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NASA Craft To Leave Vesta Heads For Dwarf Planet Ceres

samzenpus posted about a year and a half ago | from the moving-to-better-quarters dept.

NASA 116

DevotedSkeptic writes "NASA's Dawn probe is gearing up to depart the giant asteroid Vesta next week and begin the long trek to the dwarf planet Ceres, the largest object in the asteroid belt. The Dawn spacecraft is slated to leave Vesta on the night of Sept. 4 (early morning Sept. 5 EDT), ending a 14-month stay at the 330-mile-wide (530 kilometers) body. The journey to Ceres should take roughly 2.5 years, with Dawn reaching the dwarf planet in early 2015, researchers said. 'Thrust is engaged, and we are now climbing away from Vesta atop a blue-green pillar of xenon ions,' Dawn chief engineer and mission director Marc Rayman, of NASA's Jet Propulsion Laboratory in Pasadena, Calif., said in a statement. 'We are feeling somewhat wistful about concluding a fantastically productive and exciting exploration of Vesta, but now have our sights set on dwarf planet Ceres.'"

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116 comments

Frist poast (-1, Offtopic)

ThePeices (635180) | about a year and a half ago | (#41209237)

Obligatory frist poast!

Asteroid Vesta and dwarf planet Ceres (2, Interesting)

Taco Cowboy (5327) | about a year and a half ago | (#41209713)

According to NASA - http://www.nasa.gov/mission_pages/dawn/ceresvesta/index.html [nasa.gov] - Asteroid Vesta mainly consists of rock while dwarf planet Ceres is mainly ice

What is interesting is the picture of the meteorite that NASA claims is from asteroid Vesta. That rock is made up of almost entirely mineral Pyroxene - http://en.wikipedia.org/wiki/Pyroxene [wikipedia.org] - which is common in lava flow

Hmm ...

How can an asteroid of only 330 mile wide have volcano that spewed out lava ?

Re:Asteroid Vesta and dwarf planet Ceres (0)

Penguinisto (415985) | about a year and a half ago | (#41209807)

It is possible that the meteorite came from the asteroid, which in turn came from a proto-planet that had a volcano or two on it - which in turn is the likely source of the Pyroxene.

Many, many asteroids are remnants of planets, so this isn't exactly a massive leap of logic.

Re:Asteroid Vesta and dwarf planet Ceres (2)

osu-neko (2604) | about a year and a half ago | (#41210525)

Many, many asteroids are remnants of planets, so this isn't exactly a massive leap of logic.

If by that you mean, "no asteroids are known or believed to be the remnants of planets, but are believed to be formed from left over proto-planetary disk material that never successfully formed into a planet", then you are correct.

Re:Asteroid Vesta and dwarf planet Ceres (4, Informative)

reverseengineer (580922) | about a year and a half ago | (#41209813)

From further down in that link you posted, "it appears to have a surface of basaltic rock -- frozen lava -- which oozed out of the asteroid's presumably hot interior shortly after its formation 4.5 billion years ago, and has remained largely intact ever since." So no volcanic activity anymore, though meteorites believed to originate from Vesta are believed to have been formed in the impact that produced the Rheasilivia crater [wikipedia.org] , which possibly ejected material as deep as the mantle.

Re:Asteroid Vesta and dwarf planet Ceres (1)

Tastecicles (1153671) | about a year and a half ago | (#41209833)

you can't draw that conclusion. It could just as easily mean that the asteroid took a significant amount of time to resolidify after a major collision or two (it's happened to Earth several times - most dramatically when a body the size of Mars collided with Earth not just once, but twice, and the resulting debris cloud formed the Moon and the shepherd asteroids at L4 and L5, and bestowed upon our planet an abnormally large and hot iron core - if Earth didn't have that core we wouldn't have the Moon either, and the core of our planet would be as cold as New York concrete in March).

Re:Asteroid Vesta and dwarf planet Ceres (4, Informative)

mbone (558574) | about a year and a half ago | (#41209975)

How can an asteroid of only 330 mile wide have volcano that spewed out lava ?

Lot's of radioactive Aluminum-26, which melted all sorts of things in the very early solar system. (Vesta is thought to be near-primordial.)

Re:Asteroid Vesta and dwarf planet Ceres (0)

Anonymous Coward | about a year and a half ago | (#41210821)

.....which is common in lava flow

, but doesn't actually have to be formed in a lava flow.

Neither necessary nor sufficient.

Re:Asteroid Vesta and dwarf planet Ceres (1)

Anonymous Coward | about a year and a half ago | (#41212049)

You don't need volcanoes to form pyroxene-dominated rocks. Magma that cools below the surface does that (i.e. intrusive rocks). In fact, most of the eucrite meteorites [wikipedia.org] thought to be from Vesta look more like intrusive rocks (cooled below the surface) than extrusive (i.e. volcanic) ones. Either that, or they are the brecciated [wikipedia.org] equivalents of those rock types (i.e. smashed into pieces by impacts and then cemented back together).

Forming a rock dominated almost entirely by pyroxene, as some of the eucrites are, usually requires an intrusive setting because the pyroxene has to crystallize in a magma chamber and sink to the bottom, piling up in layers. This forms arrangements of mineral grains known as a cumulate [wikipedia.org] texture. If you instead promptly crystallize a melt of a more typical eucrite composition, you would get a mixture of minerals somewhat similar to an earthly basalt, and the individual mineral grains would be smaller (faster cooling == smaller crystals). To get a more concentrated assemblage of one type of mineral you have to segregate the crystals of different compositions somehow.

If your question is more generally about why a melt would form in the first place from such a small body, the answer is: A) there is a lot of gravitational potential energy that is released as heat during accretion, and B) the isotopic compositions of the material that made up the solar system were more enriched in radioactive isotopes than they are now, so a given volume of rock generated more heat back then (more than 4 billion years ago) than now. Objects therefore got hotter than they would now for a given size. There is good evidence that Vesta is a chemically differentiated body -- i.e. that it melted enough to start separating by density into a core, mantle, crust, etc. Since then, it's largely cooled and become geologically inactive except for impacts.

