecules to Earth.[122] Others suggest that Kaʻepaokaʻawela originated in the Oort cloud or that it acquired a retrograde orbit due to interactions with Planet Nine, and that it is a short term resident of its current resonance.[122]
Asteroid Surveys
Earth-impact events
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↑ "Found: Pieces of meteorite spotted before impact". New Scientist (2697): 15. February 25, 2009. https://www.newscientist.com/article/mg20126974.800-found-pieces-of-meteorite-spotted-before-impact.html.
↑ Shiga, D. (February 19, 2009). "First tracked space rock recovered after impact". New Scientist. https://www.newscientist.com/article/dn16635-first-tracked-space-rock-recovered-after-impact.html.
↑ Courtland, R. (March 25, 2009). "Meteorite hunters 'strike gold' in Sudan". New Scientist. Archived from the original on June 1, 2009. https://www.newscientist.com/article/dn16843-meteorite-hunters-strike-gold-in-sudan.html. Retrieved April 4, 2009.
↑ Kwok, R. (March 26, 2009). "Astronomy: The Rock That Fell to Earth". Nature 458 (7237): 401–403. doi:10.1038/458401a. PMID 19325604. http://www.nature.com/news/2009/090325/full/458401a.html.
↑ "Life's Building Blocks Found on Surprising Meteorite". Space.com. December 16, 2010. Retrieved August 13, 2013.
↑ Nabiei, Farhang et al. (April 17, 2018). "A large planetary body inferred from diamond inclusions in a ureilite meteorite". Nature Communications (Springer Nature) 9 (1): 1327. doi:10.1038/s41467-018-03808-6. ISSN 2041-1723. PMID 29666368. PMC 5904174. https://www.nature.com/articles/s41467-018-03808-6.
↑ Lakdawalla, E. (September 20, 2009). "A piece of an asteroid returns to the telescope that discovered it". The Planetary Society. Retrieved October 7, 2009.
↑ 162173 Ryugu (1999 JU3). Retrieved 22 June 2018.
↑ MPC/MPO/MPS Archive. Retrieved 22 June 2018.
↑ From a distance of about 700km, Ryugu's rotation was observed. JAXA. Retrieved 18 June 2018.
↑ Plait, Phil, "Asteroid Ryugu Starts to Come Into Focus", SyFy Wire, 20 June 2018. Accessed 20 June 2018.
↑ Wall, Mike. Japanese Probe Deploys Tiny Hopping Robots Toward Big Asteroid Ryugu. Retrieved 21 September 2018.
↑ Yoshimitsu, Tetsuo; Kubota, Takashi; Tsuda, Yuichi; Yoshikawa, Makoto. MINERVA-II1: Successful image capture, landing on Ryugu and hop!. JAXA. Retrieved 24 September 2018.
↑ Michael J. Drake (November 25, 2018). Bennu Full Rotation at a Distance of 50 Miles. Washington, DC USA: NASA. Retrieved 5 December 2018.
↑ Diane Murphy (1 May 2013). Nine-Year-Old Names Asteroid Target of NASA Mission in Competition Run By The Planetary Society. The Planetary Society. Retrieved 20 August 2016.
↑ Sentry Risk Table. NASA/JPL Near-Earth Object Program Office. Retrieved 2018-03-20.
↑ 101955 1999 RQ36: Earth Impact Risk Summary. Jet Propulsion Laboratory. 25 March 2016. Retrieved 20 March 2018.
↑ 79.0 79.1 79.2 79.3 Lauretta, D. S.; Bartels, A. E.; Barucci, M. A.; Bierhaus, E. B.; Binzel, R. P.; Bottke, W. F.; Campins, H.; Chesley, S. R. et al. (April 2015). "The OSIRIS-REx target asteroid (101955) Bennu: Constraints on its physical, geological, and dynamical nature from astronomical observations". Meteoritics & Planetary Science 50 (4): 834–849. doi:10.1111/maps.12353.
↑ Nolan, M. C.; Magri, C.; Howell, E. S.; Benner, L. A. M.; Giorgini, J. D.; Hergenrother, C. W.; Hudson, R. S.; Lauretta, D. S. et al. (2013). "Shape model and surface properties of the OSIRIS-REx target Asteroid (101955) Bennu from radar and lightcurve observations" (Submitted manuscript). Icarus 226 (1): 629–640. doi:10.1016/j.icarus.2013.05.028. ISSN 0019-1035. http://www.escholarship.org/uc/item/6mh8b2t5.
↑ Goldstone Delay-Doppler Images of 1999 RQ36. Jet Propulsion Laboratory.
↑ Hudson, R. S.; Ostro, S. J.; Benner, L. A. M. (2000). "Recent Delay-Doppler Radar Asteroid Modeling Results: 1999 RQ36 and Craters on Toutatis". Bulletin of the American Astronomical Society 32: 1001.
↑ Emery, J.; Fernandez, Y.; Kelley, M.; Warden, K.; Hergenrother, C.; Lauretta, D.; Drake, M.; Campins, H.; Ziffer, J. (July 2014). K. Muinonen (ed.). Thermal infrared observations and thermophysical characterization of the OSIRIS-REx target asteroid (101955) Bennu, In: Conference Proceedings Asteroids, Comets, Meteors 2014. p. 148. Bibcode:2014acm..conf..148E.
