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NASA / JPL-Caltech / UCLA / MPS / DLR / IDA
This image mosaic synthesizes some of the best views that NASA's Dawn spacecraft obtained during more than a year in orbit around the asteroid Vesta. A towering mountain, rising more than twice the height of Mount Everest, sticks out from the south pole at the bottom of the image. A chain of three craters known as the "Snowman" can be seen at top left.
NASA's Dawn mission is saying Hasta la Vesta with a series of parting shots showing the asteroid Vesta, unveiled as the probe hightails it for the dwarf planet Ceres, the next stop on its eight-year, 3-billion-mile (5-billion-kilometer) itinerary.
The newly released pictures were taken as the Dawn probe wound down more than a year's worth of observations while in orbit around Vesta, an acorn-shaped world in the main asteroid belt. Dawn's $466 million mission was launched in 2007 and is aimed at studying the composition of Vesta as well as Ceres, two huge asteroids that are thought to preserve a record of the solar system's earliest days.
Dawn's data showed that Vesta has a chemically complex surface and an iron core. Based on its scars, the protoplanet appears to have suffered a mighty cosmic impact not just once, but twice in the past couple of billion years.
If it weren't for Jupiter's disruptive gravitational influence, Vesta might well have grown to become a major planet. "We can now say with certainty that Vesta resembles a small planet more closely than a typical asteroid," UCLA's Christopher Russell, the mission's principal investigator, said last month.
Dawn officially left Vesta's orbit during the night of Sept. 4-5, and its ion propulsion drive is gently pushing the probe toward a rendezvous with Ceres in 2015. Russell and his colleagues said today's images represent the last routine daily delivery from the mission during the three-year cruise, although other images may be highlighted as fresh findings are made.
"Dawn has peeled back the veil on some of the mysteries surrounding Vesta, but we're still working hard on more analysis," Russell said in today's news release. "So while Vesta is now out of sight, it will not be out of mind."
NASA / JPL-Caltech / UCLA / MPS / DLR / IDA
An elevation map from NASA's Dawn probe shows the topography of the northern and southern hemispheres of Vesta, updated with readings gathered during Dawn's last look back. Colors represent distance relative to Vesta's center, with lows in violet and highs in red.
NASA / JPL-Caltech / UCLA / MPS / DLR / IDA
This image from NASA's Dawn mission, released Sept. 10, shows a shadowy view of the asteroid Vesta's northern hemisphere, using pictures obtained during Dawn's last look back. The mosaic is composed of five images obtained by Dawn's framing camera on Aug. 26, while the probe was at an altitude of 4,000 miles (6,000 kilometers).
This video highlights Dawn's top accomplishments during its orbit around the giant asteroid Vesta.
Researchers expect to see a markedly different world when Dawn gets to Ceres. Unlike 330-mile-wide (530-kilometer-wide) Vesta, 583-mile-wide (940-kilometer-wide) Ceres is so massive that its gravity has crushed the world into a basically spherical shape — which is why the International Astronomical Union classifies it as a dwarf planet. Ceres has a differentiated crust, icy mantle and core, and may have a higher water content than Earth.
"Almost everything we see at Ceres will be a surprise, and totally different from Vesta," Russell said last week.
Months after Dawn's arrival at Ceres, NASA's New Horizons probe will fly by my favorite dwarf planet, Pluto, and its brood of moons. How will Ceres and Pluto compare? Will we see polar frost caps on Ceres? Ice volcanoes on Pluto? Stay tuned for 2015, the year of the dwarf planets.
More about Vesta and the dwarfs:
- Vesta is a protoplanet, scientists say
- Flash interactive: The new solar system
- Take a tour of five dwarf planets
- Pluto debate is about more than just one little world
Alan Boyle is NBCNews.com's science editor. Connect with the Cosmic Log community by "liking" the log's Facebook page, following @b0yle on Twitter and adding the Cosmic Log page to your Google+ presence. To keep up with Cosmic Log as well as NBCNews.com's other stories about science and space, sign up for the Tech & Science newsletter, delivered to your email in-box every weekday. You can also check out "The Case for Pluto," my book about the controversial dwarf planet and the search for new worlds.
