Unanswered Questions
180 questions with no upvoted or accepted answers
1
vote
0
answers
47
views
Could mars become volcanically active if it is pulled into a highly eccentric orbit
Let's suppose that a passing planetary mass object pulls mars into an even more eliptical solar orbit, not accounting for other planets, to what degree of eccentricity would be needed for, let's say ...
- 550
1
vote
0
answers
16
views
cross-matched SDSS-WISE catalog
Please where can I find cross-matched SDSS and WISE dataset for a machine learning project?
(Galaxy-star-qso classification task)
2
votes
0
answers
84
views
Would we know if the universe was rotating?
I was wondering what we would observe if the universe had a small rotation. My conclusion was that galaxies on the equatorial plane of the universe would be slightly more redshifted than galaxies than ...
- 373
3
votes
0
answers
41
views
Why MIT's Benjamin Rackham says "nearby ultracool dwarf SPECULOOS-3" would look "purplish-red, spotted, and flaring" from an airless orbiting planet?
May 15, 2024 MIT News article Newly discovered Earth-sized planet may lack an atmosphere includes the following:
“We can say from our spectra and other observations that the star has a temperature of ...
- 30.3k
0
votes
0
answers
35
views
Project Analog Hypothetical Planet
For my story Project Analog, I was wondering if a hypothetical planet (Let's call it Suria). It has the same size and conditions as Earth with the same axis, tilt, and rotation, as well as one moon. ...
CommunityBot
- 1
1
vote
0
answers
87
views
Have measurements been conducted on the position of the galactic center of mass and the orbit of the presumed black hole at the center?
Related questions have been raised before
Is our central black hole actually at the CG of the galaxy?
Orbiting supermassive black hole or galactic center of mass?
, where explanations have been given ...
- 301
2
votes
0
answers
102
views
What would the Big Crunch theoretically look/feel like?
In the Big Crunch theory, the expansion of the universe reverses, resulting in all matter contracting into a single point. Imagine you are alive at the time of this event. What would the sky look like?...
- 29
2
votes
0
answers
34
views
Local anisotropies in the expansion of the universe and tidal forces...?
In the context of the large-scale structure of the universe, there can be local anisotropies (https://www.aanda.org/articles/aa/full_html/2021/05/aa40296-21/aa40296-21.html).
I understand from this ...
- 1,017
0
votes
0
answers
25
views
Deriving Faber-Jackson Relation from Milgrom's Law
I am reading Famaey & McGaugh 2011, a review paper on Modified Newtonian Dynamics. My question concerns bullet 3 in Sec 5.2, where the authors try to explain how Faber-Jackson Relation can be ...
- 779
3
votes
0
answers
107
views
Kepler to Cartesian and Cartesian to Kepler inaccuracies
I am programming a computer simulation set in a star system. I've used Rene Schwarz's wonderfully concise memorandi explaining converting from Kepler orbital elements into cartesian coordinates and ...
- 51
1
vote
0
answers
121
views
Determining Time Based on Arc Seconds
So our arc day starts at 20°41'32 which is midnight (0:00) and ends 24 hours later at 21°42'42. According to my calculations it traveled 0 degrees, 59 minutes, and 30 seconds or 3570 arc seconds in 24 ...
- 2,349
1
vote
0
answers
34
views
On the relationship between semi-major axis and the Longitude of the Ascending Node
I noticed something looking at the Longitude of the Ascending node of various planets.
Mercury: 48.331°
Venus: 76.680°
Mars: 49.57854°
Jupiter 100.464°
Saturn: 113.665°
Uranus: 74.006°
Neptune: 131....
- 376
0
votes
0
answers
66
views
Flux from the Sun on the Earth using the Stefan-Boltzmann law
What is wrong with this computation, plase? I am getting the result of 4291.65 W m^{-2} instead of 1361 W m^{-2}. Thank you very much
...
- 555
0
votes
0
answers
36
views
Should you include aberration effects during low Earth orbit observations?
I am working on calibration of some observations of low Earth orbit satellites and I am wondering should I include aberration effects? My logic is that diurnal aberration would have neglegible ...
- 309
2
votes
0
answers
80
views
Understanding laplace plane (satellite) orbits
Working on a little project (with vex+python in houdini) to calculate the planet and satellite positions using the keplerian formulae and a database of orbital elements and progressions. Primarily ...
- 5,932