14 DAY TRIAL // While the future of the Kepler space telescope is still up in the air, so to speak, the data it amassed so far has already proven invaluable to scientists.
Kepler is designed to discover extrasolar planets in bulk by staring at a portion of the sky and scanning for minute variations in the light of the star, as seen by the telescope.
Several hundreds of planets and planet candidates have been discovered so far. But one of the latest planets uncovered by Kepler is unique, not because of any of its properties, but because of how it was discovered.
Normally, Kepler records a small reduction in the amount of light from a star as a planet passes in front of it, obscuring a portion of the celestial body.
But scientists have now used the relativistic effects of gravity to discover Kepler-76b, which has been called Einstein's planet based on how it was found.
Scientists used three ways in which the light coming from a star is altered by planets around it.
The first effect is called "beaming." Stars appear brighter when planets tug them very slightly closer to Earth and dimmer when the planets pull them away. The motion of the star pushes photons closer together, a very minute Doppler effect.
Planets also slightly distort the shape of a star, pulling it into a football shape. When the wider side is facing Earth (and Kepler), more light comes in.
Finally, some of the light is reflected off the planets, depending on their position around the planet, providing another variation.
By themselves, the effects are minute, but the combined effects give astronomers a new method of discovering planets.
This new method has the advantage that planets don't have to pass directly in front of their stars to be detected by Kepler. However, Kepler-76b actually grazes by the star it orbits.
The disadvantage is that, with current technology, the method is only useful for large planets, much bigger than Earth.