Welcome to the 2016 NASA Ames summer series
Biology is a magnification of the physical laws and structures that it is made of
Planets until recently have been thought to be unique, but the Kepler mission has demonstrated
that they are ubiquitous part of the physical universe and just
a reflection of the physical universe
K2
Has taken the Kepler satellite that's lost its ability to maintain
its
Long-duration pointing stability and created a new mission that observes the fields along the ecliptic Elaine
What discoveries await?
Today's presentation entitled micro lensing and the k2 experiment will be given by dr. Thomas Barkley
Dr. Barkley is the director of the Kepler k2 guest observer office?
where he is in part as
part of the duties responsible for performing Kepler and k2
driven investigations
He received a Bachelors of Science and physics from the University of Leeds
Followed by a Masters of Science in astronomy and radio astronomy from the University of Manchester
he then went on to
receive a PhD in astrophysics from the
University College London
Several notable discoveries that dr. Barkley, led
Include the detection of the smallest known exoplanet
and characterization of the first super Earths sized planet
Orbiting close to its star's habitable zone
Please join me in welcoming dr. Barkley
Good morning everyone and thanks for coming and hopefully you're all well and rest rested from the three-day weekend
So you'll be awake for the entire presentation which is going to be a really great thing
I'm going to talk about k2 the k2 mission, but I'm going to start actually by talking about the Kepler mission
We use the Kepler spacecraft for k2 and the Kepler mission. I think was one of the most important missions
We as an agency have ever done
It's can truly say that it's redefined where we see ourselves in the universe
What is our place? Where do we come from? Where are we going?
it's it's it's telling us about ourselves, and I think that's really really wonderful and fantastic and and and
changes our paradigm
So the Kepler missions goal was to determine the fraction of habitable zone planets
That are earth sized in our galaxy
And I think the mission has really done this and it's told us that there are planets everywhere and that
Once again, we learned that we're not especially unique or special out there at least in terms of where we live so
Just a brief mention of how we find planets
What we do is. We look at stars planets pass across the face of a star
You're still going yes sure like this
This is even better planets pass across the face of a star and when they pass across
They block a little bit of the star's light and that dimming we detect we call it a transit
We named this transit after things that happen in our own solar system. This is our own solar system
This is the Sun and this is Venus passing in front of it
Fortunately, I got to see two transits of Venus if you didn't see one you're gonna
Hope that you live well eat well and live for another 100 or 200 years because then it occur very often
Certainly not again in my lifetime
But this is the transit Venus. You can see some really wonderful things like this
Do you see this jittering on the surface of the star of the Sun here? This isn't just the projector?
Putting noise in there. This is actually what's going on on the surface of our star. This is granulation
This is motion convective motion coming up one of the amazing things about our spacecraft
And and what it does and how sensitive is it is is that this?
granulation noise
And surface noise and convective features is actually what limits our ability to find planets
Across among many of our stars is it's the stars themselves are too noisy, and they they they limit our detecting ability
I think that's really wonderful
But you see see some nice things there about finding planets you see the limb of the stars
Darker than the center of the star. This is what we call limb darkening. We see this in our Kepler data
You even see a little bit of the atmosphere of Venus
and I think the next 20 or 30 years of our our agency's exoplanet hunting and search will be to try and
Model the atmospheres of other planets not just ones in our own solar system
So why is it so difficult?
Why didn't we find lots and lots of planets until we had a mission in space to detect them
Well, this is what a Jupiter would look like
transiting
The Sun you see it's pretty big, it's about
1/10 the radius of the star therefore blocks about about 1% of the area
It's fairly easy to detect we call it a 1% transit a 1% dip
We see these from the ground these were amongst the first planets trying to found now. Let's look what earth would look like
Do you see this tiny dot up here here? It is? That's what earth is look like
the amount of light blocked by earth is
About 100 parts per million now to put that another way just imagine
you know there's a million photons coming from this star just a hundred are blocked by this planet and
Yet, we can detect these things in fact. We can just take many of these things
But we needed to build a special instrument, and so I hashed up a little short movie here
Showing some of the heroes of this story, you know we scientist gets to talk a lot about the results
but it's the
engineers and their ingenuity that time and again has enabled us to both build a wonderful instrument and then
Keep the mission going and keep it operating
Throughout this talk. I think everything we've done is depended on the ingenuity and the resourcefulness
and and the the childlike excitement of brilliant engineers
So I wish me to go back to the start
And I'll just show you some of the components of the spacecraft. This is our mirror
It's a one point four meter mirror. It goes at the bottom of the spacecraft
This is our camera up there
So you'll see some images that look like this camera that they they have the same shape this is actually a movie
But they're moving very slowly
But that's the solar the solar panel and later on the solar panel is going to become very
Important for for what I'm going to tell you this is just the the thing arriving at the Kennedy Space Center
for for launch
whilst the end packets
And here they are just just putting everything together and again you see you see this this spacecraft you see the the solar panel here
Which which became very important so the spirit of the mission launched in?
