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1500 questions
35
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3 answers
Could any known, living organisms on Earth survive on Mars?
No life has been discovered outside of Earth (yet?), but do we know if anything that would be considered "living" on Earth could conquer Mars? (or maybe Venus?)
With the Mars One project on the way, I was wondering if it was possible to transplant…
Thibault
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Why do Jupiter’s moons have so much water?
Why do Jupiter’s moons have so much water by mass? Did all the bodies in the solar system start out with this much water and the planets closer to the Sun simply lost it to space?
Elhammo
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34
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Is oxygen really the most abundant element on the surface of the Moon?
I found this infographic that seems to say that oxygen is the most abundant element on the surface of the Moon. Is this really the case? If so, under what form is this oxygen?
usernumber
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34
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How could a hobbyist astronomer determine apparent magnitude of a star?
Apparent magnitude is a rather complex way to determine the brightness of a star. Quoting the introduction text from the linked to Wikipedia page:
The apparent magnitude (m) of a celestial body is a measure of its
brightness as seen by an…
TildalWave
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34
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4 answers
Are there observable changes in a star about to become supernova, minutes or hours before the explosion?
I am writing a science fiction novel, where a ship is stranded in a single star system (a red supergiant). One of the plot points is the star becoming supernova in several hours, so the characters have to fix their ship before that happens.
I have…
Alfonso de Terán
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34
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3 answers
Did I see another planet?
A couple days ago, I zoomed in with my 30x optical zoom camera, and after some exposure adjustments, a bright star in the night sky turned into this:
Are those other planets or other stars? Or is that a lens effect?
EDIT: The bright object in…
Bobdabiulder
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Is it odd that our Sun has so many planets?
The internet is abuzz with the new evidence of the possible ninth planet in our Solar System. With those nine objects, the asteroid belt, the Kuiper belt, and everything else in our Solar System - the number of objects which orbit our star is pretty…
user10467
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2 answers
How dense are Saturn's rings?
I assume that the A ring is the densest, but I might be wrong. Nevertheless, I failed to find any explicit information over the net about the minimum and maximum of densities for the different rings. As a less practical question: what would one see…
István Zachar
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Which planet, viewed from which other planet would appear the largest?
Inspired by this question, I'm curious: Which planet in our solar system, when viewed from which other planet, would appear the largest/brightest? You probably can't really see much of Uranus from Neptune as that question asked, but could you…
Darrel Hoffman
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Why don’t supergiants at least start to fuse nickel into even heavier elements before going supernova?
The last primary fusion process to take place in extremely massive stars is silicon burning, where the 28Si produced by oxygen burning is exothermically fused with alpha particle after alpha particle after alpha particle, all the way up to…
Vikki
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Is there any known moon of a moon?
As far as I understand, a moon is an object in permanent orbit around a planet, dwarf-planet, asteroid, etc. If there was another object permanently orbiting this moon, would that be a moon-moon?
Is there any natural object of such kind that we know…
Everyday Astronaut
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Did I see Pluto with my naked eye?
Early this morning going out on the balcony, I looked up on a star chart app to verify it was Jupiter I was seeing. Then I noticed the alignment of Mars, Saturn, and Pluto on the app.
Never being able to identify it before, I stared at where Pluto…
Jason P Sallinger
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Why is there a gap in this image of supernova discoveries?
I came across this gif showing supernova discoveries from the late 19th century to 2010. Here's the data in 2010:
Notice that there's a prominent region shaped like an inverted U in which there are few detection points, which I have crudely…
HDE 226868
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6 answers
Why is the Sun's density less than the inner planets?
The density of the Sun is $1410~\frac{\text{kg}}{\text{m}^{3}}$ and Mercury's is $5430~\frac{\text{kg}}{\text{m}^{3}}$, but shouldn't the Sun be denser? Because when the Solar System was forming, there was a big disk of debris, and depending on the…
user11830
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3 answers
Can our Sun become a black hole
Does every star become a black hole? Is there any probability that our sun can become a black hole? If yes then is it on its way to become a black hole? what is the current state of sun as per the black hole life cycle? What will be the effect on…
Strikers
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