# Tag Info

41

Ice. All these rockets use oxygen as the oxidizer component of their propellant. The Saturn 5 also used hydrogen in some of its engines (upper stages). They are stored in liquid state, which requires very low temperatures (below -183c for oxygen, below -253c for hydrogen). Despite insulation, some of the outside surfaces can get cold enough to condense and ...

17

How tall are these things? Are they made of ice? Are they the tallest things on Pluto? Are these the tallest ice features in the Solar System? "New close-up images of a region near Pluto’s equator reveal a giant surprise: a range of youthful mountains rising as high as 11,000 feet (3,500 meters) above the surface of the icy body." https://www.nasa....

13

For a Hohmann transfer to Saturn, I get 15.7 km/s for both burns. The transfer time is also a simple formula. I obtain roughly 6 years. Compare to the lunar ice. It is roughly 2.8 km/s to get to, and the trip time would be a few days, even from Low Earth Orbit. As suggested by the other answer, you could compare to Earth's surface. If we're using some ...

11

1. Diamond. Its hardness is legendary. That it appears in liquid form on Uranus or Neptune hasn't been directly measured (no recent probes), but lab measurements in 2009 and 2010 of diamond's phase diagram still haven't been contested to claim that diamond can't be liquid there. On the contrary, in 2017 a process was demonstrated of converting diamond ...

11

Water is extremely useful on Mars. You can use it to generate oxygen directly via electrolysis and the hydrogen byproduct can be reacted with carbon dioxide to make even more water. We drink water. If they want to come home, water+carbon dioxide+power can produce methane and oxygen. That's the most likely rocket fuel to get home. On the other hand, dust is ...

11

Ice sublimates. So does rock. Yet the planet Mercury is still there. The reason Mercury still exists is because even though rock does indeed sublimate, the rate at which rock sublimates is extremely low, even at temperatures at the surface of Mercury. The same applies to water ice at the very low temperatures in those permanently shadowed craters on the ...

11

You may not send a nuclear bomb into space if you're one of the 105 countries that have signed the Outer Space Treaty that, among other things, forbids deploying nuclear weapons or any other kinds of weapons of mass destruction in outer space. Even disregarding that... By measuring the craters of bombs we exploded in the 1950's, we found that a crater ...

9

Knowing the weather forecast, the pad crews drained the water pipes or left them running to prevent them freezing and bursting. With sub-freezing temperatures predicted, ground crews drained most of the water pipes at the launch pad to minimize ice formation. Those that could not be drained were left running overnight, and strong wind gusts blew ...

7

Actually, Ice VII has been discovered in diamonds on Earth. The water is first trapped in the diamond as the latter is formed deep in the mantle. Then when the diamond cools at the surface its rigid lattice retains the high pressure in the interior enabling the water to reach a combination of temperature and pressure where it forms Ice VII. The presence ...

7

The only form of ice that we see naturally in bulk on Earth is Ice I, all within the sub-h variety. There's no place on Earth that gets cold enough for any other form--but that's not necessarily true for the rest of the solar system. Unfortunately for this question, there is nowhere in the solar system that we could ever find any type of ice that depends ...

6

If HP³ detects water, it will be done indirectly through thermal conductivity or specific heat. It has no sensor that directly detects water, such as a chromatograph or mass spectrometer (nor room for such). The paper you cite above was published in 2011. It was written before HP³ was chosen in 2012 for InSight: The mole design goes back to the PLUTO ...

6

The term "Ice Giant" is given to planets which are thought to have formed from materials in their ice phase, not because they are made of ice. The ices changed to gas and liquid during planet formation.

6

You overestimate vapor pressure and underestimate dust power source 0.05 Pa it equivalent to a layer 0.000018382 m of dust which would (if it being a sealant) to prevent the ice from further sublimations if we assume average density of 1700kg/m3 and gravity 1.6 m/s2 There are other factors like water being polar solvent and thus adhesion to the dust ...

5

It is of course sublimating. And not only is it cold, but the sublimation cools the remaining ice even further. Since it's in lunar dust, chances are additionally that a sublimated water molecule will hit a speck of dust and re-freeze. This effectively slows the speed at which water moves from deep down to the lunar atmosphere.

4

Actually it already snows on Mars. The snow, made of carbon dioxide, has been observed and studied by orbiting spacecraft. Aside from the different chemical composition from the stuff we shovel on Earth, Martian $\text{CO}_2$ snow also is very finely divided, microscopic in size in fact; likely this is related to the low density of available material and ...

4

In short: not as much as you might think. All moons with water ice shells over liquid water oceans, and even those with no liquid water oceans but warmer and thus less rigid ice beneath a cold ice crust, modify craters after their initial formation via isostatic rebound. Imagine what would happen if you suddenly excavated a crater-shaped hole in a liquid ...

3

We can probe this matter a little more in-depth. This introductory reference describes all the giant or Jovian planets, noting that only the two more massive ones, Jupiter and Saturn, are made primarily of hydrogen and helium. Uranus and Neptune, which did not have as much material to work with and did not become powerful enough to draw large proportions ...

3

Scarp #1: According to this NASA information, this specific scarp is located at 56.6 degrees South latitude, 114.1 degrees East longitude. This picture was taken on May 7, 2011. I went to Google Earth Pro, and inputted the coordinates: -56.6, 114.1 on Mars, and it looks the same. Note the "wedge" shape. Scarp #2: Here's another one of those 8 scarps. At ...

3

You'd have to bring a pretty large bomb to do this. We've detonated lots of bombs on Earth, and none of them came close to making a hole 11 km deep. We even did tests specifically aimed at making large holes (Project Plowshare): The 104 kiloton, 1962 Sedan nuclear test formed a crater 100 m (330 ft) deep with a diameter of about 390 m (1,300 ft) These ...

2

I just ran across this reference again while writing this comment (same one as I mentioned here so I thought I would add it to the mix explicitly. The paper is quite thorough and interesting, and I think deserves a careful read. New estimates for the sublimation rate for ice on the Moon Edgar L. Andreas, Icarus 186 (2007) 24–30: This is pretty amazing, ...

2

I can't see how Saturn would ever beat Ceres as a source of water for inner solar system applications. You need a railgun or something to get things off Ceres and some way of cutting chunks of ice out of the ground, but the escape velocity is pretty low. Then you can use a low thrust tug in vacuum to put lumps of ice (no need to put a ship round them) on a ...

2

It occurs to me that the answer to this question depends on what you want to get for your money. If you are only interested in the ice itself, in a source of water for use on Earth on in LEO, then other options are preferable. However, if you wish to get greater returns on your investment in the form of ancillary benefits which themselves have value, both ...

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