Questions tagged [planetary-science]

The study of planets, asteroids, comets, etc, including weather, geology, composition, etc. This tag should be used when the focus of the question is on the the science of a non-Earth non-star natural object, and not used when designing spacecraft to cope with said challenges.

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Would a ice core samples taken on the Moon provide us with information about the past that we cannot easily obtain in other ways?

This article on NASA's website describes 10 things we’ve learned about Earth by studying the Moon, including the makeup of a newborn Earth and potential clues to how life began on Earth. The ...
phil1008's user avatar
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-7 votes
2 answers
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Nuking mars for colonization

While I have seen the idea for nuking Mars’s polar ice caps to release water, the fallout from the thermonuclear blasts could plunge the planet into a nuclear winter which could stop us from ...
Austin Phillips's user avatar
22 votes
1 answer
2k views

Could an acid-proof, solar-powered aircraft stay aloft on the sunny side of Venus more-or-less indefinitely?

The length of Venus's solar day is 116.75 earth days ($t$ = 10,087,200 s) and it's radius, $r$, is 6051,800 m, so in theory an aircraft would only need to travel at a ground speed, $s$, of... $$s=2\pi ...
phil1008's user avatar
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1 vote
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Diameters of moons in solar system

I would like to programmatically find all moons in our solar system above a certain diameter. I would like to use the api to jpl horizons if possible. (For context I am then going on to find ...
Cortado-J's user avatar
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6 votes
0 answers
102 views

What are the prevailing winds on a tidally locked ocean planet?

I am trying to picture the atmospheric circulation of a tidally locked planet, similar to Earth in mass and atmosphere. The rotational axis would need to be (roughly) perpendicular to the ecliptic if ...
Woody's user avatar
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9 votes
2 answers
3k views

Term for deformation due to gravity

In this video, If you look closely, you can see the smaller planet deforming before the actual collision. I think I remember a term existed for this. I think it is ...
user22859957's user avatar
14 votes
2 answers
1k views

Does the atmospheric pressure of Mars fluctuate because of the seasonal evaporation of the polar ice caps?

The carbon dioxide ice on the Martian poles are known to evaporate every summer and re-deposit every winter. Where does this carbon dioxide 'go' and does it mean there is a seasonal variation in the ...
Duke O's user avatar
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20 votes
1 answer
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Why are the Martian poles not covered by dust?

The Martian surface is known to have periodic 'dust storms'. Depictions of Mars typically show poles with ice at the surface. If that is the case why are the Martian poles not blanketed with a thick ...
Duke O's user avatar
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4 votes
0 answers
58 views

What document describes the scientific benefits of the LRV through an increase in the diversity of rocks returned by Apollo 15-17?

Logically, it makes sense that the rock samples returned by the Apollo 15-17 missions tend to be more diverse than the ones returned by previous missions. The astronauts could reach regions of ...
olamarre's user avatar
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1 answer
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What is the minimum pressure of a purely CO₂ atmosphere on Europa that can retain enough heat for surface liquid water?

*Ignoring external factors such as Jupiter's magnetosphere blowing this new atmosphere off. I'm not sure where to begin the maths for that
cdemr's user avatar
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2 votes
1 answer
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Will Enceladus run out of water due to it being lost to space?

The global liquid water subsurface ocean within Enceladus has been identified as being the primary source of material for Saturn's E-ring. Given that the moon is permanently ejecting large quantities ...
user1628056's user avatar
6 votes
2 answers
243 views

Is the crust of the Moon different on the near side and the far side?

If you assume that the origin of the Moon is due to an object hitting the Earth. The difference between far side and the near side of the Moon can be explained, if the 'chip' knocked off the Earth to ...
SR Clark's user avatar
5 votes
1 answer
82 views

Can waterworld exoplanets have an ocean that's fresh or brackish by terrestrial standards?

