Astronomers discover Moon-sized exoplanet called Kepler-37b

Scientists have announced that they have discovered an odd little planet that has set a new record for the smallest alien world ever discovered. According to the scientists, the exoplanet is about the same size as the Earth's moon. The planet has been dubbed Kepler-37b.

The scientists involved in the discovery say that this is the first exoplanet ever discovered that is smaller than Mercury. The planet makes an orbit of its parent star every 13 days and has an insanely high surface temperature of about 800°F. This planet was discovered along with two other larger planets orbiting the same parent star.

The parent star is about 215 light years from Earth, it and its planets were discovered using the Kepler space telescope. The two larger planets have been called Kepler-37c and Kepler-37d. The scientists say that 37b is so small finding it was unlikely, but the parent star had some attributes that made the discovery possible.

The attributes that made the discovery of the tiny planet possible included some sunspots on the parent star and the fact that the star is bright relative to its planets. These facts made it easier for Kepler to spot the dimming that takes place when a planet passes in front of its parent star, called the transit. The tiny size of the planet was estimated because the dip in the parent star's light was only 22 ppm. The scientists say that all three of the planets in orbit around the star are likely uninhabitable and all three are well inside the Earth-sun distance.