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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.

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What can I see with 10x50 binoculars in bortle class 4?

I'm just starting out with amateur astronomy and decided to buy a 10x50 Celestron Up-close G2 binoculars. I believe that tomorrow is the planet parade (the aligning of 6 planets) and I'd like to catch ...
Ryan's user avatar
  • 173
5 votes
2 answers
3k views

Visibility of Planetary alignment of 6 planets on 3 June 2024 from Prague

I have just found out about the alignment of Mercury, Mars, Jupiter, Saturn, Uranus, and Neptune on 2024-06-03 and I'd like to see if it is possible to watch the event from the vicinity of Prague, but ...
mishan's user avatar
  • 161
3 votes
1 answer
98 views

Easy guideline for using JPL Horizons DE431 for planets in aphelion and perihelion from 11000 BC to 16000 AD?

Can someone give me a step by step Guide how to use JPL DE431 or DE441 as a Beginner. I tried the Horizons website app and Webgeocalc but it didn't showed understandable Information. This websites ...
Patrick Wackenhut's user avatar
0 votes
0 answers
34 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. ...
Caemaster117 's user avatar
2 votes
1 answer
40 views

How to estimate perturbations from other planets in Apsidal Precession

I am developing a fictional system which I want to calculate to as much detail as I can. Thus I have a question about astrophysics and astrophysical formulae. I know that Apsidal Precession is ...
DanceroftheStars's user avatar
1 vote
0 answers
67 views

How can I calculate the geocentric longitude of Pluto in a similar way to VSOP87's algorithm?

The book "Astronomical Algorithms" teaches a way to calculate the position of any of the planets for almost any date, until you get to Pluto. To try to get around that, I attempted to ...
Matheus Azevedo's user avatar
0 votes
0 answers
78 views

Do all the planets in the universe rotate? [duplicate]

Do all the planets in the universe rotate by their own means. Do they rotate like the Earth? Are there any planets which don't rotate?
RANSARA009's user avatar
22 votes
3 answers
8k views

Why wasn't the planet Uranus recognized by ancient cultures?

Mercury, Venus, Mars, Jupiter, and Saturn have been identified by ancient astronomers as they are visible with naked eye at night. The planet Uranus, despite being visible during very clear nights, ...
user avatar
1 vote
0 answers
45 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
170 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
78 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
88 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
  • 338
1 vote
0 answers
126 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
160 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
  • 167
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....
DanceroftheStars's user avatar
1 vote
0 answers
86 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
  • 571
1 vote
1 answer
93 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
255 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 ...
Hudjefa's user avatar
  • 353
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
576 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
  • 24.1k
10 votes
1 answer
148 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
99 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
  • 209
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
  • 209
1 vote
2 answers
126 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
673 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
55 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
224 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
  • 5,177
2 votes
0 answers
105 views

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

...
dimitri33's user avatar
  • 167
3 votes
1 answer
223 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
109 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
108 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
832 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
167 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
202 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
  • 1,017
-1 votes
2 answers
337 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's user avatar
  • 75
-2 votes
1 answer
210 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
186 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
147 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
65 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
79 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
112 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
899 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
1k 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
523 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
  • 221
4 votes
1 answer
78 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

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