Spitzer Space Telescope discovers closest rocky planet

Discovery of a new planetary system has helped astronomers know about a super-earth that transits in front of a star and has a density similar to earth’s.

NASA researchers say that Kepler-452b gets enough sunlight to possibly support Earth-like crops and plants, which are crucial for the survival of humans and other forms of life. Its year is a not-so-lengthy 3 days long, and it has a mass approximately 4.5 times that of Earth (though it’s only 1.6 times the size).

The sheer closeness of HD 219134b to Earth makes it ripe for research by space-based telescopes. The planet was first discovered by the HARPS-North instrument located in the Canary Islands. The discovery was made using the radial velocity technique, involving taking measurements of how an invisible planet tugs at its star as it orbits. The planet was confirmed by the Spitzer space telescope, which revealed it was transiting its star relative to the Earth. Exoplanets are planets that orbit not only around its sun but also another star. From here we can calculate the planet’s density, and with that knowledge, we can know whether the planet is rocky like Mars, Venus or Earth, or gaseous, like Jupiter, Saturn or Neptune (or even icy, like Pluto).

“This one is practically a next-door neighbor”, said astronomer Lars Buchhave from the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts.

The Spitzer telescope mission is managed for NASA’s Science Mission Directorate by the Jet Propulsion Laboratory (JPL) in Pasadena, California. It appears quite close to the constellation Cassiopeia.

Spitzer followed up on the finding, discovering the planet transits its star. A planet weighing at least 2.7 times Earth orbits the star once every 6.8 days.

Hopefully these planets are orbiting in a single plane like in our solar system so they are all in transit with us. Ati Motalebi of the Geneva Observatory thinks this planet would be a good candidate for the James Webb telescope, the successor to the Hubble Telescope.

HD 219134 is an orange Type K star somewhat cooler, smaller and less massive than our Sunday. Two are smaller, but orbit close to their host stars like HD 219134b does. Although Kepler has fed us information about the number and location of super-Earths in our galaxy, observing them in greater detail has been impossible, until now. “It can be considered a kind of Rosetta Stone for the study of super-Earths“, said Michael Gillon, a member of the team that discovered the exoplanet.

“The fact that one of these crosses the face of the star once an orbit, and we now know is a rocky world, is all the more incredible”.