Kepler Space Telescope discovers two Earth size Planets.

The Kepler Space Telescope has confirmed the discovery of two approximately  earth size planets orbiting a star other than our sun. These are planets; unlike other claims, are not 2-3 time the size of Earth but actually about the size of the Earth or smaller. They are designated 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.

They are two two of five known planets orbiting a stat designated Kepler-20 that is 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. 

Designation	Obit (Earth Orbit 1 AU)	Orbital Period  (Earth Days)	Radius	Mass	Type
kepler20b	0.0454 AU	3.7 Days	1.91 Earth	8.7 Earth	Gas Giant
kepler20e	0.0537 AU	6.1 Days	0.868 Earth	»1 Earth	Rocky
kepler20c	O.093 AU	10.85 Days	3.07 Earth	16.1 Earth	Gas Giant
kepler20f	0.117 AU	19.58 Days	1.034 Earth	»1 Earth	Rocky
kepler20d	0.345 AU	77.6 Days	2.75 Earth	»12 Earth	Gas Giant

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.