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NASA Probe Finds Ice and Organics on Mercury (discovery.com)
146 points by dfischer 1579 days ago | hide | past | web | 45 comments | favorite

100 billion tons of water covered with organics has just made the Mercury polar regions two of the most desirable pieces of real estate in the solar system after Earth and Mars. The water would be helpful for establishing colonies and industry (like producing solar panels from silicon) as well as being a valuable resource in its own right. If there are enough organics of the right kind, they could be used to make thin films, possibly allowing solar sails to be made in-situ.

Combining this with the abundant energy and the advantageous combination of being low in the Sun's gravity well, this makes Mercury a prime location both for energy-intensive industry and export to the rest of the solar system. You see, the deeper in a gravity well you apply thrust, the more delta-v you get from it. Since the Sun is the biggest gravity well in the solar system, and since solar sails have their highest thrust near the sun, you get lots of highly-leveraged thrust for free, so the location is very advantageous for export.

I think one day Mercury is going to be in the business of packaging energy as antimatter and shipping it all over the solar system.

Thrust may be more efficient, but you need a lot more of it to get out of the gravity well. Delta-v from LEO to Mercury is around 18km/s. That's LEO, not the Earth's surface. If you want to travel from the ground, you'll need another 9-10km/s. Getting there and back would take enormous amounts of fuel. To put it another way: from the Earth, escaping the sun's gravity completely (going interstellar) takes less delta-v than a one-way trip to or from Mercury.

It's more cost-effective to build bigger collectors closer to Earth.

It's more cost-effective to build bigger collectors closer to Earth.

Mercury would be exporting high energy manufactured goods to the rest of the solar system excluding earth. The ground<->LEO energy loss would make lots of trade prohibitive. The rest of the solar system would be different.

What? A one-way trip to Mercury takes three times as much energy as a trip to LEO and back. If you need energy to produce goods, building power plants on Earth or Moon make much more sense.

Your ideas belong in a soft sci-fi story. The economics and orbital mechanics simply do not work out in favor of a Mercury colony.

A one-way trip to Mercury takes three times as much energy as a trip to LEO and back.

We'd be exporting things/energy from Mercury, not to it, and the energy for the export would also be supplied by the sun through the use of solar sails.

If you need energy to produce goods, building power plants on Earth or Moon make much more sense.

Maybe. I can see how the difficulty of coping with being as close to the sun as Mercury would raise expenses. With selling antimatter, you wouldn't be selling energy so much as energy in a highly concentrated package. Economies of scale are going to come into play in an industry like that, and the ability to harvest more concentrated energy with mostly in-situ resources could be a big advantage. You'd have to bring resources up from the moon and from the asteroids to make the infrastructure to do that profitably in the vicinity of Earth. If you wouldn't have to do that for Mercury, it might be viable.

It makes sense for an interstellar flight though. If you want to leave the solar system doing say 30Mm/s (i.e. .1c) you expend less delta-v doing a slingshot around the sun than accelerating directly from Earth.

Short version: it doesn't make sense.

Longer: Oberth effect says you want to do the thrusting at max speed, not "deep in the gravity well". Often they coincide but they're not the same thing.

Even longer: If you want to use the Oberth effect, you want to go into a highly eccentric elliptic orbit with a low perigee. (Ie non-circular.) Then you do your thrusting at the perigee. Your apogee is still at high altitude. The perigee burn happens at high speed and actually raises the apogee.

You can think of it this way: if you shut down your engines right now, you are in an orbit that returns to the same point. So perigee burns can only raise apogee and apogee burns can only raise perigee. (If we talk about elliptic orbits.)

Mercury is in a low circular orbit. It does not really help to go to an orbit with a low apogee, with the ultimate goal of raising apogee!

You might use a sun slingshot by lowering your perigee but your apogee would still be at earth orbit. That would mean you would cross Mercury's orbit, but with a very high speed. You couldn't stop at Mercury (match speeds with it). Then you'd do a quick high thrust burn at high speed near perigee.

All this is in vain though since for 0.1 c magnitude velocities (30,000 km/s), if you had humans, you would have to thrust for weeks to keep acceleration below say 2 g and the gravity slingshot would be meaningless anyway as the speeds are so low, these are phenomena from totally different worlds. Earth's orbital velocity is 30 km/s and Mercury's 60 km/s. Thousand fold difference.

It's like saying building rocket launchpad on a 300 m high hill is useful since you're then closer to space.

The particular application would be for the export of fungible goods from the vicinity of Mercury to the rest of the solar system. Solar sails could be used to enter a solar orbit with a low pedigree to maximize thrust from the solar sail. This would still involve very long transit times and either the use of gravitational slingshots or multiple passes by the sun. It might make more economic sense to export energy as beams of microwaves.

Arrgh. iOS changed perigee to pedigree. Should've been perihelion anyhow.

Amazing perspective. Thank you for sharing.

Sounds like a pre-Mass Effect scenario. Also, Jesus, you've been on this website for a long time.

"establishing colonies"

The radiation must be horrific.

> The radiation must be horrific.

Obviously not where there's water ice. ('doh, Antidoh!) Click on the picture on this page to look at the configuration of the shadowed craters at the poles. (Yellow indicates a permanently shadowed region, also where water was found.)


In 2312, Kim Stanley Robinson describes Mercury settlements slowly rolling along huge crawlers.


