Telescope eyes Milky Way construction
(CNN) -- NASA released new Spitzer Space Telescope images and data Thursday that show regions of intense star and planet formation in our Milky Way galaxy. Astronomers said the new findings support the idea that our solar system is likely one of many.
"It may very well be that solar systems like our own are probably not rare in the galaxy," said Alan Boss, an astronomer with the Carnegie Institution of Washington. "They may actually be a very common case."
The Spitzer Space Telescope is an orbiting observatory launched in August 2003. It surveys deep space in the infrared spectrum, meaning that its instruments pick up heat rather than light. That enables the telescope to detect objects that normally cannot be seen because they are shrouded in gas or dust, like newborn stars.
Astronomers say that as a star forms, clouds of dust and debris swirl around it, forming a disk and feeding matter onto the star as it ignites. In some cases, leftover material in the disk eventually condenses into planets. But, until recently, scientists have not had the tools to actually seek out such protostars and protoplanetary disks to watch the process happen and check their theories against observations.
"These new results on circumstellar disks show how Spitzer builds upon the results from the Infrared Astronomical Satellite (IRAS) and Infrared Space Observatory (ISO) missions of the 1980s and '90s," said Deborah Padgett of the California Institute of Technology.
"Fortunately for us, the Spitzer space telescope is a thousand times more sensitive than the IRAS satellite -- it can see disks around more-distant stars, it can see disks around fainter stars and it can see disks that are intrinsically fainter because they have less material around them."
The new Spitzer observations focus on two areas of the galaxy, both relatively near our solar system. One region, called RCW 49, is an extremely large "stellar nursery" nearly 14,000 light years away in the constellation Centaurus. Astronomers had known for some time that this was a region of fairly intense star formation, but new Spitzer imagery shows more than 300 stars with protoplanetary disks around them.
"We're incredibly excited about this," said Ed Churchwell of the University of Wisconsin at Madison. "No one, on my team at least, and no astronomers that I know, could ever in their wildest dreams have expected to find a single region like this with so many stars currently in the process of being built."
The other area of observation, 152 Taurus, is just 420 light years away. There, astronomers were able to observe extremely young stars and their protoplanetary disks in unprecedented detail. One, CoKu Tau 4, appears to have a gap in its disk of debris, suggesting a planet may have formed there already.
"The object is only a million years old," said Dan Watson of the University of Rochester. "If the planet formed within the million years that it took between star formation and when we're seeing it now, that probably makes it the youngest planet we have ever seen."
Other instruments aboard Spitzer that detect individual chemicals show the region to be flush with water, methanol and carbon dioxide ice, all of which are ingredients common in our solar system.
"We're hearing that protostars are as common as the cicadas on the trees here on the East Coast," said NASA scientist Anne Kinney, "that infant stars have a lot of ice in them that could provide for future oceans in the future systems around them, and that toddlers, at least one toddler star, has a hole carved out of it, very likely by a planet."
Astronomers announced the discovery of the first extrasolar planet in 1995. Since then, researchers have found more than 120 extrasolar planets, most by using the "wobble method" -- looking for a wobbling motion by stars that would indicate they are influenced by the gravitational pull of orbiting planets.
NASA plans to launch a host of missions over the next decade, ultimately aimed at finding nearby, habitable planets. Those include the Kepler Mission, the Space Interferometry Mission and the Terrestrial Planet Finder.