APOD: Asteroid Vesta Full Frame (2011 Aug 02)

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Expand view Topic review: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by neufer » Fri Aug 05, 2011 12:19 am

NoelC wrote:
neufer wrote:
Why wasn't Vesta (or even Uranus) discovered earlier?
How many people were looking at the sky with telescopes in the late 1700s? Not that many, I'll wager.
1) Vesta & Uranus at their brightest don't need telescopes...just exceptionally
good eyesight (which was an evolutionary advantage before glasses were common).
So it didn't have to be as late as the 1700s (or even this millenium).

2) Many astrologers made their living by watching the skies;
sometimes even their lives depended on it.
NoelC wrote:
One can imagine that as society and civilization progressed it has become easier and easier to have more free time to do things that don't directly address survival, such as staying up late and pondering the heavens.
Staying up late thanks to artificial lighting which has made a good observation of the heavens more & more rare.

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by NoelC » Thu Aug 04, 2011 10:48 pm

neufer wrote:Why wasn't Vesta (or even Uranus) discovered earlier?
How many people were looking at the sky with telescopes in the late 1700s? Not that many, I'll wager.

One can imagine that as society and civilization progressed it has become easier and easier to have more free time to do things that don't directly address survival, such as staying up late and pondering the heavens.

Image

-Noel

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by neufer » Thu Aug 04, 2011 10:18 pm

Image
Sir William Herschel announced the discovery Uranus on March 13, 1781.
(max mag. ~5.32, max retrograde motion ~2.6' per day)

Vesta was discovered by Heinrich Wilhelm Olbers on March 29, 1807.
(max mag. ~5.1, max retrograde motion ~16.5' per day)

Why wasn't Vesta (or even Uranus) discovered earlier?
http://en.wikipedia.org/wiki/Mensa_%28constellation%29 wrote:
<<Mensa was created by Nicolas Louis de Lacaille (March 15, 1713 – March 21, 1762) under the name Mons Mensae, the Latin name for Table Mountain in South Africa, where Lacaille made important early observations of the southern sky. Mensa contains no bright stars, with Alpha Mensae its brightest star at a barely visible magnitude 5.09, making it the faintest constellation in the entire sky. Alpha Mensae is a solar-type star (class G5 V) 33 light-years from Earth, and is considered a good prospect for harboring an Earth-like planet.>>

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by bystander » Thu Aug 04, 2011 9:43 pm

How to Spot Giant Asteroid Vesta in Night Sky This Week
Space.com | Geoff Gaherty, Starry Night Education | 2011 Aug 03
With all the publicity on NASA's final space shuttle flight a few weeks ago, some people may have missed another cosmic milestone: On July 16, NASA's Dawn spacecraft entered orbit around the asteroid Vesta to spend the next year orbiting the space rock before heading off to an encounter with the dwarf planet Ceres.

Vesta is unusually bright among the asteroids because of its different mineral makeup. It is actually brighter than Pallas, the largest asteroid, and Ceres, the dwarf planet formerly classified as an asteroid. At 318 miles (512 kilometers) in diameter, Vesta is slightly smaller than Pallas, which is 326 miles (524 km). Both space rocks are much smaller than Ceres at 595 miles (957 km).

Did you know that you can see Vesta with your unaided eyes?

This week Vesta will be in opposition, its closest point toward Earth, and in an area of the sky with few stars, making it relatively easy to see. The sky map of Vesta available here shows where to look to spot the asteroid this week.

Strangely enough, being in an area bereft of stars can make this asteroid easier to see, because there are no bright stars nearby to confuse the viewer. However, it takes an experienced observer to spot the constellation in which it is located, Capricornus. [Close-Up Photos of Vesta]

How to spot Vesta

To see Vesta, you will need sharp eyes and a dark country sky.

Most people will find a good pair of small binoculars a useful aid in locating the asteroid. Assuming you’re in the Northern Hemisphere, look towards the southern horizon around 1 a.m. local time. Bright Sagittarius will be off to your right, and due south will be the upside-down triangle of Capricornus.

As a whole, Capricornus is a constellation with few bright stars, but the stars that are visible form a very clearly marked triangle, with its brightest stars in its upper left and right corners.

The chart labels the stars with their magnitudes, their brightness measured on the upside-down scale which astronomers use, where the brightest stars are "1" and the faintest stars visible to the naked eye are "6."

