Hunting for exoplanets has transformed from science fiction to cutting-edge science fact in recent decades. Scientists use ingenious methods to spot these distant worlds, often looking for the subtle dimming of stars as planets cross their faces or the slight gravitational wobble planets induce in their host stars. Modern observatories like NASA’s Transiting Exoplanet Survey Satellite and the James Webb Space Telescope have turned this cosmic treasure hunt into an age of discovery revealing thousands of worlds beyond our Solar System.
Artist impression of an exoplanet around a distant star
The European Space Agency’s PLATO mission will soon join this flotilla of planet-hunting spacecraft. Set to launch in 2026, PLATO (PLAnetary Transits and Oscillations of stars) features an array of 26 high-precision cameras working together to continuously monitor vast regions of the sky. Unlike previous planet hunters, PLATO will specialise in finding and characterizing Earth-like planets orbiting in the habitable zones of Sun-like stars by simultaneously tracking the faint dimming of light from over 200,000 stars.
Artist impression of PLATO (Credit – By ESA/ATG medialab)
PLATO is rapidly taking shape with 24 of its 26 sophisticated cameras now mounted on the spacecraft’s optical bench to ensures precise alignment. The remaining two “fast” cameras will be installed in the coming weeks, while the spacecraft’s supporting structure is being assembled in parallel at OHB in Germany.
“It’s rewarding to see the progress we have made from last year when the work to mount the cameras started: with 24 cameras now in place, we see Plato taking its proper shape,” – Thomas Walloschek, ESA’s PLATO Project Manager.
PLATO’s observational prowess comes from its strategic camera arrangement: 24 “normal” cameras positioned in four groups of six, each aimed at slightly different parts of the sky to collectively monitor about 5% of the celestial sphere simultaneously. Complementing these are two “fast” cameras that rapidly image the brightest stars within the same field and provide positioning coordinates to the spacecraft’s guidance system. Meanwhile, engineers at OHB are constructing PLATO’s service module, which houses the essential computers, orientation controls, propulsion systems, power distribution, and communication components. The integration of the camera-carrying payload module with this service module is scheduled for summer at OHB’s facilities.
Main building in Bremen (Credit – Marko Schade)
Building the PLATO satellite requires a new level of precision as engineers carefully mount its delicate cameras to ensure perfect alignment for detecting the faintest signals from distant stars. The sophisticated instruments are designed to capture minute brightness variations that occur when exoplanets transit their host stars. Beyond planet hunting, PLATO will revolutionize stellar science by monitoring “starquakes”—subtle brightness fluctuations that reveal a star’s internal structure and age. This comprehensive approach, combining space observations with ground-based telescope follow-ups, will allow scientists to determine both the sizes and masses of newly discovered exoplanets.
Source : Plato grows its many eyes