Posted on 01/21/2012 3:05:44 PM PST by SunkenCiv
Astronomers using data from NASA's Kepler mission have discovered the three smallest planets yet detected orbiting a star beyond our sun. The planets orbit a single star, called KOI-961, and are 0.78, 0.73 and 0.57 times the radius of Earth. The smallest is about the size of Mars.
All three planets are thought to be rocky like Earth but orbit close to their star, making them too hot to be in the habitable zone, which is the region where liquid water could exist. Of the more than 700 planets confirmed to orbit other stars, called exoplanets, only a handful are known to be rocky.
"Astronomers are just beginning to confirm the thousands of planet candidates uncovered by Kepler so far," said Doug Hudgins, Kepler program scientist at NASA Headquarters in Washington. "Finding one as small as Mars is amazing, and hints that there may be a bounty of rocky planets all around us."
Kepler searches for planets by continuously monitoring more than 150,000 stars, looking for telltale dips in their brightness caused by crossing, or transiting, planets. At least three transits are required to verify a signal as a planet. Follow-up observations from ground-based telescopes also are needed to confirm the discoveries...
For the latest discovery, the team obtained the sizes of the three planets (called KOI-961.01, KOI-961.02 and KOI-961.03) with the help of a well-studied twin star to KOI-961, Barnard's Star. By better understanding the KOI-961 star, they could then determine how big the planets must be to have caused the observed dips in starlight. In addition to the Kepler observations and ground-based telescope measurements, the team used modeling techniques to confirm the planet discoveries.
Prior to these confirmed planets, only six other planets had been confirmed using the Kepler public data.
(Excerpt) Read more at astrobio.net ...
This artist's concept depicts an itsy bitsy planetary system -- so compact, in fact, that it's more like Jupiter and its moons than a star and its planets. Image Credit: NASA/JPL-Caltech
This chart compares the smallest known exoplanets, or planets orbiting outside the solar system, to our own planets Mars and Earth. Image Credit: NASA/JPL-Caltech
This artist's conception compares the KOI-961 planetary system to Jupiter and the largest four of its many moons. Image Credit: Caltech
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Terrific Graphics! Thank You!
Terrific Graphics! Thank You!
Very interesting.
Lemme tell ya 'bout my biga55 koi.
that is huge!
Panning for gold, or rather panning with gold.
I probably should have added width=400 to each of ‘em though. :’)
Naw...they look great. No editing needed.
That picture started out one way and ended up another. I originally had the lit side of the planet toward the viewer with no haze, sun glare or asteroids.
Funny how we always think of asteroids being all together but as I understand it, the average distance between asteroids in our own asteroid belt is more than a million miles.
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