Seeking life on other worlds? Check for volcanoes, study says.

Personal note: Should you have any questions, this study was conducted by some people I personally have met at the university I am attending.

From the University of Washington

Planets with volcanic activity are considered better candidates for life than worlds without such heated internal goings-on.

Now, graduate students at the University of Washington have found a way to detect volcanic activity in the atmospheres of exoplanets, or those outside our solar system, when they transit, or pass in front of their host stars.

Their findings, published in the June issue of the journal Astrobiology, could aid the process of choosing worlds to study for possible life and even one day help determine not only that a world is habitable, but in fact inhabited.

Volcanism is a key element in planetary habitability. That’s because volcanic outgassing helps a planet maintain moderate, life-inviting temperatures, regulating the atmosphere by cycling gases such as carbon dioxide between the atmosphere and the mantle.

Lead author Amit Misra, who has since graduated with a doctorate, said the project started in a UW astrobiology graduate seminar when a professor asked how one might detect plate tectonics — the grinding together and apart of huge slabs of a planet’s surface — on faraway worlds.

Plate tectonics is considered an aid to the origin of life because it allows for the recycling of materials from the atmosphere to the planetary interior. Some scientists have even proposed that life on Earth began at sites created by tectonic plates.

The students studied various models trying to predict whether an exoplanet might have plate tectonics, but found little in scientific literature on how to directly detect tectonic plates. So they started brainstorming.

“I came up with the idea of looking at explosive volcanic eruptions as a proxy, or stand-in, for plate tectonics,” Misra said. “I had done some work modeling aerosols produced by volcanic eruptions for other projects, so I started looking into how we might detect an eruption and what it would tell us.”

So the team used data from volcanic eruptions on Earth to predict what an Earth-like exoplanet might look like during such eruptions. The thinking, Misra said, was that explosive volcanic eruptions usually happen at the edges of tectonic plates, making them a good proxy indeed.

Gases released from smaller, nonexplosive volcanic eruptions tend to return quickly to the planet’s surface. Explosive eruptions, however, can send volcanic gases up into the stratosphere, where they “greatly affect the spectrum of the planet,” Misra said. The optical signature of the gases might be detectable by powerful telescopes such as the James Webb Space Telescope, scheduled for launch in 2018.

Co-authors are Joshua Krissansen-Totton, Matthew Koehler and Steven Sholes, all graduate students in the UW’s Department of Earth and Space Sciences and affiliated with the UW astrobiology program.

But while the connection between volcanic eruptions and tectonic plates is true on Earth, Misra said the team cannot say with certainty that the same is true throughout the cosmos. Still, he said, “An explosive eruption can probably be tied to volcanism if false positives such as dust storms can be ruled out.”

“These long-lasting, high-up aerosols can have a huge signal for an exoplanet, which is the key result for the paper,” Misra said. “What this means is that if we can detect a volcanic eruption on a planet, and if it meets other criteria like being in the habitable zone, that planet should move up our list of potential targets to search for life.”

The work may also someday help astronomers infer that a planet not only might have life, but actually does. Misra explained that while oxygen is thought an indicator of life, it’s also possible for oxygen to be produced abiotically, or by something other than biology.

Volcanism, Misra said, may help distinguish between oxygen that is produced by life or other planetary processes by helping astronomers better understand the planet’s environment.

“Volcanic gases often react with and destroy oxygen, and a detection of both oxygen and volcanism suggests that there is a source of oxygen in the planetary environment, which could be life,” Misra said.

The research was done through the Virtual Planetary Laboratory, a UW-based interdisciplinary research group, and funded through the NASA Astrobiology Institute.

a reply to: JadeStar

Surely most exoplanets would be volcanically active at some stage in their life , some longer than others depending on circumstances , so if that's the case .... ET confirmed !

originally posted by: gortex
a reply to: JadeStar

Surely most exoplanets would be volcanically active at some stage in their life , some longer than others depending on circumstances , so if that's the case .... ET confirmed !

Well yes but they're talking about recent or ongoing volcanic activity as a method to sort out false positives during life-detection observations in the not too distant future so it won't be so much "ET confirmed!" as probably a lot of "uh we might have found ET? Oh wait... nope" before we actually DO find ET*.

*by ET we're talking about any life which can generate free oxygen. So think microbes not necessarily Vulcans

a reply to: JadeStar

Does that not mean that we would effectively be narrowing our field of view, to the extent where we could easily miss a planet with amazing creatures on it, just because those creatures have evolved to live in a totally hostile, utterly unfamiliar environment, and do not necessarily produce free oxygen?

I mean, obviously it makes sense to narrow the field somehow, but surely it makes no sense to potentially throw out any significant body with an atmosphere, just because the life we might find there would be difficult to identify at a distance?

I agree with the report, but it's surely not new? I read this in a book written ten years ago which referenced research much older. Tectonic activity is essential to the carbon cycle, without which life would be extremely limited.

a reply to: JadeStar

I'll happily take microbes over Vulcans , or little fishes beneath the surface of Ganymede or Europa , I just want ET life to be confirmed within my lifetime ... I don't necessarily need to talk to it .

a reply to: JadeStar

I've always insisted that the best way to nail down the ET lifeform possibility is an intensive study of UFOs here on this planet. 'Course, that would necessitate the cooperation of the government for funding, and the non-interference of the government in the activities of the project. Deny the trees, and the forest doesn't exist.