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Very interesting! We need to boost our space traveling capabilities. ISS, space taxis to the moon, base on the moon, plans for Mars and beyond. Lets go USA, get movin!
Agreed, and that is happening, but ISS has been and remains a negative -- low-Earth orbit with no real function other than to continue the myth that humans currently have value in space. Love those robots though!
yea, it'd just be a hell of a note if the iss would of stuck around to build MORE spacestations, I dunno, maybe some ships built in LEO to leave LEO....I think servicing and placing NSA equipment ALONE would of paid for itself, after all, the dod went ahead and made one of thier own to pick up where the REAL one left off.....my god.
And of all things, I have been saying for over a decade, launch cubesats from the iss...well guess what hte japanese are doing now???
One of the dumbest things ever done was to cancel the shuttle while we had citizens on the zara, err, iss to us americans......why the political ball in the air? some people not see the white through all the red and blue???
We are not giving up. We are going back to the moon, some of you can sit on yer buts and watch.
Just one tiny CAVEAT here, in my humble opinion. ie.
Since Mother Universe has been "Show and Telling" us more and more frequently to "Get off my back, you loud, noisy, EGO-FLEAS..."
maybe it's not such a great idea to expose her to that same loud, NOISY ROCK MUSIC since that could aggravate things MORE. She'll be thinking - "Oh NO, just when I plan to take my pristine and originally QUIET EARTH back - here they come with their NOISY and angry ways up here?
Gotta rethink all this letting them explore up HERE, I guess."
?
For the benefit of those who simply comment on things BEFORE actually seeing , and / or viewing ALL the videos, etc., ie. the MAJORITY of posters, sadly and most likely, the above is in reference to the loud ROCK MUSIC that accompanies the 4th video.
You're welcome.
Great Photos.
Go Go NASA!
I like the trough explanation, never would have thought of that because it's land, but they say asteroids are softer with so little gravity
Ion drive is starting to look like a seriously useful tool. Maybe a way to get away from kissing the butts of middle-east sheiks to get fossil fuel for space travel.
The problem with fossil fuel and spacecraft is not the fact that we have to get it from crazies in the Middle East; we have some here too, crazies and fuel, quite a lot actually. It's the mass. More mass means more rocket means more fuel which means more mass, ever more, more, more....
Jerryb's comment about ion drive is right-on.
Nuclear-ion drive makes great sense for long-term acceleration to high speeds without having to do multi-year, out-of-the way, planetary flybys for a gravitational sling. The chemical ion-propulsion we are using now is orders of magnitude less powerful and efficient than that. It's like driving a spacecraft with an asthma-inhaler!
Mike, thanks for the thoughtful reply. I'll need to research nuclear vs chemical ion-propulsion. At the moment I don't understand the distinction. Thanks for planting the topic in my head.
"More mass means more rocket means more fuel which means more mass, ever more, more, more...."
Darn, ion drives aren't magic. That's true of them, too. The 'equation' changes when you have high specific impulse, but low thrust. Ion drives won't get you off Earth's surface, or that of any but the very weakest gravity objects. (to do that, total thrust must always be greater than the weight of the ship)
Even starting in space, you trade efficiency for...patience. (You don't want to depart from LEO to a deep space mission on ion propulsion because it means gradually spiraling around Earth many times as you build up to escape velocity, spending a lot of time in the Van Allen belts as you do [good for neither humans, nor solid-state electronics]. A high-thrust chemical or nuclear-thermal [still high thrust, but higher specific impulse than chemical] rocket going from LEO to escape departs almost at a tangent, cutting across the belts quickly.)
But the only way you can effect a velocity change in vacuum, under known physics, is a rocket* (throw stuff one way, go the other) of some kind...it's just that the reaction mass doesn't have to be a hot product of combustion.
(* Okay, lightsails are a little more involved, but photons carry momentum, Newton's Third Law still applies....and they, too, are inherently low thrust devices, for any practical intensity of light, and/or area of sail.)
