Scientists have found an exoplanet around the size of Earth circling a distant star within the habitable zone, which means it could contain liquid water on its surface, using data from NASA’s Transiting Exoplanet Survey Satellite.

The fifth planet in the TOI 700 system, TOI 700 e, was found 100 light-years away in the Dorado constellation.

NASA’s Transiting Exoplanet Survey Satellite (TESS), a satellite telescope built to look for planets outside our solar system, including ones that might host life, found the planet. TOI 700 e is located in the habitable region of its star, often known as the “Goldilocks zone,” where conditions are favorable for the potential development of liquid water and, consequently, life.

System TOI 700 Star

The red dwarf star TOI 700, smaller and cooler than the Sun and located 101.4 light-years from Earth in the southern constellation Dorado, has 40% of the mass, 40% of the radius, and 55% of the Sun’s temperature. Five exoplanets have been found in the system (planets TOI 700 b, c, and d were previously identified). All five of these planets may be tidally locked to TOI 700, which means that they rotate only once per orbit so that one side is always facing the star, similar to how the Moon is always turned toward Earth. The habitable zone is where planet d also revolves. However, it took researchers another year of TESS observations to find TOI 700 e.


We might have been able to detect TOI 700 e in the first year of TESS data if the star was a little bit closer or the planet a little bit larger, according to Ben Hord, a doctoral candidate at the University of Maryland, College Park and a graduate researcher at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

However, the signal was so weak that its identification required an extra year of transit observations.

The research’s principal investigator, Emily Gilbert, a postdoctoral fellow at NASA’s Jet Propulsion Laboratory in Southern California, noted that this is one of the few systems containing several small, habitable-zone planets we know of.

The TOI 700 system is thus a fascinating possibility for further investigation. The system also demonstrates how additional TESS observations help us discover ever-smaller worlds because planet e is around 10% smaller than the planet.

TOI 700 e

About 20% closer than Earth’s orbit around the Sun, the exoplanet TOI 700 e orbits its star at a distance of 20 million miles. The planet orbits the star in approximately 28 Earth days due to its proximity.

The fact that TOI 700 e is one of the closest known exoplanets to its star’s habitable zone is one of the most intriguing features of its finding. Because it is neither too close to its star to be too hot nor too far away to be too cold, it is an ideal place to support life possibly. With a size similar to that of Earth and 95% the size of our planet, TOI 700 e is also one of the smallest known exoplanets in its star’s habitable zone.

TOI 700 e

An artist’s depiction of TOI 700 e. Credits: NASA/JPL-Caltech/Robert Hurt/NASA’s Goddard Space Flight Center

It is anticipated that because of its size, it will have a solid surface and a dense atmosphere that may potentially support life in a manner comparable to Earth’s.

TESS’s ability to “help us find smaller and smaller worlds” is demonstrated by TOI 700e.

About 75% of the sky can now be seen thanks to TESS, which has also discovered 66 new worlds outside our solar system.

According to NASA, discovering additional solar systems in this region that contains Earth-sized planets aids planetary scientists in understanding the development of our solar system. The TOI 700 system is being further studied by ground- and space-based observatories, which could provide new information on this unusual system.

YouTube Video

Credits: NASA/JPL-Caltech/Robert Hurt/NASA’s Goddard Space Flight Center

Find More Articles ๐Ÿ‘‡ ๐Ÿ‘‡ ๐Ÿ‘‡



Please enter your comment!
Please enter your name here