Astronomers Find Planet Barely Larger Than Earth's Moon

The Bad Astronomer writes "A team of astronomers has announced the discovery of the smallest exoplanet orbiting a Sun-like star yet found: Kepler-37b, which has a diameter of only 3865 kilometers — smaller than Mercury, and only a little bigger than our own Moon. It was found using the transit method; as it orbits its star, it periodically blocks a bit of the starlight, revealing its presence (abstract). Interestingly, the planet has been known for some time, but only new advances in asteroseismology (studying oscillations in the star itself) have allowed the star's size to be accurately found, which in turn yielded a far better determination of the planet's diminutive size. Also, the asteroseismology research was not funded by NASA, but instead crowd funded by a non-profit, which raised money by letting people adopt Kepler target stars."

Pretty amazing

[Grayhand]

It wasn't that long ago the first planets were found and now they are detecting ones around the size of the Earth's Moon. Imaging Earth sized planets will be the big breakthrough. There's talk of imaging planets similar to space shots of the Earth and other planets but I have my doubts I'll live to see that. It's not the technology it's the investment that would need to be made. Humans walking on Mars and a detailed photo of a distant planet would be the two I hope to live to see.

Re:A planet or a dwarf planet?

[mrtommyb]

Hi, I wrote this paper: We actually looked very carefully whether this planet has cleared its neighborhood. The smallest reasonable mass we can assume for this planet is 0.01 Earth masses. With this mass it would clear its orbit of other bodies. However, if it were much further away from its star (like at the distance Pluto is from the Sun) then it would probably be considered a dwarf planet.