2009 in March and since then has been been operating firstly as a Kepler mission, and now is the k2 mission
As aboard a Delta 2 for those of you interested
One important thing to know about the spacecraft and for the microlensing component. This is absolutely essential is that Kepler doesn't orbit the Earth?
Kepler orbits the Sun and trails the earth in and what we call an earth trailing orbit
actually as time goes on Kepler gets further and further away from Earth a
Communication bandwidth goes decreases as a function of time
and
Eventually it'll drift and drift and drift until it goes behind the Sun
This is the were the main Kepler mission which lasted until 2013
we looked at a single patch of sky the entire time a reach of the sky in the
constellations of Lyra and
and and
The Cygnus that's the constellation that was escaping me and and you see here
This is the picture of the camera that camera that I was showing you earlier on board. It's about a hundred megapixels or so
It has 84 C CDs
Arranged in this pattern and so when you see big images of ours the reason they look like they do is because that's what our
Camera looks like and the bottom left here is actually an image of some of our data
People don't often show real Kepler data. They show lots the results
They show lots of artistic images, but they don't often show the data
And there's a very good reason for that our data. Doesn't look like Hubble data Hubble data
Essentially you need to take it you put it up as an image, and it looks beautiful
And then people work to make it look even more beautiful
But but the beauty's intrinsic to the image the beauty isn't intrinsic to our images our images look like fuzzy blobs
They're they're they're somewhat large blobs. These are the stars and this is where the magic happens
but simply all we do is we take a
Essentially a photograph every 30 minutes continuously we did that for four years
Of the same different regions of these weather stars are these fuzzy blobs so you have a nice time series of
Images just like this one
But what can they tell us?
This is actually how we find planets and they don't there's so much information in this time series
I showed a little bit at the movie of what a transit would look like
but remember
Stars here are just this blogs with we see them actually that they're what we call point sources and that we don't resolve the stars
We can't tell the the brightness across the surface of a star just from the image
They're just a single point of light that then gets a dispersed of it
So you can't physically see a planet passing through the middle of this you just see the integrated light of the the point source
Decreasing and that's what you're seeing here
This is actually some some real data is actually some early data, but I think it it shows nicely of
What a planet looks like you see this this random scatter this this kind of small level scatter across the data
That's the noise from the surface of a star in addition to some of the noise from our instrument you see regular dips
On top of this noise or dips down the size of these dips
Tells us that there's a planet there
there's a planet crossing across the surface of a star and the depth of the dips tells us about the
ratio of the size of the star to the size of the planet
It's actually the ratio of the area it tells us how much what percentage of the area of the star we're blocking
So if we block
If we know how big the star is and we know what percentage of light the stars?
Is being blocked we know how big the planet is it's just simple as that?
The other thing we can tell is by how frequent the dips are
We can tell how fast the star the planet goes around the star is orbital period earth that would have one transit every
365 days
That's all it is
By knowing how fast of platon that goes around the star and knowing how big the star is we know how far the planet is
away from the star we can start to understand how much energy the planets receiving from its star and then
Imaginations go wild thinking about what kind of biology could be on the star
And there actually lots of experts who know we're not a lot more than we do and really
Telling this from from being what in my mind is amazing science fiction into science fact and wonderful in-depth real new
Understanding about where we where we come from
So this is what I was saying turning pixels into planets we start off with this fuzzy blob. This is one star here
We measure it continuously for several years, and we get up the thing in the center
This is showing that dip here. This is the transit
this transits
just less than
It's like one part in
Was it one part in 10 to the 4 or so or 10 to the 10 to the 4?
That shows us that was the first rocky planet we ever found this planet was
About 50% larger than the earth, it's a the first terrestrial planet. We knew of outside of our own system and
Then there's the artistic image in the bottom right because we like artistic images
So the this this
Really tells the story of what the Kepler mission
Did and why why I think when I when I use a lot of?
