Next step for the search of life on distant exoplanets. Coming soon!

Now that finding exoplanets is a common thing (95 more has been "discovered" and confirmed a few days ago - Source), what's next?


Source

The answer is obvious: finding biological signatures of life inside the atmosphere of the top potentially habitable exoplanets.

Obvious, but not easy... Indeed one might think that "oxygen would be a fantastic biosignature, possibly indicative of photosynthetic life, but there's a big problem with using it as your go-to evidence of life" as "oxygen-making photosynthetic life may never emerge on other planets: it's a very complex metabolism that only evolved once on Earth and so could be quite rare in the cosmos."

So a new research done by a team of PhD students in Earth and Space Sciences and Astrobiology of University of Washington, Seattle, (led by Joshua Krissansen-Totton) focused on a new, simple and clever idea that consist of searching for atmospheric biosignatures other than an abundance of oxygen gas, by looking to our own Earth's atmospheric history.

For much of Earth's history, there was life here but little or no oxygen. So the research team looked at the atmospheric history of our own planet to identify anything unusual in the atmosphere that was caused by life, particularly before oxygen became abundant. The team looked at three eons of geologic history—the Archean (4 to 2.5 billion years ago), the Proterozoic (2.5 to 0.541 billion years ago), and the Phanerozoic, the past 541 million years running up to the present—to identify gas imbalances that could serve as biosignatures.

The more recent eons, the Proterozoic and Phanerozoic, have identifiable levels of oxygen gas (O2), nitrogen gas (N2), and liquid water (H2O) caused by life. But the Archean Earth was a significantly different world. There was virtually no oxygen gas in the atmosphere or dissolved oxygen gas in the oceans all those billions of years ago. But microscopic life was thriving in the oceans, releasing methane as a byproduct. Based on atmosphere and ocean data from the geologic rock record, the new study identifies the presence of methane (CH4), nitrogen gas (N2), carbon dioxide (CO2), and liquid water (H2O) as a possible biosignature.

Our calculations show that those four species cannot exist together in equilibrium, and that the methane should disappear unless it is continuously resupplied by something," says Krissansen-Totton. "On the early Earth, evidence suggests that methane was resupplied by life—many microbes belch out methane as a waste product of their metabolism.

The main idea is then that methane and carbon dioxide are unlikely to be found together unless life is producing the methane. Krissansen-Totton says this is because carbon dioxide is made of carbon with the maximum number of oxygen atoms, while methane is made of carbon with no oxygen atoms, but hydrogen instead. "It is very difficult for non-biological process to simultaneously make carbon dioxide and methane."

The first future telescope candidate for such a hunt is the JWST (James Webb Spatial Telescope) that will be launch next year, but some others ground giant telescopes are scheduled in the 2020's and they will be able to track as well atmospheric biosignatures.

Will we see the final confirmation that life exists outside our own old Earth in the next, let's say, five years? I seriously think so! Am I too optimistic?

And you?

Source: advances science mag
Popular Mechanics

a reply to: elevenaugust

I'm a bit cynical though because in the future many of these exoplanets will become corporate property. The Alien movies features a corporation called Weyland-Yutani owning not just planets but extraterrestrial creatures too.

I'm not so sure that spending money on finding them is worth it. That money would best be spent in trying to help correcting the chemical polution we are putting in the environment that is sooner or later going to severely effect all life on earth.

originally posted by: rickymouse
I'm not so sure that spending money on finding them is worth it. That money would best be spent in trying to help correcting the chemical polution we are putting in the environment that is sooner or later going to severely effect all life on earth.

Why can't we do both?

Eventually, one way, or another, this ball we live on will cease to exist. I'm sure that is a long time away, but in the interest of humans survival in the universe, it doesn't hurt to start looking around.

a reply to: rickymouse

I think they are starting to invest so much because we are already past the point of no return.

