"In the search for life beyond our solar system, the most promising planets might not be Earth twins," says geochemist Stephanie Olson.
The exoplanet, dubbed WASP-121b, is located around 900 light-years from Earth.
The three planets are among the smallest and closest exoplanets found to date, according to astronomers.
More than 4,000 planets beyond our solar system have been discovered since the first in 1992.
The Teegarden star—a red dwarf with a mass less than a tenth that of the sun—is located just 12.5 light-years away in the constellation Aries.
Build-ups of toxic gases in the atmospheres of many exoplanets in the "habitable zone" could limit the "safe zone" in which life outside our solar system could actually exist.
In 2009, NASA's groundbreaking Kepler mission identified its first potential exoplanet.
Scientists think life might survive on Proxima b, in spite of powerful lashings from its host star.
The findings could have implications for how planets form and the search for Earth-like worlds.
KELT-9b is the hottest planet ever discovered.
The enormous object sits just 20 light-years from Earth.
The planets could have similar light and temperature conditions to those that may have existed when life first emerged on Earth.
TESS may uncover planets that have the right conditions for life to exist.
A stable climate could be key to hosting life.
A year on these planets flies by, lasting between five and 10 Earth days.
The test photo includes more than 200,000 stars.
Helium is the second most common element in the universe, but more than a decade of searching for the gas in the atmospheres of exoplanets has proven unsuccessful, until now.
TESS stands for Transiting Exoplanet Survey Satellite, and its mission is to identify planets orbiting the brightest stars in our neighborhood of the universe.
TESS will scour the skies for signs of undiscovered worlds.