New Worlds Beyond Our Own: TESS and Exoplanet Discovery

Imagine planets like nothing we’ve seen before – for instance, carbon-based worlds composed largely of diamonds. This week, scientists ramp up the search for new worlds as the Transiting Exoplanet Survey Satellite (TESS) embarks upon its mission to seek out distant star systems which may harbor planets. The mission reflects the dedicated work of NASA, Orbital ATK and the many other partners who made this incredible mission possible. This mission is sure to contribute to future discoveries and greater knowledge of deep space.

Above: Concept Image of TESS in Earth Orbit (Source: MIT)

Exoplanets – planets not within our solar system – are part of a rapidly growing field of planetary science. Since the discovery of the first exoplanet in 1992, NASA has recorded 3,711 confirmed exoplanets, as well as identified an additional 4,496 candidate exoplanets. Each of these could be like the planets we know in our own solar system: gas giants like Jupiter, ice giants like Neptune and possibly even habitable worlds like Earth. However, these worlds may also be something entirely new. In a universe with billions of potential star systems, the possibilities are astounding.

Did you know?
Exoplanets were first hypothesized in the 1500s, but weren’t detected until the 1980s.

The mission of TESS will be to identify potential exoplanet star systems for deeper review by other, larger telescopes. To complete this mission, TESS will use the Transit Photometry planet-finding method pioneered by predecessor missions. According to the Planetary Society, the Transit Photometry Method searches for dips in visible light coming from stars, which can be an indication of an exoplanet “transiting” between the star and the camera. Using wide-angle telescopes and cameras, TESS will scout for these drops in visible light and identify planetary system candidates. The second phase of discovery will be undertaken by large ground and space-based telescopes such as the James Webb Space telescope.

While originally hypothesized in the sixteenth century, exoplanet research did not formally begin until the 1980s. The first exoplanet discovery to be confirmed by the scientific community uncovered two planets orbiting pulsar PSR 1257+12 on January 9, 1992. Since then, the number of confirmed exoplanets has grown dramatically. NASA Exoplanet discovery missions have been vital to these findings, with the Kepler Space Observatory accounting for nearly two thirds of all confirmed exoplanet discoveries.

Did you know?

NASA’s Kepler Space Observatory has detected over 2,300 confirmed exoplanets since its launch in 2009.

While we cannot image other planets directly, we are still able to learn a remarkable amount about them. The two most common methods of exoplanet discovery are Radial-Velocity and Transit Photometry. These methods measure the apparent motion of a start caused by a planet. Through such methods, the number and size of planets in a star system can be estimated.

Using a technique known as Spectroscopy, astronomers can also determine the composition of these exoplanets, as well as the contents of their atmosphere. As a result, it may be possible to find other earth-like planets with nitrogen-rich atmospheres. Discovery of such planets is one of the ultimate goals of NASA’s exoplanet discovery missions.

Above: An artist’s concept of four confirmed exoplanets found by the Kepler Space Observatory in habitable orbits. (Source: NASA)

TESS was funded as an Explorers Program at NASA. In our latest report on NASA’s budget, titled Funding Our Future, AIA advocates for the expansion of the Explorers Program. These programs provide a wealth of scientific value to the scientific community, advancing our understating of the universe while preserving U.S. international leadership in science. The importance of TESS and other Explorer Programs to our leadership in space cannot be understated.

In addition to supporting the James Webb Space Telescope, the findings of TESS will provide targets for the ESA’s CHEOPS Space Telescope to be launched by the end of 2018, as well as the planned WFIRST Space Telescope. These missions are vital to our understanding not only of other star systems, but of our own as well. By examining the anatomy of other star systems, we can gain a greater understanding of how our own came to be. AIA looks forward to the continued development of these missions and the great contributions they provide to our understanding of the cosmos.