Poor mother earth and her cancerous tumor that is homo sapien

originally posted by: Mach2

originally posted by: rickymouse
I'm not so sure that spending money on finding them is worth it. That money would best be spent in trying to help correcting the chemical polution we are putting in the environment that is sooner or later going to severely effect all life on earth.

Why can't we do both?

Eventually, one way, or another, this ball we live on will cease to exist. I'm sure that is a long time away, but in the interest of humans survival in the universe, it doesn't hurt to start looking around.

We don't have the money to do both.

Space exploration is really important. For evolved species who already know how to take care of its own planet. My opinion.

originally posted by: LightAssassin
a reply to: rickymouse

I think they are starting to invest so much because we are already past the point of no return.

Poor mother earth and her cancerous tumor that is homo sapien

When people are allowed to do anything they want in masses, then the environment suffers. Too much driving and flying going on, people do not need to fly to florida and hop on a cruise or fly to vegas every year for a vacation. Some say that Air travel is better than driving....no it isn't, if a person had to drive for five days out of their ten day vacation, they would not go so far. Right now someone could hop on a jet thursday afternoon, go spend a few nights in Vegas, then come back while just being on a long weekend at work. The thing is, I knew a few people who did that, they would have never done it if they had to drive. By the way, Science creates these jets and the ability to have so many in the air all the time.

What's going to happen, is, we're going to get in the middle of an galactic war, and be forced to fight for a side, in endless combat, kinda like now, only, just more of it.

but, I'm sure it'll be more, we'll just give them another resource to fight over to enslave

a reply to: Tranceopticalinclined

Optimistic view.

I would wager that we are the result of such an endeavor. Perhaps, agreements exist now, that are beyond our popular knowledge, but dictate similar terms.

Think you would know real from fake? Wakanda... What an idea. If I knew of such a place, I would probably never share it. The masses can't handle such a fragile concept. I would take a path frequently taken by those who make such "obscene" discoveries. Enjoy it, leave it secret, and leave. Those individuals, through the merit of their actions, that allegedly obtained access to such a place... They tended to share only a small glimpse with this world, expressed their discontent or weariness, and leave us.

Chandra and the iron pillar, an OOPART verified by science. Said iron pillar was inscribed with such a story. Science confirmed the complexity of it's alloy... 1600 years ago, and completely immune to normal ferrous oxide rusting reactions.

Sad...

Good luck to all those who believe that such a challenge exists out there.

Maybe it really does. Who would know?

The most intelligent girl I ever met once told me that she had a driving desire to become enlightened. We drifted apart. She married a normal human man that has made her happy. Maybe I found a path to enlightenment? Can I enjoy it? She no longer needs it, I suppose. Much of my life, spent in pursuit of something to make someone else happy... I find the cheese, and with no other mice that I wish to share it with, I have left it. I crawl back into the maze and blow wind through the ears of the hopeful. (Yes, your cheese exists... Will you care when you find it? I thought I would.)

Interesting that the scientists' calculations showed that carbon dioxide and methane are very unlikely to exist together on a planet, unless life is present. Mars is known to have both gasses in its atmosphere. So, this would mean that, by their own reckoning, Mars has life right now, it seems.

a reply to: elevenaugust

Try TESS. Launches next month, 2018, from NASA and Space X. This beats JWST by a year.

The Transiting Exoplanet Survey Satellite (TESS) is a two year survey mission that will focus on the discovery of exoplanets in orbit around the brightest stars in the sky. This first-ever all-sky transit survey will identify planets ranging from Earth-sized to gas giants, around a wide range of stellar types and orbital distances.

NASA.gov - TESS homepage.

a reply to: vinifalou

What does having enough money to do with it? The government can print as much as it wants to fund space exploration. It may take resources from other programs. But, the science behind exploration should help our own planet as well. For example, terroforming is going to be important. If we learn to do that, we can learn to fix/heal the earth. If humans really want to fix the earth, population control is a good place to start. But, good luck with that. I have 3 kids of my own, so I didn't help that cause.