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.

Filter by
Sorted by
Tagged with
5
votes
6answers
788 views

What's the scientific evidence of water for return trip methalox on Mars?

EDIT: I am not asking if you think finding water is necessary for a return flight. I'm asking for the scientific evidence that there is mineable water on Mars that could be used for this purpose. ...
2
votes
1answer
229 views

How will InSight's RISE antennas end up pointed in the right direction?

The rendering of InSight shows the RISE antennas, the two microwave horns pointed just above the horizontal over each of the solar array paddles. If I understand correctly the experiment works when ...
6
votes
4answers
2k views

How could InSight's seismometers be intentionally and meaningfully “pinged”?

I had a friend whose summer job, a long long time ago, was to travel around an unsuspecting rural area, lay a heavy steel plate on the ground, and whack the plate with a sledge hammer. Apparently he ...
74
votes
3answers
43k views

What will be the effect if we stand on Jupiter?

As we all know Jupiter is a gaseous gas giant and it has a large mass, almost twice the sum of all other planets in the Solar system. So, if it happens that we go to Jupiter, and, as we know it does ...
34
votes
4answers
10k views

Could the Moon keep an atmosphere?

When we think of terraforming a body in our galaxy Mars gets lots of consideration as the closest potential body. But what about the Moon? It is currently beyond our ability to add an atmosphere ...
14
votes
1answer
1k views

How long will it be light on Venus at night?

The atmosphere of Earth bends light such that there is still light after the sun goes down for a period of time. How would such effects appear on Venus, given the thicker atmosphere?
2
votes
3answers
304 views

Do Curiosity's reported measurements of Mars' surface gravity (~3.717 m/s^2) include centrifugal effects?

In this answer I discuss the first results in the 47th Lunar and Planetary Science Conference (2016) conference paper First Gravity Traverse on the Martian Surface from the Curiosity Rover and a more ...
22
votes
4answers
9k views

How can Mars have dust storms with such a thin atmosphere?

Mars, as I understand, has a very thin atmosphere. However, it still has weather like this: What causes the thin atmosphere to move fast enough to cause such a monster wave of dust?
13
votes
1answer
2k views

Where to find the best values for standard gravitational parameters of solar system bodies?

Where can I find the best values to use for standard gravitational parameters of solar system bodies for numerical simulation experiments? Here are two sets I've put together. The first set is from ...
21
votes
3answers
20k views

Why is the Far Side of the Moon so different from the Near Side?

Here's a photo of the Far Side of the Moon Compare that to the Near Side: Why the difference between the two? The difference is quite significant.
19
votes
3answers
5k views

Did the Mars rovers actually confirm the gravity of Mars?

For years the theoretical calculated gravity of Mars has proliferated science texts and Internet documentation - but did the rover actually do a test to confirm the theoretical gravity is truly equal ...
16
votes
1answer
635 views

Would it be possible to “ride the wave” on Venus?

Update: Newly published paper in Nature Geoscience Atmospheric mountain wave generation on Venus and its influence on the solid planet’s rotation rate has open-access links in Science News, ...
20
votes
4answers
6k views

When is the next Outer Planet lineup (Voyager)

If I remember correctly, The construction and launch of the Voyager spacecrafts in the early 1970s had an urgency as there was to be an unusual lineup of the outer planets (Jupiter, Saturn, Uranus ...
10
votes
3answers
306 views

How “locked” are Pluto and Charon? How much does each librate as seen from the other?

Discussion below Are all or some geostationary satellites tidally locked to the Earth? got me thinking about Pluto and Charon. According to Wikipedia: Charon and Pluto orbit each other every 6.387 ...
5
votes
1answer
527 views

How were Mars' zero elevation datum defined? What are their shapes?

Discussions on Boiling ponds and pools on Mars? led me to Wikipedia's Mars; Geography and naming of surface features which says: Because Mars has no oceans and hence no "sea level", a zero-...
4
votes
1answer
240 views

Why do (did) they think WT1190F is low density?

A piece of space debris WT1190F is in the news in part because it has been far from earth (farther than lunar distance) in the past but will should have already re-enter earth's atmosphere in a few ...
2
votes
1answer
120 views

Would the >100 km “knee” in Earth's atmosphere still be where MFP exceeded scale height if it were pure Ne or Ar?

There is currently one answer to How many solar system bodies have "knees" in their atmospheres? that points out that somewhere above roughly 100 km turbulent mixing drops off (thus the name ...
2
votes
1answer
124 views

Just how huge is Mars' cloud of hydrogen?

