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1500 questions
12
votes
3 answers
If the Earth had another moon would it be better protected from asteroids?
Would the moons get struck by asteroids instead of the Earth or would the moons attract more asteroids and make it more likely the planet gets hit?
user52681
12
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2 answers
Does the Oort cloud have any large holes in it and if not does this mean nothing large has entered the solar system for a long time?
Would holes in the Oort cloud be a record of what has passed through it?
user52681
12
votes
1 answer
Are there plans to detect life on Earth from the outer solar system?
This has been kicking around in my head for a while. We've been detecting planets for decades by observing regular dips in starlight from many light years away as a planet transits its host star. I've often wondered if we considered staring at our…
Greg Burghardt
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How do we know the Moon was much closer than it is now?
We know that right now, by measurement, the Moon is moving further away from the Earth. So I've heard the conclusion that the Moon was much closer to the earth in the past.
How do we know that part? Is there empirical evidence of that or is it an…
scm
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12
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1 answer
Would the Earth and Moon still have tides after the Earth tidally locks to the Moon?
Ignore the Sun's expansion.
From my understanding, tidal locking happens from torque as a result of tidal bulges being offset from the line between the two planets. So when the Earth and Moon tidally lock, will there still be tides since they…
user138890
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12
votes
2 answers
What positional accuracy (ie, arc seconds) is necessary to view Saturn, Uranus, beyond?
My son and I are building an azimuth/elevation controller to point the telescope at planets using servos and a microcontroller. Assuming that our device is calibrated (that is, we tell our device to point at a specific RA/Dec and points in the right…
KJ7LNW
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12
votes
2 answers
How has the resolution of astronomical spectrographs improved over time?
Is there something like a Moore's law for spectral resolution? Maybe a chart from which one could extrapolate?
2080
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12
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How are the masses of solitary stars weighed?
How are the masses of solitary stars weighed?
With binary stars you can measure the pull each applies to the other, but that isn't an option with solitary stars.
blademan9999
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What is the mathematical condition for the statement: "gravitationally bound"?
When talking about galaxy clusters there is the frequently used phrase "gravitationally bound", f.e. we are gravitationally bound to our neighbor galaxy the Andromeda Galaxy. But how is this statement mathematically defined since gravitation has an…
trynerror
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12
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How much light would be received on a rogue planet close to the galactic center?
I was wondering if anyone has ever attempted to estimate how much solar radiation would be received on a rogue planet floating in between star systems close to the center of the milky way, compared to say how much is received on Earth from our sun.
Schquestoning
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How can I identify if my stone is meteorite?
I found 2 stones in my village. One of them is magnet attractive, well-shaped, no bubbles etc. I just want to clarify if it is meteorite, but in my country (Azerbaijan) there's not such a lab. Is it possible to send a video of this stone to some…
Óðinn Wisdom
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12
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1 answer
What was the large green yellow thing streaking across the sky?
I just saw a large green yellow streak cross the sky. It looked like a shooting star but way bigger. It seemed closer too. I’m in North Garden VA. It was heading north. It lasted for 5-7 seconds.
Diane
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12
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If I can't unscramble an egg, how do Astronomers unscramble views gravitationally lensed by complex mass distributions?
Quanta Magazine's Two Weeks In, the Webb Space Telescope Is Reshaping Astronomy highlights two submissions to arXiv soon after the first images were released: "Three days later, just minutes before the daily deadline on arxiv.org..." It certainly…
uhoh
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12
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Early Milky Way depictions after Herschel?
We are all familiar with the 1785 drawing of the Galaxy by William Herschel, often quoted as the "First drawing of the Milky Way"
Are there any other such historical drawings after this one? I mean, something between this date and ~1950?
Gabriel
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12
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Why haven’t we observed supernova events of the hypothetical population III stars?
It’s said that we haven’t observed any population III stars because these stars are too far away, which makes them too dim to observe via small diameter space telescopes. Their light is also extremely redshifted (within the infrared spectrum) and…
哲煜黄
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