Astronomy Meeting Highlights New Planets, Hubble Images
It’s been a busy week for astronomy news, as more than 3,000 space scientists have gathered to present new research at the annual American Astronomical Society meeting in Washington, D.C.
Earlier this week, the big headline was that the Kepler Space Telescope, a satellite that launched last March and is designed to hunt for planets outside our solar system, had found its first targets — five new planets orbiting stars in the constellation Cygnus.
Kepler searches for planets by staring fixedly at a field of about 156,000 stars. It watches for the periodic dimming that occurs when an orbiting planet passes between it and a star. The five new planets wouldn’t be hospitable to life. All of them are much larger than Earth — they range from about one-third to 1.5 times the size of Jupiter. And they orbit much more closely to their stars than Earth does to the sun, meaning they’d be too hot to hold liquid water. One has the density of styrofoam. An Earth-like planet — the holy grail for scientists searching for planets outside our solar system — would be more difficult to spot. Not only because of its smaller size, but because a planet in the “habitable zone” of a star’s vicinity, with an orbit farther away from the star, would pass in front of it much less frequently — giving the telescope viewer chances to observe it. The five planets described at the meeting represent the fruit of only the first six weeks of Kepler’s observations — scientists are still analyzing eight more months of data.
“There’s a lot of real interesting stuff. That’s all we can say now,” Simon “Pete” Worden, director of NASA’s Ames Research Center, [told the Washington Post](http://www.washingtonpost.com/wp-dyn/content/article/2010/01/04/AR2010010401366.html?hpid=moreheadlines). Scaling up from planets to galaxies, on Tuesday researchers [announced ](http://www.usnews.com/articles/science/2010/01/06/hubble-goes-deep-and-wide-for-new-view-of-galaxies.html)new images from the Hubble Space Telescope, the workhorse satellite that’s been sending images back to earth since 1995. It was refurbished last April and fitted with a new camera, the Wide Field Camera 3.
Now, a new mosaic of [Hubble images](http://hubblesite.org/newscenter/archive/releases/2010/02/image/), including images from the new camera, shows about 7,500 galaxies that span more than 12 billion years. “The deeper Hubble looks into space, the farther back in time it looks, because light takes billions of years to cross the observable universe,” the Space Telescope Science Institute [said](http://www.cnn.com/2010/TECH/space/01/05/hubble.new.galaxies/) in a press release. The image allows scientists to see galaxies at all different levels of formation. The earliest galaxies in the image are smaller and filled with massive stars. “These are the seeds of later large galaxies like our own,” astronomer Garth Illingworth of the University of California, Santa Cruz, said at the Astronomical Society meeting, [according to USA Today](http://www.usatoday.com/tech/science/space/2010-01-06-hubble06_ST_N.htm).