Re:Frist poast (0)

aglider (2435074) | about a year and a half ago | (#41211593)

I have mod points to bring you down. But that would be a waste of bits. Just like you are.

Re:Frist poast (1)

Sulphur (1548251) | about a year and a half ago | (#41211923)

I have mod points to bring you down. But that would be a waste of bits. Just like you are.

Use the flag Luke.

Re:Frist poast (0)

Anonymous Coward | about a year and a half ago | (#41211933)

... I ... am ... your fu**er!

Good luck Dawn (5, Insightful)

symbolset (646467) | about a year and a half ago | (#41209251)

We're all counting on you...

Seriously though, Ceres is an awesome target and much more exciting than Vesta. Vesta is a rock. Ceres is half water ice by volume, in low g. Obviously some serious upside potentials there. A vastly superior target to Mars, or just about anywhere else in the solar system.

Re:Good luck Dawn (1)

c0lo (1497653) | about a year and a half ago | (#41209431)

We're all counting on you...

...Ceres is half water ice by volume, in low g. Obviously some serious upside potentials there. A vastly superior target to Mars, or just about anywhere else in the solar system.

Upside potentials? Care to expand a bit the topic?

Re:Good luck Dawn (2)

TFAFalcon (1839122) | about a year and a half ago | (#41209561)

My guess is that he's talking about possible colonization targets. It's much easier to just 'mine' water at the place you've just colonized, instead of hauling it in.

Re:Good luck Dawn (1, Informative)

Penguinisto (415985) | about a year and a half ago | (#41209841)

One tiny problem with that, though: Ceres is a bit further out from the sun than Mars... as in way the hell out there. [wikipedia.org]

It does have potential for fueling an orbital colony or, well, any colony that isn't at the bottom of a big gravity well. OTOH, if Mars is a screamer of a target to hit, I can only imagine what it would take to hit a relatively microscopic-sized target that's way further out, and somewhat surrounded by asteroids.

Sounds like fun, though.

Re:Good luck Dawn (1)

mbone (558574) | about a year and a half ago | (#41209981)

One tiny problem with that, though: Ceres is a bit further out from the sun than Mars... as in way the hell out there. [wikipedia.org]

It does have potential for fueling an orbital colony or, well, any colony that isn't at the bottom of a big gravity well. OTOH, if Mars is a screamer of a target to hit, I can only imagine what it would take to hit a relatively microscopic-sized target that's way further out, and somewhat surrounded by asteroids.

Sounds like fun, though.

Should be no problem, especially once Dawn gets there and nails down the orbit.

Note, however, that there is plenty of water on Mars, a good deal of it accessible from the surface at the poles.

Re:Good luck Dawn (5, Informative)

symbolset (646467) | about a year and a half ago | (#41210129)

Mars has water. A lot of it, right on the surface. Plenty to provide air and water for indefinite human habitation and fuel for the return trip, if you have the energy. That's the good news.

Mars also has a lot of gravity (.38 g). And it's the gravity that's a killer because it's not got enough atmosphere for a decent atmospheric brake. To land a significant (20 ton or better) craft on Mars in condition to lift off again demands that you set her down on the jets, and that is a very unforgiving process that costs a metric boatload of fuel. Whatever source of energy you use is going to have a lot of mass too. The 1 ton of Curiosity is actually as much mass as we can land on Mars right now. To get humans there in any condition to start a colony requires a vast quantity of fuel to shorten the trip and to land. And where are we going to get that fuel? Ceres!

Mars has too much gravity to be a good source of water for fuel in microgravity. You have to burn too much fuel to get it off of Mars. As it is on the return trip the humans are going to have to meet up in Mars orbit with a return booster fuelled by LH2/LO2 from Ceres.

Yeah, Ceres is a good bit further out and it takes longer to get there (to the GP). But the robots don't care. Planetary Resources should get us enough Near-Earth asteroid water to make the fuel to lift the craft out of LEO and send it swiftly on its way to Ceres. At 0.03 g, the water comes off of Ceres nice and easy. Once it comes back to lunar orbit (firing its LH2/LO2 jets) with its kilotons aquatic payload a lot of other things like Mars become realistically possible. There are just not enough near-Earth asteroids of the right type to provide the supply we need for this.

Ceres is the key to everything. If it really has the water.

Re:Good luck Dawn (0)

Anonymous Coward | about a year and a half ago | (#41211113)

It's not landing on Mars that costs the fuel: you can use atmospheric braking most of the way down, with jets only for the last few seconds. It's getting back up: the escape velocity is 5 km/s. With the fuel it takes to escape Mars, you could spend 23 minutes just hovering above its surface.

Otherwise, I generally agree with what you say.

Re:Good luck Dawn (1)

captainpanic (1173915) | about a year and a half ago | (#41212057)

The following goes for Ceres and Mars: Water + sunlight (on a solar panel) = fuel

Alright, so Mars is probably the better place for settling.

But Ceres and Vesta are gonna be like finding water in the desert. Not enough reason to stick around for long, but really convenient to have when you're passing by.

Re:Good luck Dawn (1)

James McGuigan (852772) | about a year and a half ago | (#41212167)

What if you where to crash Ceres into Mars for the purposes of transforming.

Would that provide a large quantity of surface water/ice for Mars, more than the oceans on Earth, the dust and heat from the collision may even help to establish a thicker atmosphere and raise the surface temperature.

Thats 10^21 kg of mass to that needs to be reduced in orbit by 1AU , it sounds a lot, but all you would need is a rather strong space elevator type cable, some rechargeable fuel efficient ion engines, proper calculations of the orbital dynamics of the various bodies and be willing to wait a few orbits to setup a natural collision.

Lets hope there is no life on Mars, else they might consider it an act of war like Starship Troopers but in reverse.

Re:Good luck Dawn (0)

Anonymous Coward | about a year and a half ago | (#41209855)

What is it with you guys and colonizing vacuum?

Re:Good luck Dawn (1)

symbolset (646467) | about a year and a half ago | (#41210317)

It is ultimately the only possible path for species survival. Once we've scaled Maslow's pyramid [wikipedia.org] the view is quite astounding and we aspire to greater challenges. Until then though, when we look up all we can see is the butt of the guy above us.

