In Brief: Astronomers discovered a Earth-like planet orbiting our closest neighboring star, Proxima Centauri which is just few light years from Earth. This brings a new area to search for the possibility of extraterrestrial life.
A potentially habitable planet about the size of Earth is orbiting the star that is nearest our solar system, according to scientists who describe the find Wednesday in the journal Nature.
The rocky planet, named Proxima b, is slightly larger than Earth and sits within its star’s habitable zone, where liquid water could theoretically exist on the surface.
Planet Proxima b orbits Proxima Centauri, a red dwarf star that’s just 4.25 light-years from Earth — about 25 trillion miles away. The star is too faint to be seen with the naked eye and is close to a much brighter and more famous pair of stars called Alpha Centauri A and B.
Pale Red Dot Campaign
Back in 2013, the first signs of a planet over four light-years from our solar system were spotted. Since then, the scientific community has been working to gather more information via further observations, primarily with the help of the European Southern Observatory (ESO).
To study and observe the red dwarf star, which was named Proxima Centauri, the Pale Red Dot campaign was started. Scientists used the HARPS spectograph on the ESO’s 3.6 meter telescope at La Silla in Chile. Combined with data gathered from other telescopes around the world, astronomers, led by Guillem Anglada-Escudé, observed a wobbling star that was apparently caused by the gravitational pull of an orbiting planet.
Research gathered from the Pale Red Dot campaign revealed a very exciting result:
The wobble they discovered shows Proxima Centauri approaching the Earth at about 5 km per hour – normal human walking pace – and then receding at the same speed.
This regular pattern repeats every 11.2 days, and when compared against natural fluctuations in the star’s brightness indicated the presence of a planet slightly more massive than the Earth, orbiting its star at only 5% of the distance from our planet to the Sun.
Search for Alien Life
While its orbit is closer to its star (compared to Mercury’s distance to our sun in our solar system), Proxima’s star is a lot fainter than our sun. This makes it more habitable and scientists estimate that it could have a surface temperature that would allow the presence of liquid.
“Many exoplanets have been found and many more will be found, but searching for the closest potential Earth-analogue and succeeding has been the experience of a lifetime for all of us. Many people’s stories and efforts have converged on this discovery. The result is also a tribute to all of them. The search for life on Proxima b comes next…” ends Anglada-Escudé.