NASA Goddard's July 2018 press release NASA’s MAVEN Spacecraft Finds That “Stolen” Electrons Enable Unusual Aurora on Mars says: But two puzzles make this type of aurora seem impossible at first ...
2
votes
1answer
197 views

3D celestial puzzler; why InSight's two RISE horns point slightly south of east, and north of west?

note: possibly helpful: LaRa after RISE: Expected improvement in the Mars rotation and interior models Contraindre la structure interne de Mars avec GINS @karthikeyan's excellent answer links to ...
18
votes
5answers
3k views

Feasibility of colonising Ceres?

Ceres is a dwarf planet in the midst of the Asteroid Belt between Mars and Jupiter - its location in the Asteroid Belt makes it a good base to mine the riches believed to exist in the asteroids. ...
13
votes
1answer
696 views

How strong is the electric charge capacity of Martian dust storms?

In my answer to What would it feel like to be in a Martian dust storm? I assert that Martian dust storms would be best avoided, and as one of the reasons (besides carrying corrosive chemicals like ...
12
votes
1answer
3k views

Is there a map or list of all the lava tube skylights the LRO has detected on the Moon?

I have read that so far the LRO has detected about 200 skylights - they appear to be holes into larger spaces below them, which could be lava tubes or domes. I would really like to know where all of ...
29
votes
6answers
9k views

Why are probes that tend to explore outer system always launched to go outwards instead of straight upwards or downwards?

Let's take a look at the trajectory of variety probe missions. New Horizons and Ultima Thule will be 4.1 billion miles away when it visits the Kuiper Belt object. This chart shows the path of New ...
12
votes
1answer
518 views

Does Venus have doldrums or horse latitudes (latitudes with lower winds)?

Because of all the heat fueling convection cells, Venus has some brisk winds especially in the upper atmosphere (up to 370 km/h). I realize the winds are quite slow at the surface, but are there any ...
10
votes
1answer
11k views

If Mars had more atmosphere how warm would it be?

Looking at Venus, Earth and Mars, the closer you are to the sun the warmer you are. At the same time the warmer planets also have thicker atmospheres. ...
18
votes
1answer
530 views

Why did the Earth based observations of methane on Mars go wrong?

ScienceNews states that: Scientists had previously identified methane on Mars using Earth-based telescopes and spacecraft orbiting the Red Planet. In 2003, researchers detected a ...
17
votes
3answers
5k views

How much sunlight gets to the surface of Titan? What would astronauts see?

Saturn being at 10 A.U. means sunlight on Titan's cloud tops is about 1/100 that on Earth's. That's 4000 times the illumination of Earth's moon. Titan's atmosphere is described as opaque smog. If ...
8
votes
1answer
381 views

Is there a system for choosing the Prime Meridian on a given body/world?

According to the answer to this question, the 0° longitude of the Moon is that which points toward Earth. On Earth it goes through Greenwich (although I was amused to hear that the French disagreed), ...
8
votes
1answer
919 views

A cloud-top colony on Venus, will it drift to the poles?

Suppose a cloud-top colony on Venus. Provided that it has no thrusting engines, where it will tend to go naturally with winds, to the equator, to the poles or elsewhere?
6
votes
1answer
134 views

How are marsquake epicenters determined using only one seismometer?

This tweet says: Cerberus Fossae is the first active seismic zone ever discovered on Mars. Located about 1,600 kilometers east of @NASAInSight lander, this huge extensive tectonic structure was the ...
2
votes
1answer
178 views

Highest velocity impact between a spacecraft and a solar system body? What about for a dedicated impactor (spacecraft component)?

In this answer I mention the proposed impact of DART: Double Asteroid Redirection Test (DART) Mission Double Asteroid Redirection Test The Double Asteroid Redirection Test (DART) Element of the ...
14
votes
3answers
2k views

Did we know the gas planets were truly gaseous before Pioneer 10?

I'm asking for historical scientific knowledge of our understanding of the outer planets, which seems hard to come by. Pioneer 10 was the first probe to an outer planet (Jupiter). Before then, did we ...
13
votes
1answer
604 views

How long have we known Pluto is red?

Recently the New Horizon's satellite has given us some lovely color images of Pluto. When did we first discover that Pluto is red? Secondly, did we suspect its color was red before we were able to ...
10
votes
3answers
3k views

Is it possible for something to fall straight down to earth? What are the requirements?

