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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1answer
228 views

Can tidally locked planets have liquid oceans on their night side, and would such a planet be habitable?

Let's say we have a tidally locked planet orbiting a star. And let's say that the conditions on its surface are just right for water to exist on its surface. Conventional wisdom says that the water on ...
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1answer
173 views

Caves traced in nine planets of solar system

Are there chances of caves being found or traced on other planets of the solar system? What's the solution? Manufacturing special telescopes for viewing or observing caves on other planets? or ...
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1answer
186 views

Photographing Mars, Jupiter and Saturn

I want to take pictures of planets, well at least Mars, Jupiter and Saturn with some surface details. I have a Canon EOS 7D Mark-II and a Tameron 150 - 600mm lens (very heavy), a 1.7X extender, and a.....
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Why do the planets orbit in the same direction?

Theoretically, planets would have an approximately equal chance of going one way in their orbit or another but in reality, this is not the case (at least in our solar system). Why is this?
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3answers
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Do celestial objects need to be big to have liquid water on their surfaces?

I mean no asteroid, planetoid that I am aware of has water on its surface. It is way more common to see ice in it. So I figured that the size of the celestial body has something to do with the cycle ...
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1answer
251 views

Kepler and the Sun position

When Kepler went to Tycho Brahe, he learned that Tycho Brahe was using the mean position of the sun to note down the position of Mars. Well, Kepler needed to convert these datas of Brahe to do his own ...
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1answer
2k views

How to Calculate Planetary Equilibrium Temperature in Binary systems

I'm working on a program that generates the basics stats of a terrestrial planets in binary star systems. I'm not the best at this kind of math, so I'm having trouble calculating the planetary ...
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2answers
299 views

How do we weigh a planet?

How do we weigh a planet? My friend asked me how do scientists weigh a planet. He is not from science background so I need to make him understand with simple analogy. How can I explain to him?
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What astronomical observations would give conclusive proof of alien life?

There are several ways we are coming closer to answering the question "is there life elsewhere in the universe?". One is by first understanding very well the origin life on our own planet. Another is ...
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1answer
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Is there a name for a planet and its moons/satellites?

I'm wondering if there's a name that encapsulates the concept of a planet and the objects that orbit in its gravity. There's a solar system that encapsulates a star and its multiple planets and other ...
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1answer
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How to calculate the expected surface temperature of a planet

I'm writing a program to generate solar systems but I'm having trouble calculating the expected temperature of a planet. I have found a formula to calculate this, but I haven't been able to get a ...
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1answer
152 views

What is this planet or satellite in this picture?

I took this photo in Shijiazhuang, Hebei Province, China, 38°13'N 115°18'E (+38.23, +115.31) on the night of February 8, 2020. Here you can see a round object above the moon, and it was moving fast,...
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1answer
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Why do the planets in our solar system orbit in the same plane?

(Yes I'm excluding Pluto from this the same way it was excluded for not being a planet) Observing the planets orbit of the Sun they all seem relatively planar and roughly all orbit along the same ...
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1answer
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Is there a possibility of finding a system where a star is orbiting a planet?

Is it possible for a star to orbit a planet IF the planet is bigger than the said star? Or is it possible even if the star is bigger than the planet and still the star is orbiting the planet? I have ...
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0answers
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How can I see planets with my telescope? [duplicate]

I have bought a Celestron Astromaster 130 telescope and I am relatively new to astronomy, when I tried to view Jupiter a few months ago I could not make out any details. It was just a white orb. Any ...
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Is there a useful measure of how "life-dominated" a planet is?

If life exists on Mars or Venus, then in contrast to life on Earth, it must be "just scraping by". I can imagine a few ways to quantify this: Life on Mars or Venus is hard to detect -- any ...
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1answer
149 views

Are all the planets differentiated?

