Itsy Bitsy, Teeny Weeny PLANET
Just this morning, scientists using the Kepler Space Telescope located a new planet over 200 light years away from Earth. The planet, known as Kepler b, is part of a three planet solar system around the star Kepler 37.
Kepler 37b is only slightly bigger than Earth’s moon! It travels around its sun in only 13 days, and has a diameter of 2,400 miles. As you can see on the left, Kepler 37b is dwarfed by its neighbor planet Kepler 37d, which is twice the size of Earth. We know these planets all are about as close to their sun as Mercury is to our own. We also know that the star Kepler 37 is actually older than our Sun by about a billion years.
The discovery of the small planet is a major breakthrough in the search for extra-solar planets; up until now, astronomers were only able to find planets either equal to or bigger than Earth.
The Kepler Space Telescope, which located the planet was first launched in 2009. It surveys 150,000 stars at a time, and watches for planets to pass in front of their parent stars. By observing the shadow of an exoplanet, the scientists watching the image from Kepler can determine its size and rotation. Kepler also locates planets by observing the gravitational pull they exert on the star they orbit.
So far, the total exoplanet database contains over 800 objects with 669 confirmed planets.