↑ Chesley, Steven R.; Farnocchia, Davide; Nolan, Michael C.; Vokrouhlický, David; Chodas, Paul W.; Milani, Andrea; Spoto, Federica; Rozitis, Benjamin et al. (2014). "Orbit and bulk density of the OSIRIS-REx target Asteroid (101955) Bennu". Icarus 235: 5–22. doi:10.1016/j.icarus.2014.02.020. ISSN 0019-1035.
↑ 85.0 85.1 Hergenrother, Carl W; Maria Antonietta Barucci; Barnouin, Olivier; Bierhaus, Beau; Binzel, Richard P; Bottke, William F; Chesley, Steve; Clark, Ben C et al. (2018). "Unusual polarimetric properties of (101955) Bennu: similarities with F-class asteroids and cometary bodies". arXiv:1808.07812 [astro-ph.EP].
↑ Hergenrother, Carl W.; Nolan, Michael C.; Binzel, Richard P.; Cloutis, Edward A.; Barucci, Maria Antonietta; Michel, Patrick; Scheeres, Daniel J.; d'Aubigny, Christian Drouet et al. (September 2013). "Lightcurve, Color and Phase Function Photometry of the OSIRIS-REx Target Asteroid (101955) Bennu". Icarus 226 (1): 663–670. doi:10.1016/j.icarus.2013.05.044.
↑ Bottke, William F.; Vokrouhlický, David; Walsh, Kevin J.; Delbo, Marco; Michel, Patrick; Lauretta, Dante S.; Campins, Humberto; Connolly, Harold C. et al. (February 2015). "In search of the source of asteroid (101955) Bennu: Applications of the stochastic YORP model". Icarus 247: 191–217. doi:10.1016/j.icarus.2014.09.046.
↑ Lauretta, D. S.; Bartels, A. E.; Barucci, M. A.; Bierhaus, E. B.; Binzel, R. P.; Bottke, W. F.; Campins, H.; Chesley, S. R. et al. (April 2015). "The OSIRIS-REx target asteroid (101955) Bennu: Constraints on its physical, geological, and dynamical nature from astronomical observations". Meteoritics & Planetary Science 50 (4): 834–849. doi:10.1111/maps.12353.
↑ WikiPedant (10 December 2007). asteroid belt. San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2015-08-31.
↑ Low, F. J.; et al. (1984). "Infrared cirrus – New components of the extended infrared emission". Astrophysical Journal, Part 2 – Letters to the Editor 278: L19–L22. doi:10.1086/184213. http://adsabs.harvard.edu//abs/1984ApJ...278L..19L.
↑ Hannes Alfvén (October 1981). "The Voyager 1/Saturn Encounter and the Cosmogonic Shadow Effect". Astrophysics and Space Science 79 (2): 491-505. doi:10.1007/BF00649444. http://adsabs.harvard.edu/abs/1981Ap&SS..79..491A. Retrieved 2013-12-19.
↑ Edward Tedesco, Leo Metcalfe (April 4, 2002). New study reveals twice as many asteroids as previously believed. European Space Agency. Retrieved 2008-02-21.
↑ World Book at NASA
↑ 94.0 94.1 Sue Lavoie (January 29, 1996). PIA00069: Ida and Dactyl in Enhanced Color. Pasadena, California USA: NASA/JPL. Retrieved 2013-06-01.
↑ Alvarez-Candal, A.; Duffard, R.; Lazzaro, D.; Michtchenko, T. (December 2006). "The inner region of the asteroid Main Belt: a spectroscopic and dynamic analysis". Astronomy and Astrophysics 459 (3): 969–976. doi:10.1051/0004-6361:20065518. https://www.aanda.org/articles/aa/pdf/2006/45/aa5518-06.pdf. Retrieved 21 April 2018.
↑ Nesvorný, D.; Broz, M.; Carruba, V. (December 2014). "Identification and Dynamical Properties of Asteroid Families". Asteroids IV: 23. doi:10.2458/azu_uapress_9780816532131-ch016. https://arxiv.org/pdf/1502.01628.pdf. Retrieved 23 June 2017.
↑ Plotner, Tammy (2011). Did Asteroid Baptistina Kill the Dinosaurs? Think other WISE... Retrieved 2011-09-19.
↑ Russian meteorite sheds light on dinosaur extinction mystery. 2014-07-17.
↑ Holm, Jeanne (June 1994). Jones, Jan. ed. "Discovery of Ida's Moon Indicates Possible "Families" of Asteroids". The Galileo Messenger (34). http://www2.jpl.nasa.gov/galileo/mess34/Moon2.html. Retrieved 2008-10-23.
↑ Ridpath, John Clark (1897). The Standard American Encyclopedia of Arts, Sciences, History, Biography, Geography, Statistics, and General Knowledge. Encyclopedia Publishing.
↑ Raab, Herbert (2002). "Johann Palisa, the most successful visual discoverer of asteroids". Meeting on Asteroids and Comets in Europe. Archived from the original on 2008-10-30. https://web.archive.org/web/20081030190303/http://www.astrometrica.at/Papers/Palisa.pdf. Retrieved 2008-10-23.
