Gliese 581c = another Earth ?
The science of determining the nature of planets outside our solar system keeps improving. For example, scientists use the wobble a planet causes in its home star’s motion as it orbits to determine the type of planet itself.
Now comes news that a team of European astronomers has discovered 20 light-years away in the constellation Libra a planet similar to Earth. Roughly similar: about 50 percent bigger than Earth and about five times more massive. Still, it’s pretty small as planets go, and it’s the right distance from its sun (a red dwarf) to be within the “habitable zone” where surface water, a key ingredient for the creation of the kind of life we know about, could exist if other conditions are right.
Star map
Enter your location at this website, and you can see the stars above you (on your computer at least). http://www.wikisky.org/
From childhood trick, to a space telescope
Have you ever tried looking at a far away object, but had an annoyingly bright light source nearby? It helps to put your hand up, and block off the nearby light source or reflection. I think I first tried doing this at about age 5.
NASA’s latest telescope does something very similar, but on a more sophisticated level. The James Webb Space Telescope has an eight million-pixel infrared detector (that’s the telescope’s eye). In front of the detector there are 62,000 shutters measures 100 by 200 microns, or roughly the width of three to six human hairs, arranged in four identical grids in a layout of 171 rows by 365 columns. The shutters can close to help the detector only detect weaker sources of far away light.
For more, check out the NASA press release: http://www.nasa.gov/home/hqnews/2007/jan/HQ_07014_Webb_microshutters.html
Many planets alot like Earth?
Check out this article: http://www.eurekalert.org/pub_releases/2006-09/uoca-epm090506.php.
Here’s a snippet from it :
More than one-third of the giant planet systems recently detected outside Earth’s solar system may harbor Earth-like planets, many covered in deep oceans with potential for life, according to a new study led by the University of Colorado at Boulder and Pennsylvania State University.
Of course such studies are based on computer models, which are (ironically) notoriously subject to human error. But if it were true, it certainly makes it more likely that there is life similar to Earth life elsewhere.
