The European Space Agency (ESA) announced today that it has formally adopted the Planetary Transits and Oscillations of stars (PLATO) space observatory. The new phase of the mission means construction of the spacecraft and its science instruments can begin. PLATO will be a satellite platform with 26 mounted telescopes to search large areas of the sky for exoplanets, or planets beyond our solar system. ESA is aiming to launch PLATO to orbit in 2026.
The number of known planets outside our solar system is steadily increasing. Just yesterday, NASA announced the Kepler space telescope discovered 219 more planet candidates. The new data brings the total number of planets in the Kepler catalogue up to 4,034, and 2,335 of those planets have been confirmed by follow-up observations from other telescopes. Additional missions such as the Transiting Planets and Planetesimals Small Telescope (TRAPPIST) have discovered even more planets beyond our sun's orbit, including seven Earth-sized planets orbiting a nearby red dwarf star.
The PLATO mission, headed up by the German Aerospace Center (DLR) in Berlin, seeks to expand our knowledge of the tantalizing worlds that lie beyond our little neighbourhood in the galaxy. We know of dozens of exoplanets that are roughly Earth-sized, almost certainly rocky, and orbit in the habitable zone where temperatures could be favourable to surface water. Could one of these planets host extra-terrestrial life?
"Using observations of stellar vibrations, PLATO will for the first time fully characterize these stars and their planets with regard to mass, radius, and age," says Laurent Gizon, director of the Max Planck Institute for Solar System Research (MPS) and head of the PLATO Data Center, which will analyse the mountain of data from the spacecraft's telescopes. PLATO will operate for a minimum of four years, observing large areas of sky for years at a time to look for planets with similar properties to Earth. It is crucial for PLATO to keep its telescopes pointed at one spot for long periods of time, because if we do find a "twin" of the Earth, it will only pass in front of its host star once a year for observations.
PLATO will pick up where Kepler leaves off, expanding the catalogue of known exoplanets and providing more information about these mysterious worlds than ever before. Once we have pinpointed nearby planets similar to Earth orbiting stars similar to the sun, astronomers will attempt to analyse the elements present in these Earth-like planets' atmospheres with powerful telescopes currently under construction. If the atmospheres contain bio signatures, such as abundant oxygen, we might finally find a true "Earth twin" with flowing extra-terrestrial rivers and sprawling alien forests.
This dream might be overly-optimistic, but there is only one way to find out for sure: launch more telescopes. PLATO will carry 26 to space in the year 2026.