↑ Schmadel, Lutz D. (2003). "Catalogue of Minor Planet Names and Discovery Circumstances". Dictionary of minor planet names. IAU commission. 20. Springer. ISBN 978-3-540-00238-3.
↑ Berger, Peter (2003). "The Gildemeester Organisation for Assistance to Emigrants and the expulsion of Jews from Vienna, 1938–1942". In Gourvish, Terry (ed.). Business and Politics in Europe, 1900–1970. Cambridge, UK: Cambridge University Press. ISBN 978-0-521-82344-9.
↑ "Images of Asteroids Ida & Dactyl". National Aeronautics and Space Administration. 23 August 2005. Archived from the original on 21 October 2008. Retrieved 2008-12-04.
↑ Thomas, Peter C.; Belton, Michael J. S.; Carcich, B.; Chapman, Clark R.; Davies, M. E.; Sullivan, Robert J.; Veverka, Joseph (1996). "The shape of Ida". Icarus 120 (1): 20–32. doi:10.1006/icar.1996.0033.
↑ 106.0 106.1 106.2 Zellner, Ben; Tholen, David J.; Tedesco, Edward F. (March 1985). "The eight-color asteroid survey: Results for 589 minor planets". Icarus 61 (3): 355–416. doi:10.1016/0019-1035(85)90133-2.
↑ Owen, W. M., Jr.; Yeomans, D. K. (June 1994). "The overlapping plates method applied to CCD observations of 243 Ida". The Astronomical Journal 107 (6): 2295–2298. doi:10.1086/117037.
↑ 65.94.44.124 (11 December 2010). Trojan point. San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2015-08-31.
↑ 65.94.44.124 (11 December 2010). Trojan asteroid. San Francisco, California: Wikimedia Foundation, Inc. Retrieved 2015-08-31.
↑ C. Porco (31 January 2011). Flying by Helene. Washington, D.C. USA: NASA's Science Mission Directorate. Retrieved 2016-11-06.
↑ "This asteroid came from another solar system—and it's here to stay". Science.
↑ SnoopY (21 December 2005). Centaur. San Francisco, California: Wikimedia Foundation, Inc. Retrieved 31 August 2015.
↑ 113.0 113.1 V. V. Emel'yanenko (December 2005). "Structure and dynamics of the Centaur population: constraints on the origin of short-period comets". Earth, Moon, and Planets 97 (3-4): 341-51. doi:10.1007/s11038-006-9095-5. http://dccm.susu.ac.ru/acm2005.pdf. Retrieved 2011-10-06.
↑ Steven J. Ostro (October-December 1993). "Planetary radar astronomy". Reviews of Modern Physics 65 (4): 1235-79. doi:10.1103/RevModPhys.65.1235. http://rmp.aps.org/abstract/RMP/v65/i4/p1235_1. Retrieved 2012-02-09.
↑ "The stable retrograde orbit of the Bee-Zed asteroid explained". Phys.org. 28 June 2017.
↑ "Discovery of the first body in the Solar System with an extrasolar origin". www2.cnrs.fr (Press release). CNRS. 22 May 2018. Retrieved 31 May 2018.
↑ 117.0 117.1 117.2 Wiegert, Paul; Connors, Martin; Veillet, Christian (March 2017). "A retrograde co-orbital asteroid of Jupiter". Nature 543 (7647): 687–689. doi:10.1038/nature22029. PMID 28358083. http://www.nature.com/nature/journal/v543/n7647/full/nature22029.html#videos. Retrieved 7 March 2018.
↑ Plait, Phil (Mar 30, 2017). "Meet Jupiter's backwards little friend: Asteroid 2015 BZ509". SyFy Wire. Retrieved 30 March 2017.
↑ "(514107) Ka`epaoka`awela = 2015 BZ509". Minor Planet Center. Retrieved 7 March 2018.
↑ Wiegert, Paul (30 March 2017). "The first retrograde co-orbital asteroid: 2015 BZ509 – a Trojan in retreat". University of Western Ontario. Retrieved 7 March 2018.
↑ "JPL Small-Body Database Browser: 514107 Ka`epaoka`awela (2015 BZ509)" (2017-09-17 last obs.). Jet Propulsion Laboratory. Retrieved 3 December 2018.
↑ 122.0 122.1 122.2 Billings, Lee (21 May 2018). "Astronomers Spot Potential "Interstellar" Asteroid Orbiting Backward around the Sun". Scientific American. Retrieved 1 June 2018.
↑ Namouni, Fathi; Morais, Maria Helena Moreira (21 May 2018). "An interstellar origin for Jupiter's retrograde co-orbital asteroid". Monthly Notices of the Royal Astronomical Society: Letters 477 (1): L117–L121. doi:10.1093/mnrasl/sly057. ISSN 1745-3925.
↑ Halton, Mary (21 May 2018). "'Permanent' interstellar visitor found". BBC News. Retrieved 1 June 2018.
Canada-France-Hawaii Telecope
Catalina Sky Survey
Sentry Impact Risk
Learn more about Asteroids
Retrieved from "https://en.wikiversity.org/w/index.php?title=Radiation_astronomy/Asteroids&oldid=2028590"


