Post by Chicago Astronomer - Astro Joe on Oct 6, 2006 0:38:19 GMT -6
Hubble Points to Billions of Planets in the Milky Way
NASA scientists using the Hubble Space Telescope have discovered what they believe are 16 new planets deep in the Milky Way, leading them to conclude there are probably billions of planets spread throughout the galaxy.
Over the past 15 years, astronomers have identified more than 200 planets outside our solar system, but the new ones identified by the Hubble are at least 10 times as far from Earth.
That planets can be found at the center of the galaxy, as well as near our solar system, has given NASA researchers confidence that they are likely to be everywhere. If that is the case, then the likelihood of other Earth-like planets becomes greater.
The new planets were introduced yesterday as mostly "candidates," since only two could be definitively described as planets. But Livio and team leader Kailash Sahu said the chances are good that some, or even all, of the 16 will ultimately meet all the criteria to be called planets.
Based on the number of planets identified and the number of stars in the Milky Way, the scientists estimated that as many as 6 billion Jupiter-size planets exist in the galaxy.
"Our discovery . . . gives very strong evidence that planets are as abundant in other parts of the galaxy as they are in our solar neighborhood," Sahu said.
One of the biggest surprises of their work, Sahu said, was that five of the likely planets orbit so close to their suns that they make it around in less than one Earth day. These close-in, Jupiter-size planets are not necessarily the most prevalent, he said, but rather are the ones most easily identified using the techniques available for peering deep into the galaxy. The planet closest to its star has an inhospitable estimated surface temperature of 3,000 degrees Fahrenheit.
Full story: www.washingtonpost.com/wp-dyn/content/article/2006/10/04/AR2006100401730.html
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I remember, not too long ago, that the idea of extra-solar planets was considered folly and the stuff of dreamers. The detractors are quite silent now.
I like dreaming...
