I don't think they were talking about the hill, they were pointing to the canyon filled with dust next to it.Originally Posted by cjameshuff
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I don't think they were talking about the hill, they were pointing to the canyon filled with dust next to it.
Forming opinions as we speak
Order of Kilopi
Then why'd they title the picture "Unusual Hill on Vesta" instead of "Unusual Canyon on Vesta", and include an arrow pointing at said hill?
My best guess is that it doesn't really look like an impact-formed feature. If they're going to take the time to include an arrow, though, a few words of explanation would be nice...
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Is it perhaps the sawtooth shape? But it seems not that unusual for this asteroid.
Order of Kilopi
As far as I know, this is the only body we have come across with a straight arrow of material with an exceptionally high albedo
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It does look to be one example of Vesta's ripply hills: http://apod.nasa.gov/apod/ap110919.html
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Dawn has achieved the altitude for HAMO. It will take another little while before the orbit is perfected.
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Every time I see GRaND referenced, I see GRoND, instead. I have to stop myself wondering why Dawn would have a battering ram.
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From Science News
Vesta might be a planetary runt, but it holds bragging rights to one of the solar system’s highest peaks.
Rising 20 kilometers from the floor of an enormous impact basin in the asteroid’s south pole, Vesta’s massif is taller than Hawaii’s Mauna Kea — Earth’s highest mountain when measured from the bottom of the ocean. Vesta’s peak is still smaller than the solar system’s reigning giant, a Martian volcano called Olympus Mons. But then, Vesta is only 530 kilometers in diameter to Mars’s 6,800 kilometers. Scientists haven’t named the protrusion yet, but the crater is named Rheasilvia, after the mythological mother of the twins who founded Rome.
Chris Russell, principal investigator of NASA’s Dawn mission, says he now considers Vesta the smallest terrestrial planet in the solar system. “Like Earth, Mars, Venus and Mercury, Vesta has an ancient basaltic crust, lava flows going across the surface, and it also has a large iron core,” he says. “It has tectonic features, like on Earth: rift valleys, ridges, cliffs, hills and a giant mountain.”
These and other new results from the Dawn spacecraft, which has been circling Vesta since mid-July, were presented October 3 during a joint meeting of the American Astronomical Society’s Division of Planetary Sciences and the European Planetary Science Congress.
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Has the Dawn team released new figures for the mass and size of Vesta?
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Yes, they have. I'll give you the numbers straight. I can't find my source for these figures, but they should be right. Diameter is averaged.
Mass: 2.59E+20 kg (259,000,000,000,000,000,000 kg)
Diameter: 524 km
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Transitioning from high-altitude orbit to low-altitude orbit
With a truly amazingly productive HAMO phase complete and the spacecraft ready to venture on, plans are all in place for what may be the most arduous phase of the mission. On November 2 at 5:20 a.m. PDT, the ship will set sail again with its ion propulsion system to push down to its lowest orbit. It will take more than five weeks to reach LAMO. In the next log we will check in on the probe’s progress and consider some of the obstacles to be overcome in dipping so low.
Everything I need to know I learned through Googling.
Order of Kilopi
A bit lighter than expected; and less dense...very low density, considering the composition
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LAMO is expected to start on 12 December. This is the latest comment from the Dawn status update.
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3.44 g/cc, that's between the densities of the moon and mars.
Order of Kilopi
So Vesta's a terrestrial planet? But it hasn't cleared its orbit!
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
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Who said planet? No one. Please don't be a provocateur.So Vesta's a terrestrial planet? But it hasn't cleared its orbit!
Forming opinions as we speak
Order of Kilopi
In answer to your question, from NASA:
(Quoted by Swift in post #68)Chris Russell, principal investigator of NASA’s Dawn mission, says he now considers Vesta the smallest terrestrial planet in the solar system.
Last edited by Noclevername; 2011-Nov-19 at 11:30 PM.
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
Order of Kilopi
Large iron core...I wonder what other metals could be found there...
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Latest press release:
NASA's Dawn Spirals Down to Lowest Orbit
The full version of this story with accompanying images is at:
http://www.jpl.nasa.gov/news/news.cf...lease_2011-384
PASADENA, Calif. – NASA’s Dawn spacecraft successfully maneuvered into its closest orbit around the giant asteroid Vesta today, beginning a new phase of science observations. The spacecraft is now circling Vesta at an altitude averaging about 130 miles (210 kilometers) in the phase of the mission known as low altitude mapping orbit.
“Dawn has performed some complicated and beautiful choreography in order to reach this lowest orbit,” said Marc Rayman, Dawn chief engineer and mission manager based at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “We are in an excellent position to learn much more about the secrets of Vesta’s surface and interior.”
Launched in 2007, Dawn has been in orbit around Vesta, the second most massive object in the asteroid belt between Mars and Jupiter, since July 15. The team plans to acquire data in the low orbit for at least 10 weeks.
Dawn’s framing camera and visible and infrared mapping spectrometer instruments will image portions of the surface at greater resolution than obtained at higher altitudes. But the primary goal of the low orbit is to collect data for the gamma ray and neutron detector (GRaND) and the gravity experiment. GRaND will be looking for the by-products of cosmic rays reflected off Vesta to reveal the identities of many kinds of atoms in the surface of Vesta. The instrument is most effective at this low altitude.
Close proximity to Vesta also enables ultrasensitive measurements of its gravitational field. These measurements will tell scientists about the way masses are arranged in the giant asteroid’s interior.
“Dawn’s visit to Vesta has been eye-opening so far, showing us troughs and peaks that telescopes only hinted at,” said Christopher Russell, Dawn’s principal investigator, based at UCLA. “It whets the appetite for a day when human explorers can see the wonders of asteroids for themselves.”