text:
The hidden force behind sustainability
The hidden force behind sustainability is a photo series by Femke Juffermans, in which eight female founders of Amsterdam based sustainable companies are portrayed. Our founder and director Marian Duff participated, and talked to Femke Juffermans about sustainable forces within local and global entrepreneurship. Marian stated:
Art with a capital A should be accessible to all. It is important that the depositories of museums worldwide, but first of all in Amsterdam, are opened up as much as possible and that everyone has access to them. Because everything that is in those depositories belongs to all of us.
To see the complete series, click here!

redpajama_set_name: RedPajamaCommonCrawl


text:
Brutal, intense '1984' represents full-length debut of Monument Theatre Company
Among dystopian novels, "1984" seems to be the most enduring. The fantasy elements may be more deftly
Nathan Thomas plays the aggrieved victim of state terrorism in '1984.'
brought off in Aldous Huxley's "Brave New World" and in Yevgeny Zamyatin's "We," but George Orwell's novel of a totalitarianism more widespread than ever has captured the collective imagination better.
True, there's a certain dutifulness about the book's case against oppression and a dearth of pure literary magic in the storytelling. But, as has been commonly asserted, no 20th-century writer more than Orwell has had so thorough a set of insights into politics in the modern era. And all of that vision is bluntly, almost obsessively, detailed in "1984."
The production of a stage adaptation that opened Friday night at Indy Convergence ramps up for the stage the novel's atmosphere of paranoia and all-encompassing oppression, which has wowed countless readers for 70 years.
David Ian Lee directs Michael Gene Sullivan's play in a production for the Monument Theatre Company. a new professional venture based here. There's not much let-up in the intensity as the cast of six represents Orwell's vision of absolutism undergirded at every turn by modern technology. The availability of private lives to the state through constant spying is updated here with the ubiquity of iPhones. These devices we can't seem to do without are under state control, like everything else in the dystopian meganation Orwell dubbed Oceania.
The production's dialogue is rapid-fire and usually thundering, punctuated by four Party Members' throwing of metal chairs and hurling to the floor the trailing shackles that bind Winston Smith, the novel's miserable hero. Nathan Thomas gave a highly keyed-up performance that maximized Smith's aggrievement and fear, his facial expression knotted and his voice quavering, pleading, whining. In the leading actor is concentrated all the dire effects of a menacing, all-powerful government. Thomas' performance summed up the victimization of everyone, including those ostensibly favored by Big Brother.
That is evident in the performances of Smith's minders and interrogators, who also wander in and out of the hero's almost hallucinatory memories, enacting them in devastating fragments. The playwright thus effectively represents the erasure of private lives in Oceania. The official bullies are played, in an often alarmingly menacing way, by Riley Leonard, Raven Newbolt, Kim Egan, and Deont'a Stark. The Party Members serve the state through constant dehumanizing pressure on Smith, guided by a frequently heard but never seen "telescreen" announcer (Karen Sternberg).
But there is no one more effective among Smith's tormentors than O'Brien, whose appearance in the second act rings with unmistakable authority as Winston Smith is moved to the final stage of forced ideological conversion. This character, whom Smith had taken for a like-minded lover of liberty, was given an authoritative portrayal by Michael R. Tingley. Though this role is especially crucial to the finishing off of Smith's independence, I would have liked to see its flickers of humanity more evident among the Party Members. One of the fascinating things of any fiction based on a "what-if" premise is how well it makes people caught up in a counterfactual scenario seem like us. Clearly, functionaries of an oppressive state participate in their own dehumanizing, but I think a few more touches of ordinary humanity among the Party Members might have served to make Winston Smith's plight even more moving.
Caleb Clark, who co-founded the company in 2016 with Maverick Schmit, is responsible for "1984"'s design of set, lighting, and sound. All elements worked well together, and were thoroughly taken advantage of in Lee's turbulent but well-knit direction of the show.
Where are these folks performing?
You can see the show at Indy Convergence in Indianapolis, IN. You can also get tickets at this link if you're interested!!
https://m.bpt.me/event/4056438?fbclid=IwAR1lBSBZ7vJc7bVPghBEYH1hwcMwLSlHrOto4lMRW_YDkrAc9E-p9fejH2A
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Scholarships.com - Agnostic/Atheist Scholarships. ... However, just like their religious counterparts, there are scholarships for the non-religious student population including Atheists, Agnostics, Secularists, and anyone who considers themselves to be non-religious. Organizations ... FFRF Student Scholarship Essay Contests.
CFI Announces Free Expression Essay Contest Winners. March 19, 2010. Terri Murray. The Center for Inquiry is pleased to announce that Terri Murray is the winner of its Free Expression Essay Contest, in which students were asked to expound on the topic, "The Importance of Free Expression and Its Limits (If Any).
Freedom From Religion Foundation. Over $4,000 in cash scholarships are awarded to the winners of the Freedom from Religion Foundation's annual essay contest. A set topic for the essays is announced each year, and students are asked to respond specifically to it using their best writing skills.


