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55
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4 answers
What would happen if an ice cube is left in space?
Recently I boarded a flight and noticed outside air temperature as -53°C at an altitude of 36860ft (11.23km). I don't know what causes such a freezing temperature in that altitude but was wondering higher altitudes (space) may have even freezing…
Praveen Kadambari
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Is there a star over my head?
Say I'm standing up straight, and I draw a straight line from my core through the top of my head (perpendicular to the ground). What is the probability that that line intersects with a star?
EDIT: I'm not trying to exclude any stars. This should…
user68873
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5 answers
Why is moon light not the same color as sunlight?
The light from the moon is light being reflected from the sun. The sun, in space, is white. But on Earth, when the light is filtered through an atmosphere, the light appears yellow. So then, why is moonlight white through the atmosphere?
Andrew Johnson
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53
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4 answers
Is there any role today that would justify building a large single dish radio telescope to replace Arecibo?
It seems that most of the modern radio astronomy instruments and observations that make the news are interferometers or phased array systems of one kind of another.
Is there any application left for which a single huge dish is better (or cheaper)…
Steve Linton
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53
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3 answers
Does the Milky Way orbit around anything?
We know most of the objects in the Universe have a spherical or elliptical shape. The object which has less mass and gravitational pull orbits around the nearest object with more mass and gravitational pull. For example:
Moon orbits around…
Zeeshan Ahmad Khalil
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52
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2 answers
Two species of dark matter?
At this point in time, evidence for the existence of dark matter has accumulated in many ways:
it affects galactic rotation curves
plays a major role in cosmology, and the evolution of structure in the universe
is predicted in copious amounts by…
Alexey Bobrick
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3 answers
How powerful a telescope would allow me to view the astronauts aboard ISS do a space-walk?
This arose from a comment posted against a question elsewhere on the stackexchange
How powerful a telescope/binoculars would allow me to view the astronauts aboard the ISS do a space-walk? Aperture? Magnification?
Everyone
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51
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7 answers
What is in the center of the universe?
If the universe has formed & originated by a Big Bang Explosion, then there must be empty space left in the center of the explosion site, as all the matter is travelling at tremendous speeds away from the center, and there must be more matter,…
Engineer Ishrat Hussain
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51
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4 answers
Why does it take so long to transmit an image from New Horizons to Earth?
I just got the news that the New Horizons space probe has passed by some remote planet on the edge of the solar system.
I was surprised that the guy from NASA says that it might take 24 months from us to get the photo of that planet.
The solar…
S. Kohn
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50
votes
6 answers
Is the Solar core hard?
This may seem like a weird question, but something got me thinking about it just recently.
The Sun's core is composed of mainly hydrogen and helium, and is present in the form of a extremely hot supercrushed plasma. The Sun's core is mind-bogglingly…
Alastor
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Is there a better explanation of this picture showing the very distant star "Earendel"?
"Close-up of the tiny region where Earendel happened to fall right on top of the narrow line where the magnification increases by (tens of) thousands of times. A cluster of many stars is seen slightly offset from the line, resulting in a much…
Roger Wood
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3 answers
Is it possible to achieve a stable "selenostationary" orbit around the Moon?
Is there a stable geostationary orbit around the Moon?
My feeling is, that the orbit would collide with Earth, because of the Moon's slow rotation.
Christian
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49
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11 answers
Why do Black Holes in the middle of galaxies not suck up the whole galaxy?
As stated in several sources, it's supposed that in every galaxy there is a black hole in the middle.
My question is, why do these black holes in the middle of galaxies not suck up all the surrounding matter in the galaxy?
OiRc
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48
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5 answers
Where does the Solar System end?
The Sun is roughly 4 light-years away from the closest star system, the Alpha Centauri system. The planets in our Solar System, however, aren't even close to that far away from the Sun. Where does our Solar System end? Is the edge considered to be…
HDE 226868
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48
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3 answers
If Earth is tilted, why is Polaris always above the same spot?
Why is Polaris, the North Star, always above (or near) the North Pole? If Earth is tilted, Polaris' path should be in winter 23 degrees away from its path in summer, or not?
Guest55
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