superlatives to describe
The impact of this mission, I don't think I'm overstating things
This is our understanding in 2009 of what the planets outside our own solar system did
so the first planet was found in 1995 that was 51 peg first planet outside our own solar system and
then since then they've been a
Though there was a number of discoveries most of them very large planets most of them things jupiter-sized
so this is a graph here the the y-axis the up the vertical axis shows the size of a planet and
The relative to earth where Earth at one Jupiter's at 11 Neptune's about four and the orbital period of the planet so it's planets year
You can see there's lots of giant planets there were some hot giant planets in pink
These are ones found by the transit method the method that we use with Kepler
And then there are a few smaller ones found but nothing nothing really that was was definitely earth
Looking looking like Earth there was really a dearth of planets around Neptune sized so
Before we launched Kepler. We didn't know if earths were rare or common
We didn't know if Neptune's were rare or common on most planets Jupiter sized
You know the most things we found was Jupiter sized, but that's because that's all we could find
And this is what happened over the next four years
BAM there's about 4600 planet candidates in here of which so far. We know
2,300 of those are real confirmed exoplanets
So this has gone from knowing of
tens of planets Jupiter size to knowing that there are thousands of planets out there and
Most of them interestingly aren't aren't like the earth era they're not like Neptune either
They're in this middle range between Earth and Neptune what we call super Earths
Super Earths are wonderful and fantastic because we don't have any of them in our own solar system
So we we really don't understand very much about them
You know if we find something
Sighs we can make a good guess that it's maybe like Venus or maybe like earth we find something Jupiter sighs well
Maybe it's like Jupiter. We find something super earth-sized. We really don't know
So it's an exciting time trying to learn what these are made of and and and why they stopped coming
But you can see there's no planets out here
so this is 2013 and
Since then when the mission stopped and since then we've been working extremely hard to develop our algorithms and software to improve our detection
methods and methodologies and
Signal to noise so we can find these we can dig in the noise and find these new the planets out here
Which is where we were really hoping to find find exoplanets because at least as far as we we can understand planets
Like like ours have liquid water, and they are the size of ours
So we're trying to find things in that regime that a temperate enough to have liquid water perhaps
and so this is the latest as of
the latest planet candidate come out in 2015
There are very little updates since then, but there'll be another update later this year
And you can see that finally we're starting to find small numbers of planets out at this earth, Earth region
That means we're sensitive to earth sized things and we're finding earth sized things orbital periods of one year
This is places like where we live
Perhaps and the next mission is going to try and understand them do they have atmospheres
What do they like to they have water? This is the future this is for the interns in the room?
This is this is the jet your generation is to
Help us learn and help us understand or even just to exist at the time when we're finding
atmospheres on other planets
Okay, so as I mentioned one of the before Kepler launched we knew of
Just Jupiter sized things so are they common the answer's no
Jupiter's are extremely rare if you look at what we find we find very few jupiter-sized planets
Other detection methods are finding the same thing Jupiter isn't a common thing in fact if we if you found another
Earth-sized planet in the habitable zone it probably doesn't have a Jupiter companion
The most common things we're finding a sort of Neptune super-earths and neptune-like
Things when you correct for our
detection sensitivity you find that probably the most common planets out there are things that are earth sized I
Just wanted to touch upon some of the individual discoveries a lot of them led by people who work within NASA Ames
along with some wonderful external scientists
Who've been involved with our team this includes things that are the first earth-sized planet?
The first capital 20 to be the first planet inside of its habitable zone
And then as we move along the first earth-sized planet inside. It's habitable zone
This is kepler 186f in the first so a super earth sized thing
Orbiting within the habitable zone none of these are quite earth-like yet, so these are this the most exciting
Planets we've discovered so far, but I think we're moving towards every step. We make things that remind us of Earth
And
If you think of we found these thousands of planets we must be looking at a lot of a lot of the sky
Actually, no. We look at at one tiny area
This is this region just shows you the tiny span where we're finding planets with Kepler in fact
It's even smaller than this because we can only find planets that cross in front of their star
But of course the vast majority of planets don't cross in front of their star. They're the ecliptic plane is an angle towards us
therefore we don't find them we only detect a few percent or less than a percent of of
Planets around their stars so while we found thousands of galaxies huge, and we detect very few so there really are truly planets everywhere
So cap was
Unfortunately the the Kepler mission came to an end after four years in 2013
In 2012 we had a good inkling that the that our time
operating the Kepler mission was was going to come to an end we lost a
Reaction wheel so on the spacecraft we launched we have four reaction wheels you can actually see them here these are wheels
These things are now
We're not actually pointing to the wheel those are wheels
these actually
this is how we point the spacecraft you have wheels you have them orthogonal to each other and you spin them and
By spinning in the right way
You can turn the spacecraft or you can hold it pointing steady the solar wind is constantly blowing towards us
And it's trying to return the spacecraft and so we need to counteract that by spinning wheels it's very simple. It's nicely
just just using angular momentum to keep us pointing unfortunately losing one is okay, because you still have three axes and
Dement three dimensions, and you still have three wheels losing two is not good and in 2013 we lost the second of these
so that
meant that we have two axes and three spatial dimensions and
And many people thought that that was that was the mission over, but here are some some nice headlines. I found
kepler planet hunting suffers major failure says NASA
That was it perhaps that was it perhaps that was the end of the mission
Rest in peace care for
NASA gives up hope of fixing it
One thing you should learn about engineers is I I think they they never give up even if they're told there they have to give
Up they're gonna keep keep digging away
And and I think talking to some of the engineers at Ball Aerospace?