This past weekend, ZROC showed (yet again) how we roll. We had 25 cars at Mid-Ohio Sports Car Course on Sunday June 25th for the Vintage Grand Prix.
Several members departed from Delaware headed to Lexington, Ohio to meet up with other members who were already there or took their own routes to get there. We parked our cars and instantly it was obvious what club was present – ZROC of course! As one of the staff members said to us, "Oh, you're with ZROC – you guys always bring really great numbers to this event!" This is one of those events that is on our annual schedule and will always be on the calendar.
It was a great day spent watching some racing – and supporting our own ZROC racer, Lowell Marx #50 – enjoying the weather when it wasn't chilly and windy, and having a delicious potluck lunch of burgers, hot dogs and LOTS of dessert options! Thanks to ZROC for providing the hot dogs and burgers for the club!
Let's not forget the greatest part of the day – when we found out that ZROC got the "Best Club" Award again. Thanks to our members who come out to this event year after year. We wouldn't get awards like this if it weren't for our wonderful ZROC family!
Check out some pictures from the races and other events we've had here. And don't forget about some of our upcoming events – Columbus Clippers Game & Fireworks, The Arthritis Foundation Car Show & many more through the rest of the year!
It was great to meet other owners who attended the Mid-Ohio Vintage Grand Prix event. I see they are members now upon discovering what ZROC is all about: Z car fanatics..


text:
Q: Can i preview a document and the changes live? i'm creating an application, its purpose is to print a document with specific info, the info are loaded into the document by some text in textboxes.
i want to to preview the changes in the information live, assuming that the textboxes are in the left side of my application, and the preview of the document is in the right side of the document, instead of pressing a button that will open the preview page that is before printing.
is there is any possible way? i just need a lead and i will continue the job.
i tried having the document to preview in the datagridview but ofcourse it didn't work :(.

