Galactic Wheels within Wheels How many rings do you see in this
striking new image of the galaxy Messier 94 (NGC 4736) as seen
by the infrared eyes of NASA’s Spitzer Space Telescope? While at
first glance one might see a number of them, astronomers believe
there is just one. Historically, Messier 94 was considered to
have two strikingly different rings: a brilliant, compact band
encircling the galaxy’s core, and a faint, broad, swath of stars
falling outside its main disk. Astronomers have recently
discovered that the outer ring, seen here in the deep blue glow
of starlight, may actually be more of an optical illusion. Their
2009 study combined infrared Spitzer observations with
ultraviolet data from NASA’s Galaxy Evolution Explorer, and
ground-based surveys in visible (Sloan Digital Sky Survey) and
near infrared light (Two Micron All Sky Survey). This more
complete picture of Messier 94 indicates that we are really
seeing two separate spiral arms that, from our perspective, take
on the appearance of a single