And here at here at Ames
Who are involved in this the time when kepler broken things look pretty dire? I think they they had the most fun
They've ever had in their entire lives nasa nasa missions are fairly
Restricted you know you you don't want to go out straw outside the lines because your spacecraft's operating its operating well
And you don't want to break anything, and it's very easy to break things in space
But suddenly you had something that was broken, and you couldn't make it more broken
It didn't work, so you're allowed to do anything you win reason anything you like to try and get
Fixing all wacky ideas were entertained
About what we could do with a spacecraft?
And you've got to play doing all these things that at graduate school and undergraduate you got to you learnt about
Or as a writing
So this was the this is the next report that came out all is not lost
Suddenly someone had an idea of how how we can keep going and Hubble spacecraft down the hunt for a new mission
So this was great. What was this new mission this new mission was the k2 mission
Many people are saying why is it called k2?
Why is it not Kepler - well as a matter that was well as its named after the mountain?
k2 not not Kepler Wow Everest may be the highest mountain a
Higher proportion of people died climbing k2, so I thought this was a appropriate metaphor for our for our mission an extremely challenging
thing that
to
Do and to to to try and try and keep operating, so how does this new Kepler mission work so you have three axes I?
Brought a model I have a prop so you have three axes and
If you think you point it like this and your solar pressure goes like this you're gonna roll
Like this and tumble and you might be able to hold two dimensions
But you're still gonna start to roll and you're gonna start to tumble
So what we need what the engineers realize is we need to find a way to
balance the spacecraft to hold the spacecraft in fine pointing Wow
With the two reaction wheels and then balance it against the solar pressure
Then once you come up with that idea the answer is fairly simple
The solar pressure comes at you like this so you need to point like this at the Sun
You can hold the pitch in your steady you guys are the Sun in this image
Pitching your steady. That's this way and then all its uncontrolled is this roll vector
So if you point your solar panels the thing I told you would be important at the Sun so that they're finely balanced so the
spacecraft looks symmetrical and the normal to the Sun you minimize roll
And you can balance your spacecraft you can point precisely right over here, and you can operate your mission again
So this Ridge this is what we call the balance point
And this is this is just another image showing you
This way down the bore sight of the spacecraft
And you can see what we need to do is we need to find
Finer ways of the soul of son coming from here is just balanced and so we spent several months commissioning the spacecraft
Essentially learning what the spacecraft looked like in the normal to the Sun?
so our commissioning involves us pointing at the start pointing a field of the sky and seeing how much we
reroll, and then changing that angle of it and seeing how much we roll until we learn where the balance of the spacecraft was and
Amazingly, we could we were able to do this
We're able to learn the shape of the spacecraft in in the in space and point the spacecraft precisely
Using wheels and by balancing it now. It's not a fire finally precise
balance it's an unstable equilibrium
Eventually you're going to roll one way or the other
So the way we control for that is that if we point it. We start to roll if you roll too far
We fire a thruster which puts us back and the thrusters
Our thrusters are on here it puts us back to where we were and so you have this continual motion of pointing roll
Reset roll reset, and we do that about every 6 6 to 12 hours
So this is the nice headline, I thought this was well described exactly what we're doing there that that description kepler
kepler resurrects planet-hunting NASA resurrects counts on attending Kepler with broken parts with magical Sun
So I think that's I thought that was very nice
So yeah magical Sun
Because of what we're doing this actually limits us
But also create created our mission and created what we're doing our
Limitations though that we could only look for us at a part of the sky for about 80 days
the reason being if you think of the again, you're the Sun and you're going around the Sun like
Around the Sun like this looking backwards
you can look at somewhere over here and
You your limit is you can't go too far around?
Are you gonna start getting light down the barrel the spacecraft which is terrible? You don't want something like down there and then
That's around here. You don't and then the other side. You can't get too far around
This way as you over at the Sun because you don't want you want to get the solar panel
I keep having lights
So that limits us to observations of in one way about 30 degrees in there the way about 50 degrees so about 80 degrees
Because we our orbital period is roughly
360 degrees that's about one degree a day so it gives us an 80-day campaign
This is what this is showing this is us going around the Sun this way we pointed a field over here
We move around we keep pointing and then we point up to 190 degrees away
And this is an 80 days of motion we point backwards so we don't get bugs on the mirror when we move
It's actually so we don't get earth in the field of view if you point forwards you
You would get earth in the field of view very naturally if I would have to pass through the field of view Earth's
extremely bright and
When we were commissioning this we weren't sure
What would happen if something that bright fell onto our focal plane?
