NASA's Pandora satellite starts studying alien worlds

NASA's Pandora satellite began its real science mission this week, seven months after launching into orbit. It's now watching distant stars and the planets circling them. It's gathering data on at least 20 exoplanet systems in its first year. Pandora is small and inexpensive by NASA standards. It's the first mission funded through the agency's Astrophysics Pioneers program for low-cost science.

Studying an exoplanet's atmosphere from light-years away is hard. A star's own flickering and flares can look a lot like signals from the planet itself. Pandora's job is to watch the same star and planet over and over, long enough to tell the two apart. Bigger telescopes, like the James Webb Space Telescope, spend expensive observing time on these same targets. Pandora's data helps scientists know which of Webb's exoplanet readings to trust.

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What will Pandora actually find? Nobody expects one dramatic discovery from a satellite this size. Its value shows up gradually. Its repeated observations help astronomers clean up years of murky exoplanet data from bigger missions. It's a quiet, unglamorous kind of space science, but arguably as important as anything with a bigger budget.