redpajama_set_name: RedPajamaStackExchange


Richard Bacon MP said today (Tuesday 17 April 2007) that the health service would be better off without Connecting for Health, the Department of Health agency responsible running the national programme for IT in the NHS.
Bacon was speaking as the Commons' Public Accounts Committee published a damning report on the £12.4bn programme. The report concludes that "at the present rate of progress it is unlikely that significant clinical benefits will be delivered by the end of the contract period".
He has called for the agency to be wound up, with most of its budget handed over to local hospital bosses and any remaining functions handled by the Department of Health.
Bacon, a member of the committee, said: "Connecting for Health has produced exceptional anger and frustration among doctors, nurses, and hospital managers. It is a nightmare organisation and I think the NHS would be better off without it".
He added: "The bulk of the programme should be handled by local hospital chief executives in consultation with their own clinicians, who all have a direct interest in delivering IT that works. Local hospitals should have freedom to buy from a wide range of suppliers whose technology conforms to national standards. Functions such as setting common standards could be transferred to the Department of Health. There is no need for an expensive separate agency.
"This is a truly grim tale. The NHS IT programme has already cost over £2 billion, with five times more than that in the pipeline, and yet the programme is unlikely to deliver significant clinical benefits by the end of the contract. There have been six bosses in five years. The programme has left doctors, nurses and hospital managers spitting with rage.
"Most GPs think the appointment booking system is a joke. And three fifths of the programme is dependent on a software supplier, iSoft, which is under investigation by the Financial Services Authority and whose flagship software product, 'Lorenzo', does not yet exist even though the company said it was available three years ago, and which in the meantime has been merrily selling old software which pre-dates the national programme. You just couldn't make this up.
"The limited deployment of administrative systems which has taken place so far has caused havoc in various hospitals, leading to significant delays in providing inoculations to children, waiting list breaches, missing patient records, extended shut downs of some systems and the inability to report activity statistics". [PAC report page 14, paragraph 13].
"The central problem arises from a set of huge contracts which were signed in great haste, before either the government had understood properly what it wanted to buy or the suppliers had understood what it was they were expected to supply. It is impossible to avoid the conclusion that this project has been an expensive failure. It will continue to fail unless there are drastic changes".
The report calls on the Department of Health to commission and publish an independent assessment of the business case for the Programme in the light of the progress and experience to date.
In view of the slippage in the deployment of local systems, the MPs also recommend that the Department of Health should commission an urgent independent review of the performance of Local Service Providers against their contractual obligations.
Clinical benefits unlikely to be delivered by end of contract.
No firm dates for development of patient clinical record.
Clinicians not persuaded of benefits.
High costs yet no detailed record of overall expenditure.
Concern over of software supplier iSoft, which is under investigation and which is selling old software which pre-dates the Programme.
MPs call for independent assessment of business case for the Programme.
MPs recommend urgent independent review of the performance of Local Service Providers against their contractual obligations.
No published plans exist for implementing shared electronic patient clinical records in line with the original vision for the Programme. PAC report page 13, paragraph 10.
The delivery of the patient clinical record, which is central to obtaining the benefits of the programme, is already two years behind schedule and no firm implementation dates exist. By now almost all acute hospital Trusts should have new NPfIT patient administration systems (PAS) as the essential first step in the introduction of the local Care Record Service. As of June 2006 the actual number was 13 hospitals. In June 2006 the Department wrote to us stating that by October 2006 there would be a further twenty-two. So far as we are aware, up to the end of February 2007 the number has increased by only five acute hospitals. The introduction of clinical as opposed to administrative software has scarcely begun; indeed, essential clinical software development has not been completed. PAC report page 5, paragraph 1.
The frequent changes in the leadership of the Department's work to engage NHS organisations and staff have damaged the Programme and convey that the Department attaches a low priority to this task. PAC report page 6, paragraph 6.
Leadership in securing support from NHS staff and organisations has changed several times over the life of the Programme: at the time of our examination, responsibility for this task had passed between six Senior Responsible Owners. PAC report page 20, paragraph 26.
The Department has not sought to maintain a detailed record of overall expenditure on the Programme and estimates of its total cost have ranged from £6.2 billion up to £20 billion. PAC report page 5, paragraph 2.
Note that £20 billion was quoted by Lord Warner in an interview with the Financial Times on Tuesday 30 May 2006, although the £20 billion figure was later qualified. Connecting for Health has separately acknowledged that costs could rise to £15 billion.
The Department of Health has paid at least £639 million in advance payments to suppliers despite its supposed approach of payment only on successful delivery. PAC report page 14, paragraph 15.
We are concerned in particular that iSOFT's flagship software product, 'Lorenzo'–on which three fifths of the Programme depends–is not yet available despite statements by the company in its 2005 Annual report that the product was available from early 2004. PAC report page 6, paragraph 8.
At the time of our hearing in June 2006, some 13 acute Trusts had had their Patient Administration System (PAS) replaced, which itself provides no care record functionality beyond what they already had. In those regions where iSOFT is the main software supplier, the replacement has been an old iSOFT PAS which pre-dates the Programme because the PAS element of the new system, Lorenzo–which is being developed for the Programme and which the company stated was available from early 2004 — is not yet available. PAC report page 13, paragraph 10.
In view of the slippage in the deployment of local systems, the Department should also commission an urgent independent review of the performance of Local Service Providers against their contractual obligations. PAC report page 5, paragraph 4.


text:
Q: Better way to build relational database with EF Core I am new to EF Core and having troubles with designing proper models.
My goal is to have three database tables:

*

*Users (contains users of an application(using Identity));

*Lanuages (indicates what languages a user can speak) with following columns:

*

*Id

*UserId

*LanguageId

*LanguagesList (static list of available languages) with following columns:

*

*Id

*Name

*Code

*etc.

The idea is to bind users and their languages via third table which would include only ids like this:
Id    UserId    LanguageId
1     56        1
2     56        2
3     57        1

The classes I create are:
User class:
public class ApplicationUser : IdentityUser
{
   public List<Language> SpokenLanguages { get; set; }
}

Lanuages:
public class Language
{
    public int Id { get; set; }
    public ApplicationUser User { get; set; }
    public LanguageList LanguageList { get; set; }
}

And LanguageList
public class LanguageList
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Code { get; set; }
}

My database context class:
public class ApplicationContext : IdentityDbContext<ApplicationUser>
{
    public DbSet<Language> Languages { get; set; }
    public DbSet<LanguageList> LanguageList { get; set; }
}