The Earth is differentiated, as it has a distinguishable core, mantle and crust with different compositions and densities. Are all the other planets differentiated as well?
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603 views

Can the paper narrowing Solar System's barycentre to within 100m help find Planet Nine?

I've just read this recent news article, Astronomers Have Located The Centre of The Solar System to Within 100 Metres, reporting on a paper[1] that claims narrowing the Solar System barycentre to ...
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280 views

How to find the temperature of a planet accounting for the atmosphere?

Recently, I started writing a program to generate star systems, and I need a formula to find the approximate surface temperature of a planet. I know of several formulas for this, for example this one ...
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53 views

Software apps for calculating distances between planets

Are there somewhere any software apps for calculating distances between any planets in our solar system?
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52 views

Do retrograde spin-orbit resonances exist?

The end state of rotation of an initially fast-spinning prograde terrestrial planet (in the absence of additional forcings such as "thermal tides" in an atmosphere, e.g. Venus) is a spin-...
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2answers
1k views

"Official" time for other planets

I want to make clock that shows current time on different solar bodies. For that I need to know how to count time on those planets. Is there any official definition of times on other planets in our ...
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Have Earth, Mars and Jupiter and Neptune not cleared their orbits of space debris? [closed]

According National Geographic's Space Encyclopedia (p68, column 3) written and illustrated by David A Aguilar Pluto has not cleared its orbit of space debris but neither have Earth, Mars, Jupiter and ...
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1answer
455 views

What is the average temperature of all planets at 1 bar?

Jupiter's (and Saturn's) "surface" temperature is defined as that at 1 bar. It is inconsistent to say the other planet's surface is their hard surface. Applying the same measure what is the ...
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Planet orbit circumbinary planet

I was wondering about a planet who orbits two stars. Could it be that it moves as in the image?
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3k views

Compute Planet's Apparent Visual Magnitude

In a hypothetical solar system there exist: a sun of radius $r_s$ and absolute visual magnitude $V$ the Earth, with radius $r_e$ and distance from the sun of $1\,AU$ another planet, wit radius $r_p$, ...
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1answer
471 views

Is it possible to have a trinary star system with a planet that orbits their barycenter?

I am trying to model a 3-star system with a planet. The three stars have the same mass. I have gotten the stars (Yellow, Pink, Blue) into a stable orbit. However, I am wondering if a "free-...
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2answers
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Is there a reason why the IAU differenciates objects in the SS orbiting the sun into a particular classification but it doesnt for satellites?

The IAU has different classifications for objects in the solar system orbiting the sun, they can be according to their shape and if they clear their neighborhood of other material around its orbits , ...
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2answers
434 views

How to calculate the orbital period and the density of a planetary body?

I'm a student studying in 9th grade, I am making this fictional habitable planet named "Darwin B" for a planet making competition. It orbits a sun-like star at a distance of 1.15 AU or 172 ...
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Spotted fast, VERY bright, moving object in the sky tonight in Gex, France [duplicate]

Tonight around midnight, I spotted a very bright moving object in the sky. Confused and intrigued with my sighting, I decided to go on google to find some answers. It clearly was not a plane as it was ...
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2answers
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If the Sun's trajectory were altered, would the solar system follow?

I was reading a text state that the sun is not stationary: "it orbits the Galactic center once approximately every 226 million years as the galaxy spins which is also traveling through space ...
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1answer
99 views

Is there any thing special with an axial tilt of roughly 25°?

Half of the planets in the solar system have an axial tilt of $25.5\pm 3^\circ$: earth (23.5°), mars (25.3°), saturn (26.7°) and neptune (28.3°). If random collisions in the early solar system caused ...
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6answers
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Why hasn't the "9th Planet" been detected already?

In the comments to this question, there was considerable doubt placed as to the subject of if the so called "9th planet" really exists. That wasn't really the intent of the previous question, so I ask ...
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1answer
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Could a near collision with small black hole account for the effects of the 9th planet?

