Tuesday, December 27, 2011

Two Earth size Planets by Discovered Kepler Space Telescope.

Astronomers working with the Kepler Space Telescope have confirmed the discovery of two roughly earth size planets orbiting a star other than our sun. The good news is that these are planets; unlike other claims, are not 2-3 time the size of Earth but actually about the size of the Earth. Designated as Kepler-20e and Kepler-20f they are the smallest planets found out side the solar system so far.

Kepler-20f is slightly bigger than Earth with a diameter of 8,200 miles in diameter, which is only 1.03 x Earth’s 7961 miles. The difference of in diameter 3% suggests that a human could stand on the surface with only a few pounds increase in weight definitely tolerable.

Kepler-20e is slightly smaller than Venus with a diameter of 6,900 miles in diameter, or 0.87 x that of the Earth. For comparison Mars is about O.53 Earth’s diameter and Venus is 0.949.
These two planets two of five known planets orbiting a stat designated Kepler-20 that it 1,000 light years away and a little smaller and dimmer than our sun. The other three planets are Neptune size gas giants.

The bad new for Earth like planet hunters is that these planers are uncomfortably closet o the sun. Kepler-20e obits the star every 6 earth days at 0.0537 AU (Earth’s Orbit is 1 AU) and has an estimated surface temperature of 1,412.33 Fahrenheit. Kepler-20f obits the star every 20 earth days at 0.117 AU and has an estimated surface temperature of 809.33 Fahrenheit. 

What is even stranger about the Kepler-20 system is the planet order. Not only do all five planets orbit closer to their sun than Mercury dose to our sun but they have an odd order. The Solar system has all terrestrial planes closer to the sun than all four gas giants. The Kepler-20 system on the other hand goes gas giant, terrestrial, gas giant, terrestrial, gas giant. This raises yet another issue for planetary formation theory.

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