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1500 questions
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Are there any old/ancient star maps that we can compare to today’s and see drastic differences?
Stars move through the sky very slowly, which is not noticeable in a human lifespan. I’m aware of proper motion of Barnard's Star and things of the sort but I’d like to obtain a noticeable record of changes from 1000s of years ago.
There are old…
Beans
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Can you see something active in the sky apart from satellites? Can there be amateur time-domain astronomy?
What I mean is an event unfolding that is viewable by naked eye or telescopes, and doesn't take comparing days of footage to see moving pixels. Apart from satellites, is there something that moves or happens so quickly that humans could sense it…
Firsh - justifiedgrid.com
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21
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Why is Starlink polluting the night sky a big concern if we have space telescopes?
There's a lot of concern in the Astronomy community over the deployment of Starlink satellites. For a good discussion, see the related question How will Starlink affect observational astronomy?
But why is there so much concern over this problem,…
JonathanReez
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How hard is it to find the Sun's "sisters?"
As @ProfRob stated in his excellent answer regarding the ejection of the Solar System's fifth gas giant,
It is for similar reasons that, even though the Sun was probably born in a cluster of $\sim 10^4$ stars, none of those siblings have been…
WarpPrime
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Why would it be very light out at 3 AM?
My brother noticed something very odd last night: it was amazingly light out when he stepped outside for a smoke even though it was between 3 AM and 3:30 AM EDST and we are near Toronto Ontario Canada, not in the Far North. He is outside at that…
Henry
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21
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Do the axes of rotation of most stars in the Milky Way align reasonably closely with the axis of galactic rotation?
The axis of rotation of the Solar System makes a large angle of about 60 degrees relative to the axis of rotation of the Milky Way. That seems unusual - for example, most of the bodies within the Solar Sytem are better behaved than that.
Do most…
Roger Wood
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21
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Why are there no gamma-ray bursts detected in our galaxy?
I found from Wikipedia and other sites that there are no GRBs detected in the Milky Way. Can someone give a feasible reason for that? Why are there no GRBs detected in the Milky Way galaxy?
sd_Dhara.45
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Was this an astronomical phenomenon observed in 1689?
In a Swedish church record from 1689 a phenomenon in the sky is described. With my very limited understanding it could be a meteorological or an astronomical phenomenon, so here I ask if it could have have an astronomical phenomenon, and what it was…
pst
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Was the Sun's gravitational lensing observed in other solar eclipses than the one in 1919?
In 1919 the gravitational lensing by the Sun has been observed during a total solar eclipse. Did someone observe the lensing in any other total eclipses? Last year there was a total eclipse in Chile and there were many scientists observing it. Did…
user30007
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Have we ever observed a large meteor hit the Moon?
Since the moon has no atmosphere, its surface has many more meteorite impacts than Earth's does.
Image source
Have we ever observed a meteor strike the surface of the Moon?
user19
21
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3 answers
How often do Type Ia supernovae occur?
Type Ia supernova are used as standard candles. But they also are transient events. This means that to determine the distance of a galaxy using supernovae, you have to wait for one to occur. How often do type Ia supernovae typically occur in a…
usernumber
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21
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How will Starlink affect observational astronomy?
I have recently found that people around the world have been posting observations of a line of moving objects in the sky which is very likely to be a part of Starlink satellite constellation, such that there is even a meta question here about them:…
Leo Liu
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Can we detect pulsars that aren't "pointed" towards us?
A pulsar is a highly magnetized rotating neutron star that emits beams of radiation through its magnetic poles, in the direction of the Earth. This makes it seem to pulse, as seen from Earth. There likely are similar objects that pulse as seen from…
usernumber
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21
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4 answers
Would an object shot from earth fall into the sun?
Would an object shot from earth fall into the sun?
If an object is shot at 107,000 km/h via rocket or otherwise, in the opposite direction to our orbit about the sun, it will be traveling at 0 km/h relative to the sun. The moon is not close enough…
Taku
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Does this smartphone photo show Mars just below the Sun?
I live in Essex, England (51.7678° N, 0.0878° E). On 25 July 2019 (hottest day ever in the UK, btw), 06:43 BST, I took this smartphone photo of the Sun. Is that white dot just below and left of the Sun the planet Mars? I've checked with my SkySafari…
Peter
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