TESS mission team talks discoveries of planets outside solar system

Landry Allred

Space aficionados filled the Manchester Ballroom at the Fairmont Austin hotel to hear about the discovery of planets outside the solar system.

Last spring, NASA launched the Transiting Exoplanet Survey Satellite (TESS) mission in search of exoplanets orbiting neighboring stars. TESS team members — Andrew Vanderburg, Thomas Barclay, Natalia Guerrero and Jennifer Burt — discussed exoplanets, the discovery process and their findings at SXSW on March 14.

Vanderburg, a NASA Sagan postdoctoral fellow from UT, began with the history of exoplanets. As people have studied the solar system, he said they’ve noticed the smaller, rocky planets with thin atmospheres remain near the sun, while larger, colder planets with thick hydrogen atmospheres are further away. This observation urged them to think critically about planets.

“Is that typically the case of other solar systems in the galaxy?” Vanderburg said. “Are there planets surrounding other stars similar to ones in our solar system?”

From 1988 to 1995, they discovered multiple planets orbiting other stars. Vanderburg said they then launched the Kepler mission, the first mission to detect other planets like Earth. Though Kepler discovered planets, Vanderburg said Kepler had limitations, because it only focused on one part of the sky. Thus, they started TESS.

Barclay, deputy director of the TESS Guest Investigator Program and associate research scientist at NASA Goddard Space Flight Center, introduced TESS and the process behind creating the satellite.

Unlike Kepler, he said TESS has four cameras, each three times the size of Kepler’s field of view, that focus on nearby stars rather than an anonymous space area. The satellite rotates the camera view every month to view a different part of the sky, Barclay said. Now, TESS is in their ninth month of science operations.

“We’re doing the science we hope and are meant to do,” Barclay said.

The conversation shifted to how the satellite actually detects planets, in which Guerrero, the Objects of Interest deputy manager at TESS, discussed her experience on the camera testing team. As stars relocate over time, she said the satellite detects the brightness produced, converting it into pixel data. To interpret, the team makes a series of graphs factoring out things like spacecraft or star behavior.

So far, they have discovered 408 planet candidates, 100 of them between the size of Earth and Neptune, and 19 published planets.

Burt, postdoctoral fellow from Massachusetts Institute of Technology, ended the discussion with the importance of using the resources TESS possesses to focus on a handful of stars. The difficulty with pixels is that one single pixel can contain thousands of stars.

Luckily, teams around the world in almost every timezone combine data from their telescopes and instruments to decide which planets to focus on. However, Burt said it’s not only help from large observatories but from homes.

“This isn’t solely astronomers who have access to huge telescopes,” Burt said. “These are exoplanet enthusiasts getting involved from their own backyards.”

Although TESS has potential in bringing the answer to whether or not Earth is alone in the galaxy, Burt said it’s a joint process.

“TESS has a huge amount of potential to revolutionize how we think about planets,” Burt said. “But it needs help from all of us on the ground.”