Questions tagged [astrobiology]

Questions regarding the study of life outside of Earth.

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7 answers
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Why are we trying to prevent life from spreading via landers rather than actively encouraging it?

The question How certain are we that we have not accidentally sent life to other planets/moons? talks about all the precautions taken to avoid spreading life to other planets/moons. But why even try ...
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39 votes
3 answers
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Why did the Chinese send flies and plants to the far side of the moon?

The Chinese space craft that just landed on the moon had a tube with a biosphere in with flies and plants. What are they expecting to learn? Didn't we already experiment that on the ISS? Source ...
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32 votes
3 answers
3k views

Is it possible to get pregnant through natural means in space?

The Russians did some early testing with rats (Packing for Mars: The Curious Science of Life in the Void, By Mary Roach pg 245) and natural means did not result in pregnancy. Later testing shipped ...
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27 votes
4 answers
7k views

Why do deep space probes have to be sterilized?

Correct me if I'm wrong but a probe to Mars will take months, during which time it's exposed to a vacuum and irradiated by the sun. It sounds to me like this would kill any micro-organisms on the ...
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27 votes
4 answers
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Are there types of animals that can't make the trip to space? (physiologically)

I thought about what kind of animals could make it to space, and I thought about how vertebrates can apparently withstand the G forces need to travel to the ISS, but I hadn't really thought about ...
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2 answers
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Is there any demonstrated or even proposed technology that can sterilize a spacecraft with 100% certainty and yet leave it electronically functional?

In this answer to Why are there no robotic missions on Europa or Enceladus I wrote: Missions going through the ice and into the ocean are currently hypothetical and problematic. You need a lot of ...
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19 votes
3 answers
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Could a spacecraft be made out of wood?

Could a spacecraft use organic materials, like wood or bone or shell or other tissues, as an interface to the vacuum and radiation of space? Would wood outgas and crack up in space? I wonder if life ...
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16 votes
4 answers
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Why aren't there any robotic missions on Europa or Enceladus?

As per Space.com's Methane in plume of Saturn's moon Enceladus could be sign of alien life, studies suggest that Enceladus and Europa are the two most promising solar-system bodies on or in which to ...
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16 votes
2 answers
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How would the search for life on Mars be affected by having boots on the ground?

It is looking like Mars One might continue to go forward, and even if it doesn't it is fairly likely that we will have people on Mars sooner or later. Have there been any scholarly estimations of the ...
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15 votes
7 answers
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What would be the practical benefits of finding life in the Solar System?

An interesting article on the World Economic Forum website talks about the benefits of exploring Mars: There are also reasons for visiting Mars that transcend the purely scientific. Sending humans to ...
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15 votes
1 answer
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Did the Viking landers detect life on Mars?

The two Viking landers had an experiment on board where they attempted to find life on the planet. The initial results said yes, there was life, but later there were questions raised about the results....
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14 votes
2 answers
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Why not bring life to Venus along with the next exploring mission?

Why not bring cyanobacteria and fertilizer to the atmosphere of Venus to improve conditions for life there by producing oxygen ? Planetary protection could be a reason. According to Wikipedia: ...
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14 votes
4 answers
366 views

What exactly do they look for when searching for extraterrestrial intelligence?

There are some experiments and projects that are searching for extraterrestrial intelligence.(SETI) I want to know what signs exactly are they looking for? Do they just look for monotone sinusoidal ...
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14 votes
4 answers
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What properties are used to quantify the odds of a star harboring earth-like life?

Say you start with a list of stars. What properties do we believe to be critical in the present existence or future formation of earth-like life in those star systems? How can one reasonably pare down ...
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13 votes
1 answer
869 views

Has any country stated its official position on how it would respond to a discovery of intelligent extra terrestrial life?

There are currently many programs that are attempting to find intelligent extraterrestrial life. Putting aside the fact that I believe that the chances of this are slim to none, I'm interested in ...
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13 votes
1 answer
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How certain are we that we have not accidentally sent life to other planets/moons?

Recently phosphine was discovered on Venus, and that led to some speculation that life exists on Venus because phosphine is a known biosignature on Earth. Considering that we've sent probes to Venus ...
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13 votes
1 answer
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How big is Earth's sphere of broadcast influence?

The question Interstellar eavesdropping points out that we have been broadcasting to space for a long time, currently we are approaching a century. This means every star system in within 100 light ...
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13 votes
1 answer
2k views

Melanized fungi on the ISS - are they 'enjoying' the elevated radiation levels there?

