By Rory Zeman

National/World Editor

On Jan. 10, NASA revealed that they discovered a new planet that shares similar characteristics to earth and is possibly habitable. The TESS (Transiting Exoplanet Survey Satellite (TESS) came across the planet after spending almost four years in space.

Since TESS’s initial launch in 2018, it has discovered 285 exoplanets and two Earth-sized planets alone in the TOI 700 system. TOI 700, the system’s star, is a red dwarf star — a small and colder type of star. TESS uses small dips in the star’s light in order to indicate when a planet crosses between the telescope and the star. Astronomers can then estimate the size of the planet and the speed of its circulation around the star, and therefore they can predict the habitability of the star. 

In the case of the​​ TOI 700 system, TESS originally discovered two planets that were too close to the star in order to be habitable.​​ The TOI 700 system shows promise because astronomers believe that the star is incapable of overheating its orbiting planets. Emily Gilbert, an astronomer at NASA’s Jet Propulsion Laboratory, stated, “In the full, two-year data set that we have from TESS, we see no evidence of optical flare.” 

In 2020, TESS had a major breakthrough, discovering the first of the two habitable planets, TOI 700 d, a planet in the habitable zone of the system. Using TESS, astronomers estimated that the planet is around 20 percent larger than Earth and it orbits the TOI 700 star every 37 Earth days. TOI 700 d is also at a proper distance from the star where it is possible for liquid water to form on the surface of the planet.

In January, astronomers came upon another sibling of TOI 700 d, TOI 700 e, a planet around 100 light years away. The planet is located in what astronomers normally do not consider a habitable zone. However, scientists still hope that the planet contains liquid water since Venus and Mars, other planets outside the deemed habitable zone of a solar system, once contained liquid water on their surfaces.  Astronomers estimate the planet to be around 95 percent of Earth’s size and to orbit the star every 28 Earth days. The planet is likely rocky and shows signs of being tidally locked, meaning that it only shows one side of it to its star at all times. 

  NASA originally intended for TESS to be out for around two years; however, its data has shown tremendous promise, so NASA has extended the mission twice. TESS  will continue its mission of discovering the cosmos in the southern sky until late 2024. 

(Sources: Space.com, Wilx)