The search for extraterrestrial life is undoubtedly one of the most profound scientific events of our time. If extraterrestrial biological life will be found near another world around another star, we’ll finally know that life outside of our Solar system possible. To find the traces of extraterrestrial biology in distant worlds is extremely difficult. But astronomers are developing a new technique that will be used powerful telescopes of the next generation and allow them to accurately measure substances in the atmosphere of exoplanets. The hope, of course, is to find evidence of extraterrestrial life.
Recently, the search for exoplanets has attracted a lot of attention, thanks in part to the discovery of seven small alien worlds orbiting a tiny star — a red dwarf TRAPPIST-1. Three of these extrasolar planets spin in the potentially habitable zone of a star. That is, in the region near any star, which is not too hot and not too cold so that water could exist in liquid form.
Everywhere on Earth where there is liquid water there is life, so if at least one of potentially habitable worlds TRAPPIST-1 will have water, it may be life.
But life potential TRAPPIST-1 remain pure speculation. Despite the fact that this amazing star system located in the back yard of our galaxy, we have no idea whether there is water in the atmosphere, at least one of these worlds. We don’t even know if they have atmosphere. All we know is how long exoplanets are in orbit and what are their physical dimensions.
“The first detection of biosignature in other worlds can be one of the most significant scientific discoveries of our lives,” says Garrett Rouen, an astronomer at the California Institute of technology. “This will be a major step to answer one of the biggest questions of mankind: are we alone?”.
Rouen working in the Laboratory ekzoplanetoy technology Caltech, ET Lab, which is developing new search strategies ekzoplanetoy of biosignature such as molecules of oxygen and methane. Usually molecules like these actively react with other chemicals quickly decaying in the planetary atmosphere. Therefore, if astronomers can find a spectroscopic “fingerprint” of methane in the atmosphere of extrasolar planets, it could mean that his production responsible of alien biological processes.
Sorry, we can’t just take the world’s most powerful telescope and direct it to TRAPPIS-1 to see whether the atmospheres of those planets methane.
“To detect molecules in the atmospheres of exoplanets, astronomers must be able to analyze the light of the planet without being completely blinded by the light of a neighboring star,” says Rouen.
Fortunately, red dwarf stars (or M dwarfs) like TRAPPIST-1 cold and dull, so the problem of glare is less severe. And since these stars are the most common type of stars in our galaxy, scientists pay attention to the very first red dwarfs in search of discoveries.
Astronomers use a tool known as a “coronagraph” to isolate the reflected starlight from exoplanets. Once the sec catches the dim light of exoplanets, a spectrometer with low resolution analyses of the chemical “fingerprints” of this world. Unfortunately, this technology is limited by studying only the largest exoplanets, rotating away from their stars.
New methods ET Lab use coronagraph, optical fibers and spectrometer high-resolution work together, highlighting the glow of the stars and catching the detailed chemical fingerprint of any world in its orbit. This method is known as the high-dispersion coronography (HDC) and could turn our understanding of the diversity ekzoplanetoy atmospheres. Work on this subject was published in The Astronomy Journal.
“What makes the method powerful HDC is the fact that it is possible to identify the spectral signature of the planet, even when it is buried in the bright light of the stars,” says Rouen. “This allows us to detect molecules in the atmosphere of planets that are extremely difficult to visualize”.
“The trick is to divide the light into multiple signals and to create what astronomers call a spectrum of high resolution, which helps to distinguish the signature of the planet from the star light.”
All you need now is a powerful telescope to connect to the system.
At the end of 2020-ies of the thirty-meter telescope will be the world’s largest ground-based optical telescope, and when it will be used in conjunction with HDC, astronomers will be able to explore the atmospheres of potentially habitable worlds orbiting red dwarfs.
“Detection of oxygen and methane in the atmospheres of earth-like planets orbiting M-dwarfs, similar to Proxima Centauri b, the forces of the thirty-meter telescope will be extremely exciting,” says Rouen. “We still have much to learn about the potential habitability of these planets, but it may well be that these planets would be like Earth”.
It is estimated that in our galaxy there are 58 billion red dwarfs, and we know that most of them will have planets, so when a thirty-meter-telescope will come into operation, astronomers will be able to find a lot of things that were previously unavailable.
In 2016, astronomers have discovered an exoplanet the size of Earth, circling at the nearest to the Earth M-dwarf, Proxima Centauri. Proxima b also rotates within the potentially habitable zone of its star, making it a Prime target for the search of alien life. At a distance of just four light-years, Proxima b literally teasing us with the opportunity to visit her sometime in the future.
We will look for life on distant exoplanets?
Ilya Hel