Questions tagged [planet]

Questions on astronomical objects orbiting a star massive enough to be rounded, not massive enough to cause fusion, and which have cleared its orbit of planetesimals.

Filter by
Sorted by
Tagged with
1 vote
0 answers
37 views

Timelapse Video Of Motion of Mars?

I'm trying to find a timelapse video of mars moving against a fixed background of stars - could someone point me in the right direction? Thank you!
Stephen W.'s user avatar
3 votes
0 answers
153 views

How can Jupiter rotate faster at the equator than at the poles (in degrees per second)?

Jupiter rotates slightly faster at the equator. If inertia is conserved as average angular momentum, what is the physical mechanism that creates a gas which is ~1% faster angular momentum at the ...
Wolfgang Weber's user avatar
2 votes
0 answers
72 views

How can I calculate current position of planet in sky

How can I calculate current position of planet in sky from earth's point of view. I want to calculate based on given DATETIME and Location For example, if I see current position of planets on "23 ...
Mangesh Sathe's user avatar
5 votes
0 answers
85 views

Is there a noob-friendly website/app for tracking a astronomical body's apparent movement over time?

As I walk home along my road most nights in winter, I see the Moon and one-or-more planets. Unsurprisingly, over the last 2 months, if it's been the same planet and it (and the Moon) has been in ...
Brondahl's user avatar
  • 348
1 vote
0 answers
116 views

The rocky planet sizes between the Sun and Jupiter are small, big, bigger, small, and unfinished. Is there a reason?

The rocky planet sizes between the Sun and Jupiter are small (Mercury), big (Venus), bigger (Earth), small (Mars), and unfinished (the asteroid belt). Is this just random chance or is there a theory ...
phil1008's user avatar
  • 119
1 vote
1 answer
72 views

calculating apogee and perigee for moon and sun

The perigee does not necessarily happen when we have a full moon, using swevents we can easily determine the moon phases. Now can we use python to determine when ...
dimitri33's user avatar
  • 127
1 vote
0 answers
33 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....
DanceroftheStars's user avatar
1 vote
0 answers
78 views

What would happen if a low-mass primordial black hole was captured by a brown dwarf or planet mass object?

Prompted by a recent PBS SpaceTime video The video in question discusses what would happen if a low-mass (asteroid-mass) primordial black hole were captured in the core of a Sun-like star (a so-called ...
asgallant's user avatar
  • 461
1 vote
1 answer
89 views

Planetary Conjunctions

Was there a conjunction between Jupiter and Mercury in 2 BC seen from Persian Gulf? Was there a conjunction between Jupiter and Venus in 4 BC seen from the Persian Gulf? If so, what day, time, and ...
Maddog's user avatar
  • 11
1 vote
1 answer
153 views

Planets Named After Roman Gods, Except Earth

I’ve looked this up, but not necessarily sure the internet has the right answer. Why are the planets in our solar system named after Roman gods, except Earth, and why is only one of the nine planets ...
allthings27's user avatar
15 votes
2 answers
3k views

Why is it impossible to infer the surface temperature of Venus by spectroscopy observation from earth?

It is well known that the surface temperature of the sun is determined by fitting the sunlight with the black-body spectrum. Why is this inappropriate for Venus? I have the question because of the ...
S. Kohn's user avatar
  • 879
3 votes
3 answers
1k views

Celestial "orbits"

I heard that we're losing our moon, its slipping away from us in such tiny imperceptible steps that we don't notice any significant change even over kiloyears. The same must apply to planets, inching ...
Agent Smith's user avatar
8 votes
1 answer
3k views

Why did the dust between the planets disappear during the birth of the solar system?

I'm catching up on my childhood mistakes. One of them was the "nuclear flash", the enormous explosion when the sun ignited. Apparently, this did not happen as the ignition of the sun was a ...
Dominique's user avatar
  • 445
7 votes
1 answer
561 views

Is there a formula for calculating surface temperature of a rocky world based on atmosphere and solar input?

For example, a thicker atmosphere would probably lead to less temperature variation . . . I assume that much is obvious. And, greenhouse gases trap heat. But when posed with a question like "...
userLTK's user avatar
  • 23.9k
10 votes
1 answer
140 views

How is a Planet's Moment of Inertia Measured Remotely?

In the July 2023 issue of Sky & Telescope there is an article titled Sights Set on Uranus. In that article the following statement is made: Since the 1930's we've suspected that Uranus and ...
GrapefruitIsAwesome's user avatar
0 votes
1 answer
92 views

For what period of time can planets be viewed from the North Pole as just being there?

I would like details on observations (since North Pole is not possible, approximately around the North Pole) which tell us for how long are planets visible from the North Pole? I understand that ...
Adiyarkku's user avatar
  • 201
8 votes
1 answer
4k views

How much of the surface of other planets is lit by the sun?