Meteorites leave strewn-fields before impacting, SpaceX rockets come in at an angle and stand up straight at the last second, the Soyuz capsule doesn't fall straight. I assume this has to do with the ...
6
votes
2answers
868 views

Source for up-to-date values of Mars' standard gravitational parameter

Wikipedia currently gives the standard gravitational parameter of Mars as: $$ GM_{Mars} = 4.2828(9) *10^{13} (m^3/s^2)$$ The (9) is the uncertainty of the last digit, so it works out to about ...
6
votes
1answer
219 views

Are we still able to terraform Mars using greenhouse effect?

In the last month, a group from University of Colorado, Boulder, published a paper on Nature Astronomy entitled "Inventory of $CO_2$ available for terraforming Mars", which was highly publicized on ...
5
votes
1answer
111 views

Would there be snow, rain, fog or clouds in a deep, sealed, subsurface cavern on the Moon if water were present?

The question Most efficient method of storing energy with water on the moon? proposes a several hundred meeter tall subsurface cavern on the Moon. I added the following comment to an answer: I keep ...
5
votes
1answer
131 views

Will the ExoMars rover offer some unique science capability?

The BBC article Europe's science ministers to decide on ExoMars rover describes a substantial amount of discussion and soul-searching about the level of funding and capabilities for the rover part of ...
4
votes
1answer
255 views

Is Earth's “pear shape” mostly J₃?

@OrganicMarble's answer to 1959 Peanuts cartoon about the Fischer ellipsoid (Earth is “pear-shaped”)? finally let me see the cartoon that Mathematician, Engineer and Geoscientist Irene Fischer wrote ...
4
votes
1answer
134 views

What are the technologies that can identify, validate, and quantify water-rich locations on Mars?

As the discussion progresses from the likelihood that there is water on Mars through yes, near the poles, now to to Is there really a frozen lake near the equator on Mars? and There's a lot of ...
4
votes
1answer
168 views

How do they measure the voltage of the Moon?

@DavidHammen's answer to If a solar flare happened during a total lunar eclipse, would the Earth block the flare from hitting the moon? And for how long? describes the regular lashing of the Moon by ...
3
votes
1answer
107 views

How many solar system bodies have “knees” in their atmospheres?

Discussion lead to citing Why does Earth's atmospheric density have a big "knee" around 100 km? Is there a good analytical approximation? who's answer is "monatomic oxygen". ...
2
votes
1answer
299 views

Mars: Readily usable sulfur for sulfur concrete?

Sulfur concrete is a mix of sulfur and aggregates that make a strong, quick-hardening concrete that is likely to be used for construction on Mars, which has a great deal of sulfur. Most experiments, ...
1
vote
1answer
61 views

How will “InSight's onboard communications gear perform a radio-science experiment to shed further light on Mars' innards?” (Space.com)

The Space.com article How NASA Mars Lander's 'Steampunk' Claw Will Work (Video) says: InSight's mission aims to provide a detailed look at Mars' interior structure and composition. The lander ...
24
votes
1answer
4k views

Can I harvest diamonds from the rain of Saturn and Jupiter?

A recent news article on BBC News indicates that 1,000 tonnes of diamonds a year are being created on Saturn This is like science fact that screams it must be Science Fiction! Assuming the ...
22
votes
3answers
5k views

Is water on Mars the same as Earth water?

I would like to know how similar Mars water is to Earth water. Can we survive on Mars with Martian water without any major health issues etc?
19
votes
3answers
2k views

What defines the radius of a ball of gas like Jupiter?

I've seen statements to the effect of: "the gravity on the surface of Jupiter is about 2.5 times that of Earth". The problem with such a statement is that as essentially a ball of gas, Jupiter is not ...
14
votes
2answers
3k views

How will Juno establish existence of solid core within Jupiter and determine its size?

One of the set goals for NASA's New Frontiers Juno mission is studying Jupiter's interior and determining if this gas giant has a solid core and if, how large it is. This is mentioned several times on ...
12
votes
1answer
116k views

What are the dark areas on the moon?

The Moon has a large number of dark spots, as can be seen on the photo below (Wikipedia), that differ significantly from the lighter areas. The dark areas often seem to be roundish, but not ...
4
votes
1answer
231 views

Is Cassini equipped for detection of non-water-based exobiology?

Looking at one of the latest images of Titan's north pole as taken by Cassini probe made me curious how well equipped this NASA's probe actually is to detect non-water-based exobiology?   &...