Two Earth-Like Planets Found Orbiting Nearby Star, Could Hold Liquid Water and Support Life
TL;DR
Astronomers have identified two rocky planets orbiting Teegarden’s star, located just 12 light-years from Earth. These planets are similar to Earth in mass and could support liquid water, increasing the chances of habitability. The star is remarkably stable and calm, unlike other red dwarfs known for violent flares, further boosting hopes that these planets may be habitable. Teegarden’s star is over 8 billion years old, meaning these planets might have had billions of years to potentially develop life. Scientists are using advanced telescopes to investigate whether these planets could host extraterrestrial life.
After reading the article, Marcus gained more than 3.1k upvotes with this comment: “Imagine if there was an intelligent civilization on a tidally-locked red dwarf planet. They might be theorizing and looking for other life-bearing worlds, and they might rule out hot, young stars like the sun, because any planet close enough to be tidally-locked would be fried to a crisp, and the idea of life on a world that spins like a top and has the sun rising and setting all the time is just too preposterous to believe. How could life adapt to such a chaotic environment, really?”
Astronomers have revealed the potential discovery of two rocky planets orbiting a small star located just 12 light-years away. If confirmed, these planets would be very similar to Earth in terms of mass and exist in orbits that might support liquid water on their surfaces.
Teegarden’s star, the host of these planets, is estimated to be over eight billion years old—nearly twice as old as the sun. This means the planets could be ancient as well, giving life plenty of time to evolve. Remarkably, the star is currently very calm, with no signs of the violent stellar flares and quakes often seen in such stars.
These factors, combined with its proximity, make the system a promising candidate for astronomers who are using next-generation telescopes to look for signs of extraterrestrial life.
“Both of Teegarden’s planets could potentially support life,” says Ignasi Ribas of the Institute of Space Studies of Catalonia, part of the team that shared these findings in Astronomy & Astrophysics. “We will soon learn whether they are truly habitable or possibly even inhabited.”
Small but Mighty
The star itself was so faint that it wasn’t even discovered until 2003, when NASA astrophysicist Bonnard Teegarden identified it while scanning astronomical data for nearby dwarf stars that had yet to be found.
Teegarden’s star is a tiny one, only about 9 percent of the sun’s mass. It’s classified as an ultra-cool M dwarf and emits most of its light in the infrared, much like the star TRAPPIST-1, which has seven rocky planets. However, Teegarden’s star is three times closer to Earth than TRAPPIST-1, making it an excellent target for further study.
Illustration by Andreas Hougardy, University of Göttingen
Ribas and his team are hunting for planets around 342 small stars, so they focused on Teegarden’s star using the CARMENES instrument at Spain’s Calar Alto Observatory.
Over three years, CARMENES monitored the star for any movements that might indicate the presence of orbiting planets. More than 200 observations revealed two small planets, each about 1.1 times the mass of Earth. The team estimates that one of these planets, Teegarden’s star b, completes an orbit in just 4.9 days, while the second planet, Teegarden’s star c, takes 11.4 days to complete an orbit.
A Calm Star
Before they could confirm the planets’ existence, the researchers had to rule out other factors, such as star spots and flares, which can sometimes mimic the appearance of planets. This is often difficult with red dwarf stars, as they tend to be highly active. However, Teegarden’s star is surprisingly quiet, making it much easier to identify any planetary signals.
“The number of observations is so large, and the star is so stable that there’s almost no room for another explanation,” says Ribas. “I’m very confident these planets exist. I’d bet my little fingers on it.”
“These planets look like solid candidates to me,” says Lauren Weiss from the University of Hawaii. “The data quality is very impressive.”
Still, Weiss notes a few uncertainties. For example, scientists don’t know the precise rotation period of Teegarden’s star, which could potentially be mistaken for one of the planet signals.
“Even so, the star’s rotation might only mimic the orbit of one planet, not both, so at least one planet is almost certainly real,” she says.
Another point Weiss raises is that the planets might be orbiting the star faster than expected, which could affect their habitability prospects.
“This is a small technical issue,” Weiss adds. “Even if their orbital periods are off, they’re still planets.”
