Starship Asterisk*

quigley wrote:A silly question that I believe was answered by the distance question posted answer, but I was not sure what took these video frames? I now assume that it was the Dawn spacecraft.

Donnageddon wrote:I have a hunch this is what you seek http://www.psi.edu/

simone wrote:
Do you know at what distance was the picture taken? Strangely they didn't state it in the caption as usual. Thanks

APOD Robot wrote: Approaching Asteroid Ceres

Explanation: It is the largest asteroid in the asteroid belt....

MarkBour wrote:I suppose the use of the ion-propulsion thrusters, which are new tech and have a limited maximum power output, make this more challenging. On the other hand, Dawn is the only spacecraft that is about to attempt to orbit a celestial body who can say: "I'm experienced. I've done this before." So, perhaps it actually has a lower likelihood of failure than most.

Chris Peterson wrote:

Ron-Astro Pharmacist wrote:The explanation says "..and attempt to orbit.." Is this, in the scheme of efforts, a fairly difficult undertaking? . . .

Getting to the right place isn't that hard. But trying to enter orbit around a fairly low mass body is problematic, because you typically have to shed a lot of the velocity that was used to get there in the first place. That's why we're doing a Pluto flyby and not going into orbit. . . . But it depends on rocket motors working correctly, and there is always a risk associated with that. Most mission failures seem to involve the rockets.

Jan. 22, 2014: Scientists using the Herschel space observatory have made the first definitive detection of water vapor on the largest and roundest object in the asteroid belt, dwarf planet Ceres.

January 20, 2015 ... First Hubble and Now Dawn Have Seen This White Spot on Ceres. What is it?

Chris Peterson wrote:

Ron-Astro Pharmacist wrote:The explanation says "..and attempt to orbit.." Is this, in the scheme of efforts, a fairly difficult undertaking? It's easy to take for granted our abilities with respect to our capabilities. Landing on a comet was difficult for many reasons but easy to understand in difficulty from a lay persons viewpoint but navigation to, far off, smaller targets may seem a bit easier from the standpoint we've done it more frequently.

Getting to the right place isn't that hard. But trying to enter orbit around a fairly low mass body is problematic, because you typically have to shed a lot of the velocity that was used to get there in the first place. That's why we're doing a Pluto flyby and not going into orbit. At Pluto's distance, we needed to build up such a high velocity just to get there in a reasonable time that there's no practical way to get rid of it once we're there. It's not quite so bad with asteroids, because they're closer and we can utilize more reasonable transit velocities. But it's still a tricky problem. I think all the math has been worked out and the engineering is solid, so there's no reason Dawn shouldn't be able to enter orbit. But it depends on rocket motors working correctly, and there is always a risk associated with that. Most mission failures seem to involve the rockets.

Ron-Astro Pharmacist wrote:The explanation says "..and attempt to orbit.." Is this, in the scheme of efforts, a fairly difficult undertaking? It's easy to take for granted our abilities with respect to our capabilities. Landing on a comet was difficult for many reasons but easy to understand in difficulty from a lay persons viewpoint but navigation to, far off, smaller targets may seem a bit easier from the standpoint we've done it more frequently.

captainwiggins48 wrote:Anticipation! How does this sound: Mercury, Venus, Earth, Mars, Ceres...!

JuanAustin wrote:I was curious to know how thick vertically the asteroid belt was in terms of distance. Do spacecraft have a relatively safe passage through the belt on their way to explore the planets or do they have to hop over or under the belt to avoid a random collision?

starsurfer wrote:Wasn't Ceres discovered by Giuseppe Piazzi?

workgazer wrote:Any ideas as to what the bright spot is moving across the top left of ceres, The hubble image also shows a white spot, could this be a storm?

epitalon wrote:In this simulated view, the constellations look as seen from human eye, contrarily to some pictures obtained by photography.
This allows me to point to some idea that I had in mind for a while : constellation names come really from their resemblance with natural objects.
It is not so evident from today's standard partition of the sky in constellations.