The end of this excellent answer lead me to Wikipedia which linked to The blacker the better… especially in Chernobyl and Chernobyl Fungus Feeds On Radiation. One passage in 'blacker the better' ...
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12 votes
2 answers
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Why do we worry about contaminating some solar bodies but not others?

On 15th September 2017, the Cassini probe will be destroyed by crashing it into Saturn. This will be done in order to eliminate the unlikely risk of it crashing into and forward contaminating one of ...
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4 answers
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Is a combination of 'space is big' and 'humans haven't been around long' a good solution to the Fermi paradox?

The Fermi paradox is basically that: There are billions of stars, life is probably abundant throughout the universe. Even though it may take tens of thousands or millions of years for life on other ...
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12 votes
2 answers
788 views

What existing life on Earth is best suited for the Martian environment?

What existing life on Earth is best suited for the Martian environment? By best suited, I mean it could theoretically be placed on Mars and easily adapt or thrive within the existing environment the ...
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12 votes
2 answers
565 views

Interstellar eavesdropping

For about a century, humanity has broadcasted noise to space in the form of TV broadcasts, radio, etc... The nearest star is 4.242 light-years away, so for about 90 years, aliens -- if they exist in ...
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12 votes
4 answers
672 views

Are we searching for life "as we don't know it"?

The phrase "Life as we know it" is often spoken with a knowing wink, and implies the speaker is in on the big secret. Life on Earth is carbon based and every form of life we know of is on Earth. Which ...
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11 votes
2 answers
592 views

Are we alone after all? Understanding the recent re-evaluation of the Drake Equation

The Quartz.com article We may have answered the Fermi Paradox: We are alone in the universe says: Researchers of Oxford University’s Future of Humanity Institute have another answer. It’s likely ...
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11 votes
2 answers
611 views

Why is the surface of Mars oxidized?

Before 2.5 to 2Gya, Earth's surface was a chemically reducing environment (evidence includes reduced forms of iron, sulfur, and uranium in rocks before that time). It is believed to have become ...
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11 votes
1 answer
538 views

Plankton found outside the ISS, what is the substance in that claim?

There's been a news article around claiming that cosmonauts have found sea plankton on the outside of the international space station, for example here. Is there any substance to this claim? Have any ...
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11 votes
1 answer
508 views

Fish in space: what were the results?

I've been interested in the Japanese experiment on the ISS involving raising fish in space, but in all my reading the results seem a bit ambiguous/conflicting (depending on source). What are the ...
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11 votes
1 answer
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Could there be liquid hydrogen oceans on the surfaces of worlds (including frozen gas giants) in the distant Kuiper belt or Oort cloud?

This is something I'm wondering for a science book I'm writing (not science fiction) where I cover the various forms of life that could exist especially in our solar system - such as life on Mars of ...
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10 votes
4 answers
31k views

Why can't plants grow on Mars?

Mars has a lot of carbon dioxide in its atmosphere. It also gets a lot of sunlight. On Earth, plants use carbon dioxide and sunlight for photosynthesis. So, why can't plants live on Mars?
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3 answers
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Agriculture on an exoplanet

If we find a hypothetical Earth-like planet A with a rocky terrain that we could colonize, how would we go about planting the first plants, knowing that there is a deficient of nutrients and the ...
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10 votes
3 answers
450 views

Does man send any signal to attract aliens?

Does man send any signal (such as electromagnetic radiation) to space to attract aliens?
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10 votes
1 answer
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How will the Voyager Golden Record last for 1 billion years?

In the Radiolab podcast Space episode (2004) Ann Druyan mentioned that the contents of the Voyager Golden Record will last for 1 billion years before the contents of the Record becomes unreadable. ...
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10 votes
1 answer
681 views

Does NASA have any documented procedures in the event of discovery of extraterrestrial life?

Say that one of NASA's probes discovers definite evidence of life outside of Earth. Does NASA have any procedures in place on how to deal with such a situation? For instance, do they have to inform ...
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10 votes
1 answer
195 views

Would we be able to detect signs of life from the contents of a water plume?

Hubble has detected water vapor plumes shooting out of Europa Wikipedia writes to say it is predicted that the outer crust of solid ice is approximately 10–30 km (6–19 mi) thick Getting to ...
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9 votes
2 answers
321 views

If I wanted to try to terraform Mars, who would have the authority to stop me?