The way I am trying to update database is (console style):
public class _TestController : Controller
{
    // Database context.
    private ApplicationContext ApplicationContext { get; set; }
    // ctor
    public _TestController(ApplicationContext applicationContext)
    {
        this.ApplicationContext = applicationContext;
    }

    public IActionResult Index()
    {
        List<LanguageList> allLanguages = this.ApplicationContext.LanguageList.ToList();
        ApplicationUser user = new ApplicationUser();

        Language language = new Language
        {
            LanguageList = allLanguages.FirstOrDefault(lang => lang.Name == "English"),
            User = user
        };

        user.SpokenLanguages = new List<Language>();
        user.SpokenLanguages.Add(language);

        this.ApplicationContext.Languages.Add(language);
        this.ApplicationContext.Users.Add(user);
        this.ApplicationContext.SaveChanges();
    }
}

This code creates proper rows in data tables, but when I am trying to get an ApplicationUser from context it's property SpokenLanguages is always null.
What is wrong with this code and why value of SpokenLanguages property is always null?

A: You have some relations set up, but EF won't follow those relations unless you tell it to. You do this with the Include method:
var users = ApplicationContext.Users.Include(u => u.SpokenLanguages).ToList();

... or something like that.
See https://learn.microsoft.com/en-us/ef/core/querying/related-data


text:
) – archbishop [vol. 23, p. 306]
Ofihely, Maurice
, archbishop of Tuam, was otherwise called Maurice de Portu, from having been born near the port of Baltimore, in the county of Cork, though others say he was born at Down, or Galway. He was some time a student at Oxford, where he became a Franciscan. He afterwards travelled to Italy, and studied philosophy, and school-divinity at Padua. About 1480 he removed to Venice, where he was employed by Octavian, Scott, and Locatelli, as corrector of the press, which was then considered as an employment worthy of the greatest scholars. In 1506, after he had taken his degree of D. D. at Padua, pope Julius II. made him archbishop of Tuam in Ireland. In 1512 he assisted at the first two sessions of the Lateran council, and in the following year set out for Ireland, but died at Galway, May 25, 1513, where he landed, before he could take possession of his archbishopric. He was at this time not quite fifty years of age. He was buried in a church at Galway, where his humble monument is yet shown. He was a learned, pious, and amiable prelate, and held in such veneration by some authors, that they have given him the name of "Flos Mundi," the flower of the world. His works are, 1. "Expositio in questiones dialecticas Divi Joan. Scoti in Isagogen Porphyrii," Ferrara, 1499; Venice, 1512, fol. 2. "Commentaria doct. subtilis Joan. Scoti in XII. lib. metaphysics Aristotelis," &c. Venet. 1507, fol. 3. "Epithemata in insigne formalitatum opus de mente doctoris subtilis," &c. Venice, 1514, fol. This is what Possevin calls "Theorems for the explanation of the sense of Scotus." 4. "Dictionarium sacra? scripturee," &c. Venice, 1603, fol. which reaches no farther than the word extinguere, but there is said to be a complete ms. of it in the Bodleian, as far as the word zona. 5. "Enchiridion fidei," 1509, 4to. &c. &c. 2
Ath. Ox. vol. I. new edit.—Harris's edition of Ware.—Tanner.
Odo, Cantianus (?–1200)
Oecolampadius, John (1482–?)
Oecumenius
Oeder, George Christian (1728–?)
Oeser, Frederic (1717–1799)
Ofihely, Maurice (?–1513)
Ogden, Samuel (1716–1778)
Ogilby, John (1600–1676)
Oglethorpe, James Edward (1698–1785)
Oisel, James (1631–?)
Okely, Francis (1718–1794)
Paaw, Peter (1564–1617)


Candace Ramsey draws blood from Philip Davis Tuesday morning as the Dallam-Hartley County Hospital District lab hosted a free event at the Dalhart Senior Center. Attendees had the opportunity to receive a Chem 14 and, if they were fasting, a hemoglobin A1C test. The hospital also hosted events at Bower's Prescription Shop and the United Supermarket Pharmacy yesterday.


I grew up primarily in southwestern Pennsylvania and like many families in the area, potatoes were a big part of family meals, especially dinners. I never particularly cared for potatoes but in my house you ate what you were served.
Mashed, scalloped, twice baked, you name it, we had it. Every meal. Sometimes we had french fries or hash browns or tator tots. Or another, lesser known variety, the crispy crown. It was a lot of potatoes. With all of those variations of potatoes you would think I would have found one that I liked. I didn't.
I don't even really like potato chips very much.
I know it's almost unheard of and it is decidedly un-American but I can't help it, I just don't like them. And I've eaten enough potatoes in my life to be able to make that declaration with confidence.
I distinctly remember the day I stopped eating potatoes. I was home from college for the weekend and my mother made dinner. I sat down and loaded up my plate with vegetables then reached for the mashed potatoes. It had become habit for me to take a small amount of potatoes and choke them down out of expectation.
That day though, I had an "a-ha" moment. I was 18. I had moved out of the house. I was an adult and I could eat whatever I wanted.
And I didn't want potatoes.
That moment was a long time and I haven't eaten too many potatoes since. If you want me to eat a potato your best bet is to serve me a french fry dipped in ranch dressing or a crispy, seasoned curly fry. Or layer a potato with so much cheese and sour cream I don't even know there is potato mixed in.
This post really isn't about potatoes. It's about knowing yourself, taking charge of your life, and making the decisions that are right for you.
If that means you declare your independence one night at dinner over a vat of mashed potatoes, then so be it.
You be you. Love yourself. Choose yourself. Be true to yourself. Potatoes are optional.