Re:Good luck Dawn (0)

Anonymous Coward | about a year and a half ago | (#41210905)

Because if we stay on earth, it's one extinction event and the whole human race is done for.

Re:Good luck Dawn (1)

K. S. Kyosuke (729550) | about a year and a half ago | (#41212147)

Because if we stay on earth, it's one extinction event and the whole human race is done for.

We're done for anyway, what are we going to do with all the accumulated entropy of the Universe, huh? Move to another one?

Re:Good luck Dawn (2)

Electricity Likes Me (1098643) | about a year and a half ago | (#41213893)

With many many trillions of years with which to ponder that question, one supposes we might eventually come up with a solution. Of course, we won't have those trillions of years if we don't engage in some basic future-proofing of our survival in the meantime.

Re:Good luck Dawn (1)

K. S. Kyosuke (729550) | about a year and a half ago | (#41211879)

What is it with you guys and colonizing vacuum?

They want to fill in the void, for the Universe to suck less.

Re:Good luck Dawn (3, Interesting)

symbolset (646467) | about a year and a half ago | (#41210427)

Colonization of Ceres requires that the humans live in a huge centrifuge because humans don't bear up well under such a tiny gravity in the long term and centripetal force is a fair substitute. Construction of such a centrifuge on Ceres would require considerable resources we don't have because Ceres has both significant gravity and spins on an axis. Ultimately a human habitat on orbit of Ceres seems more likely to me than one burrowed into the ice for this reason, as the centrifuge is simpler on orbit. In fact, the operation of human habitat polar centrifuges would alter the poles of Ceres and be self-defeating. But given such a habitat on orbit, short-term surface ventures and shelter from solar storms are trivial with a surface gravity of 0.03 g and unlimited available fuel from refinery operations. A space elevator on Ceres though, that would make better sense than anywhere else in the solar system.

No, I'm excited about Ceres only as a source of water for LH2/LO2 fuel, O2 for breathables, water for drinking, minerals for refining and fabrication - not as habitat. It may be 50 years or more before we put people there and that will be out of scope for me.

Re:Good luck Dawn (2)

mug funky (910186) | about a year and a half ago | (#41209573)

i'm guessing it's about potential fuel for even further expeditions.

take a 50/50 rock/ice object and a "sufficiently advanced probe", you can extract aluminium from the rock, make nanoparticles, then use the ice with the nanoparticles as a rather powerful thermite style propellant.

or just make a shirtload of liquid H2, but that's possibly a bit more energy intensive.

Re:Good luck Dawn (2)

jamstar7 (694492) | about a year and a half ago | (#41209759)

Or crack the ice down to hydrogen and oxygen, you know, that stuff we breathe? With plenty of solar energy, it shouldn't be a problem. Where there is water, there can be life, even if it lives in a habitat. Bonus if the ice is 'dirty', contaminated with various hydrocarbons. They'd make great feedstocks and precursors for your plants and animals.

Hell, sign me up!!!

Re:Good luck Dawn (0)

Anonymous Coward | about a year and a half ago | (#41210059)

Don't forget the 80% nitrogen mix we need to breathe otherwise we get oxygen toxicity.

http://en.wikipedia.org/wiki/Oxygen_toxicity [wikipedia.org]

Why do you "colonizing" geeks always fail so utterly at high school science? I think I just answered my own question...

Re:Good luck Dawn (1)

Anonymous Coward | about a year and a half ago | (#41210085)

Couldn't that problem be avoided by simply using lower pressure?

From the link you gave:

"In low-pressure environments oxygen toxicity may be avoided since the toxicity is caused by high partial pressure of oxygen, not merely by high oxygen fraction."

Re:Good luck Dawn (1)

mortonda (5175) | about a year and a half ago | (#41210141)

Of course, then there's the fire danger...

Re:Good luck Dawn (2)

tragedy (27079) | about a year and a half ago | (#41210231)

If the oxygen partial pressure matches, the fire danger is the same. Well, not exactly the same since the extra mass from the nitrogen acts as a heat sink and the airflow characteristics will be different, etc., but it will still be largely the same.

Re:Good luck Dawn (4, Informative)

Teancum (67324) | about a year and a half ago | (#41210295)

There is no extra fire danger in a 100% Oxygen environment as long as the partial pressure of Oxygen is identical to typical seal level pressure or slightly less. The extra fire danger (as in what happened with the Apollo 1 fire) comes from a 100% oxygen atmosphere at standard sea level pressure. That is a fire just begging to happen with almost any material.

BTW, the Apollo spacecraft used a 100% Oxygen atmosphere because it was less mass to haul up to the Moon and back (thus more Moon rocks to bring back and more stuff to bring to the Moon in the first place). The Apollo astronauts seemed to have done just fine with that for a week or so in space at a time, and in fact the Skylab environment was also 100% Oxygen (with CO2 scrubbers in both cases to pull that gas out of the mixture as it was produced).

The reason the Space Shuttle went to a more normal 80/20 mixture of Nitrogen to Oxygen ratio had more to do with the electronics they were using than anything about the astronauts themselves. Since electronics are designed to operate here on the Earth, an assumption is made that other kinds of atmosphere environments won't be used by anybody using those components. Yes, milspec equipment can be made to overcome that problem, but sometimes things like test equipment and a whole bunch of stuff being used inside of the Shuttle simply can't be made economically with that strict standard.

Interestingly enough, the space suits used for EVAs still stuck with the 100% Oxygen environment. One of the reasons for that is because of the lower pressure made it easier to bend joints... something sort of important if you want a practical space suit. The downside is that it takes longer for astronauts to get in and out of the airlocks.

Re:Good luck Dawn (1)

symbolset (646467) | about a year and a half ago | (#41210491)

Pure oxygen is a very real danger, as we found on Apollo 13 [wikipedia.org] . Mortonda is correct about this. We shall have to be careful.

Re:Good luck Dawn (0)

Anonymous Coward | about a year and a half ago | (#41211075)

Are you so thick? Apollo 13 suffered an electrical fire inside a LOX tank; spacecraft with an 80% nitrogen atmosphere still keep oxygen in its own tank, so there's fuck-all relation there.

