As NASA scientists search for water on Mars with the Phoenix Mars Lander, astronomers are finding Earth-like planets orbiting other suns. Yesterday they found three planets they called “super-Earths” orbiting a star that’s 42 light-years away from us. They found the planets by using clever tech — they can’t see the planets themselves, but measure the effect they have on a star, making it wobble with their gravity as they orbit.
Using a new Chilean telescope that uses a technique of planet discovery called HARPS (High Accuracy Radial velocity Planet Searcher), the astronomers say they can now detect planets as small as two times Earth’s mass. The three planets found yesterday are 4.2, 6.7, and 9.4 times the Earth’s mass, and all three of them orbit their sun in less than 20 days.
This is a big deal, especially considering that most of the other 270 planets detected around other stars using other methods are Jupiter-like gaseous planets. Another promising fact: One-third of the stars the scientists have studied using the HARPS system of spectrographic instruments have planets orbiting around them that resemble super-Earths or Neptune-like planets. Maybe we are not alone.