The image below is a panoramic shot of a familiar sky captured by NASA’s TESS spacecraft. The panorama is a composite image assembled from 208 individual pictures. So far, TESS has imaged about 75 percent of the sky in its two-year-long mission that is still going on. Among its accomplishments so far is the discovery of 74 exoplanets.
Astronomers working on the project have approximately 1200 potential exoplanets to investigate. Over 600 of those candidates are in the northern sky. TESS locates potential exoplanets by monitoring large sections of the sky and watching for changes in the brightness of stars. When a planet passes in front of a host star, the light of the star dims temporarily from our perspective.
The event is called a transit, and the observation technique has proven to be the most successful planning-finding strategy so far. The method has been used to discover three-fourths of the nearly 4300 known exoplanets. Data collected by TESS is used to study other celestial phenomena, including stellar variation and supernova explosions.
NASA notes that the northern mosaic covers less of the sky than the southern counterpart, which was imaged during the first year of the spacecraft’s operations. The team decided to angle the cameras further north to minimize the impact of scattered light from the Earth and Moon, resulting in a coverage gap.
TESS splits each celestial hemisphere into 13 sectors. Each of the sectors is imaged for nearly a month using the quartet of cameras aboard the spacecraft carrying a total of 16 sensors. During its primary mission, cameras capture an entire sector of the sky every 30 minutes. So far, TESS has sent more than 40 terabytes of data back to Earth.