Questions tagged [extra-terrestrial]

For questions about objects or phenomena outside Earth, generally on other planets.

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1 answer
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How to know if an exoplanet is terrestrial?

NASA exoplanet archive, open exoplanet catalog and exoplanet.eu are some of the most famous catalog of exoplanet discovered by all techniques. However, all of these catalogs are missing the ...
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1 vote
1 answer
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Calculating "maximum" distance to an alien civilization

I'm planning on making a video related to Fermi Paradox, and I've used Omni Calculator's Alien Civilization calculator as a reference. I noticed they have a field that calculates the "maximum&...
-2 votes
1 answer
119 views

I believe I saw a UFO, what else could it be? [closed]

When looking at the night sky some time ago I noticed a white dot. The amount of light coming from or being bounced on that object made it the same size of a average star. But differently from a star, ...
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3 votes
1 answer
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Would we be able to discover a Voyager-style probe from a stellar civilization?

If some stellar civilization sent a space probe (say something similar to our Voyager probes in shape/size/materials and communication capability) and it ended up in a regular orbit around the Earth ...
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1 vote
2 answers
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Detection of the existence of any extraterrestrial life

We can't see things in "real-time" but we see the "past versions" of the things because it takes time for the light from that object to travel to us. So looking far away means ...
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3 votes
0 answers
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Could the timing of the oxygen spike on Mars be used to determine if photosynthesis is responsible?

I am wondering if the timing of the oxygen spike on Mars could be used to determine if photosynthesis is the source (which would be another indication of life on Mars), or if it is purely heat related?...
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4 votes
0 answers
83 views

Has SETI searched the solar system for life?

I know SETI is searching the stars for radio signals emitted by advanced alien civilizations, but has SETI searched inside our solar system - particularly moons, planets, and Lagrange points? I would ...
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7 votes
6 answers
2k views

Are there other life giving sources of energy in space apart from stars (like nebulae, radiation, etc.)?

Are there other life giving sources of energy in space apart from stars? (like nebulae, radiation, etc.)? Or are all possible life giving potential sources some variation of a star?
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5 votes
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Did Aliens make Oumuamua?

Dr. Avi Loeb, the distinguished astrophysicist and chair of Harvard's Astronomy Program, just published a book called Extraterrestrial: The First Sign of Intelligent Life Beyond Earth. In the book, Dr....
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2 votes
2 answers
144 views

What does the amino acid found in the atmosphere of Venus mean?

An amino acid is a part of DNA, but it has only been found on Earth. Is the amino acid maybe from one of the space vehicles that has orbited, scanned, or surveyed Venus? How can a part of DNA survive ...
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2 votes
2 answers
179 views

How to communicate Fine Structure Constant to aliens? [closed]

Sorry if this is not the right question for this channel, I just need to know and there is no good place to ask. It is said the Fine Structure Constant α is one of the most fundamental constants in ...
7 votes
2 answers
222 views

Would we detect a spacecraft before it landed on Earth?

We have satellites and telescopes looking outward and inward to the earth. Would any of these detect an extraterrestrial spacecraft before it landed, or in other words, would we know a spacecraft was ...
2 votes
1 answer
172 views

Would it have been possible to send a radio signal towards ʻOumuamua?

As we could not get any radio signals from asteroid ʻOumuamua, couldn't we have sent a powerful radio signal to it and then check if we can get any radio signal in response? This way we can at least ...
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1 answer
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Kardashev scale [closed]

Why is becoming a type 3 from a type 2 civilization the hardest? I have watched many videos on the topic and still can't figure out why? Also is there a difference in technology between a type 4 and a ...
1 vote
2 answers
75 views

Is there a way to know if there are/are not solar-system-like systems of objects without a star?

There's an extremely high amount of variation in All of Known Existence. We do see many many stars, with an extensive amount of evidence for planets orbiting around stars. However, is there are way to ...
2 votes
2 answers
390 views

What planets or exoplanets orbit the Sun’s elder twin HIP 102152?

Has anyone done any research on the planets that orbit the HIP102152? Since that star is similar to ours and older, I postulate that it’s likely those planets are most worthwhile searching for ...
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0 votes
1 answer
48 views

Is it only possible to look at solar systems with stars at least as old as ours to be able to find intelligent life?

Assuming the speed it takes to development intelligent life is the same in all solar systems, would we need to look at exoplanets with stars as old or older than ours to find intelligent life? A young ...
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1 vote
2 answers
165 views

How to listen to our world from 10,000 light years away?

If you were 10,000 light years away from all radio stations and digital broadcasts from our world, what equipment would be necessary to detect and capture some information like a voice or a photo? If ...
0 votes
2 answers
329 views

How to prove to my friend that aliens have never visited earth [closed]

I come from a physics background where I don't believe something unless the evidence is shown to me, however I have a friend who believes Aliens have visited earth , which he believes based on ...
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6 votes
1 answer
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How bright would it be on the "face" of Titan

If you were planing a maned mission to Titan and wanted to find a landing site that would get the most visible light for the longest amount of time, your first logical choice would be the dark side of ...
1 vote
1 answer
348 views

What programming languages does SETI (Search for ExtraTerrestrial Intelligences) most commonly use for signal processing?

Please give preference to those most widely used in the field, if possible.
3 votes
5 answers
667 views

Why would discovering life on another planet be important/matter to us?

I had a funny thought, and would like to pose it to you: When I was a kid, reading any kind of astronomy or similar books would all say that there was no other life in the universe, and made it ...
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3 votes
3 answers
460 views

Could the KIC 8462852 (Alien megastructure star) be explained by orbiting gas clouds?