And so we decided well given the balance between putting forwards and backwards. It's fairly even less point backwards
We since learnt that it's actually fine. If gets into our field of view. It doesn't cause any long-term damage or anything
But that was just the way we built the mission
So what happens then is you get a lot of fields observed along this ecliptic plane the plane that our spacecraft
Our spacecraft
Looks out on the plane that the Earth and Sun are in and so this is that this is nice you all know the constellations
The ecliptic plane or probably most of you because there's a dial constellations
So the first two years of our mission was shown in in in
Brown, it's probably brown Brown here, and and the next two years are shown in green
So these next two years have just been funded so we know we're gonna go be at least a four-year mission
I'm going to talk a little bit
Soon about the the yellow arrow here. This is campaign 9. This is our microlensing campaign
We did a dedicated campaign to microlending and you're gonna hear some of that later
I
Might give you a talk of someone else will give you a talk in two years telling you about the the next arrow the supernova
Focus campaign a a single experiment dedicating to understanding supernovae and the the early rise are when a supernova happens
But that's that's going to happen sometime next year
K2 isn't just Kepler, but worse that's the important thing
It's a very different mission, and we knew we couldn't survive being Kepler, but worse Kepler Kepler changed everything
But Kepler took all this data, and we're using it to understand
Around us, but I think
Kepler's done. I mean we've got the data. We needed to learn a lot about our universe
We don't want to collect that data again and learn the same things we want to do something new
So k2 enables us to do that we can do things
We couldn't do with Kepler because of the way the spacecraft operates here are just some some examples
Of things that we didn't do with Kepler this is
M35 this is a cluster of stars
Clusters of stars are fantastic laboratories to study astrophysics all the stars formed at the same time or roughly the same time
Therefore they probably all have the same composition so you have stars the same composition same age
Why do they differ and their differences should tell you something about what them?
How old they are how massive they are how?
What their radius is what the evolution his eerie history is our binary is more common a binary is less common
What are planets like in clusters so so you can learn about how things form as as?
Universe goes on by looking at different clusters at different ages Kepler didn't look at many clusters
We can look at lots because we look along the ecliptic
Ecliptic is full of clusters. We look at Kepler looked at one field
We're gonna look at 18 fields so we get 18 amount of the x amount of area that Kepler saw
This this is star forming regions Kepler intentionally didn't look at star forming regions
Why is that because star forming regions are full of dust and dust absorbs optical light, and if you absorb optical light?
You don't see as many stars. You don't find as many planets and you can't find earth-like things
With caplet with k2, that's not a limitation anymore. We look at a single field for 80 days if it's got lots of dust
we'll just look at somewhere with less dust in three months and
Now we can start to study these youngest stars
We can study how stars form we can study how planets form we can study
When planets form do planets form right away at the same time the star they take a few million years after the star
Do they form close to the star do they form far out from the star these are questions k2 can answer that?
Kepler wasn't able to answer these a new new science. We're learning and something
I'll show you a little bit of a movie of this is a a comet here
The ecliptic plane as we learn very quickly when we started getting our commissioning data is full of
Moving objects because it looks at where our own solar system is our solar system forms in a disk and so kept k2 is looking
Into this disk and so we see thousands and thousands of asteroids and we see planets
But plants closer to home than what we're used to
There's a little bit about focus, but this is a cover image from our proposal we put in
But this is showing you all the constellations along our ecliptic and things that either we have observed or will observe in those
constellations, and you can see this huge variety from from
galaxies to planets to
To clusters to planetary nebulae all different science in all different fields
Were depending where you look you find different things you have different science
So I think I think
K2 is really far exceeded our expectations of the the breadth of science. It's doing it's it's it's really
changed from this somewhat narrow mission of Kepler into this extremely broad mission of a general astrophysics Observatory in
Addition to astrophysics we also do some planetary science work planetary sciences is looking at things in our own solar system
Here is
Just a quick movie of us an object from our own solar system. This is the planet Neptune and
You can see something going around Neptune. That's the moon, Triton
This is I think about 60 days of data?