The basic system is a terrestrial-type exoplanet in the liquid water zone around a star. The planet has a worldwide, liquid ocean with at most small islands above the surfaceMy question is what the ...
Heteromeles's user avatar
1 vote
1 answer
83 views

Apparent diameter of a planet

I made a simple sheet that based on apparent diameter of a celestial body which shows to me which of my eyepieces I should use to view an object in my telescope. However, some of bodies like planet ...
no one special's user avatar
7 votes
3 answers
7k views

By my calculation the cumulative mass of Mercury, plus Venus, plus Earth's moon, plus Mars, plus Mars' moons, total 99% of Earth's mass. Am I correct?

Does cumulative mass of Mercury, Venus, Earth's moon and Mars total 99% of Earth's mass ?
Reid's user avatar
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6 votes
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Is the net electric charge of Venus about 0.01 Coulombs?

A few years ago Venus was measured to be at a surprisingly large electric potential of $\Phi_{Venus}=+10.6$ volts, which may be one of the reasons Venus lost its water. Does this mean that Venus has a ...
David Bailey's user avatar
6 votes
1 answer
993 views

Upper limit of human comfort in higher atmospheric pressures?

At what atmospheric pressure, assuming an earth-like atmospheric composition, do humans start to feel uncomfortable? I am not asking for the max survivable pressure, but the point where long term ...
GoingFTL's user avatar
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3 votes
1 answer
119 views

Why does Earth's North Pole RA flip by ~180 deg around AD2000 relative to SSB? (JPL Horizons data)

Using JPL's Horizons API I see that the Earth's North Pole RA flipped by ~180 degrees quite suddenly around AD 2000. It was pretty stable around 180deg for at least 1000 years prior, and then remains ...
angst's user avatar
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23 votes
3 answers
3k views

How does Titan have hydrogen in its atmosphere?

Titan's atmosphere contains few tenths of a percent of hydrogen. This seems odd to me, as Earth with a 4x greater escape velocity cannot retain hydrogen or even helium in its atmosphere. Titan is 3x ...
blademan9999's user avatar
3 votes
1 answer
196 views

Why do two craters in Utopia Planitia look like dark holes and are of the few ones on Mars that look this way?

Screenshot from Mars Trek This enigmatic crater lies in southern Utopia Planitia at 28.72⁰ N, 119.96⁰ E, is about 10 km wide and has a min. height difference between its floor and rim of ca. 1650 m. ...
Cornelis's user avatar
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2 votes
3 answers
787 views

How can you warm up Mars?

Mars experience extreme temperatures. Highest temperature being 21 degree celsius. So if we are to terraform mars one day then we first need to warm it up. So any ideas on how to warm up mars?
Joydeep Mohanto's user avatar
7 votes
3 answers
533 views

What are the calculations for the time it would take to create a minus 50⁰ C liquid CO2 ocean on Venus by shielding it totally from the Sun?

Cooling down Venus will probably be by far the most efficient method to start terraforming the planet because then you wouldn't have to deal with the high temperatures and pressures at its surface. I'...
Cornelis's user avatar
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6 votes
1 answer
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Which were the more than 60 (!) candidate locations for the Mars 2020 rover?

Four years ago I asked for the 21 potential landing sites for the Mars 2020 mission in this question, but now I've learned that there were more than 60 candidate locations ! From NASA Announces ...
Cornelis's user avatar
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1 vote
0 answers
63 views

What will be more important for the first NASA led human mission to Mars, the exploration of important science targets or the mining of water ice?

A few months after NASA's decision in November 2018 that Jezero Crater would be the landing site for the Mars 2020 rover mission, the research article The Geology and Astrobiology of McLaughlin Crater,...
Cornelis's user avatar
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2 votes
2 answers
191 views

best way to generate electricity on any planet's dark side

What options are available for generating electricity in a space colony if it is at the planet's darkest point all year around without help from nearby outposts?
Osm's user avatar
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2 votes
1 answer
138 views

Density vs ocean planet?