I was wondering about the light dimming of the 'alien megastructure' star. From what I understand, for it to be a planetary body, it would have to be some 20 times the size of Jupiter. Is it possible ...
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9 votes
5 answers
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Is it possible for a virus to come from a meteorite?

So I am not a true scientist and I was just wondering if an extraterrestrial rock from space can have some dangerous unidentified virus or bacteria that can be deadly and wipe out the Earth if it not ...
3 votes
1 answer
109 views

Can a tidally locked planet have their own habitable zone?

As we know, if a planet is near a star and is tidally locked, then at near side it is very hot and at far side it is very cold. But between 2 sides there should be a gradient of temperature change and ...
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7 votes
1 answer
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The contents of potential "message" in the Wow! signal lost?

The Wow! signal is still an enigma. I understand the incredibly high signal strength it entails. This during some time-period because the sweep of the alignment (or rather the receiving station). ...
3 votes
3 answers
321 views

Why can't this be the simple (and obvious) explanation for the dimming of KIC 8462852?

Couldn't it be just a relatively large object, anywhere in the interstellar space between the star and Earth? I mean, look out the window at a far away car or a tree, then stretch out your hand and ...
3 votes
3 answers
493 views

How astronomers distinguishes between natural and artificial signals coming from outer space?

How astronomers really distinguishes between the natural and artificial signals? From time to time astronomers detects many signals from outer space and SETI is always trying to find signals that ...
2 votes
1 answer
101 views

How will the Breakthrough Initiatives affect other astronomy observations?

BACKGROUND The Breakthrough Initiatives is in the news because of a $100 million private donation for a SETI project. It doesn't seem to be for building any new observatory (but maybe for buying ...
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8 votes
3 answers
655 views

What astronomical observations would give conclusive proof of alien life?

There are several ways we are coming closer to answering the question "is there life elsewhere in the universe?". One is by first understanding very well the origin life on our own planet. Another is ...
3 votes
2 answers
756 views

Why do scientists think life requires water? [duplicate]

As far as I know, scientists seeking extraterrestial life are simply looking for plantets containing water in liquid state. To be honest, I find this weird. It is true that life - in the form we know ...
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11 votes
0 answers
288 views

Method to determine the amount of reflected starlight necessary for an exoplanet to be visible from a given distance/angle? [closed]

What is the method to determine the amount of reflected starlight necessary for an exoplanet to be visible from a given distance/angle? (Not from occlusion but actually visible on its own.) Further, ...
-2 votes
2 answers
252 views

Lack of contact with Aliens [closed]

Lack of contact could be due to one of three things ? Interstellar space travel is just not possible . There is no other Alien Life in the Galaxy . There exists Alien life and interstellar space ...
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8 votes
3 answers
406 views

How should one rationally deal with the issue of space travelling alien civilizations?

What kind of reasoning is appropriate to understand the as of today unanswered question of whether there are (other) interstellar space travelling civilizations in the Milky Way? We have already sent ...
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-2 votes
1 answer
108 views

As of now did a radio telescope ever recorded something else than the silence of space? [closed]

When a radio telescope listen to the Universe; a constant sound is recorded. Is it the noise "of the mic" : interferences? Scientists says that when they will notice variations on this basic constant ...
1 vote
3 answers
187 views

Do extraterrestrial landscapes or planets count as nature? [closed]

If I am talking about the surface of Mars, is this still nature, comparable to uninhabited places on earth, or does nature exclusively describe not man-made things on earth. I am asking this ...
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2 votes
0 answers
50 views

How could we observe Dyson spheres? [duplicate]

Hypothetically, if Dyson spheres were already present, how could we observe them? My layman understanding of the reason we believe dark matter exists is that our current estimates of the total mass of ...
7 votes
2 answers
444 views

Can we conclude with reasonable certainty that there is/are no Type 3 Civilizations in our galaxy?

As per the Kardashev Scale, type-3 civilizations are defined as "civilization(s) in possession of energy on the scale of its own galaxy, with energy consumption at ~ 4 x 10^44 erg/sec". Considering ...
1 vote
0 answers
57 views

Max. speed that a space probe can communite with the Earth? [closed]

Question: Which is the average or maximum speed of a telematically sent message that a space probe can send? Is as simple as radio waves travel at the speed of light in a vacuum? Context: I have been ...
10 votes
1 answer
424 views

If the Wow! signal was not directed at us, then where?

We probably all know the Wow!-Signal, happened on August 15, 1977. Assume that it wasn't meant for us. What was it pointing at then? The signal at that time came from RA= 19h25m31s ± 10s or 19h28m22s ...
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5 votes
2 answers
205 views

Is the discovery of Alien or Extra Terrestrial Life a function of the science of Astronomy?

Is the discovery of Alien or Extra Terrestrial Life a function of the science of Astronomy? When i read astronomy articles on the search for new Planets or discussions on Mars a lot of the topic is on ...
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16 votes
4 answers
878 views

How would we detect an Earth doppelganger planet?

With our current technology, or technology available in the near future (up to 2025), how would we detect a planet exactly like our own, and how close would it have to be to be detectable? Which ...
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12 votes
1 answer
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Is it possible to observe if there is traces of life on an exoplanet?

We can observe exoplanets, but is it possible with today's technology to observe if there is life as we know it on an exoplanet? What do you look for when doing this kind of observation?
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15 votes
1 answer
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What are the current observational limits on the existence of Dyson spheres/swarms/rings?

A Dyson sphere/swarm/ring is a hypothetical structure an extra-terrestrial entity would construct to collect a large fraction of its host star's light, and would likely generate a fairly strong ...
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