One month after its launch, NASA’s Transiting Exoplanet Survey Satellite has sent back an initial test image that shows more than 200,000 stars in the southern sky.
TESS’ image was taken by one of its cameras with a two-second exposure. The picture is centered on the constellation Centaurus, with the edge of the dark Coalsack Nebula at upper right and the star Beta Centauri prominent along the lower edge.
The picture provides only a hint of what TESS will be seeing once it starts delivering science-quality images next month. When all four wide-field cameras are in operation, TESS’ images should cover more than 400 times as much of the sky.
The refrigerator-sized spacecraft was launched from Cape Canaveral Air Force Station in Florida atop a SpaceX Falcon 9 rocket on April 18. On Thursday, the probe completed a lunar flyby that brought it closer to its intended orbit for scientific observations..One more thruster burn is scheduled on May 30 to complete the orbital maneuvers.
TESS is designed to monitor 85 percent of the night sky from a highly eccentric Earth orbit, ranging from 63,000 to 200,000 miles in altitude. It’ll zero in on 200,000 of the brightest stars in our celestial neighborhood, looking for telltale changes in brightness that result when a planet crosses over the star’s disk.
Astronomers expect to identify more than 1,500 of such transiting exoplanets during TESS’ two-year primary mission. About 500 of those are expected to be Earth-sized or slightly bigger than Earth.
TESS’ findings will serve as a catalog for follow-up observations using more powerful instruments — such as NASA’s James Webb Telescope, which is currently slated for launch in 2020.