Re:Good luck Dawn (1)

Teancum (67324) | about a year and a half ago | (#41213553)

While perhaps blunt, this AC post is 100% spot on. Apollo 13 was caused due to a LOX tank failure and not due to the 100% oxygen atmosphere inside of the spaceship.

I will note that the Apollo spacecraft, on the launch pad at KSC, had an 80/20 mixture for the cabin pressure as a way to prevent fire.... they just pumped in air from Florida with a fan while the astronauts waited on the launch pad. The reason why the Apollo 1 spacecraft had the 100% oxygen @ sea level pressure was because they knew that they would need to pressurize the cabin. After the Apollo spacecraft was launched into space, that Nitrogen atmosphere is eventually vented away with the partial pressure and 100% Oxygen atmosphere.

That is also the reason why you see Apollo astronauts getting into the command capsule already wearing space suits with helmets, as they were adjusting to breathing in an atmosphere without Nitrogen even before the launch happened. It was also an air conditioning unit attached to the suits, but they were also trying to get the Nitrogen out of their blood. Shuttle astronauts didn't need to go through that step (although they still wore spacesuits during launch for other reasons).

Re:Good luck Dawn (1)

dargaud (518470) | about a year and a half ago | (#41213507)

We have problems with electronics not evacuating their heat well enough through convective transfer at 3000m altitude already, and the pressure is only 2/3 of sea level.

Re:Good luck Dawn (1)

Teancum (67324) | about a year and a half ago | (#41213837)

Which is why the Space Shuttle used an 80/20 Nitrogen-Oxygen mix. The Apollo Guidance Computer was simple enough that it didn't need such of an atmosphere.

My point is that it isn't because of human needs but rather other engineering problems where the Nitrogen is a nice addition. In this case, it is being used as a conductive heat sink for things like electronics. The main Shuttle guidance computers don't need the mix nor do most of the other really critical systems in the Shuttle (those are all milspec components), but there are a whole bunch of other computers used in places like the SpaceLab module or used in the ISS for monitoring science experiments, laptops for sending reports to Mission Control, or for other various housekeeping tasks that didn't exist in the Apollo era that it became an issue.

Re:Good luck Dawn (1)

tragedy (27079) | about a year and a half ago | (#41210223)

I'm pretty sure you're the one who is failing science. All you need is for the oxygen partial pressure to match Earth's and you can have a pure oxygen. In that situation, we get the right amount of oxygen to avoid deprivation and toxicity. Also, things are no more flammable than in a normal Earth atmosphere. The lower overall pressure is within the range that human beings can adapt to. We don't actually _use_ the atmospheric nitrogen for anything. Plus, if decompression occurs, no bends (of course, you'll die anyway).

Re:Good luck Dawn (1)

jamstar7 (694492) | about a year and a half ago | (#41216245)

I'm pretty sure he's more of the 'Why waste money on space when we can use it to buy votes?' school. Dealing with a 100% oxygen atmosphere is an engineering problem. Getting the oxygen where there is none is a resource/supply problem. If it's confirmed that Ceres has ice, that means there's oxygen, and a lot of problems dealing with supply ships are reduced. If the ice on Ceres is 'dirty' or if there are carbonaceous lodes on Ceres, then we can probably support a habitat there with a few years' work. Even if it takes robots to reduce the raw asteroid down. Recycling the organic materials also becomes an engineering problem.

I repeat my last. Sign me up for a colonist slot! Especially if I can take all my media files with me. Hey, gotta have something to do on my offshift. Might as well use the time to corrupt female colonists...

Re:Good luck Dawn (1)

jamstar7 (694492) | about a year and a half ago | (#41210239)

We only 'need' an 80% nitrogen mix at 1000 millibars of pressure. Drop the pressure down to 200 millibars, we'll do quite nicely on straight oxygen.

Re:Good luck Dawn (3, Interesting)

symbolset (646467) | about a year and a half ago | (#41209961)

Space is cold, and dry. It can be pretty hard to find water out there, and gas stations are far between.

Planetary Resources [planetaryresources.com] is a company in Seattle set up to mine asteroids. The big deal at first is asteroid-borne water, which comprises up to 30% of some asteroids. They are going after asteroids that pass near the Earth at first.

The big deal is what potentials this opens up for expoloration of our solar system and the stars. With energy water can be converted into LH2/LO2 fuel. The problem is that lifting up the fuel from our deep gravity well makes this prohibitively expensive.

Ceres may have 200 million cubic kilometers [wikipedia.org] of water ice, almost all of it relatively pure and on the surface, 100km thick. That's more water than all of the fresh water on Earth. Ceres has a surface gravity of 0.03 g, so getting the ice or fuel away from there is no big deal. There may be other volatiles there as well - Xenon would be a great find. We've found water on the moon and Mars, but getting the water away is nearly impossible because the gravity on these bodies is just too high. Small asteroids aren't plentiful enough for a huge explosion of exploration and manned habitation in space.

Abundant water and energy are the two essential keys to human and robotic exploration of the solar system. If we can somehow with robots bring energy and equipment to this ball of water we can bring back enough fuel to scoop much larger payloads out of much cheaper near Earth Orbits and move them anywhere from there. That enables larger habitations with centrifugal simulated gravity, water ice mass shielding from radiation, million-kilo LH2/LO2 rockets that start in microgravity and so don't have to spend 90% of their fuel lifting up out of our gravity well.

Ice makes a great construction material too, so if we found a way to put humans on Ceres they need not worry too much about radiation or building materials. It's also a great thermal insulator, and we've learned how to carve habitats out of ice in Antarctica.

In short if that water is really there it is the key to humans establishing a permanent occupation of space, and maybe the fuel we'll use to send the first probes to nearby stars. We'll know in about 30 months.

Re:Good luck Dawn (1)

c0lo (1497653) | about a year and a half ago | (#41210201)

Abundant water and energy are the two essential keys to human and robotic exploration of the solar system.

I can see the water on Ceres, the energy part is a bit tricky.
- Mars-Sun distance - varies between 1.38 AU and 1.66 AU (say 1.5 AU as an average)
- Ceres-Sun distance - varies between 2.55 AU and 2.99 AU (say 2.7 AU as an average) With a variation of of irradiation going with the inverse of square distance => a unit of surface on Ceres receives 3 times less energy from Sun then the same area on Mars. Same calculation knowing that the solar constant for Earth (1 AU) is approx 1 kW/m2 results in a 137 W/m2 on Ceres (put on top of it the 20% efficiency of a photovoltaic and you'll get... what... 27 W/m2?)