According to Nasa.gov: Details: Ocean planets are long imagined but difficult to confirm, and TOI-1452 b is no different. About 70% larger than Earth, and roughly five times as massive, its density ...
DialFrost's user avatar
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3 votes
0 answers
107 views

How far could we see (horizontally), floating inside the acid clouds of Venus at 56 km and at 51 km height above the surface?

Screenshot of Fig. 4 in the article The microphysics of the clouds of Venus: Results of the Pioneer Venus Particle Size Spectrometer Experiment From the Wikipedia section about the troposphere of ...
Cornelis's user avatar
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3 votes
0 answers
51 views

Regarding planets capturing gases from space with their gravitational pull;

We know most (or all) planets suffer atmospheric escape. Now, can planets gain atmosphere from drawing in gases drifting in space? Is there a formula for that? Is there a cutoff point between gravity, ...
Mindwin Remember Monica's user avatar
6 votes
1 answer
297 views

Depth to diameter ratio of impact craters

Two questions on this site concern themselves with the depth to diameter ratios of craters: Catalog of lunar crater depths and diameters Where on Mars are there possible other collapse features with ...
Fred's user avatar
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3 votes
2 answers
332 views

Could there be caves on Mars in the areas inside Jezero crater and the watershed west and north of it where the Mg carbonates are detected?

Both images above are screenshots from Fig. 1 of the article Formation of Magnesium Carbonates on Earth and Implications for Mars The green coloured regions indicate where Mg carbonates were detected, ...
Cornelis's user avatar
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6 votes
3 answers
267 views

Is crater counting accurate for relative dating between celestial bodies?

This Planetary Society article explains how crater density per unit area on the lunar surface helps identify what regions are older/younger than others. It also mentions that this chronology can be ...
olamarre's user avatar
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9 votes
4 answers
1k views

Is it possible for a planet to be habitable by just geothermal activity

Is it possible for a planet (with an atmosphere and breathable air obviously) to be super far away from its star but still have a habitable surface temperature just from geothermal activity alone, if ...
NuclearTaco's user avatar
3 votes
1 answer
172 views

3U CubeSat components

as a project for school, we are designing a preliminary conceptual 3U CubeSat design. The mission is to launch in orbit at 1,000 km and Maintain orbit for 1 month. After orbit is maintained for 1 ...
GEAUXTIGHAS's user avatar
1 vote
0 answers
69 views

Sensor for charged particle density [closed]

How would I go about specifying a sensor that measures charged particles in Low Earth Orbit deployed at 1000 km? Are there designs for instruments already that do this, or would I have to actually ...
GEAUXTIGHAS's user avatar
2 votes
0 answers
45 views

Sensors for measuring charged particle density and particle density [closed]

We are designing a 3U CubeSat using solar sail. We have everything we need for all the subsystems except payload. Our mission is to measure charged particle density, particle density and temperature. ...
GEAUXTIGHAS's user avatar
1 vote
0 answers
20 views

How to model the kinematics of gases expelled from comets and planetary atmospheres? [closed]

Once the ices of comets sublimate, where do they move to, and with which equations do you describe their motion in the interplanetary medium? Similarly, where do the gases that are stripped from the ...
Astrolien's user avatar
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1 vote
0 answers
57 views

What should be the mission plan in order to reach TITAN (SATURN) by a group of 15 people for Scientific Exploration? [closed]

I am working on a project where we have to design a Mission to TITAN by Digitally construct and document the development of a six-month long human settlement on Titan (Moon), bearing the capability to ...
Pranay's user avatar
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4 votes
0 answers
89 views

How much will global warming increase the density of debris in LEO? What are predictions currently saying?

After about 08:00 in Scott Manley's hot off the press new release SpaceX Loses 40 Satellites To Solar Storm linked below he drifts away from the solar activity-...
uhoh's user avatar
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12 votes
3 answers
504 views

How brightly does Venus's hot surface glow at night? Could you see it? Could you see well enough to walk around?