Let’s say hypothetically I could fund a rocket ship and pack it with lots of biomaterial. Biomaterial that would hopefully survive the impact, reproduce and potentially alter the atmosphere of Mars. ...
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9 votes
1 answer
520 views

Why is the northeastern region of Syrtis Major Planum a selected landing site for the Mars 2020 mission?

Image below: One of the 3 selected landing sites, on the left side of Jezero crater, which is also selected ! A workshop for the Mars 2020 Rover mission was held in February 2017 that selected 3 ...
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9 votes
1 answer
571 views

Has Earth ever sent out a repeating signal into space?

My understanding is that for us to confirm that a signal is of artificial origin, we have to get the same signal at least twice. However, as far as I can tell, most of the signals we've sent out to ...
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9 votes
1 answer
620 views

What type of rock or soil on Mars will give Nostoc Commune cyanobacteria the best chance to survive there?

Photo taken by YAMAMAYA Cyanobacteria are a group of photosynthetic bacteria, who use the energy of light to synthesize organic compounds from carbon dioxide, and producing oxygen this way. Nostoc ...
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9 votes
2 answers
392 views

Why not simulate certain regions of the atmosphere of Venus?

Many people would like to know if any form of life could survive anywhere in the atmosphere of Venus. Researchers have simulated conditions on Mars and found that after a month some cyanobacteria ...
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8 votes
1 answer
686 views

Which earth-based lifeforms can survive the vacuum of space?

The Tardigrade (or Water Bear) is a remarkable creature: It is able to survive in all sorts of extreme environments (taken from wikipedia): temperatures from just above absolute zero to well above ...
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8 votes
1 answer
915 views

What evidence would be needed to determine a signal was artificial in origin?

Humanity has received some odd signals in the past. We've also sent out some signals ourselves. How could we determine that a signal we'd received was artificial in origin? Or of course inversely, ...
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8 votes
2 answers
1k views

DNA or even life in vacuum of space

Does anyone know of any missions planned or in progress that are searching in the very vacuum of space for the complex organic molecules that are key indicators of life (such as DNA, RNA, etc.), or ...
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8 votes
0 answers
138 views

How often have signs of life been dismissed as abiotic?

Today, there are rumors about an upcoming announcement of the discovery of (non-conclusive) evidence for life on Venus, apparently they detected some phosphorus compound that is not produced by any ...
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  • 1,066
7 votes
3 answers
3k views

Is it ethical for Chang'e-4 to bring an entire ecosystem to the moon? [closed]

As far as I know, it isn't ethical to contaminate outer space with life from Earth, because then we will never be sure if life can actually grow there. However, I just read reports that the latest ...
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7 votes
2 answers
791 views

What other bodies in the solar system are most likely to contain forms of life?

There have been many candidates stated as potential habitats for life outside of Earth, but what are considered to be the most likely to harbor life?
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7 votes
3 answers
325 views

Why is Enceladus the "most interesting place for astrobiology" in the Solar System other than Earth?

In season 1 episode 1 of Space's Deepest Secrets (IMDB), Dr. Chris McKay, a planetary scientist for NASA, says around 1h:40m into the show, "This is the single most important and interesting place for ...
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7 votes
1 answer
272 views

If extraterrestrial life exists in our Solar system, is it believed to be unicellular or multicellular?

The Wiki article Life on Mars states the following: The primary mission of the Viking probes of the mid-1970s was to carry out experiments designed to detect microorganisms in Martian soil because ...
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  • 1,071
7 votes
1 answer
246 views

How did Spirit and Opportunity identify ferric sulfate and jarosite on Mars?

In the short BBC video Spain's otherworldly red river, Ricardo Amils, a researcher in Spain's Astrobiology Center says the following (amateur transcription): Río Tinto is a peculiar place in our ...
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  • 148k
7 votes
1 answer
228 views

Does exploration of Venus' atmosphere now require any planetary protection protocols?

This answer quotes Marc Rayman's August 21, 2018 Dawn Journal entry: Not all solar system bodies need such protection. The Moon, Mercury and Venus, for example, have not been of interest for ...
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7 votes
1 answer
196 views

Iron Oxidation Mechanism on Mars

My question relates more to the possibilities of life on Mars than to mining mineral deposits. QUESTION: Is it possible to have oxidized iron in the quantities that we see on Mars with only available ...
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