Which leads me to believe one is not going to get the energy for getting LHOx from Sun - ''t'll take ages to get something significant or deployment of a quite large area for capturing Sun's radiation.
A fission (thermo)pile [wikipedia.org] then? For a non-trivial power, it will be heavy like hell to raise it as such from the bottom of Earth's gravity well - maybe as an intermediary step, build it from materials found on... Vesta or the like? Or build/launch it on/from the Moon surface?

Re:Good luck Dawn (1)

WCguru42 (1268530) | about a year and a half ago | (#41210323)

Same calculation knowing that the solar constant for Earth (1 AU) is approx 1 kW/m2 results in a 137 W/m2 on Ceres (put on top of it the 20% efficiency of a photovoltaic and you'll get... what... 27 W/m2?)

Isn't part of the 1kW/m2 on Earth due to the atmosphere absorbing some of the energy? Ceres wouldn't have that problem. Still, that distance-squared reduction would still create issues.

Re:Good luck Dawn (2)

c0lo (1497653) | about a year and a half ago | (#41210467)

Same calculation knowing that the solar constant for Earth (1 AU) is approx 1 kW/m2 results in a 137 W/m2 on Ceres (put on top of it the 20% efficiency of a photovoltaic and you'll get... what... 27 W/m2?)

Isn't part of the 1kW/m2 on Earth due to the atmosphere absorbing some of the energy?

Yeah... [wikipedia.org] - my lazy ass didn't want to be too exact: the solar constant as seen by a satellite is approx. 1.36kW/m2. Which means on Ceres it would be 186 W/m2.

Ceres wouldn't have that problem.

I wouldn't be so sure: it can actually be worse due to the water subliming [wikipedia.org] at "day" time (a "haze" which would create an absorption - mostly in IR and UV) and condensing back at night time.
Now, if the sublimation/condensation process is not energetically balanced - and because the PV "steal" some energy it is definitely not balanced, thus the condensed ice on the PV won't get the energy to sublimate entirely - it is very likely that the PV panels will get covered in ice pretty quick (BTW the Cererian day is 9 hours and 4 minutes).

Re:Good luck Dawn (1)

symbolset (646467) | about a year and a half ago | (#41210651)

Insolation is a serious issue. It would be necessary to either use nuclear power, or first move the water closer to the sun before converting it to fuel with solar power. On orbit around Ceres the unfiltered solar energy is only a little less than on the Sahale in summer, and that is not nearly enough to do the job in a reasonable amount of time. It takes a LOT of energy to convert water to its constituent elements and then liquefy the proceeds. Think of LH2/LO2 as more of an energy storage medium than a raw product.

Re:Good luck Dawn (1)

symbolset (646467) | about a year and a half ago | (#41210615)

Very good question. Yes, we are likely to use nuclear energy for this. Remember, the plan is to lift it only to LEO, and use the Hydrox from Planetary Resources to lift it higher and send it to Ceres. Nuclear fuel is a high-density, high-value cargo and we'll need quite a lot of it. To fully exploit Ceres' water resources would deplete the entire world's available nuclear weapons and some fraction of nuclear waste from power production, and then some. Convenient, no? We were done with that stuff here anyway, and this is a cheaper way to be rid of them than any other. We need not bury them for 100,000 years if they're useful in the Asteroid belt.

Of course some legal formalities will have to be lubricated to work this out, but that's an implementation detail.

Solar panels will be used too for redundancy and for essential operations, but the bulk of the energy will probably be fission if we want to get this done in a reasonable amount of time.

Nuclear powerplants on craft like Curiosity and Voyager use an entirely different type of fuel and engine than we are talking about here, and I don't want people to think I've confused that issue here. I haven't. I know that these are different things. Frankly the kind of engine that powers Curiosity has nowhere near the energy output required to do the work we're talking about by about four orders of magnitude at least.

Re:Good luck Dawn (1)

Anonymous Coward | about a year and a half ago | (#41209627)

I'm not convinced Ceres is particularly useful as a destination. I guess I'm just not American. The ESA has given the go ahead to the only mission to interest me since Cassini Huygens - the JUICE mission to explore the moons of Jupiter, and in particular it's focusing most of its interest on Ganymede - the largest moon in our solar system, with its own magnetic field - just like Mercury. If I was going to bet on life being found in our solar system, maybe even complex life - Ganymede would be my bet. I honestly couldn't care if they find life, or more answers to age old philosophical questions I don't care about. I see our solar system in terms of these planets - Earth, moon (next most important) - we need a permanent and significant economically self-sustaining presence there imo - need to get to the ice there. Mercury (useful for studying our sun), Ganymede (object of extreme interest and studying other objects in the Jovian system - eg. Europa and the other moons. Jupiter also serves as a good sling shot for deep space missions further afield if necessary. The rest of the solar system is lower priority for me, but the most important planet and the most useful one for our space future imo is our own moon. We have been gifted with a body useful enough to provide a permanent presence near Earth. It's low gravity makes it useful and efficient for heavy engineering. As for long term colonization on another planet, I have to admit that Mars is one of the only serious candidates. I think it's possible Ganymede, with its potential geothermal energy, and a stable magnetic field could be a potential candidate for this too. But in the great scheme of things, we need to look outside our solar system, and that means propulsion is vital. I'm not interested in human missions to Mars, but if they insisted, Mars semi-direct is the way to go there I think. Is there a secret space program run by the air force?

Re:Good luck Dawn (1)

mister_playboy (1474163) | about a year and a half ago | (#41209777)

As this image [wikipedia.org] makes clear, Ganymede's magnetic field protects only the equatorial latitudes from Jovian radiation. The rest of surface is bombarded with heavy ions, although the surface radiation levels are admittedly much lower than on Io or Europa.

If life were to exist there, it would probably be in the subsurface oceans (as with other candidate moons) where the presence of the magnetic field is of less importance.

