Is Alpha Centauri habitable? Alpha Centauri, a triple star system
Our search for habitable worlds will lead us outside the solar system. Some of the greatest minds are working to make it a reality.
Alpha Centauri is a triple star system that is 4 light-years away from Earth. But it is three times closer than the next nearest Sun-like star. Alpha Centauri, also called Rigil Kentaurus. Alpha Centauri A has 1.1 times the mass and 1.519 times the luminosity of the Sun.
The star system is constituted of three stars, which include Alpha Centauri A, Alpha Centauri B, and Alpha Centauri C, which is often referred to as Proxima Centauri.
Alpha Centauri A and B make up a binary star system. They both are close together and orbit around their center of mass once every 80 Earth years.
Their orbit is elliptical so the distance between both the stars changes throughout the year. And there could be a planet orbiting the binary system as a whole.
Alpha Centauri A and B orbit relatively close to each other. Alpha Centauri A is exactly like our own sun, in almost every way including age. While Alpha Centauri B is smaller and dimmer but still quite similar to our own sun. The third one, Alpha Centauri C which is also known as Proxima Centauri C is a much smaller red dwarf star that travels around the A and B pair in such a large orbit that it takes more than 10,000 times from the A & B pair.
Alpha Centauri is located in the Centaurus constellation, which is only visible in the Southern Hemisphere. Proxima Centauri cannot be seen from Earth.
Which star is much near to our earth?
Proxima Centauri is the closest one to us. It is about 4.22 light-years away. We would reach the Proxima Centauri first once we master interstellar travel. Proxima Centauri is a dim red dwarf star. Its mass is 12% of our sun and its radius is around 15% of our sun.
Proxima Centauri B:
In 2016, astronomers detected an Earth-sized planet orbiting the Proxima Centauri within the stars’ habitable zone. The right distance to support liquid water on its surface.
Even though it is so close because the star is so smaller and cooler than ours Proxima Centauri B is actually in the habitable zone of its star which means it could harbor liquid water. Based on density calculations, it seems like it has a rocky surface. It has an orbital period of around 11 Earth days. Its orbital radius is around 0.05 AU (astronomical units). Proxima Centauri B is way more massive than the Earth.
Because Proxima b is so close to a red dwarf, habitability problems are already coming to scientists’ minds. The planet is so close that it is tidally locked to the star which means that one side of the planet is always facing the star. This means one side of the planet would always be very warm, while the other side would be very cold.
That makes it hard for life to exist.
NASA’s Chandra x-ray observatory:
NASA’s Chandra x-ray Observatory provides encouraging news about key aspects of planetary habitability. It indicates that any planets orbiting the two brightest stars in the Alpha star system are likely not being pummeled by large amounts of x-ray radiations from their host stars.
NASA’s Voyager 1:
NASA’s Voyager 1 is Earth’s farthest space probe to date. It was launched in 1977 and in 2012, it was the first spacecraft to enter interstellar space. Voyager 1 is one of the oldest space probes. Voyager 1 is still working and didn’t come back to Earth it flew past Saturn in 1980. It still sends data back to Earth.
If Voyger1 spacecraft would travel in the direction of Alpha Centauri (which it is not) then the trip there would take more than 70 thousand years.
Some scientists believe that our best attempt at interstellar travel is light sails. These sails would be made of ultra-thin sheets that will be propelled using light instead of wind.
Stephen Hawking, Yuri Milner, and Mark Zuckerberg helm the board for a new initiative. Breakthrough Starshot, whose technology could be used to someday reach Earth’s neighboring star Alpha Centauri after just a 20-year journey.
