To date, we’ve landed men on the Moon, a few contraptions on Mars, and a butt-ugly Soviet lander on Venus way back in the 1970s.
But which planets/moons in our solar system could astronaturs physically explore–providing they could get there–factoring in crushing atmospheric pressure and corrosives (Venus), radiation (Mercury and Jupiter/Jupiter’s moon), excessive heat (Mercury/Venus), and other nasties. For instance, what about Jupiter’s moons–would Jupiter’s intense radiation fry astronauts?
In this scenario, we’re talking realitistic space suits, not those personal force fields seen in sci-fi flicks.
Well, Mars´s satellites, Phobos and Deimos wouldn´t be much different than the Moon, although the gravity force would be minimal. Also asteroids fall in the same category, however the point is not wheter is possble or not to go there, but why.
Asteroids. We’ve landed one unmanned craft on Eros, although it wasn’t originally intended to actually land. Ceres and the other large asteroids have enough gravity that the explorers would not be able to jump off the them by mistake.
Titan, the largest satellite of Saturn, should be an interesting place to explore. It has an atmosphere about twice as dense as Earth’s and probably has hydrocarbon lakes.
Interestingly, my astronomy book from last semester informed me that Titan was probably the only place in the Solar System were one would freeze to death wearing a space suit like the ones used on the moon. It’s freezing cold, and has a thick atmosphere to draw heat from the suit.
This question is too broad, you can explore almost anything in this solar system with enough effort.
The question should be what’s worth exploring?
Europa, Ganymede and Callisto maybe.
And I think Venus is the only planet worth considering of Terraforming…as it is the only remaining planet with Geologic activity that is considerable enough to maintain an atmosphere.
Any of Jupiter’s moons will be a problem - anyone not very well shielded won’t live long in that kind of radiation environment. Saturn’s moons shouldn’t be as much of a problem.
The backside of Mercury might be a possibility. Mercury rotates slowly enough that you could land on its night side and explore for months before having to leave. You will have to bring lights and heated spacesuits, but other than that it’s not much different that walking on the Moon.
I suspect it would be feasable to walk on the surface of Pluto, provided a way to deal with the long travel time could be found.
My first thought was what heavenly body I’d want to explore if I was an astronaut. Ruling out Jennifer Aniston and confining ourselves to places we haven’t been before:
1- Back side of Mercury. However, taking enough fuel to overcome solar gravity for return trip, not to mention Mercurian gravity in leaving the planet.
2- One of the larger asteroids. Technically the easiest, but probably of little value.
3- Mars.
4- Moons of Saturn. Probably one of the smaller ones. Jupiter’s radiation output probably precludes us from ever visiting its moons. Sheer distance rules out the outer planets, although probably Saturn’s system is likely out just for distance.
A substantial geological exploration of a near earth asteroid (NEA) would be ideal. Easy to get to, easy to leave and in a way an idea step between going to the moon and going to Mars.
After that I’d say similar mission to each kind of asteroid (iron, rock, carbon rich) and then the Martian moons. After that the distances and energies are too great for anything near term.
Yes, it would be nice if we could terraform Venus, considering its mass (only slightly less than the Earth’s) and distance from the sun. However, Venus’s atmosphere pretty much rules that out. It’s very thick, and made up almost entirely of CO[sub]2[/sub]. At the surface the atmospheric pressure is about 90 atmospheres, and temperatures can reach 800[sup]o[/sup]F. There are also clouds and rain of H[sub]2[/sub]SO[sub]4[/sub] (sulfuric acid). The Soviets landed a few probes on Venus back in 70s, and none of them remained functional for more than an hour. No one’s ever bothered sending any more probes to the surface because it just isn’t worth it.
If machines can’t function down there, plants and animals certainly can’t live. Short of sucking off the whole atmosphere and starting over, I can’t really think of a way to terraform (or even visit) Venus.
Actually, it would be more appropriate to say that none of them transmited for more than an hour, that was because the lander relayed data to the orbiter, that, because of it´s trayectory remained in line of sight for only that time.
Here´s an interesting site about the VENERA probes.
Genetically engineered bacteria might. Aren’t there Earth bacteria that live at the Mid Atlantic Ridge that can survive extreme termperatures of 300[sup]o[/sup]F and pressures. Such modified life forms could be used to begin the terraforming process.
I wonder if it’s easier to terraform Titan with its intense cold or Venus with its intense heat.
Some things going for Titan. There are Earth bacteria that can live on Methane and it’s conjectured that Titan has an ocean of Methane. While it might be cold on the surface, if Titan has tectonic activity there might be hot spots deep below.
Fascinating answers–but can anyone answer these questions:
Dopers have talked about the intense gravitational field on Mercury, given the planet’s closeness to the Sun. About how strong would this gravity be experienced by a 200-lb astronaut?
Wouldn’t the Sun’s radiation make visiting Mercury very risky—even if approaching from the “dark side”?
I thought Venus’ atmospheric pressure is so dense that it would crush astronauts, but maybe I’m confusing atmospheric pressure with gravity. Can someone explain what an astronaut would likely experience on Venus?
Roughly how intense is the radiation emitted by Jupiter, as experienced by an astronaut on one of its moons?
P.S. I like the Jennifer Anniston suggestion very, very much. Heavenly indeed.
Mercury’s gravitational field is fairly small, a little over a third that of Earth. In other words, even if the astronaut’s equipment weighs twice as much as himself, he could still walk around comfortably. The problem isn’t Mercury’s gravity, but the Sun’s: It would take a lot of fuel to go to or from Mercury. Note, incidentally, that assuming equal masses going each way, it’s just as hard to get to Mercury as it is to return.
The Sun’s radiation wouldn’t be a problem at all on the surface of Mercury (five thousand kilometers of rock makes for a pretty decent radiation shield), but it would be an issue on the trip itself. The simplest solution is to just bring along a lot of lead, but that’s heavy (and hence expensive). NASA is also looking into drugs which would increase human tolerance to radiation, and there’s probably some research into magnetic rad shielding.
An astronaut on Venus would likely experience death. The pressure (due to the thick atmosphere, not to gravity) is crushing, the heat is Hellish, and the atmosphere is vitreolic. I suppose that, given enough effort, we could overcome all of those problems, but short of one of those science-fiction personal forcefields, you’re not going to have something you can walk around wearing.
And I don’t know exactly how bad the radiation situation is on Jupiter’s moons (it probably depends on which moon you’re interested in), but let’s just say that I wouldn’t want to live there. The Galileo probe was designed for that environment, but the engineers still kept their fingers crossed whenever it crossed Io’s orbit (where the radiation is most intense).
How long has the radiation from Jupiter been known? It seems like travel to Jupiter/colonization of the moons has been a staple of science fiction since at least the 40s (and you’ve still got stories set around Jupiter being published today).