And you can see this this planet moving you see a smear because the planet
bleed of the bright because the planets very bright we can see very nicely the moon the motion and the orbital dynamics
you know we a lot of us learned orbital dynamics in in an undergraduate in high school in PhD at different levels I
certainly had never seen orbital dynamics happen in real time or or in a movie like this as the moon goes around the
Planet here, you can see Kepler's laws in in acts in a single movie
And the reason the Neptune is moving so much isn't that net cheese moving fast. It's that the the para lactic angle of
Kepler-22 - to Neptune here is changing as
the spacecraft moves around the Sun the the
Position of Neptune compared to the background stars moves we call this a parallax, and that's what's going on here
This is just showing you some of the other solar system stuff
We're doing this is the the brightness change of some Astrid
transept tuning objects things in orbit in the same orbit as Pluto and you can see this little wiggle in brightness as
They rotate we can learn the shapes of
Bodies in the outer solar system we can learn how they rotate we can learn how bright they are
This can help us learn how the solar system formed
The reason I'm showing planetary science stuff is because I think nobody predicted that we would do a lot of planetary science work
But it's actually become a very important part of the mission as we learn about our own solar system and that informs us about
exoplanets and vice-versa I
Like this movie because it's the faintest thing we ever observed with k2. This is something for those who understand magnitudes 23rd magnitude is
Extremely faint you can see something going up and down. Do you see that?
That's a transit tuning object. I don't know if you can you can see that in the movie
You have to get your eye in there we go up and down the faintest thing. We've ever observed
Kepler observes from okay - we observe objects from the extremely bright to the extremely faint we have this huge dynamical range of brightness
Okay, so I mentioned clusters clusters is extremely important. This is an image of the Pleiades
I show Hubble images because Hubble's beautiful as I mentioned earlier. This is a Hubble image of the Pleiades
this is actually our image of the Pleiades the Seven Sisters as
Many of you'll know it
And the seven bright stars here, which are used really?
Heavily in astrophysics to try and understand how how stars operate?
Let's zoom in here, and this is showing you this - the shape of RC CDs
This is showing you where where are where we looked for a given campaign
And then we put masks around the and we put mass around them and we can observe these bright stars
In the in this field of view and you can see them actually because they're moving here
That's the movement of the spacecraft
I mentioned there's six hour roll so by looking at these we can look how their brightness changes over time we can look at seismology
Inside of these stars as they oscillators as gas moves up and down and can
Convex inside them and we can understand the internal structure of these stars that people have been observing for
millennia
Giving you insights on them
This is just a just show. I'll show you some of the
Full frame images as we call them. This is our full frame
You'll see that there are two to CCDs that are no longer operating, but the the rest of the the area
Really is vast and and can teach us a huge amount about that our galaxy
And this is so this is where the Pleiades is this is another cluster the Hyades that many of you heard of
Prosecco or M or the Beehive cluster falls into things
So so this is a hugely diverse field and hugely new things that we can we can look into
Of course k2 is still an exoplanet powerhouse
Exoplanets really is what the mission primarily seems to do while we're a general observatory people propose
To do science and exoplanets is obviously a very big part of this
There are 50 confirmed more than 50 confirmed planets from k2
I think there's about a thousand planet candidates as of yesterday
There was an eight announcement of about eight hundred new planet candidates so K twos
Pushing up there
Towards the Kepler numbers of things detected and crucially we're finding planets around the nearest stars and the nearest and brightest stars
Things that perhaps we can hope to characterize with missions like James Webb
So this is the as of a month ago the number of planets
We're finding you see this actually mirrors kept look quite nicely very few bigger things
many more of these smaller things
Peaking in the super earth size regime where we're most sensitive
So this is just showing you some of these as why we differ from Kappler
Those this is a popular hand out image that we we gave to many people as opposed to for Kepler
And then we made one for k2 and and with Kepler you thought how small the Sun is with k2 you think how big the?
Sun is that's because k2 lots looks with lots of nearby planet stars trying to find planets around the
Smallest stars these M. Dwarfs as we call them the reason being small stars are have a bigger transit depth
I said transits a function of the the area of the planet divided by the area of the star blocked or
The area of the star and therefore if you shrink the star you find big smaller planets easy it more easily
So that's what we're doing k2. We're finding these planets around the smallest stars
So
Kepler's told us a lot about the inner part of the solar system of the solar systems
It's taught us about the occurrence of things interior basically of Earth's orbit around other stars
But if you look at this graph this shows you how?
where the the inner system of
Our solar system and where Kepler's sensitive the blue region here is showing Kepler sensitivity as a function of of
Distance from from a star and it tails off as you get towards the Earth's orbit
And then if you shrink that region down and look at how big our solar system is
You realize that Kepler while teaching us so much about other planetary systems
It's just a tiny window into the into even our own solar system in fact
If you think of what Kepler could detect in our own solar system
Kepler might find one perhaps two planets in our own solar system of which our system has many
So we've just probed this tiny regime
Fortunately there's something called micro lensing that may may come out to inform us of other
Regions around other stars
Teach us things about Neptune Saturn Uranus and there a frequency that we simply don't know right now
and
K2 is going to be an important part of this
So what is gravitational microlensing very very simply gravitational microlensing uses the fact that gravity warps space-time
So if you have a lot of gravity and you have a background star the light from that bat
Or a background galaxy in a traditional micro lensing the the the light from that galaxy is going to be bent
That's gonna. Be focused and so you see
That light these background galaxies is brighter than they would actually be this is nutritional gravitational microlensing
It's been used for for a long time to weigh
Foreground galaxies you can understand the mass of things by how much they bend the light
Grab a micro lensing
guys that was gravitational lensing micro lensing
Uses this effect
But in on the much much smaller scale you
take a background star a star on our Galactic bulge say in the center of our galaxy and
Then you have that light coming towards you and then you have a foreground star perhaps even a star
That's too thin to see but the light of that background star is bent around the foreground star
So as that foreground star moves past because everything's moving moves past the background star
You see the background star get brighter because the light is focused towards us we call this a micro lens
And so that's what you're seeing here
Background star foreground star moving, and you see this shape of the brightening, but what if this foreground star had a planet?