Re:Good luck Dawn (2)

Dr. Spork (142693) | about a year and a half ago | (#41209873)

Exactly, and there wouldn't be much point to humans living in some under-ice ocean, just to be able to say "Gee whiz, I'm actually living on Ganymede! Look at me here, living!". There are many more places for us to live under the sea on our own planet. Yes, that sounds stupid, but us living on any other planet - with the possible exception of Mars - would be even more stupid. But there are "sky is falling people" who think we will screw up the Earth, and will only survive as a species if we move to space. To them I want to say that if this is what you're worried about, start an undersea colony. It's orders of magnitude cheaper than a Martian colony, much more likely to be self-sustaining (drawing uranium from seawater, using that for energy and desalination), and will hardly even notice climate change, massive nuclear wars or most meteorite strikes. I think the Beatles had a song about this.

Re:Good luck Dawn (0)

Anonymous Coward | about a year and a half ago | (#41209947)

and to you they may say "Then some day, land based carnies will come and find me and wreck my colony".
Not to mention that mankind has a greater chance of survival if an apocalypic event destroys the Earth.

Re:Good luck Dawn (3, Interesting)

symbolset (646467) | about a year and a half ago | (#41210191)

This is an interesting point. A sufficiently deep subsea human habitat that was self-sufficient might be enough to preserve mankind against even a planet-killer asteroid, if it survived the initial shock wave. Certainly many aquatic species survived the last dinosaur killer, including sharks. If you put it at the equator it should be safe from ice ages. Geothermal energy would be persistent enough, even if the uranium from seawater thing didn't work out. It would have to be a subsea city with pop > 100k though to provide a persistent level of science and culture.

There's probably a good trilogy of books in this one if you want to develop it.

Not proof against nuclear war though. If I know anything about my fellow men, they're griefers and when the shit hits the fan a subsea survival habitat is going to have several torpedos with its name on them, some of them nuclear.

Re:Good luck Dawn (1)

Teancum (67324) | about a year and a half ago | (#41210373)

As much as the notion of aquatic habitats may seem romantic, the engineering requirements for sustained deep sea habitation are in some ways much more extreme than even going to Mars or the Moon. Keep in mind that the pressure going underwater doubles after just a few feet. Going from sea level to the Kármán line in altitude only has a drop of about 1 bar of pressure. Since that is practically zero, it can't get any worse. If you go diving just a few feet deeper, depending on where you are at, it can get a whole lot worse going down.

I'm not saying that it shouldn't be attempted either, but the engineering requirements for seabed habitation in some ways make Mars look very hospitable for human civilizations. The plus side of seabed habitation is that logistical supply lines are much easier to maintain than going to Mars, so there are compromises either way.

Surface seasteading, on the other hand, seems to be very promising in spite of the fact that nobody has really been successful at doing that with 21st Century technology. It has been done on some lakes in South America by indigenous people, so in theory it should be possible to sustain a culture in that manner.

Re:Good luck Dawn (1)

khallow (566160) | about a year and a half ago | (#41210609)

Surface seasteading, on the other hand, seems to be very promising in spite of the fact that nobody has really been successful at doing that with 21st Century technology.

They've been successfully doing it since ancient times. The current very successful model is seasteading by ship with occasional stops in specialized structures called docks and harbors.

Re:Good luck Dawn (1)

Teancum (67324) | about a year and a half ago | (#41213261)

Surface seasteading, on the other hand, seems to be very promising in spite of the fact that nobody has really been successful at doing that with 21st Century technology.

They've been successfully doing it since ancient times. The current very successful model is seasteading by ship with occasional stops in specialized structures called docks and harbors.

While a few people do seem to live their lives almost permanently aboard ship, they really are transportation devices to get you from one place to another and not a place where civilizations form and act independently.

There really is a difference between a ship and an island or city. There is also the difference between a spaceship and a settlement in space as well, even though you can build a city in the middle of the ocean just as much as you can build a city in some random spot in space.

I think it could be argued that if you are going to try and build the L-5 colony, why not at least at first try to build a "colony" in the Sargasso Sea? Unlike claims about people trying to "settle" Antarctica before trying Mars (or in the above discussion Ceres), there really aren't any significant international treaties that are stopping a group of folks building a whole bunch of barges and other relatively stable vessels and building a city in what could arguably be a pretty nice place to live (as temperate as the Bahamas, plenty of access to food and even fresh water (if you collect rain), and far enough away from other locations on the Earth that you can in theory flip the bird to other governments and start your own if you care. Unlike a micronation like Sealand, there is also room to expand and grow so in theory you could have a large enough population for a viable community as well.

There are limited locations where such a sea community could legitimately be established, but many of the same issues that will eventually need to be addressed for space colonization certainly could be applied from efforts at such "seasteading" efforts.

The only real ancient example of seasteading is with the people who lived on Lake Titicaca [environmen...affiti.com] , where a society exists with children being born "at sea" is normal instead of a very rare exception, and for those children along with hundreds of other children to spend their lives on floating platforms as a way of life where they reasonably expect to have their own children also live that way. It does require some technology in order to make that happen even in the case of the , but it doesn't need to be very sophisticated. [wikipedia.org]

If you can show a similar kind of group existing today to the Uru people but using cruise ships or something like that, I love to know about it. There is a group at seasteading.org [seasteading.org] which has a bunch of dreamers hoping some day to do a thing like this. It is worth looking at, but there certainly are challenges to the idea.

Re:Good luck Dawn (1)

khallow (566160) | about a year and a half ago | (#41216419)

While a few people do seem to live their lives almost permanently aboard ship, they really are transportation devices to get you from one place to another and not a place where civilizations form and act independently.

Even so, they're seasteading examples. And some of the most profound changes in society have come from ships such as the voyage of the HMS Beagle on which Charles Darwin made the observations that became the theory of evolution, or any number of decisive sea battles (such as the battles of Midway, Jutland, or Salamis).

Re:Good luck Dawn (1)

symbolset (646467) | about a year and a half ago | (#41210681)

Surface seasteading doesn't protect us against an asteroid or nuclear war. It's an interesting social solution to other problems, but it doesn't address the whole "We're all going to die" thing. I'm all in favor of it for the benefits that you present, but it doesn't address the core issue in this discussion. An asteroid hit wipes it out. A nuclear hit wipes it out. It's not a backup plan.