Since the sun is much larger than the earth, it should ideally light up a considerable portion of the earth rather than only half of it. However the sun lighting only half of the earth can be ...
Adiyarkku's user avatar
  • 201
1 vote
2 answers
120 views

Potentials of space mining [closed]

I'm conducting research on the potential benefits of space mining on asteroids, like 16 Psyche. I'm hoping that those who are more knowledgeable than me can help with the following questions: Are ...
Just want to know more's user avatar
5 votes
1 answer
609 views

Difference in results between JPL Horizons and cspice (rust-spice)

I am calculating the apparent planetary position of planets using the cspice library (I am specifically using rust-spice, which is a wrapper of cspice in Rust). when I calculate the same values in the ...
AviD1511's user avatar
  • 151
14 votes
5 answers
4k views

Why can't a half-illuminated planet support life at all?

Here is my own translation of the Polish version of the Drake equation article in Wikipedia: (...) They must provide the right amount of heat. The smaller the star, the less heat it gives off and the ...
trejder's user avatar
  • 251
1 vote
1 answer
53 views

Is the magnetic permeability (mu_0) necessary in the expression for planetary magnetic field?

To numerically analyse the Lorentz effect due to the magnetic field, say, radial component on a charge particles which of the expression would be correct, $\{ B_r = \frac{2R}{r^3} g_1^0 \cos(\theta) \}...
Lunthang Peter's user avatar
0 votes
1 answer
204 views

Why don't scientists believe Earth's surface water came up from the mantle?

I read, periodically, that there is more water trapped in the mantle than there is in the oceans - possibly a lot more. If so, why don't any geologists believe that Earth's surface and near-surface ...
Kurt Hikes's user avatar
  • 4,927
2 votes
0 answers
99 views

True node (NN) calculation .. off by 10 seconds

...
dimitri33's user avatar
  • 127
3 votes
1 answer
191 views

When did Venus get as hot as it is now?

My previous question turned out to not ask the question I thought I was asking. I have read that Venus began its heating-up around 700-750 million years ago. When did the Venusian atmosphere get ...
Michael Bonnet's user avatar
4 votes
1 answer
98 views

When did Venus reach approximate radiation equilibrium?

I have read that Venus is roughly at radiation equilibrium - that is, heat out is approximately equal to heat in. I have also read that Venus began its heating-up around 700-750 million years ago. My ...
Michael Bonnet's user avatar
1 vote
1 answer
101 views

Does the Sun have different unique orbits around barycenters?

After reading this question and seeing its image I thought about this question I'm going to publish. Does the Sun have different unique orbits around the barycenter for its multiple planets? If yes, ...
Snack Exchange's user avatar
7 votes
2 answers
279 views

How common for all 7 planets to be above the horizon?

I was planning for the Solar Eclipse in April 8th 2024 and noticed that at the time of totality at my location in Western NY, all 7 planets will be above the horizon. Earlier in the day it's all of ...
scm's user avatar
  • 301
-5 votes
2 answers
148 views

Is Proxima Centauri a Planet?

Proxima Centauri meets all the requirements for Planet status, although it is a star, can an object be a star and a planet at the same time? normally, the answer should be no, but this is the problem ...
Benjamin1945 's user avatar
5 votes
1 answer
194 views

Can rings last around planets indefinitely?

Apparently, Saturn is losing its rings (https://weather.com/en-IN/india/space/news/2023-05-04-saturn-is-losing-its-rings-webb-may-tell-us-how-long-they-have-left) However, is there any way or ...
vengaq's user avatar
  • 827
-1 votes
2 answers
328 views

What is the most common method that a scientist uses to study the cyclones in the universe?

Cyclones have been observed throughout the universe as seen in the following examples: Jupiter's Great Red Spot is perhaps the most well-known cyclone in our solar system. It is a giant storm that ...
Arunabh Bhattacharya's user avatar
-2 votes
1 answer
178 views

Planets revolving counter clockwise around the Sun

Planets revolving around the Sun Hypothetical case: What could have been or no impact if the planets viz Earth, Jupiter, Saturn, Mercury, Venus, Mars, Pluto, Uranus, Neptune in different orbits ...
Prashant Akerkar's user avatar
3 votes
1 answer
162 views

How is a planet (or star's) radius defined?

The radius of a rocky planet like earth is fairly easy to define based on the fact that the ocean's surface is fairly smooth, and it is a natural point to measure. Other planets like Mars, the surface ...
Fraser Orr's user avatar
1 vote
3 answers
145 views

Are there such circumbinary planet configurations that two suns move towards each other by the sky?

Is it possible that suns move towards each other (not necessarily in opposite directions)? Such a configuration would cause interesting dusk and midday light cycles, in my opinion. Basically the ...
ivan866's user avatar
  • 109
-2 votes
1 answer
61 views

Can a star with a stellar mass of 1.176 with a similar composition to the Sun have a planet with these characteristics?