Of course, the program is to build a solid road to the forest before the trees along the way can be acknowledged, but you know, as a UFO abductee from way back in 1964 I'm getting damned tired of waiting.

originally posted by: TrueBrit
a reply to: JadeStar

Does that not mean that we would effectively be narrowing our field of view, to the extent where we could easily miss a planet with amazing creatures on it, just because those creatures have evolved to live in a totally hostile, utterly unfamiliar environment, and do not necessarily produce free oxygen?

Not necessarily.

There are likely to be multiple strategies to look for biosignatures. This is just one of them to look for stuff like photosynthetic life or oxygen producing life.

The reason we'd look for such life is because:

1) We know what to look for. It's easier to look for something you know exists than something you don't.

and

2) Free oxygen is something which doesn't last long in the atmosphere of an exoplanet if it isn't being replenished by something. Oxygen likes to bond with other things so if we find free oxygen then we would want to eliminate abiotic sources of it.

I mean, obviously it makes sense to narrow the field somehow, but surely it makes no sense to potentially throw out any significant body with an atmosphere, just because the life we might find there would be difficult to identify at a distance?

Nope, those planets would just be studied differently.

There is not going to be just one technique which fits all planets when we look for life. Some techniques might simply look for disequilibrium or an unexplained shift of the chemical composition of an atmosphere due perhaps to seasonal changes and this technique would not be biased simply to life as we know it but would look for anything strange which could be disturbing the equilibrium of a planetary atmosphere.

The research in the original post could help that type of broad search as well.

originally posted by: 321Go
I agree with the report, but it's surely not new? I read this in a book written ten years ago which referenced research much older. Tectonic activity is essential to the carbon cycle, without which life would be extremely limited.

What is new is that we've had our first detection of volcanoes on a planet around another star.

originally posted by: gortex
a reply to: JadeStar

I'll happily take microbes over Vulcans , or little fishes beneath the surface of Ganymede or Europa , I just want ET life to be confirmed within my lifetime ... I don't necessarily need to talk to it .

I would say, "stay healthy and stay tuned" it would not shock me if we had such confirmation before 2030.

originally posted by: Aliensun
a reply to: JadeStar

I've always insisted that the best way to nail down the ET lifeform possibility is an intensive study of UFOs here on this planet. 'Course, that would necessitate the cooperation of the government for funding, and the non-interference of the government in the activities of the project. Deny the trees, and the forest doesn't exist.

Of course, the program is to build a solid road to the forest before the trees along the way can be acknowledged, but you know, as a UFO abductee from way back in 1964 I'm getting damned tired of waiting.

Well I don't know about all that but if you are in regular communication with aliens perhaps asking them where they live would speed the whole process up?

I'm really surprised this thread hasn't been jumped all over by the ET crowd. Without doubt, this discovery is the best yet of finding life outside of our own solar system, and yet it remains silent.

I'm seriously wondering who is the most ignorant group.

This discovery is what I was referring to:
news.nationalgeographic.com...

a reply to: JadeStar

Will this project have the funding to set aside JWST viewing time to compare the spetra of a chosen extra-solar planet, compared to when it has huge volcanic explosions? Won't this take time away from JWST at looking at different targets? How do we know if a given planet has volcanic activity?
This frustrates me. Instead of wasting money on wars and pork-barrel nonsense, we should have launched three JWSTs by now.
I know..I'm ranting.

originally posted by: TrueBrit
a reply to: JadeStar

Does that not mean that we would effectively be narrowing our field of view, to the extent where we could easily miss a planet with amazing creatures on it, just because those creatures have evolved to live in a totally hostile, utterly unfamiliar environment, and do not necessarily produce free oxygen?

I mean, obviously it makes sense to narrow the field somehow, but surely it makes no sense to potentially throw out any significant body with an atmosphere, just because the life we might find there would be difficult to identify at a distance?

Biochemically, oxygen is a component of water. Water at habitable zone temperatures is in liquid form and is one of the most efficient ways to tranfer molecules within an organism. Whether it be tube worms on Earth or E.T. on Gliese something something.

Just things to consider.

I fail to see how volcanic activity, which is a natural part of a forming planets "cooling down" period would indicate life.

Cool, great study.

Looks good for Venus then......she must be teaming with life.......

originally posted by: woogleuk
I fail to see how volcanic activity, which is a natural part of a forming planets "cooling down" period would indicate life.

Except if it continued after full formation, strongly indicating a molten core, which would encourage a tectonic surface, which would enable a carbon cycle, which would support continued life.

a reply to: JadeStar

Wow...now that is interesting...

Just recently as I was thinking about my observatory, and it's design...I came to the realization that I might, even IF under somewhat extraordinary circumstance, actually be able to view the atmosphere of a transiting planet. If such a view was available it would not be difficult to apply a spectrometer to the area and get a "reading" of the atmospheric spectra, and associated absorption lines. Applying a bit of differential spectrometry would quickly isolate many of the atmospheric properties, which of course would include any volcanic gasses, or indeed, things like partially burned hydrocarbons...

The problem I would have with this is the size of my telescope...I would need several pixels of atmosphere, so I would have to be rather lucky with the micro-lensing...A larger telescope however, wouldn't be quite so handicapped. And, there are software technique that can be applied "on the fly" to produce absorption line sets.

Some of these techniques may work on existing images and data...

originally posted by: woogleuk
I fail to see how volcanic activity, which is a natural part of a forming planets "cooling down" period would indicate life.

Young planets would be excluded.

And how do we know the age of planets? Because planets form roughly around when the star they circle does.

And how do we know the star such young planets are circling is young?

By getting its spin rate (young stars spin faster than older stars) and this we can measure through very advanced prism like devices called spectrographs.