Much interest has been raised about the existence of a 9th planet. One reason for this is the strange orbits of bodies in the outer solar system. Could the orbits be explained by a near collision of a ...
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Which kind of strategy should we take to discover Planet 9 and other KBOs?

What are the differences between the discoveries of Sedna, 2012vp 113, and the supposed Planet 9? All need deep infrared surveys at the ecliptic plane, but P9 needs a much deeper survey?
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1answer
114 views

If I know apparent planetary positions how do I calculate the date?

I have planetary position in retrograde how do I calculate the date? For eg, I know Mars was in retrograde in Scorpion (Sidereal 210 to 240 deg), how do I calculate the date and year of this? As of ...
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1answer
92 views

Hypothetical planet jump: Will it perturb star systems?

In a more speculative corner of SE somebody was dreaming up a story of planets traveling between star systems through wormholes. I was wondering how much the appearing/disappearing of a planet the ...
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2answers
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Why is there so little nitrogen in the Martian and Venusian atmospheres?

Why don't our neighbors have much nitrogen? You would think that, without 'nitrogen-fixing' organisms and such, there might be more.....
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2answers
321 views

When was the concept of rogue planets first theorized?

So after watching the Kurzgesagt video about life on rogue planets I became fascinated by the concept. I did some digging, and the earliest reference to the concept I could find was Philip Wylie's ...
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2answers
516 views

What is the minimum mass of a celestial object so that it can have a moon?

I was wondering how massive something have to be so that it it can attract moons by pop culture standards (ellipsoid/round shape). Could a planetoid have a moon? What is the relation between the mass ...
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2answers
253 views

Can a star turn into a planet?

I have read in a magazine that a star can actually form back to a planet... is it true?! Does it mean all the planets in our galaxy can be revived back to what they were before?
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2answers
344 views

Keplerian Elements for Approximate Positions of the Major Planets

Simple question here. I am working on something that needs to compute an orbital path using Keplerian Elements. When doing some research I came across this JPL page: Click Here. Within that link is a ...
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171 views

Kepler - Creating the Ellipse (Astronomia Nova)

In Chapter 58 in Astronomia Nova, Kepler made his final step to finally create the ellipse (for the orbit of planets) http://science.larouchepac.com/kepler/newastronomy/part4/58/index.html In the ...
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2answers
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Up to 384 minor planets (including Pluto) qualify as planets?

In 2006, the International Astronomical Union redefined the definition of planet in order to exclude Pluto, Eris, and several other objects whose category was disputed. This new definition of a planet ...
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3answers
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Why don't we have in-between planets?

The planets in our system are most often grouped into two categories: Terrestrial: Mercury Venus Earth Mars Gas Giants: Jupiter Saturn Uranus Neptune Why is it that we don't see "in-between" ...
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284 views

Is it ever possible to see Earth's shadow on other planets?

Is it ever possible to see Earth's shadow on other planets? How would the shadow present, and what would be the magnification, equipment, or other conditions necessary to see it? Is there any way of ...
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255 views

What would happen to the Earth if the orbit of another planet in the Solar System was disrupted by a cataclysmic collision with a large body?

There's plenty of speculation about what would happen if a large asteroid collided with the Earth itself, but less about the effect on Earth of a large asteroid or even a moon or minor planet ...
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0answers
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Help identifying a very slow-moving object during meteor shower photography

I just wonder if anyone could shed any light on this puzzle. Two nights ago whilst I was out photographing the Lyrids meteor shower from the UK something else showed up on my images when I checked ...
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How quickly do planetary rings form?

Just a very general question, but I haven't seen this discussed elsewhere. If a moon gets busted up for some reason, say a collision with another moon, and is at the right orbital distance from its ...
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4answers
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Is this render of a ringed planet's shadow accurate?

I've noticed that when it's the equinox on this planet I'm making, the sun seems to cast a double shadow on the planet. How come the planet's ring seems to make two shadows with a space in between, ...

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