A privately owned space telescope may start looking at planets around Alpha Centauri by 2025. This would be the first step in an attempt to find out if life has evolved there. Scientists are looking in our galactic backyard for life.
Alpha Centauri consists of two stars that are slightly more than around 25 trillion miles (four light-years) away and these stars are the closest to our solar system that are similar to our sun. This is the focus of new efforts to discover planets that may show signs of life. The project revolves around building a tiny space telescope, which is named TOLIMAN after the star’s medieval name, which will be sent into the orbit of the Earth in around 2 years and may start identifying planets by around 2025.
Although Alpha Centauri is close by in astronomical terms, planets have not been found around its binary star system. If there are any to be found, their atmospheres will be scanned for the “bio-signatures” that extraterrestrial life creates. This is a relatively recent astronomical method that may permit scientists to evaluate if there’s alien life on distant planets by telescope, especially microbial life.
A professor of astrophysics at the University of Sydney, Peter Tuthill, is the project leader and he said that the more than four thousand alien planets that have so far been confirmed have mostly been discovered due to lucky alignments.
He added that this was a little dark secret that astronomers had been keeping. Astronomers are actually not very good at finding planets.
Most “exoplanets,” as they are called, have been identified by automated systems such as the Kepler space telescope, which monitors for planets continuously as they cross in front of a multitude of stars.
It is however much more difficult to find planets around a specific star system like Alpha Centauri.
To improve the opportunities, the new space telescope will use a specially etched mirror to generate what is known as the “diffractive pupil” effect. This spreads incoming starlight from a minute point into a much bigger, flower-shaped pattern that can easier reveal the very slight “wobbles” caused by orbiting planets’ gravity.
Tuthill said there were two stars similar to the sun in the Alpha Centauri system, and they orbit each other at around 20 X the distance between the Earth and the sun.
Each planet has what is known as a Goldilocks Zone, which means they have the correct temperature to contain liquid water on their surface. This is believed to be a requirement for life to evolve as we understand it.
Two planets were discovered around what may be the third star in the system in 2016. The star is a red dwarf named Proxima Centauri, and it was in 1915 discovered by telescope and is slightly closer to Earth than the other two.
According to Tuthill they are however not believed to be suitable for life as Proxima releases dramatic flares that could be 100 times more powerful than the sun’s flares.
As a result, Alpha Centauri’s sun-like stars may offer the best possibility to locate signs of alien life.
If there is an Earth-mass planet in the habitable zones, that would create a true Earth analogue, a Holy Grail. It could potentially contain an environment that may have the same conditions that are known on Earth.
Breakthrough Initiatives, a California-based space exploration fund backs the TOLIMAN project.
The group has suggested that Alpha Centauri should be explored with Breakthrough Starshot. This project consists of thousands of very small space probes that are propelled at extremely high speeds by Earth based lasers.
The theory is that the “nanocraft” from Breakthrough Starshot could reach Alpha Centauri in around 20 years. This epic voyage of 25 trillion miles would take the fastest spacecraft that exist now tens of thousands of years.
Tuthill said as Alpha Centauri was so close that for people wanting to dream visionary dreams about interstellar flight someday, Alpha Centauri has to the first stop on the way further into the galaxy.
If the TOLIMAN telescope finds a planet, it would be studied with other telescopes to determine their atmospheres’ composition and maybe even to discover chemical “bio-signatures” generated by life.
An astrophysicist at Queen’s University Belfast, Chris Watson said the newest astronomical methods to study the exoplanets’ atmospheres only work properly with really large planets that orbit close to their star, and they can currently not study the atmospheres of Earth-size planets.
Chemicals are however now being discovered on smaller planets as scientists design new methods to analyze data and as new instruments, like the James Webb space telescope, become available.
Watson is not involved in the TOLIMAN project but is part of the team that detected hydroxyl radicals in the atmosphere of a planet that orbits a star around 400 light-years from the Earth.
He said possibly detecting bio-signatures and chemicals on Earth-like planets around Alpha Centauri’s stars would be difficult, but investigating the brightest and nearest planetary system will provide the most likely path to success. As the signals would be very faint, every photon of light was required to get it to work.