European Space Agency this week said it was putting together a new space telescope that would take aim at discovering habitable exoplanets in our solar system.
By integrating 34 separate small telescopes and cameras, the Planetary Transits and Oscillations of stars, or PLATO, will be parked about 1.5 million km beyond Earth and monitor what the ESA called “relatively nearby stars, searching for tiny, regular dips in brightness as their planets transit in front of them, temporarily blocking out a small fraction of the starlight.
The PLATO mission, which wouldn’t launch until 2024, will measure the sizes, masses, and ages of the planetary systems it finds, so detailed comparisons with our Solar System can be made.
“In the last 20 years more than one thousand exoplanets have been discovered, with quite a few multi-planetary systems among them,” said mission leader Dr Heike Rauer at DLR, the German Aerospace Center. “But almost all of these systems differ significantly from our Solar System in their properties, because they are the easiest-to-find examples. PLATO firmly will establish whether systems like our own Solar System, and planets like our own Earth are common in the Galaxy.”
PLATO will use an array of telescopes rather than a single lens or mirror. PLATO will use high quality cameras, and will have the advantage of observing continuously from space, without the interruption of sunrise, or the blurring caused by the Earth’s atmosphere, the ESA stated.
Its position will let PLATO discover planets smaller than Earth, and planets at distances from their host stars similar to the Earth-Sun distance. So far, only a few small exoplanets are known at star-planet distances comparable to or greater than Earth’s. Unlike previous missions, PLATO will focus on these planets, which are expected to resemble our own Solar System planets, the ESA stated.
The mission sounds most like NASA’s successful Kepler space telescope which has catalogued some 3,583 planet candidates. Recently released analysis led by Jason Rowe, research scientist at the SETI Institute in Mountain View, Calif., determined that the largest increase of 78 % was found in the category of Earth-sized planets. Rowe’s findings support the observed trend that smaller planets are more common, NASA stated.
But Kepler has been out of commission since May 2013 with technical problems. Currently NASA and Ball Aerospace engineers say they have developed a way of recovering Kepler and tests to repurpose the craft are ongoing.
The ESA pointed out some interesting factoids about the PLATO mission:
During its six year long planned mission, PLATO will observe one million stars, leading to the likely discovery and characterization of thousands of new planets circling other stars. PLATO will scan and observe about half the sky, including the brightest and nearest stars.
The satellite will be positioned at one of the so-called Lagrangian Points , where the gravitational pull of the Sun and the Earth cancel each other out so the satellite will stay at a fixed position in space. Each of the 34 telescopes has an aperture of 12 centimeters.
The individual telescopes can be combined in many different modes and bundled together, leading to unprecedented capabilities to simultaneously observe both bright and dim objects.
PLATO will be equipped with the largest camera-system sensor ever flown in space, comprising 136 charge-coupled devices (CCDs) that have a combined area of 0.9 square meters.
The accuracy of PLATO’s astroseismological measurements will be higher than with previous planet-searching programs, allowing for a better characterization of the stars, particularly those stellar-planetary configurations similar to our Solar System.
The scientific objective is based on previous successful projects, like the French-European space telescope CoRoT or NASA’s Kepler mission. It will also take into account the mission concepts that are currently under preparation which will “fill the gap” between now and PLATO’s launch in 2024 – NASA’s Transiting Exoplanet Survey Satellite (TESS) mission and ESA’s ChEOPS mission.