Starship Asterisk*

Leaving Vesta

Explanation: Next stop: Ceres. Last week the robotic Dawn spacecraft ended its year-long mission to asteroid Vesta, becoming the first spacecraft ever to visit this far off world located between Mars and Jupiter, in the Solar System's main asteroid belt. Many of the best images taken by Dawn at Vesta have been compiled into the above encompassing view. Vesta shows evidence of being a leftover from the early years of our Solar System, a building block for rocky planets like Earth. Vesta's ancient surface shows heavy cratering and long troughs likely created by huge impacts. The minor planet's low gravity allows for surface features like huge cliffs and a large mountain that reaches twice the height of Earth's Mount Everest, visible at the image bottom. Vesta, however, spanning about 500 kilometers across, is only the second most massive object in the asteroid belt. And so, two weeks ago, Dawn fired its gentle ion rockets and has begun chasing the most massive: Ceres. If everything goes as planned, Dawn will reach Ceres in 2015. Ceres looks quite different to the distant telescope -- but what will Dawn find?

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We had prolonged discussion when the surface detail of Phobos was revealed. 'Grooves' there were said to be evidence that it was a piece of sedimentary rock ejected into space, or were due rocks rolling across the surface. The more likely possibility that they were confluent crater chains was discounted by such enthusiasts.

So what has caused the Divalia Fossa, long troughs on the surface of Vesta? They are clearly ancient, massively overlaid by fresh cratering. Are they too crater chains, or should we consider the possibility of interplanetary warfare?

John

JohnD wrote:
We had prolonged discussion when the surface detail of Phobos was revealed. 'Grooves' there were said to be evidence that it was a piece of sedimentary rock ejected into space, or were due rocks rolling across the surface. The more likely possibility that they were confluent crater chains was discounted by such enthusiasts.

So what has caused the Divalia Fossa, long troughs on the surface of Vesta? They are clearly ancient, massively overlaid by fresh cratering. Are they too crater chains, or should we consider the possibility of interplanetary warfare?

Note that the 'grooves' on Phobos are radial to the main impact crater; whereas,
the long troughs on the surface of Vesta are concentric to the main impact crater.

APOD Robot wrote:
Explanation: Next stop: Ceres. Last week the robotic Dawn spacecraft ended its year-long mission to asteroid Vesta, becoming the first spacecraft ever to visit this far off world located between Mars and Jupiter,

Have a safe trip Dawn!

The article includes the statement "a large mountain that reaches twice the height of Earth's Mount Everest." What is the base from which that height was measured?

never wrote:the long troughs on the surface of Vesta are concentric to the main impact crater.

So, the troughs are "crinkle zones" ?

FloridaMike wrote:

never wrote:
the long troughs on the surface of Vesta are concentric to the main impact crater.

So, the troughs are "crinkle zones" ?

I never wrote THAT!

See: http://www.space.com/11540-photos-aster ... -dawn.html
Picture 36, I think, view of the South pole, with very crinkly troughs!

John

Steve S. wrote:The article includes the statement "a large mountain that reaches twice the height of Earth's Mount Everest." What is the base from which that height was measured?

If I remember correctly the base is measured from the average height of the asteroid. Something along the lines of "if the astroid was covered in water with half of the land above water where would sea level be?". I'm not completely sure if I remember that right but it was something like that

neufer wrote:

FloridaMike wrote:

never wrote:
the long troughs on the surface of Vesta are concentric to the main impact crater.

So, the troughs are "crinkle zones" ?

I never wrote THAT!

"never" "never" is, as "never" does.

Sorry if this is a stupid question, but what's the link between Dawn's 2015 arrival at Ceres, or just 2015, and that 'MyCopter' ?

I'm curious if there's something more than e.g. a lighthearted plug for this vehicle that's planned for first public sale in 2015, or something.

Thanks.

You can find a nice image comparing the size of the four largest asteroids to the United States. Look in:
Groups.yahoo.com
Questar telescope group >> Files >>Asteroids compared to the USA.jpg