Frank, I understand that ion drives are not magic and do not escape physical principles. Only crystals are magic :). The key is.... patience..... which I have and many who post here lack. My patience may cost me the opportunity to live to see humans on Mars but my principles don't change for selfish reasons.
Rest assured, I realize that nothing is free.
Alan... you have the coolest job in the world, and you do it well. :)
sorry about all that, really just wanted to say, wonder how long till we get a manned observation post on vesta!!!...will it be before or after the diamond mining companies tear it up???....hope I get there and get the platinum first!!!
Holy crap.... nice work NASA. Thanks for continuing to inspire imagination, even after the shuttles have fallen silent. This is really amazing stuff, what an amazing age we live in!
So, we'll spend a year studying a 330 mile -wide asteroid, which is about 170 million miles from Earth but we'll pass up more manned exploration of our Moon, which is 6 times bigger, and only 240,00 miles away! Given the way Mr. Obama calculates and sets priorities, I shouldn't be surprised! (Let's throw Israel under the bus and be friends with Libyans!) No doubt, some interesting things were learned about Vesta. Same will true for Ceres. We could mine materials on the Moon and set up a permanent base there, with a mission to include looking for potential life-killer asteroids What do we get from Vesta? It's like studying gnats in a dinosaur fossil bed!
"So, we'll spend a year studying a 330 mile -wide asteroid, which is about 170 million miles from Earth but we'll pass up more manned exploration of our Moon, which is 6 times bigger, and only 240,00 miles away!"
1. This is cheaper. It's not either/or. Not doing this would not get you back to the Moon instead.
2. We were operating planetary probes when we were going to the Moon. NASA does not, and never has done just one thing. But if boots on the ground are all that matter to you...
3. Don't you think that at some time in the future, humans will go to the main belt asteroids, too? Best we get some information now...
"No doubt, some interesting things were learned about Vesta."
That's the idea, isn't it?. Even when you send people somewhere, that's what they do.
"We could mine materials on the Moon and set up a permanent base there,..."
We could do plenty of things with deep enough pockets. What's your point? Again, you won't do it for the cost of this mission. And profitable mining anywhere is more in the realm of commercial space flight. Actual mining's not NASA's job, is it?
"...with a mission to include looking for potential life-killer asteroids."
You don't need to leave Earth at all, to get better at that. Lobby for more and better (and not large at all) telescopes dedicated to such searches. But since virtually every near-Earth object was once a main belt asteroid (generally deflected by Jupiter), I guess we should have missions to learn something of their physical natures (and learn some other 'interesting things'), so as to devise the best way to deflect them...oh wait. We're doing that, aren't we?
Every time I look at photos of different asteroids, I cringe because it appears that every square inch of them is covered with craters. I can't even imagine the violence of such a thing and how the original mass of rocks would survive. It would seem like a car getting shot by a one of those Gatling guns using Uranium bullets: it would just disintegrate under the impact. Ouch!
I also keep wondering why we haven't sent out a rocket to investigate some of the asteroids that zip by earth so frequently, since these are the guys that count. However, in thinking on it, perhaps even a small rocket circling these very small asteroids would deviate their orbit a tiny bit, enough to then hit the earth. So, perhaps they don't want to deal with the possible liability?
"I can't even imagine the violence of such a thing and how the original mass of rocks would survive. It would seem like a car getting shot by a one of those Gatling guns using Uranium bullets: it would just disintegrate under the impact. Ouch!"
Sometimes they do, depending on the mass and velocity of the incoming object. But the impacts are also not great enough to do that. Some may be just barely enough to break something up, but not enough for most of the fragments to reach 'escape velocity,' and they gradually re-coalesce under their weak gravity. Such 'rubble piles' may be especially difficult to deflect if one comes this way. They may not respond to, say, a nearby nuclear detonation as a solid body would.
"I also keep wondering why we haven't sent out a rocket to investigate some of the asteroids that zip by earth so frequently, since these are the guys that count."
By the time we know it, it's too hard to throw a probe together that could match speeds with one of these. Besides, the closer a NEO comes, the easier it is to study with existing ground-based and orbiting assets, even radar.