NASA's Parker Solar Probe Captures its First Images of Venus' Surface in Visible Light, Confirmed links to the new Geophysical Research Letter Parker Solar Probe Imaging of the Night Side of Venus. ...
uhoh's user avatar
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4 votes
1 answer
303 views

Why does Scott Manley say "the gravity of Europa is low enough that it's at the high end of what is possible in scuba with highly technical gear"?

Scott Manley's January 30, 2022 video Deep Space Radiation, Black Holes And Other Questions - Episode 14 discusses radiation levels and human survivability on Jovian satellites, and after ...
uhoh's user avatar
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13 votes
1 answer
2k views

BBC: "In 2009 Prof McDowell & other astronomers performed an experiment in which a similar-sized rocket was crashed into the Moon." Really? Which one?

The line following the title of BBC's Elon Musk SpaceX rocket on collision course with moon reads: A rocket launched by Elon Musk's space exploration company is on course to crash into the Moon and ...
uhoh's user avatar
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2 votes
0 answers
88 views

How to make diamagnetic lunar simulant that would "float" in a strong enough magnetic field? (for China's 60 cm high field simulator)

Live Science's China builds 'artificial moon' for gravity experiment says: Chinese scientists have built an "artificial moon" research facility that will enable them to simulate low-gravity ...
uhoh's user avatar
  • 149k
6 votes
2 answers
255 views

What is the largest possible rocky body? [closed]

Suppose you start with a rocky sphere about 12,742 kilometers in diameter and continuously add more rocky material such that you don't smash this sphere to bits. What is the upper limit for this? ...
Frotz's user avatar
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4 votes
1 answer
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Fjeldbo, Kliore, & Eshleman 1971 Fig. 22 planetary atmosphere index of refraction increasing with altitude; physics insight or convenient abstraction?

this answer to Is it possible for a spacecraft to communicate with Earth when a planet is in the way? suggesting that atmospheric refraction could be used to get at least some kind of signal around a ...
uhoh's user avatar
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4 votes
0 answers
120 views

Just how locked is Titan? Does it exhibit libration due to eccentricity? Have residual oscillations not yet damped out been detected or ruled out?

Under Where is the Selk crater on Titan with respect to Saturn? there is @BrendanLuke15's comment which provides a helpful hint: Tidally locked moons have their 0° longitude defined as the 'sub-...
uhoh's user avatar
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7 votes
1 answer
139 views

Could and should not the search for the location(s) of the Martian methane spikes become the main scientific objective for the Curiosity rover?

In Nature Geoscience's article Independent confirmation of a methane spike on Mars and a source region east of Gale Crater is announced that the reported methane spike on sol 305 by the Tunable Laser ...
Cornelis's user avatar
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0 votes
1 answer
123 views

Where are the meteorite remnants related to the craters they've produced on the moon?

On Earth, in every crater there's usually at least some remnant of a meteorite. But with all the craters on the Moon, where are the meteorites in the middle of them?
user118161's user avatar
6 votes
1 answer
642 views

Just how steep are Pluto's tallest ice mountains?

This answer to How tall are Pluto's mountains? Are they the tallest ice features in the Solar System? is worth a read and an upvote and says they are upwards of 3,500 meters and most likely water ice! ...
uhoh's user avatar
  • 149k
3 votes
2 answers
181 views

Can "prolateness" be characterized by a $J_2$ coefficient like "oblateness"?

When an imperfect sphere can be obtained by rotating an ellipse around an axis, it is called a spheroid. There are two types of spheroids, oblate ones and prolate ones. Most solar bodies can be ...
Ng Ph's user avatar
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4 votes
3 answers
1k views

What kind of experiments would a scientist do on Mars?

If we have people on Mars around 20, 25 years from now, what kind of scientific study would they be doing on a daily basis? I know places we'd want to study, places where ancient water flows might ...
WasatchWind's user avatar

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