Scientists discover Earth’s fiery doppelganger
Kepler-78b is the first known planet that's similar in size and composition to Earth.
By Alexander Thompson
The sci-fi worlds of Star Wars and Star Trek have trained us to think there are rocky, solid planets orbiting far away stars that are so similar to Earth we could walk upright and breathe their atmosphere. In reality, scientists have yet to identify a single planet outside of our solar system that's comparable to the size and composition of Earth.
Until now, that is.
Two independent research groups, reporting in Nature, have found that a far-off planet, Kepler-78b, has a similar mass and composition to Earth. While previous observations of Kepler-78b had estimated the size of the planet to be 1.2 times wider than Earth, these latest measurements focused on observing the gravitational interactions between the planet and its star. The result? Researchers can combine the previously known size of the planet with the newly measured mass to determine its makeup. ...more