Imagine a solar system similar to ours that has a star with a similar composition to the Sun and a stellar mass of 1.176 and an Earthlike planet with about 1.18 times the mass of Earth in its ...
Galactic's user avatar
  • 113
0 votes
1 answer
75 views

What stellar conditions and orbital distance are needed to produce a year length of 515 Earth days and 9 Earth hours on an Earthlike planet?

A planet has a year length of 515 Earth days and 9 Earth hours. It is the same size and has the same climate as Earth. What stellar conditions would be needed to produce this and what orbital distance ...
Galactic's user avatar
  • 113
4 votes
1 answer
1k views

Can one or more moons orbit around a double planet system?

Given a double planet system where the two bodies are of similar mass; Can a moon orbit one or both planets in a stable orbit? How about an artificial satellite?
Martin's user avatar
  • 61
3 votes
1 answer
100 views

Why do the radii of the outer planets' epicycles have to be aligned with the earth-sun radius in the Ptolemaic model?

I read that in the Ptolemaic model (or the geocentric system), for the retrogade motion to occur at opposition, the radii of the outer planets' epicycles have to be aligned with the earth-sun radius. ...
Bach's user avatar
  • 143
1 vote
3 answers
788 views

why does earth have speed?

I understand that Earth has a quite big speed such as it ends up around the orbit. The sun can't really attract it till the end due to Earth's speed and earth really can't escape due to gravity, hence,...
Matt's user avatar
  • 203
3 votes
2 answers
982 views

Have we observed other habitable planets like Earth? [duplicate]

Have we observed other planets within the “Goldilocks Zone” of a star to have reasonable temperatures, that have a breathable atmosphere, water, and gravity within a healthy range for human life? ...
Kal Madda's user avatar
  • 149
2 votes
1 answer
522 views

Planet and star rotation through gas in the galaxy

If 10% of the galaxy is filled with gasses, and stars contribute to only 1%–2% of the total matter, then shouldn't the gas create friction for the movement of stars around the galactic center and also ...
Angela's user avatar
  • 201
4 votes
1 answer
73 views

How does carbon end up in the remnants

We know that one way carbon ends up in the interstellar medium which by the way is one or the heavy elements that help form the planet. But we also know that in the core, carbons fuse with another ...
Giorgi Lagidze's user avatar
4 votes
2 answers
1k views

How small stars help with planet formation

As I understood, low mass stars in their core go through fusion, but only the fusion of hydrogen happens. When it depletes hydrogen, fusion stops as temperature is still not high enough to support ...
Giorgi Lagidze's user avatar
1 vote
0 answers
66 views

What do chthonian planets look like?

Obviously, a chthonian is going to be hot, but what colours could it have? What would the surface composition be? Would it keep patterns from the gas-bands it used to have, or would those have been ...
Kazon's user avatar
  • 587
3 votes
1 answer
120 views

Trouble seeing Mars and Venus more than specks of light

Finally been breaking out the telescope to get a better look at things recently, and have been attempting to take advantage of Mars's and Venus's positions in the sky, but I haven't been able to see ...
BeardedChemist9's user avatar
4 votes
1 answer
99 views

Formation of a non-Sol Oort cloud with high mass planets

Based on recent developments in astronomy, pertaining to a greater degree of measurement, the mass of the Oort cloud around Sol is apparently only about 1.5 times the mass of earth, in contrast to ...
Broken ECLSS unit's user avatar
14 votes
1 answer
2k views

Could it be possible to detect planets from stars that went supernova through the resulting nebula shape?

It ocurred me, if a star with at least one planetary companion undergoes a nova or supernova, we shoud expect the debris to be deflected to some degree, on exit. To ilustrate it, first let's take the ...
ksousa's user avatar
  • 1,109
2 votes
1 answer
171 views

What is the maximum radius of a pure iron-56 planet?

Suppose we are building a pure iron-56 planet atom by atom, how large can it get in terms of radius before it collapses into a black hole?
EFanZh's user avatar
  • 123
22 votes
6 answers
5k views

Why doesn't the IAU definition of "Planet" disqualify Mercury and Venus as planets?

Here's the IAU definition of a planet (source): A celestial body that (a) is in orbit around the Sun, (b) has sufficient mass for its self-gravity to overcome rigid body forces so that it assumes a ...
Schroeder's user avatar
  • 513
9 votes
3 answers
3k views

Are the 2 planets in this image Venus and Saturn? And is this a fireball shooting star in top right of picture?

I took this picture with my iPhone on January 23, 2023 @6:01pm CST. I am in West Central Alabama very close to the Tenn-Tom Waterway a few miles from the MS state line. I was facing west-southwest. I ...
Tammy Kent's user avatar
4 votes
2 answers
201 views

Everything always looks the same

By now I have used 3 different telescopes and a pair of binoculars and no matter what I try to look at at night, whether it be stars, planets, drones, the moon or whatever, everything looks the same. ...
Carina's user avatar
  • 51

1
2 3 4 5
16