Inspired by the diet of the wolf, BLUE Wilderness Salmon & Chicken Grill is a high-protein, grain-free food that will provide your dog with a higher concentration of the salmon and chicken he loves.
BLUE Wilderness Salmon & Chicken Grill canned food. Your dog will thrive on it.
Salmon, Chicken, Fish Broth, Potatoes, Carrageenan, Flaxseed (source of Omega 3 and 6 Fatty Acids), Guar Gum, Cassia Gum, Potassium Chloride, Salt, Zinc Amino Acid Chelate, Iron Amino Acid Chelate, Choline Chloride, Vitamin E Supplement, Copper Amino Acid Chelate, Manganese Amino Acid Chelate, Sodium Selenite, Thiamine Mononitrate (Vitamin B1), Cobalt Amino Acid Chelate, Niacin Supplement (Vitamin B3), Calcium Pantothenate (Vitamin B5), Vitamin A Supplement, Riboflavin Supplement (Vitamin B2), Biotin (Vitamin B7), Vitamin B12 Supplement, Potassium Iodide, Pyridoxine Hydrochloride (Vitamin B6), Vitamin D3 Supplement, Folic Acid (Vitamin B9).


text:
Thymeleaf is a Java XML/XHTML/HTML5 template engine that can work both in web (servlet-based) and non-web environments. It is better suited for serving XHTML/HTML5 at the view layer of MVC-based web applications, but it can process any XML file even in offline environments. It provides full Spring Framework integration.

In web applications Thymeleaf aims to be a complete substitute for JavaServer Pages (JSP), and implements the concept of Natural Templates: template files that can be directly opened in browsers and that still display correctly as web pages.

Thymeleaf is open-source software, licensed under the Apache License 2.0.

Features
From the project's website:
 Java template engine for XML, XHTML and HTML5.
 Works both in web and non-web (offline) environments. No hard dependency on the Servlet API.
 Based on modular feature sets called dialects.
 Dialect features (e.g.: evaluation, iteration, etc.) are applied by linking them to template's tags and/or attributes.
 Two dialects available out-of-the-box: Standard and SpringStandard (for Spring MVC apps, same syntax as Standard).
 Developers can extend and create custom dialects.
 Several template modes:
 XML: validating against a DTD or not.
 XHTML 1.0 and 1.1: validating against standard DTDs or not.
 HTML5: both XML-formed code and legacy-based HTML5. Legacy non-XML code will be automatically cleaned and converted to XML form.
 Full (and extensible) internationalization support.
 Configurable, high performance parsed template cache that reduces input/output to the minimum.
 Automatic DOCTYPE translations –from template DTD to result DTD– for (optional) validation of both template and result code.
 Extremely extensible: can be used as a template engine framework if needed.
 Complete documentation including several example applications.

Thymeleaf example
The following example produces an HTML5 table with rows for each item of a List<Product> variable called allProducts.

      Name
      Price

      Oranges
      0.99

This piece of code includes:
 Internationalization expressions:  #{ ... } rh
 Variable/model-attribute evaluation expressions:  ${ ... }
 Utility functions:  #numbers.formatDecimal( ... )

Also, this fragment of (X)HTML code can be perfectly displayed by a browser as a prototype, without being processed at all: it is a natural template.

See also
 Template engine (web)
 JavaServer Pages
 Spring Framework
 FreeMarker
 Apache Velocity
 Template Attribute Language

References

External links
 Thymeleaf

Java enterprise platform
Template engines
Java (programming language) libraries
Free software programmed in Java (programming language)

redpajama_set_name: RedPajamaWikipedia


DDM Laser are the sales and service agent for TCI Cutting. DDM Laser's team is committed to total customer satisfaction and will assist you to find a solution tailored to meet your individual requirements. Customer satisfaction is DDM Laser's priority and we are continually seeking new ways to deliver the best value for money machinery, as well as the best after sales service experience. DDM Laser also supplies high quality spare parts and consumables. While we have already stocked our store with a large array of consumables and spare parts, we are adding more everyday. We are confident in the quality and value of our products, and we stand behind them with our guarantee of satisfaction.