For questions about objects or phenomena outside Earth, generally on other planets.
Questions tagged [extra-terrestrial]
45 questions
7
votes
2 answers
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 that we have detected none, despite projects like…
pat_nafs
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7
votes
2 answers
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 approaching before it did (assuming its going at…
hisairnessag3
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3
votes
0 answers
How could we observe Dyson spheres?
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 the universe is very different from the observed…
Guillaume CR
- 131
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3
votes
5 answers
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 pretty clear that anyone thinking there could be was…
Mark
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3
votes
3 answers
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 carries the sign of intelligent beings. The Wow…
Kushal Bhuyan
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vote
3 answers
Do extraterrestrial landscapes or planets count as nature?
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 question in Astronomy, because I would like to know what…
P.R.
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0
votes
2 answers
How to prove to my friend that aliens have never visited earth
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 conspiracy theories.
My question is: is there any solid…
Matthew
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