After the science collection is complete at the low altitude mapping orbit, Dawn will spiral out and conduct another science campaign at the high altitude mapping orbit altitude (420 miles, or 680 kilometers), when the sun will have risen higher in the northern regions. Dawn plans to leave Vesta in July 2012 and arrive at its second destination, the dwarf planet Ceres, in February 2015.
Dawn's mission to Vesta and Ceres is managed by JPL for NASA's Science Mission Directorate in Washington. JPL is a division of the California Institute of Technology in Pasadena. Dawn is a project of the directorate's Discovery Program, managed by NASA's Marshall Space Flight Center in Huntsville, Ala. UCLA is responsible for overall Dawn mission science. Orbital Sciences Corp. in Dulles, Va., designed and built the spacecraft. The German Aerospace Center, the Max Planck Institute for Solar System Research, the Italian Space Agency and the Italian National Astrophysical Institute are international partners on the mission team.
More information about the Dawn mission is online at: http://www.nasa.gov/dawn .
To follow the mission on Twitter, visit: http://www.twitter.com/NASA_Dawn .
Jia-Rui C. Cook 818-354-0850
Jet Propulsion Laboratory, Pasadena, Calif.
jccook@jpl.nasa.gov
- end -
Everything I need to know I learned through Googling.
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Dawn Obtains First Low Altitude Images of Vesta
NASA's Dawn spacecraft has sent back the first images of the giant asteroid Vesta from its low-altitude mapping orbit. The images, obtained by the framing camera, show the stippled and lumpy surface in detail never seen before, piquing the curiosity of scientists who are studying Vesta for clues about the solar system's early history.
At this detailed resolution, the surface shows abundant small craters, and textures such as small grooves and lineaments that are reminiscent of the structures seen in low-resolution data from the higher-altitude orbits. Also, this fine scale highlights small outcrops of bright and dark material.
A gallery of images can be found online at: http://www.nasa.gov/mission_pages/da...ery-index.html .
Everything I need to know I learned through Googling.
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Dawn Journal: The Om of orbit adjustment
Also the news that the mission planners kept 40 days in reserve for contingencies. None of those days have been used, so they're putting them all into the Low-Attitude Mapping Orbit (LAMO) session. Once that is done, they'll go into HAMO-2 and in July head out for Ceres.Dawn concludes 2011 more than 40 thousand times nearer to Vesta than it began the year. Now at its lowest altitude of the mission, the bold adventurer is conducting its most detailed exploration of this alien world and continuing to make thrilling new discoveries.
Everything I need to know I learned through Googling.
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Dawn Journal: How does Dawn know where "down" is?
Since the last log, the robotic explorer has devoted most of its time to its two primary scientific objectives in this phase of the mission. With its gamma ray and neutron detector (GRaND), it has been patiently measuring Vesta's very faint nuclear emanations. These signals reveal the atomic constituents of the material near the surface. Dawn also broadcasts a radio beacon with which navigators on distant Earth can track its orbital motion with exquisite accuracy. That allows them to measure Vesta's gravity field and thereby infer the interior structure of this complex world. In addition to these top priorities, the spacecraft is using its camera and its visible and infrared mapping spectrometer (VIR) to obtain more detailed views than they could in the higher orbits.
Everything I need to know I learned through Googling.
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As awesome as this asteroid has been, I really think Ceres is going to be better. Much more planet-like and probably a substantially different composition.
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^
Ditto. I'm really looking forward to any possible atmosphere. On top of that--assuming Dawn is never redirected to Pallas--they will get to stay there indefinitely, allowing for more daring orbital maneuvers past the primary mission.
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I can't find support for it now, but my impression is that the scientific opinion is just the opposite, which may explain why all the extra time found in the schedule has been added to investigating Vesta. Of course, the solar system has always been full of surprises, and Ceres is bound to have a few.
Everything I need to know I learned through Googling.
Order of Kilopi
Would that because Ceres is much more like some of the larger moons we've visited; and less like a typical asteroid?
Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.
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I've read that Ceres is expected to have areas of clay-like surface from a much earlier epoch when it could have been damp. On the other hand it will be an object whose self-gravity has done more to make it round, and so some aspects of the early days of the solar system will be more concealed on Ceres than on Vesta.
Forming opinions as we speak
Order of Kilopi
No - they WILL leave Ceres - planetary protection dictates that.
Will they go on to Pallas? That's a combination of securing funding for a mission extension, the health of the vehicle at the time, and presumes continued efficient, reliable ion engine performance.
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I was wondering about this, but it turns out Ceres is (or might be) special:
- http://www.scientificamerican.com/ar...res-new-worldsAnd what will happen to Dawn? According to Rayman, "because of the possibility of there being a substantial inventory of water at that mysterious body [Ceres], we have 'planetary protection' requirements." (Did someone say "Prime Directive"?)
Essentially this means that Dawn will not be sent hurtling into Ceres. Rayman continues: "Now there is no reason whatsoever to believe there is life on Ceres, but there may be chemistry occurring there that is related to the chemistry that preceded the development of life on Earth—and perhaps elsewhere! Therefore, to protect that fascinating environment, we are currently required to leave the spacecraft in an orbit in which it will not crash into Ceres for at least 20 years."
Everything I need to know I learned through Googling.
Order of Kilopi
I wonder when we'll get around to actively defying planetary protection and try to terraform something. Not in my lifetime, I suppose.
Cum catapultae proscriptae erunt tum soli proscript catapultas habebunt.
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