Pandora starts watching the star that lies a little

Pandora, NASA’s first Astrophysics Pioneers satellite, is now taking science data on exoplanets and the stars they orbit, NASA Science reports. The smallsat launched Jan. 11. Deputy project manager Jordan Karburn says the spacecraft is healthy and commissioning is done.

The problem it was built for is a cheat in the light. During a transit, starlight skims a planet’s air and picks up chemical fingerprints, including water. The instruments also see the whole star, which is splotchy: hot faculae, cool spots, all of it moving as the star rotates. Those features can fake or hide a water signal, MIT’s Benjamin Rackham says.

Pandora stares in visible and near-infrared at once, and it stares long: at least 20 planets, 10 times each, 24-hour visits with a transit inside. Its near-infrared detector is a spare originally made for Webb. Principal investigator Elisa Quintana says the point is to know how the star’s light is messing with the planet’s.

Pair the two telescopes and you can start separating star from air. That is the whole mission in one sentence.