It's an interesting segwey I'd like to see have its own discussion, but it's out of place here.

Re:Good luck Dawn (1)

symbolset (646467) | about a year and a half ago | (#41210893)

The advanced technology I need to preserve atmosphere at any reasonable depth is called a "cup".

Re:Good luck Dawn (1)

Teancum (67324) | about a year and a half ago | (#41213375)

The advanced technology I need to preserve atmosphere at any reasonable depth is called a "cup".

Or so people used to think, including John Roebling [wikipedia.org] when he was building the Brooklyn Bridge in New York City. Unfortunately the workers on that bridge developed something called Caisson Disease [wikipedia.org] , named after the affliction first significantly noticed by the workers who died building that bridge in NYC. In fact Roebling himself died from complications of decompression sickness as he entered the cassion regularly to check on the progress of the workers.

There are numerous health problems with using a cup like you are mentioning, and "reasonable depths" are only a hundred meters or so before it stops being effective. That is hardly living on the bottom of the ocean, where you need other kinds of technology simply to survive going to those depths. Even trying to live on the deeper parts of a continental shelf require some interesting technologies that really haven't been built out too much. It isn't nearly as romantic as it seems at first glance, and you need something more than a simple cup.

Nice try though. At least you are thinking about the idea.

Re:Good luck Dawn (1)

Legion303 (97901) | about a year and a half ago | (#41211749)

But there are "sky is falling people" who think we will screw up the Earth, and will only survive as a species if we move to space.

I've never heard of a single person who wants the species to get into space because he's worried about humans screwing up the planet. I have heard of many, many people who want us to get into space because of the odds of another asteroid strike destroying most of earth's life again.

Re:Good luck Dawn (1)

symbolset (646467) | about a year and a half ago | (#41210039)

Jupiter is twice as far out from the sun as Ceres, meaning that it's usually almost three times as far from the Earth at closest approach. Coming away again is harder too, as surface gravity is 6 times as high. I should think that having a heavy-duty supply of propellant from Ceres or other sources would help get the resources there for proper development of Ganymede.

Re:Good luck Dawn (0)

Anonymous Coward | about a year and a half ago | (#41211143)

Given that Ceres has the water that Mars lacks, as well as additional mass, perhaps researching how Ceres could be crashed into Mars would be worthwhile. That's be the fastest terraforming job ever.

Re:Good luck Dawn (1)

Provocateur (133110) | about a year and a half ago | (#41211597)

But if we do nail both Ceres and Mars somehow, then we can have the Vesta both worlds. How about it, science?

But... what about Tony Orlando? (1)

macraig (621737) | about a year and a half ago | (#41209287)

Are they leaving him behind on Vesta? I guess it's about time. Maybe his act will be fresher for the Vestans....

Re:But... what about Tony Orlando? (2)

Mathinker (909784) | about a year and a half ago | (#41209407)

This has to be the first time my brain has ever associated Tony Orlando with Marooned Off Vesta.

Dwarf Planet (0)

Anonymous Coward | about a year and a half ago | (#41209321)

Sounds like an idea for a trilogy of movies by Peter Jackson... beginning with a release late November.

Re:Dwarf Planet (1)

catmistake (814204) | about a year and a half ago | (#41209455)

weirdly... it kind of does. Once again I find myself questioning the alleged import of noting the distinction between so called dwarf planets and all the others. Why did we need to do that again?

Of dwarves and giants (1)

aNonnyMouseCowered (2693969) | about a year and a half ago | (#41209547)

This is so we can fight over whether to call some rock a "dwarf" planet or a "giant" asteroid. Or we can start call Vesta a mini dwarf planet and Ceres a super giant asteroid.

Re:Dwarf Planet (1)

DMUTPeregrine (612791) | about a year and a half ago | (#41209631)

It clears up the "planet vs asteroid big enough to be round" debate. While I don't fully get how the "cleared the vicinity of its orbit" is unambiguous in most cases it seems that Astronomers think it is, so I'll take their word on that. Unambiguous definitions are almost always better.

Re:Dwarf Planet (1)

symbolset (646467) | about a year and a half ago | (#41210259)

If you want an unambiguous definition of Vesta, use the entire Wikipedia article [wikipedia.org] . It is "Vesta," a thing unique unto itself. If we want to group it into classes of similar things and give those classes names, we have to agree on the scope and definition of those classes, and generally we don't because we disagree about the relative importance of various aspects of the objects worthy of categorization. I'm OK with that. It's a thing. It has a name. The various classes have very little value-add.

Re:Dwarf Planet (1)

Teancum (67324) | about a year and a half ago | (#41210401)

The part about the IAU definition that I can't get over is the strongly heliocentric definition, as the only bodies that can be legitimately called a planet according to the definition can only be orbiting the Sun. Ditto on the "clearing vicinity of its orbit" debate as that sort of presumes a 2-4 billion year minimum age of the planetary body in question as well which none of the current planets in the Solar System would have qualified under during an earlier era of even the Solar System.

That also sort of precludes that anything being discovered by the Kepler spacecraft even being called legitimately a planet, especially since there is no reason to believe that "clearing the vicinity of its orbit" can even be determined at all other than to say smaller Earth-sized planets aren't necessarily in the same rough orbit as a gas giant like Jupiter... perhaps. Some weird stuff has been discovered by Kepler, so even that might be something to look for.

Re:Dwarf Planet (1)

mbone (558574) | about a year and a half ago | (#41210003)

So that the people finding big things in the Kuiper belt don't get to call the ones bigger than Pluto planets, and thus give us a solar system with 15 or 20 planets.

(Hey, I didn't say it was a good reason, but that is what I heard drove it.)

"NASA Craft to Leave Vesta Heads" (0)

Anonymous Coward | about a year and a half ago | (#41209325)

It leaves me wondering what "Vesta Heads" is.

Orbiting an asteroid (3, Insightful)

tomhath (637240) | about a year and a half ago | (#41209359)

This kind of control just amazes me. Orbiting a dinky little asteroid, just amazing.

