According to the BBC Dawn has sent back signals confirming it's in orbit:
Probe orbits asteroid Vesta
Order of Kilopi
According to the BBC Dawn has sent back signals confirming it's in orbit:
Probe orbits asteroid Vesta
Established Member
Dawn herself confirms
http://twitter.com/#!/NASA_Dawn
Order of Kilopi
!
Established Member
I've been following the progress of Dawn since launch. I get all the emails from the Dawn mission site, so I was very happy to hear that Dawn had entered orbit around Vesta successfully!
I'm looking forward to seeing the great images we can expect shortly as Dawn lowers its orbit.
Established Member
Nice image released today. Phil has a blog entry about it here.
Emily has been strangely silent about it (the approach and entry in to orbit), even though she's been back from vacation. I expect she'll have a rather nice write-up when she gets to it, though!
CJSF
Last edited by CJSF; 2011-Jul-18 at 09:10 PM.
"In the nightgown of the sullen moon, How the windows lean into the room, In the nightgown of the sullen moon."
-They Might Be Giants
Established Member
Seems I was right. Here's Emily's Planetary Society blog entry.Originally Posted by CJSF
CJSF
"In the nightgown of the sullen moon, How the windows lean into the room, In the nightgown of the sullen moon."
-They Might Be Giants
Member
So, what's the data on surface composition?
Administrator
They just achieved orbit 2 days ago. I suspect they haven't even started collecting that data yet, let alone transmit it to Earth, process it, and then do the human analysis. This is a year long mission (at least), they are not going to do everything in the first three days.
Member
Of course, I was just wondering if they've done some analysis during the approach phase.
Established Member
Emily makes an interesting observation: Vesta's lumpier and less spherical than some moons having lesser diameters.
Order of Kilopi
Member
Big article with new images from orbit:
http://www.nasa.gov/mission_pages/da...20110718.html#
How come all the images appear a bit blurry? They're not as crisp and detailed as I was hoping they'd be at this point.
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Order of Kilopi
They're taken with the framing camera, a wide angle instrument. They're scaled up...you can see some pixelation left over.
Order of Kilopi
From the UT article:
“We will not have a steady stream of images until we are in one of our three science phases,”
... “When we are in transit from one place to another we thrust, stop, turn, image, turn, transmit, turn, thrust, and several days later repeat. All time spent not thrusting is time taken away from science later.”
[Prof. Chris Russll, Dawn’s Science Principal Investigator of UCLA]
STARGAZING: All I see are the lights of a billion places I'll never go. --Howard Tayler, Schlock Mercenary
Administrator
Some more details from this R&D Magazine on-line article:
Although orbit capture is complete, the approach phase will continue for about three weeks. During approach, the Dawn team will continue a search for possible moons around the asteroid; obtain more images for navigation; observe Vesta's physical properties; and obtain calibration data.
In addition, navigators will measure the strength of Vesta's gravitational tug on the spacecraft to compute the asteroid's mass with much greater accuracy than has been previously available. That will allow them to refine the time of orbit insertion.
Dawn will spend one year orbiting Vesta, then travel to a second destination, the dwarf planet Ceres, arriving in February 2015. The mission to Vesta and Ceres is managed by JPL for the agency's Science Mission Directorate in Washington. Dawn is a project of the directorate's Discovery Program, which is managed by NASA's Marshall Space Flight Center in Huntsville, Ala.
Member
New photo taken July 18th, released yesterday.
http://dawn.jpl.nasa.gov/feature_sto...back_photo.asp
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Established Member
She has explained that is likely because the other satellite's have a high ice content, which deforms easier.
CJSF
"In the nightgown of the sullen moon, How the windows lean into the room, In the nightgown of the sullen moon."
-They Might Be Giants
Order of Kilopi
That ice/rock thing puts the whole "dwarf planet" thing into question.
Order of Kilopi
You mean the hydrostatic equilibrium part of the definition? It's true that a lumpy, misshapen rocky object can be much heavier than an icy one that's formed itself into a sphere, but it's not like there's any particular mass you can draw a line at. In this case, it seems likely that Vesta was big enough to pull itself into a sphere, its current condition being a result of impacts after it had completely solidified.
Newbie
Fascinating pictures from the spacecraft so far, I eagerly await the rest of the photographs.
Order of Kilopi
Would Vesta look different in color, or would it be more or less a colorless lump of rock like the Moon? I ask because this fuzzy picture of Ceres looks tantalizingly colorful.
Established Member
Hubble took similarly looking fuzzy photos of Vesta. So probably Vesta nad Ceres are gray and peperred with craters. Of course, you can hope for more interesting features on Ceres.
Established Member
The collision that created the big crater at the south pole did not heat up the planet sufficiently to restore hydrostatic equilibrium even temporarily. My intuition says that it should have, so obviously I need to recalibrate my intuition...
At any rate, is it possible with the instruments on Dawn to get an idea of what latitude the collision actually happened at? It's very unlikely to have happened exactly at the south pole, and if it happened elsewhere, forces would tend to tilt the planet until the crater was centered on the nearest pole, since that's the minimal energy state.
Assuming Vesta had a magnetic field in its early days, there should be magnetic grains in the rocks that would show the orientation of the field at the time the rocks cooled. But that would require measuring the rocks in situ, which Dawn is incapable of. So any ideas based on what instruments Dawn has?
Honored Member
In terms of scientific discoveries, I would assume that the observations of Dawn's orbit around Vesta will tell a lot about density, mass distribution and the like.
Established Member
^
I'm guessing a magnetometer was very high on the team's wish list (it could also clinch the existence of a ionic mantle in Ceres), but was probably excluded partly for cost, and perhaps (though I'm no expert) possible interference from the ion drive with any readings.
Established Member
The magnetometer was removed as a cost-cutting measure to prevent it from staying cancelled, IIRC.
Order of Kilopi
New image from Dawn:
http://dawn.jpl.nasa.gov/multimedia/...age_072311.asp
Order of Kilopi
Dark side?Image of the Dark Side of Vesta Captured by Dawn on July 23, 2011
It's a rotating body, how can it have a dark side?
Established Member
Just the "side" that happened to be in shadow. A bit sloppy, there.Dark side?
It's a rotating body, how can it have a dark side?
Order of Kilopi
And the picture shows half of it in the light. So, it's not even the whole "side".
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