Sunday, April 21, 2013
A Gorgeous New Hubble Image and News from Kepler
Scientists working with the Hubble Space Telescope have just released a magnificent new image of one my favorite astronomical objects -- the Horsehead Nebula, a great cloud of "cosmic dirt" in the constellation of Orion. What makes this image a little different from usual is that we are not seeing the tower of dust with visible light, but with heat-rays (what scientists call the "infra-red.")
It is in such clouds of dust and gas that new stars and planets are being regularly born. Because dust can block regular light, infrared images like this allow us to peer deeper into these regions of star birth. This particular image is about 2.5 light years across (where each light year is about 6 thousand billion miles) -- so we are seeing a good-sized pillar of cosmic "raw material" here. (Yet the Horsehead is just a part of a much larger complex of gas and dust called the Orion Molecular Cloud, which is roughly 1500 light years away from us.)
You can see two recently born stars at the top ridge of dust in the Horsehead in this image, confirming that star birth is happening in this dusty clump. Note that the colors we see on this picture are not real (since these are rays our eyes are not sensitive to.) The colors were picked by Hubble scientists to give a sense of the dustiness of the Horsehead.
You can contrast this infrared picture with a visible-light Hubble image taken with the Hubble in 2000-2001:
and with an image of a larger region around it taken with the Canada-France-Hawaii Telescope on the ground at:http://www.nasa.gov/multimedia/imagegallery/image_feature_89.html
Aren't they gorgeous images?
In other news you may have read that the Kepler mission, photographing 150,000 stars regularly in its search for planets orbiting other stars, has found three more planets that are just a little larger than Earth and orbiting in the "habitable zone" of their stars -- where water could be warm enough to be liquid.
For the full story, see: http://www.kepler.nasa.gov/news/index.cfm?FuseAction=ShowNews&NewsID=243
That page gives you access to the quick info, the paintings of what the planets might like, animation, etc. To get the story in a more organized way, scroll down toward the bottom and click on the link to the full NASA news release.
The gist of the discovery is that we are finding more and more planets that are roughly earth-like -- perhaps a bit bigger, not always around the same kind of star as our Sun -- but Earth-like in their temperatures and other conditions. The Kepler team said that the current discovery is just an appetizer. Many more such planets may be among the 2740 candidate planets Kepler found that they are still examining and not yet ready to confirm.