Dark skies needed

Vesta is at the faint end of that scale at magnitude 5.6, but for the next week it will be located in a part of Capricornus which contains no stars anywhere near that bright, so Vesta will stand out against that dark area.

The skywatching chart mentioned earlier shows Vesta in its position at opposition on Friday, Aug. 5. It is moving from left to right in a line parallel to the lower right side of the Capricornus triangle.

Vesta moves about half the moon's diameter every 24 hours, so its movement will be obvious from one night to the next. In a telescope at high magnification, you can see it move over a few minutes watching.

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by dushyant01 » Thu Aug 04, 2011 9:56 am

StormForces wrote:Is the appearance of heavier cratering toward the north not just the lighting (angle the sunlight was hitting it)? (you get the same effect when taking photos of the moon) Guess i'll have to check out more of the Vesta pics...
exactly my thoughts.. opened this page to write and found your post :)
in the movie, I could not see any more cratering on any side. Regarding the alternate explanations of solar system passing through some objects, its not very likely that it was local to Vesta. So, that would affect all the asteroids and even Mars, Earth and Moon.

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by Czerno1 » Thu Aug 04, 2011 9:12 am

Hi everybody !

I can't decide with certitude where the origin of the illumination is in this picture, will someone please help me to interpret what I can see here? (I mean, the still photograph - my system won't show movies).

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by Astronymus » Wed Aug 03, 2011 4:18 pm

Buzatti wrote:Sorry, my friends, but I see the form of a white cross, even with the shadows inside the larger crater on the right??
Yeah, means: Jesus was here. :roll:

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by rstevenson » Wed Aug 03, 2011 12:05 pm

Buzatti wrote:Sorry, my friends, but I see the form of a white cross, even with the shadows inside the larger crater on the right??
Given an essentially random arrangement of rocks, dust, craters, and other features, it's very possible to see such things as crosses, faces, roads, or anything else your imagination can conjure up. No need to apologize for it; it's a natural human tendancy.

Rob

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by Buzatti » Wed Aug 03, 2011 10:27 am

Sorry, my friends, but I see the form of a white cross, even with the shadows inside the larger crater on the right??

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by TechDud » Wed Aug 03, 2011 7:27 am

The video seems to betray a low data rate; it could take time to capture enough images for smooth animation.
http://www.youtube.com/watch?v=FaUaoy33gHE

why does the fact that there are more craters on the north side of Vesta remind me of the ice plasma plumes & subsequent comet-like tails streaming in what appeared to be a southerly polar flow?

Enceladus in this NASA photo: http://www.nasa.gov/centers/goddard/new ... ponge.html Anyone for enchiladas?

That being as it may, I understand that has nothing to do with Vesta directly. I wonder if they will find much trace sulfur from io, & would they find most of it on either (not both) hemispheres.
This leads to the question of whether what streams up through these large magnetic fields (whatever gas giant) would draw on nearby debris, propel it, and hurl any stray NiFe, or other magnetically-influenced object/field northward to hit home.(collector)

Were it to be an object already en route in the general direction of a magnetic episode during heavy solar winds (such as the previous decade) could it not be influenced by the magnetic flux and in-effect steered away from a large mass, aligned with the lines of magnetic force. Even if this predicted effect was unsuccessful at navigating the full loop of the lines of force, it would enable a re-capture event as the object(s) travel directly through the loop, instead of through the loop along the lines of force. Even a small acceleration could act like a 'natural' ion propulsion. If the object had company, say from a rubble-field, the effect could be pronounced like a 'stellar shotgun'.

If so, NASA has a new orbital class of asteroid to start looking for, as we might not be entirely immune.

The mysterious lines running along the surface are reminiscent of a good-sized encounter with that very effect. An object in motion will tend to find the path of least resistance to continue said motion.

If this was a natural feature of this solar system to be able to preferentially separating exo-solar meteorites and depositing them on a single pole, waiting for an explorer (robotic or otherwise) to discover exactly what was deposited. What if there was heavy, or even rare-earth metals propelled to their ultimate fate? Of course this could make such an exploration much riskier.

Perfectly pertinent is to find out how the solar flux effects, affects &/or how the magnetosphere of Jupiter can influence events in or around the asteroid belt. What would be the attenuation of the solar flux.

can anyone find cool pictures of io (or any other moons) emitting plumes of sulfur (or other gas) for me. I've been unsuccessful at that venture thus far.

