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1500 questions
23
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3 answers
How do we know Milky Way is a 'barred' spiral galaxy?
In reference to the question, "How can we tell that the milky way is a spiral galaxy?"
The answers there clearly sum up the question asked. But Milky Way is not just a spiral galaxy. It is further classified as a barred spiral galaxy.
Question:…
Cheeku
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23
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2 answers
At what distance from Earth would our Sun be the same apparent magnitude as the next brightest star in the sky?
When I stand outside looking at the night sky, to my untrained eye, everything except the moon looks like a star. I know intellectually that some are planets circling our sun, and some are entire galaxies far away, but they all look basically the…
James Jenkins
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23
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9 answers
Is there any practical use for astronomy?
Although astronomy is very cool and the things we are learning are awesome, is there really any practical use to knowing the things we know about the universe?
Do other fields of science draw from the current tome of astronomical knowledge?
Scottie
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22
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7 answers
Do we know the exact spot where big bang took place?
If you rewind the universe back 14,7 billion years, all matter were in one spot, and then started expanding. Do we know where this is in reference to our own solar system? And is there anything there? Or are all matter in the universe just blown inn…
bogen
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22
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3 answers
Does the Earth have another moon?
I was just wondering what are the chances that there is a small object (say less than 1 km but more than few meters) that orbits the Earth but has remained undetected by us? Are we actually scanning the space around the Earth continuously for…
Sathish
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22
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2 answers
How long do planetary rings last?
I'm surprised that this question hasn't been asked before (here or on Physics), to the best of my knowledge. It's one that I might have asked when I was a bit younger, and one that I think other people will ask.
Anyway, it's clear that Saturn's…
HDE 226868
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22
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6 answers
How big would the asteroid belt planet be?
As I understand it, the asteroid belt exists because the gravitational force of Jupiter prevents the asteroids from accreting (is that a word?) into a planet.
If, however, Jupiter didn't exist and they did create a planet, how big would that planet…
Scottie
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22
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2 answers
Do all the objects in the universe exert force on all other objects?
Do all the objects in the universe exert force on all other objects? Like a type of gravity; also, how much does it decrease as it gets farther away?
Timtech
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22
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3 answers
Why wasn't the planet Uranus recognized by ancient cultures?
Mercury, Venus, Mars, Jupiter, and Saturn have been identified by ancient astronomers as they are visible with naked eye at night. The planet Uranus, despite being visible during very clear nights, wasn't recognized as such. Why?
anon
22
votes
5 answers
Why is Uranus called a "green planet"?
Uranus is called a green planet, although it appears blue in many of the photographs including those taken by spacecraft, like Voyager 2, Hubble, and JWST. NASA's Uranus page mentions it to be bluish-green.
One of the reasons mentioned is due to the…
Dhruv Nayak
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22
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2 answers
Do stars become more metal-rich as they evolve?
Since we determine the metallicity of a star ([Fe/H] or Z) from surface emission, does this change as it ages? For instance, can a young star with a measured [Fe/H] of -0.02 have a higher value when we hypothetically look at it 10 billion years from…
Jack R. Woods
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22
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5 answers
How do we know the expansion of the universe is not centered around our position?
It is my understanding that the red shift of galaxies in whatever direction we look shows the universe is expanding in every direction around us. That could be explained in two ways:
A (accepted): The universe is expanding in every point, like the…
armand
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22
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1 answer
How does JWST position itself to see and resolve an exact target?
Let's say the James Webb Space Telescope wants to move from observing the Andromeda galaxy millions of light years away to looking at the Trappist-1e planet some dozens of light years away, what actions are need to change targets and find and…
joeyfb
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2 answers
How many light seconds away is the JWST?
The processing for JWST's alignment is done on Earth. How long does it take for a signal from Earth to reach the JWST?
Zamicol
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22
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What causes the sharp if irregular boundary line in the "Cosmic Cliffs" JWST Carina image?
In this recently released JWST image:
we can see a relatively sharp, if irregular, boundary line between a region appearing mostly bluish and a region appearing mostly reddish or orange (understood that these are assigned, not natural colors). What…
Anthony X
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