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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6 votes
0 answers
72 views

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 ...
6 votes
1 answer
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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 ...
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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 ...
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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. ...
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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?
5 votes
1 answer
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What are the calculations for the time it would take to cool the surface and atmosphere of Venus to -50⁰ C 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'...
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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 ...
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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,...
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2 answers
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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?
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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 ...
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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 ...
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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, ...
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1 answer
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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 ...
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2 answers
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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, ...
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3 answers
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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 ...
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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 ...
3 votes
1 answer
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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 ...
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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 ...
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0 answers
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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. ...
1 vote
0 answers
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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 ...
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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 ...
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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-...
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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. ...
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1 answer
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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 ...
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1 answer
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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 ...
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2 votes
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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 ...
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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 ...
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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-...
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7 votes
1 answer
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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 ...
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1 answer
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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?
6 votes
1 answer
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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! ...
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3 votes
2 answers
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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 ...
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4 votes
3 answers
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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 ...
10 votes
3 answers
1k views

Agriculture on an exoplanet

If we find a hypothetical Earth-like planet A with a rocky terrain that we could colonize, how would we go about planting the first plants, knowing that there is a deficient of nutrients and the ...
1 vote
0 answers
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How does the wind behave throughout the day in Jezero Crater? (worried about Ingenuity)

JPL tweet links to mars.nasa.gov's Flying on Mars Is Getting Harder and Harder which explains that seasonal changes are lowering the density of the local atmosphere, presumably due to warmer seasonal ...
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1 vote
1 answer
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Impact Venus with Comet Leonard?

do we have the means to slightly alter Comet Leonard's trajectory so it impacts Venus instead of 'grazing' it in December 2021??
2 votes
1 answer
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How are astronauts aboard the Tiangong space station keeping busy?

Per Wikipedia's Tiangong space station viewed today: Days in orbit: 3 months, 15 days (13 August 2021) Days occupied: 1 month, 27 days (13 August 2021) Currently it is just the single core ...
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4 votes
2 answers
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Has opalescence ever been observed on any solar system body besides Earth? Or at least from a sample from one?

New method for exoplanet detection based on iridescence? in Astronomy SE asks about observations of exoplanets, but here I'm asking about our own solar system bodies. Question: Has opalescence ever ...
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1 vote
1 answer
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Has iridescence ever been observed on any solar system body besides Earth? Or at least from a sample from one?

New method for exoplanet detection based on iridescence? in Astronomy SE asks about observations of exoplanets, but here I'm asking about our own solar system bodies. Question: Has iridescence ever ...
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2 votes
1 answer
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Perseverance's First Borehole looks like its particles of sand stuck together by something; composition of this material and source of adhesion?

Resampled and sharpened detail from PIA24796: WATSON Image of Perseverance's First Borehole This is reminiscent of a day at the beach digging a hole in wet sand. The walls remain standing as long as ...
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DAWN CERES HAMO CYCLE1 PDS DATA ARCHIVE seems to be corrupted

I'm working on Ceres VIR_IR data from PDS3 Archive. The downloaded data seems to not be right as I'm getting lines of various colors and not the target area, when opened in ENVI. Is the QUB file ...
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Is there believed to be sharp boundary between Jupiter's liquid and metallic hydrogen layers and is there much convection and flow between them?

If it's not known, is it reasonable to assume that some Jupiter-like exoplanets might have well separated liquid and metallic hydrogen layers given moderately different temperature and mass? Author: ...
7 votes
1 answer
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Habitable rocky exoplanet with radius 2 times of Earth but similar surface gravity

Planet Earth has radius 2x of planet Mars, while having 10x times of Mars mass and 60% higher surface gravity. Could there exist rocky exoplanet with 2x radius of Earth but similar surface gravity (+-...
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How does ECOSTRESS measure both temperature and emissivity of the Earth's surface simultaneously? (Science package aboard the ISS)

The This Week at NASA video A U.S. Commercial Spacecraft Departs the Space Station on This Week @NASA – July 2, 2021 includes the following quote: Data from NASA’s Ecosystem Spaceborne Thermal ...
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How do they know the sub-surface radar reflections (potential underground ice or "lakes") on Mars are not natural dielectric or metallic in origin?

Gizmodo's NASA Scientists Find More Subsurface Lakes on Mars links to Characteristics of the Basal Interface of the Martian South Polar Layered Deposits (paywalled, but there is this 52nd Lunar and ...
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3 votes
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How does Curiosity's X-ray diffractometer work? Does it measure only one angle at a time or does it have an area detector?

Per this answer to Are quasicrystals common on the Moon and Mars?, Curiosity has an X-ray diffractometer. X-ray diffraction from 3D crystals can (begin to) be understood by embracing Bragg's law. A 3D ...
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1 answer
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Plot of the thermally-induced tilt in Martian surface during solar eclipse by Phobos? (slope of 1 atom per meter?)

Space.com's Mars lander InSight picks up tiny ground tilt caused by Phobos moon transit says that both Insight's ultra-sensitive seismometer picked up a very tiny transient shift in attitude during a ...
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5 votes
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Is Geothermal Cooling on Venus Possible?

Would geothermal type cooling be possible for a stationary base on the surface of Venus? Would the subsoil temperature of Venus hotter or cooler than the atmospheric temperature? (464C / 867F average ...
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4 answers
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When do Mars, Venus and Earth Align?

I found that all planets in the solar system align on 6 May 2492. How can I find when Mars, Venus and Earth align? Perhaps it is sooner.
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Why is the Southern Hemisphere of Mars is heavily struck by asteroids while the northern part is relatively smooth?

The northern hemisphere of Mars is smooth with flats lands but areas particularly below the Tharsis rise is heavily cratered, also Hellas basin, one of the largest impact craters is located in the ...
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