But with the permanently shadowed craters, you wouldn't need them.

Why do you say that? Being so close to the Sun and without the protection of a magnetosphere you'd be pummeled by high energy radiation from solar flares (deeply penetrating protons, mostly). Because of the nature of the solar wind, you couldn't just rely on being in the shade to protect you.

I was just thinking of electromagnetic radiation. Just do the same as you'd do on Mars or on the moon. Bury the habitats in 6 feet of regolith.

Radiation is proportionally more intense at Mercury so you'd need thicker cover and you'd probably want to spend less time outside. Also, just getting there would be kind of a problem, radiation protection wise. Probably easier than trying to set up a base on a Galilean moon though.

Not on the dark side, Mercury is almost tide locked with the Sun. I always dreamed of a colony that could harvest the temperature gradient between the two sides.

Emily Lakdawalla has posted a good explanatory write-up, with more details on the methodology and background on the research, at the Planetary Society blog: http://www.planetary.org/blogs/emily-lakdawalla/2012/1129120...

Can someone explain why the discovery of ice and organics on Mars and Mercury such a surprise? If the prevailing opinion in science is that life formed spontaneously on Earth because the required chemistry was already present, doesn't it follow that similar compounds would be found through out the solar system? I get that each planet has a dramatically different composition in terms of what it primarily consists of, but I would expect traces of things like water and simple organic compounds to be found in various concentrations through out the solar system, no?

>Can someone explain why the discovery of ice and organics on Mars and Mercury such a surprise?

It isn't a surprise, the hypothesis has been around for a long time, this is just new supporting evidence.

>If the prevailing opinion in science is that life formed spontaneously on Earth because the required chemistry was already present, doesn't it follow that similar compounds would be found through out the solar system?

The big difference with Earth is position and the presence of a protective magnetosphere [1].

1: http://science.nasa.gov/science-news/science-at-nasa/2001/as...

It's like the Higgs boson. It's a resounding "yes, we were on the right track."

Additionally, enough gravity to maintain an atmosphere. Mars isn't in a terrible spot, but it can't hold on to water vapor, oxygen, etc.

Agri-domes and underground habitats. I think that would be a cool world to live on.

It's not a surprise, although not for the reasons you mention. We've known about similar deposits in permanently shadowed craters on the Moon, and one of Messenger's early discoveries was of craters with similar conditions on Mercury. However the source of the volatiles is not the type of chemistry that happened on early Earth, but rather cometary deposits and exospheric interactions.

Agreed. These are simple combinations of the 4 most abundant atoms in the universe. If anything it speaks to a lack of scientific understanding in the amazed, or maybe it's my (and your?) cynical nature.

Ice on Mercury, the closes planet to the Sun? Unbelievable. Indeed Wikipedia tells that the temperature gradient on the planet ranges "from a very cold 100 K at night to a very hot 700 K during the day." I used to think that Mercury is a half-molten radioactive hell.

For me organic material is not that exciting. Such substances as methane seem to be everywhere in space.

>Ice on Mercury, the closes planet to the Sun? Unbelievable.

Amazing what an atmosphere, or the lack thereof, can do for a planet.

Many of my friends have the same views of Mercury during discussions and I find it funny. I learned about these peculiarities of planets from Dav Pilkey (known for his Captain Underpants books) in his RIcky Ricotta's series. (http://en.wikipedia.org/wiki/Ricky_Ricotta%27s_Mighty_Robot_...)

I used to think that Mercury is a half-molten radioactive hell.


For the organic material to be on top of the frozen ice is a fascinating find. I wonder what's below that? I suppose any permanently shaded areas on that planet have huge potential.

Organic material could easily just mean some kind of light oil (even gasoline floats on water)

I've always wondered if something like the Chixclub (sp?) asteroid impact could impart enough energy to eject water and soil to escape velocity. Clearly easier to do at an angle than straight into the ground but the interesting calculation would be this, what size rock would have to collide with the ocean at what level to knock a chunk of the earth to Mercury ? We know this sort of transfer takes place since we've got meteorites that are from Mars so something hit Mars and knocked bits of it here.

Surely there is an astrophysicist in the house who could tell me if this is possible or just crazy talk.

I'm pretty sure that KSR mentions the possibility of some of his characters finding a chunk of Yucatan on Mars - so its perhaps not completely crazy...

Some impact events appear to have been a lot larger (and therefore presumably a lot more energy) than Chicxulub - e.g. the Vredefort Crater in South Africa


Youza! That is a big hole. Thanks for the link, filed under "things I don't want to be near when they happen." :-)

Is this the first time organic material has been confirmed outside of Earth?

No, it is known for a long time that organic compounds like Methane are found in the atmospheres of planets and comets.

Titan, the largest moon of Saturn, even has lakes of either methane or ethane. (It is pretty cold out there.)

Alcohol was also found in space: http://www.nrao.edu/pr/2001/vinylalco/

That gives me interesting sci-fi imagery. That would be a cool setting for a pirate/blackmarket trade.

well , it's not the kind of brewery one wants to ingest ,but yeah , i hear you ;)

Is this the announcement Nasa was talking about, or is this unrelated?

No, the announcement you had in mind is related to the findings from Curiosity on Mars.

The hyped announcement was about Mars, and hasn't been released yet.

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