[Music throughout] TESS, the Transiting
Exoplanet Survey Satellite, is NASA’s newest planet hunter.
The mission has operated for two years and has now mapped about
75% of the sky. This enormous area of coverage
gives scientists unprecedented opportunities to search for new worlds
beyond our solar system as well as other cosmic phenomena.
TESS completed its initial sky survey in July 2020.
This giant mosaic is made from 26 sector images.
Each sector is a 24-by-96-degree strip of sky,
monitored by TESS’s four cameras for about a month. Here
are some of the noteworthy discoveries from TESS’s second year.
TESS discovered a trio of planets around GJ-357, a
red dwarf star just 31 light-years away. The system’s farthest planet,
with about six times Earth’s mass, is especially intriguing.
It orbits in the outer part of the star’s habitable zone. If this planet has an
atmosphere thick enough to keep its surface warm, liquid water could exist there.
TESS found another planetary trio around the star
L98-59. The innermost world is the littlest found by TESS,
and is 20% smaller than Earth. Later,
scientists announced TESS had observed a star being torn apart by a black hole.
Catching one of these tidal disruption events showcases
the mission’s ability to spot many kinds of short-lived phenomena, like
stellar outbursts and supernovae, underscoring TESS’s importance
for studies beyond exoplanets. In early 2020,
scientists announced TESS’s first Earth-size planet orbiting in its star’s habitable
zone. This world, called TOI 700 d,
is a little larger than Earth and probably rocky. Based on
TESS and Spitzer data, researchers were even able to model potential
weather systems. Analysis of the planet’s atmosphere, if it has one,
will have to await future space-based observatories like NASA's
James Webb Space Telescope. Missons like TESS — and later Webb —
help contribute to the field of astrobiology, the interdisciplinary
research on the variables and conditions of distant worlds that could
harbor life as we know it. TESS has found many systems different
from our own. TOI 1338 has a Neptune-size planet
orbiting a pair of stars. KELT-9 has a fast-spinning
star with hot poles and a cooler equator. KELT-9 b
orbits over the poles, resulting in star-induced seasons that only
last a few hours. Now that its primary mission is
complete, TESS will return to the southern sky for another yearlong survey.
Many new planets, as well as more brief cataclysmic events,
await astronomers as they scour the flood
of TESS observations.
Explore: solar system & beyond
NASA