You'd see two dips
You'd see first the main different micro lensing of the star a little dip caused by the lensing of the planet
The planets causing and this is a micro lensing event so this goes up, then you see the secondary dip that lasts
You know of order a few hours to a day and the main event might last a few weeks
We've detected a few planets like this
But very few and the Kepler mission is going to help us to take many more of these this is a
Brief movie, I'm gonna show showing you how this effect works not just for stars of planets
But also perhaps for free-floating planets the idea is that there's planets orbiting no star
wandering planets or rogue planets
I call the free-floating planets so in addition to finding planets around distant distant around their own star we can also find planets
That orbit with no star
So this is just the my cleansing effect
This is the lens here move across this is the the back
This is the foreground star that you can't see warping the lights
And then you see this ring as it is it focused the light towards you and then when you add up all that light you
See this this
bright brightening
So k2 is going to look towards the center of the galaxy where there are the most stars you have the most chance of something
passing in front of a a
Background star and it's going to try and find these events by looking looking a large patch of the sky towards there
We just look at what Kepler probe in its tiny region we can see
That in comparison is very small
Compared to the way the microlensing region is going to probe Micronesia region has a much more higher volume of space where it can find
Events towards the center of the galaxy looking for these these very faint
Stars that pass in front of these background things so but why k2?
Okay, these micronized events have been observed from the ground some wonderful ground-based observing projects to detect them
And they found planets or have found few low tens of planets
Kepler gives you something else Kepler
Isn't orbiting Earth it's far from the earth in fact as I mentioned. It's about
8/10 of the way to the Sun as is the distance that Kepler's away
So that means that Kepler and Earth look at a different angle towards these micro lensing events and these microlensing events are extremely
Precisely tuned and the shape of this brightening is very precise and very
Sensitive to the angle that you're looking at it
So if both of them look at a slightly different angle they see different things the events look slightly different
This is just a example of what something would look like here
You see the the my cleansing event from Earth and you see a slightly different time a center and a slightly different
magnification from what the the space crack the k2 mission would detect with a Kepler spacecraft
And you can use these differences in the shape to learn things about the unseen lens star
Primarily and the unseen lens planet. Hopefully primarily you learn about its mass. You know how massive these planets are
Without the extra line-of-sight. It's very hard to uniquely determine the mass
I'll skip that one
of course doing this requires a
Lot of ground-based observing the Earth's a challenging place to look at continuously
Kappa k2 can look at a place continuously fairly easily. We just point on the earth
There are two reasons one the Earth rotates, and you have daytime two you have whether you're clouds
So because we wanted to observe this region simultaneously from Earth and space for three months with no break
We put together a huge network of spare telescopes to observe
This is just some of the the telescopes that are observing these regions of sky
continuously both doing
observing of large regions and also follow-up
Events are found
These telescopes I think most of them are observing every single night for the campaign campaign 9. Which which ended a few days ago
It was and and most of these are manual so you needed people observing at the telescope's for 3 months
straight for all these telescopes
I like to think that we we actually observed the the micro lensing region for more than 24 hours a day because we had multiple
telescopes going simultaneously for three months
And so that meant that when there's weather and when there's daytime there wasn't a break
This is just the the the first image that we pulled down from the spacecraft. This is our full-frame image
This was made courtesy of Doug Caldwell who works within the project and I try to
Show you what this looks like it looks nothing like any of our previous full-frame images
And that's because it's just packed with stars the stars everywhere
and
You know this is like looking at the Milky Way in fact if any of you have been lucky enough to be in the southern
Hemisphere it's like looking in the Milky Way in the southern hemisphere, or you see more stars
and
So this is a region the dark regions where there's lots of dust and here you've seen huge numbers of stars
And this is where we we do some of our microlensing experiments
And as of today there are about 500 micro lensing events detected from the ground and from from from the spacecraft
Which we hope to find planets in still working progress that campaign stopped over the weekend
And we're gonna be working hard to find find more events as time goes on
I'm just going to stop here and saying that this isn't the end of the story my cleansing we understand as a
An agency to be an extremely valuable
way to
Determine what other planetary systems are like Kepler told us about the hot planets the planets that are hotter than Earth and equal to Earth
k2 and
W first in the future are telling us about the cold planets
Don't be first to launch in 2024 and we'll be detecting
thousands of jupiter-like planets and neptune-like planets, and maybe cold earth-like planets orbiting their best distant stars
and
Hopefully lots of free-floating planets
Orbiting no star road planets, so I know I say
it's just thanks for coming and stay tuned for our early estimates of
Micra lensing events when we find them they'll be coming out of the next 12 months. Thank you
So we have time for some questions if you have a question
Please raise your hand and wait for the microphone ask one question only. Thank you
Hi Richard art reader was sort of Colorado. Thanks for that great. Talk. I have a question regarding the
Regions of planets that are detected you had mentioned that there's an issue of sensitivity in terms of noise
Versus detection and it's in this sort of Earth analog or sorry earth earth
Weejun
I'm wondering if you are aware of the star shade project
And I'm wondering if you have any information regarding that how it's proceeding if it's proceeding yeah
so so yeah our
limited sensitivity of Earth's sides can because
When you build a spacecraft you tend not to?