Re:Orbiting an asteroid (1)

symbolset (646467) | about a year and a half ago | (#41210235)

Yes, it really is, even though calling Vesta dinky is a bit of a stretch. It has more surface area than Texas by almost twice. Almost a million square kilometers.

Re:Orbiting an asteroid (1)

daid303 (843777) | about a year and a half ago | (#41212117)

If you want to feel this kind of control yourself, try the Kerbal Space Program.

Vesta flyby video (4, Interesting)

Narishma (822073) | about a year and a half ago | (#41209417)

Here's a cool video [youtube.com] generated from pictures taken by the probe as it orbited the asteroid.

Face on Vesta (1)

aNonnyMouseCowered (2693969) | about a year and a half ago | (#41209643)

Too bad it's just a CGI animation. Around the 0:30 mark you see what looks surprisingly like a coconut with two eyes and the beginings of a mouth or nose. More stuff for alien conspiracy theorists to shake their stick at.

And the point is... (-1)

Anonymous Coward | about a year and a half ago | (#41209423)

Why, when we have a recession that has not seen any improvement since '08, are we borrowing billions from China for this stuff? Shouldn't the Federal government actually do something other than ensure a "lost century", just like what Japan had, except for far longer, especially when people stop respecting useless fiat currency fresh off the printing press?

This is something that private industry needs to do. Not fat-cat bureaucrats.

Re:And the point is... (1)

mug funky (910186) | about a year and a half ago | (#41209611)

i think once it's left the planet we stop spending money on it, and just maintain the systems down here.

btw, you're a dick.

your interest in finance would make you a good accountant, however i fear you only have sufficient imagination to be a mediocre accountant.

Re:And the point is... (0)

Anonymous Coward | about a year and a half ago | (#41210855)

Why, when we have a recession that has not seen any improvement since '08, are we borrowing billions from China for this stuff? Shouldn't the Federal government actually do something other than ensure a "lost century", just like what Japan had, except for far longer, especially when people stop respecting useless fiat currency fresh off the printing press?

This is something that private industry needs to do. Not fat-cat bureaucrats.

I see the tea-party contingent has returned home from the RNC.

Dear Slashdot: (5, Insightful)

fustakrakich (1673220) | about a year and a half ago | (#41209633)

When posting NASA news, it's always best to go to NASA itself [nasa.gov] . Avoiding ad cluttered sites will help reduce excess traffic on our limited bandwidth.

Re:Dear Slashdot: (1)

Teancum (67324) | about a year and a half ago | (#41210417)

That mostly depends on the submitter. Next time you submit a story like this, make sure you follow your own advise on this matter. Perhaps eventually it will catch on too.

Re:Dear Slashdot: (1)

fustakrakich (1673220) | about a year and a half ago | (#41210505)

I always go as close as possible to the source of a story* when making a submission... 100% of the time. The editors can do the same before posting the submissions that don't. But they and Google Analytics have a different agenda.

* short of linking to paywalls and anything that requires registration.

Equipment problems? (1)

Tablizer (95088) | about a year and a half ago | (#41210741)

Didn't the probe have some flaky gyroscopes or the like a few months ago? Last I read, they risked the entire Ceres mission. Two were malfunctioning, not just one. Haven't seen an update.

Re:Equipment problems? (1)

Anonymous Coward | about a year and a half ago | (#41211985)

Eh, the second (of four) reaction wheel was shut down due to excessive friction torque; when the first one failed in 2010, they started working on software to fly with only two (+ hydrazine jets, but using much less fuel than hydrazine-only). It also spent most of the rest of the cruise phase with none, using hydrazine jets + gimballing the ion thruster for all attitude control, to save the remaining wheels' wear life for use on orbit at Vesta and Ceres, and will do the same while cruising to Ceres. They also changed RCS parameters to reduce hydrazine consumption, so it's not really a big issue -- they'll definitely get to Ceres and perform a lot of science, possibly the entire mission. Just means they'll have less attitude control budget at Ceres, and there's still the possibility that one or both failed wheels can be recovered (e.g. by running it back and forth repeatedly, though this seems unlikely), or permitted to operate with higher friction limits, if the situation becomes bad enough.

Re:Equipment problems? (1)

Anonymous Coward | about a year and a half ago | (#41212111)

I don't know what it is with reaction wheels, but there's a long line of missions where they have been one of the most serious things to fail, sometimes very early in the mission (Dawn, Hubble, FUSE, Hayabusa, Kepler, etc.). It seems like every second mission has unexpected problems with them. I know they are mechanical, mechanical means wear-and-tear, and space is about the harshest environment to operate in, but is it really the case that we've been building these things for 4 or 5 decades and yet early and sometimes multiple failures is still a problem? I know the general principle behind reaction wheels, but can anyone with more experience explain why these things are so tricky to build?

ASTEROID STRIKE ON THE WAY? (0)

Anonymous Coward | about a year and a half ago | (#41210961)

It amazes me how naive people have become. Last week there was a mass fish kill along hundreds of miles of Texas beach. Tens of thousands of fish are dead because of red tides, that are caused by agricultural runoff. Of course, most Americans wouldn't be too concerned about the death of our oceans, especially if they live inland. I mean, it would stink a bit is all, right? I hate to be the one to inform you that our Oceans create 75% of the Earth's oxygen. Duhhhhhh! World population is doubling every 35 years, more and more countries are industrializing and creating more and more pollution, and you're worried about an asteroid strike or life on Mars? Google: red tides, ocean dead zones, and mass fish kills to monitor how long you have left to live. Perhaps only 20 years. Mankind is just a zombie breeder like a cancer. Breeding, breeding, breeding, until the host dies. For more wisdom, read "The Healthcare guide for Republicans", ebook at Amazon or Apple. In the first two pages I explain how you can get free healthcare at any hospital in the U.S. mensunion org

Punctuation (1)

wonkey_monkey (2592601) | about a year and a half ago | (#41211047)

NASA Craft To Leave Vesta Heads For Dwarf Planet Ceres Forgets To Include Comma Makes Headline Hard To Parse

DevotedSkeptic [devotedskeptic.com] writes^H^H^H^H^H^H^H copies and pastes

And FTFY too.

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