Determining if there is alien life on distant planets could start happening sooner than previously expected, way sooner — maybe within the next few years.
Last year an Earth-like planet was discovered in the inhabitable zone of Proxima Centauri, the star closest to our solar system. Unfortunately, in astronomical terms, “closest” in this case means approximately 4.24 light years away, according to Sky & Telescope. That translates to roughly 24,689,699,202,000 miles away. Roughly.
In other words, humans are not going to be doing any first-hand explorations for alien life on Proxima b, the name given to the planet, anytime soon. As Calla Cofield of Space.com points out, scientists trying to determine if there may be life on Proxima b would need to rely on “massive, next-generation, space-based telescopes.”
The problem is that those types of telescopes do not exist yet. Thus the “next-generation” part. Such telescopes are expected to come online in the 2030s.
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However, two groups of researches think they might have found an alternate solution with ground-based telescopes that will hopefully be available in the 2020s, according to Cofield.
“Thousands of planets have been identified around stars other than our own, a majority of them in the past six years, thanks to the dedicated Kepler space telescope (although many other observatories have contributed to this exoplanet treasure trove),” Cofield says. “But finding planets is much different from characterizing their properties — things such as a planet’s mass and diameter; whether it is made of rock or primarily of gas; its surface temperature; whether it has an atmosphere; and what that atmosphere is composed of.”
Astronomers can see distant planets, but they cannot really tell what is going on within the planets’ atmosphere or on their surface. There is definitely not currently any way of actually seeing if there is alien life on a distant planet.
Matteo Brogi, a Hubble fellow at the University of Colorado, discussed a means of possibly overcoming this obstacle at a forum on the search for alien life on other planets hosted by the National Academy of Sciences late last year.
Brogi and his team believe that by using “direct imaging” of a star and a potentially life-sustaining planet around it, they can then use high-resolution spectroscopy to determine the atmospheric make up of the planet. Knowing the atmospheric make up could help identify alien life on the planet.
Direct imaging relies on getting a direct “snapshot” of the star and planet in orbit. Once they have that image, they can apply high-resolution spectroscopy to it, which stretches lightwaves much further than a normal prism, exposing the “unique fingerprint” of chemical elements in the light spectrum.
In other words, with high-resolution spectroscopy, you can tell what chemicals were present at the source of the light. As Cofield explains, this is the same technique by which scientists discovered we are all made of stardust.
The only obstacle right now is the development of telescopes that can produce the type of direct imaging needed to study planets like Proximus b.
Most of the direct imaging of planets taken to date involves brown dwarf stars because they are dimmer than other stars and thus do not outshine the planets around them, an earlier Space.com article explains.
The light emanating from planets orbiting red dwarfs however, is often drowned out by the light of their stars, rendering direct imaging impossible or ineffective with current telescopes.
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Cofield acknowledges telescopes needed are not available just yet, but several capable of the task are expected to come online within the next few years, such as the Giant Magellan Telescope (2021) and the European Extremely Large Telescope (2024).
And once those telescopes are up and running, it won’t be just Proxima b scientists will scour for signs of alien life, there’s the potential to study possible alien life on numerous Earth-like planets in our galaxy.
“The approach could be applied to other planets that, like Proxima b, are rocky, and orbit in the habitable zone of relatively cool stars, known as red dwarfs,” Cofield says. “The astronomical community is already emphasizing the search for ‘Earth-like’ planets around these small stars because the latter are incredibly common in the galaxy; astronomers have even jokingly referred to red dwarfs as the ‘vermin of the sky.'”
“The frequency of small planets around small stars is extremely high; on average, there are about 2.5 planets per star,” Brogi said. “Regarding habitable planets around small stars, there should be more or less a frequency of close to 30 percent. So every three stars should have a habitable planet.”
That’s a whole lot of planets to search for possible alien life.
[Featured Image by European Southern Observatory/Getty Images]