Fund it to do things far and beyond your actual what you want to do
You know you what you want to come in as cheap as possible, but still do amazing science
So you make what you want to do, just possible and so
That's why we're not detecting many because it's extremely hard and our mission ended after after just four years
However, we are finding things, which is which is really fantastic
The starshade project is just mind-blowing
It really is you launch a spacecraft to look at a star you then launch this huge thing that can be you know
tens of meters across looks like a
petals of a flower to block light from the star and by blocking light from the star
You can start to see the planets around the star
reason if you look at a star in the sky
you can't see planets even if your eyes were incredibly sensitive because your Swap pumped by light from the
light from the star swamps any light coming from the planet
but if you use very
Clever optics sort of block out light from the star you can see that see the planets these star shades are gonna orbit
Millions of miles from the from the spacecraft is it's an incredible undertaking
But there are certainly there are plans that this star shades going to be launched
Perhaps in the 2020s there are certainly investigations going on right now perhaps even
As part of the w first experiment, it's it's it's a very much an exciting new area of research
But it's it's very challenging to do one of the reasons is you can look at once over here
And then you have to move your star shade
millions of miles in order to look at another star in another part of the sky
That and the optics which incredibly hard to create
But I think I think coronagraphs which are much smaller things to block the light and star shades which are much bigger things
But all but far for the spacecraft are going to be how we're gonna find
And understand life outside our own solar system because you can actually image the planets themselves you can see
Directly the light coming from these planets you can understand perhaps. What's in the atmospheres of these planets?
Hi, I'm Morgan from Florida Tech
And I was wondering what the most common solar system
Configuration is for exoplanets, and if we have enough data to speculate about
about that
Kepler
Really, you know it probes the inner solar systems
It doesn't probe the outer solar systems, but other things do I think the average solar system?
doesn't have
Many giant planets the average solar system probably has planets closer in than ours
We're probably a little unusual in that we don't have anything interior to mercury
That said the universe is so large that I think if you
And and the number of parameters so high that if you looked at any planetary system
You'd say this one's unique for reason eggs
But because there's so many parameters every every planetary system is unique and we can point to things in our solar system that are unusual
but
Unusual things happen all the time
I think one thing we have you know as we increase our knowledge as a species we learn how insignificant. We are
We're just learning that again planetary systems like ours are likely common
Maybe not maybe not the most common, but they're certainly not rare
Hi, I'm Karina, and thank you for your talk
You mentioned earlier that there's a focus on refining?
Algorithms to find planets that are the same size as Earth and I was wondering why the priority is on finding
Same size instead of like maybe the same energy or like why does size make a planet more inhabitable?
Why can't we inhabit bigger or smaller planets?
Yeah, so that the Kepler mission was focused on finding planets like ours so orbiting stars like ours
orbiting
Dis planets at distances like ours and sizes like ours the reason being is we have a sample of one
One planet with life, and we extrapolate from there
I think probably anybody if you explained that you've discovered one thing and you're going to extrapolate to the universe any
kind of statistical person will critique that method
Somewhat harshly, but that's all we have and that's what we do. We know life on our planet needs liquid water and
We we need
RoR solid surface we we don't have
Life that just at least not much life that floats around with no surface perhaps it exists
But it's probably hard to detect it wouldn't be complex life like we have
Probably so the reason being is because we know that we exist therefore we look for places that look like our own
It's probably not a very good strategy, but it's the least worst just right now
So please join me in thanking dr. Tom Barkley
You
