Scientists have recently discovered two Earth-like exoplanets relatively close to us in comparison to other planets that have been found in the last several years. Teegarden’s star is the 24th closest star to our sun and it’s only 12.5 light years away from us in the constellation of Aries. What’s even more exciting is that these two planets – named Teegarden b and Teegarden c – are ranked in the top 19 known exoplanets that could potentially contain habitable environments. And Teegarden b ranked the highest on the Earth Similarity Index.
Mathias Zechmeister, who is the lead author of the study (which can be read here) and is also an astrophysicist at the University of Göttingen, stated, “The two planets resemble the inner planets of our Solar System.” As a matter of fact, one of the two planets could be the most similar to Earth that they’ve ever found. The planets are just a bit heavier than Earth and they’re positioned conveniently in the habitable zone, meaning that liquid water could very well be present there.
Scientists only discovered Teegarden’s star in 2003 and it’s one of the smallest stars that they’ve ever found – approximately ten times lighter than our sun and around 8 billion years old. With a star that small, they’ve had a hard time studying it in order to find any planets orbiting it. Astronomers had to use the CARMENES next-generation telescope located at the Calar Alto Observatory in Spain to find out if the star had any changes to its radial velocity.
They studied the star for three years and during that time was when they discovered Teegarden b and Teegarden c. “These studies demonstrate that the signals of the two planets cannot be due to the activity of the star, even though we could not detect the transits of the two new planets,” explained astronomer Victor Sánchez Béjar who is from the Instituto de Astrofísica de Canarias (AIS).
Of the two planets, Teegarden b is the closest to the sun and has a 60 percent chance of having a temperature of between 0 degrees and 50 degrees Celsius, with the most likely surface temperature being around 28 degrees Celsius. Since Teegarden c is further away, it would have a surface temperature of around -47 degrees Celsius – similar to Mars.
The research team believes that Teegarden b does a full orbit in 4.9 Earth days, while Teegarden c completes its orbit in 11.4 days. However, it’s still possible that they could complete their orbits in even lesser time, which would reduce the possibility of them being able to sustain any life. They’re also unsure as to the length of time it takes for Teegarden to rotate on its axis.
While much more research needs to be done, it’s still exciting to think that two newly discovered exoplanets that are located not too far from us could possibly sustain life.