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Unanswered Questions

1,828 questions with no upvoted or accepted answers
16 votes
0 answers
256 views

What 1° x 1° region is the optically darkest patch in the sky?

What 1° x 1° region of the night sky has the lowest flux of light? (considering the typical visual/luminance filter range, approximations using other filters/bands are acceptable, but should be in the ...
15 votes
0 answers
361 views

What is the limiting abundances of elements at the end of the stelliferous era?

Is there any reputable published source on expected elemental abundances at the end of the era of stellar fusion? I am here interested in the contents of galaxies; much of intergalactic gas will be ...
12 votes
0 answers
220 views

Estimating the tangential and cross component of the galaxy's shear using Gnomonic projection

I would like to know how I can estimate the tangential and cross component of the galaxy's shear using Gnomonic projection of the right ascension and declination the galaxies relate to the center of ...
10 votes
0 answers
215 views

How well conserved is etendue in extreme gravitational lensing scenarios?

This excellent answer to Could dark matter exist in the Universe in the form of sufficiently dense objects? includes the following image and description: Light from the background galaxy circles a ...
10 votes
0 answers
140 views

Spatial wind speed distribution on Mars using dune shapes?

As a fan of exometeorology (the study of atmospheres of other planets), I scanned through a whitepaper Measuring Mars Atmospheric Winds from Orbit which says Measurements of Mars atmospheric winds ...
10 votes
0 answers
214 views

Water vapour in space

This question is inspired by, but different from, What happens if an ice cube is left in space? Mark's accepted answer says "…if you stick your ice cube out in the Oort Cloud, it'll grow: the mean ...
10 votes
0 answers
509 views

What are the analysis steps in taking raw data from Kepler to a planetary system determination

I wish to get a concise list of the analysis steps required to take raw light data from a Kepler data set of a star through the steps needed to get to an analytical determination of the existence of a ...
9 votes
0 answers
93 views

The presence of maars on the Moon

Wondering if there's any evidence to date of the existence of maar craters on the Moon? If not, how probable is it that the moon ever supported the necessary conditions for maars to form? A report ...
8 votes
0 answers
238 views

Is there a standard deconvolution procedure to remove JWST's diffraction pattern yet? If so, would Arp 220 be a good candidate on which to try it?

Source: Webb captures the spectacular galactic merger Arp 220 Shining like a brilliant beacon amidst a sea of galaxies, Arp 220 lights up the night sky in this view from the NASA/ESA/CSA James Webb ...
8 votes
0 answers
632 views

Black spot in Mars' sky

There is a sequence of three raw images by Mars Curiosity Rover taken during Sol 3066 (22/03/2022, roughly) that show the same features of Mars' landscape and sky. They are separated by 38 seconds' ...
8 votes
0 answers
125 views

How long would it take to first detect a new object in the night sky given its apparent magnitude?

If an object as bright as the star Polaris (Apparent Magnitude +1.8) showed up in the night sky, it would be detected almost instantly by stargazers. If an object as bright as Pluto (Apparent ...
8 votes
1 answer
623 views

Why do the Sun and gas planets rotate faster at equator than at poles?

From this site, it states that: The Sun spins faster at its equator than at its poles. I have also read somewhere that the gas giants (gaseous planets like Jupiter, Saturn, Uranus, and Neptune) also ...
8 votes
1 answer
187 views

What is the history of the average pressure, density, and temperature of the matter in the universe over time?

This question is inspired by this more specific question where Cerelic wanted to know if conditions were suitable for liquid water to exist during an epoch when the characteristic temperature of the ...
7 votes
0 answers
157 views

Can terrestrial infrared telescopes see through clouds or haze, sometimes at least?

My answer to Could UV-A imaging sensor reasonably see a total eclipse in progress through clouds? suggests that while clouds blocking visible light observation of the (partially) eclipsed solar disk ...
7 votes
0 answers
96 views

Is it possible that the inner Solar System formed in a different configuration to today?

I have recently been reading about the formation and early evolution of the Solar System, and how the outer Solar System very likely did not form in its current configuration and has almost certainly ...

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