Yep, just another boring hunk of dwarf planet. :wink:

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by thongar » Tue Aug 02, 2011 7:34 pm

Looking at the picture of Vesta and the cratered North comment, there seem to be some obviousities:

1. If I were to slam a large rock into the bottom of an otherwise uniformly cratered object, of the size that made a crater large enough to flatten a third of an otherwise "spherical" object, I would think the craters nearest to the said collision would be flattenned by just the pressure of the impact. Analogous to hitting the underside of a dent in the metal of your car will flatten the dent.

2. Likewise the same impact would create wrinkles where the acceleration for the impact material runs up against the inertia of the mass of the planetoid. wrinkling will occur, and depending on the material will show up vividly. Mimas and Phobos I believe have the same such wrinkles. Miranda is at the extreme end it came apart and it too has collision wrinkles.

So add a little observational logic to your mysteries, and an answer may spring forth :)

Thanks
Thongar

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by NoelC » Tue Aug 02, 2011 7:15 pm

Dmpalmer wrote:Based on my intuition of orbital mechanics of non-spherical dissipative bodies.
Wow, that's impressive all by itself! I have a lot of intuition, but I don't think I have even one brain cell involved in that particular aspect of it.

Amazing how much thought is spurred on just by having a good picture of something!

-Noel

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by nstahl » Tue Aug 02, 2011 5:51 pm

The Planetary Society Blog contains some thoughtful observations and conjectures about what we're seeing and a different version of the rotation movie.

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by zbvhs » Tue Aug 02, 2011 4:37 pm

It looks like some of the impacts occurred on hard spots so that lower-velocity impactors would splatter rather than digging craters in softer material.

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by Dmpalmer » Tue Aug 02, 2011 3:17 pm

The upper left area is not the northern hemisphere, it is the equator.

If you look at the rotation movie, you will see that Vesta has grooves all around its equator. These look to me like impact grooves rather than, e.g. rift valleys.

Vesta is so oblate that most objects in low orbit around it (e.g. debris from collisions that didn't immediately fall back nor escape) will be tend to be dragged into a prograde equatorial orbit that eventually decays. (Based on my intuition of orbital mechanics of non-spherical dissipative bodies.)

Ground speed of a prograde equatorial circular orbit at touchdown height is about 150 m/s ~ 330 mph. This is much slower than most cratering impacts you are used to (in particular it is MUCH slower than sound speed in rock) so you don't get a point deposition of blast energy like you do with the more familiar case asteroid hitting the Earth or Moon with a much more vertical impact. Instead you are going to get a rock that comes in horizontally and slowly enough to gouge out a furrow as it touches down and starts rolling.

It wouldn't surprise me to see rubble piles at the ends of some of those furrows where the debris stopped rolling and then collapsed.

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by neufer » Tue Aug 02, 2011 2:26 pm

bystander wrote:
better than Obama wrote:... vespa has lots of features ...
liebencrantz wrote:named after princess vespa. huh? ...
It's Vesta, not Vespa!
wikipedia: Vesta wrote:
Vesta was the virgin goddess of the hearth, home, and family in Roman religion. Vesta's presence was symbolized by the sacred fire that burned at her hearth and temples. Her closest Greek equivalent is Hestia
Indigo_Sunrise wrote:... And I was just going to ask: who is 'princess vespa', and what does she have to do with asteroid Vesta? ...
  • ----------------------------------------------------------------------
    [list]Memorable quotes for Spaceballs:
Princess Vespa:
I am Princess Vespa, daughter of Roland, King of the Druids.

Lone Starr: Oh great. That's all we needed. A Druish princess.
---------------------------------------------------------------------- Private Judy Benjamin:
To be truthful with you, I can't sleep in a room with 20 strangers.

Capt. Lewis: Oh dear.

Private Judy Benjamin:
And I mean look at this place. The army couldn't afford drapes?
I'll be up at the crack of Dawn here!

----------------------------------------------------------------------[/size][/list]

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by Psnarf » Tue Aug 02, 2011 1:51 pm

Will Dawn be able to analyze the composition of Vesta's surface? Pretty-much all of the meteorites we have found are composed of nickel and iron, but that's after the outer bits burn off in the upper atmosphere. I wonder Vesta's surface is similar to the Moon samples that our Heroes brought back. [Anyone who makes a round-trip to the Moon and brings back souvenirs is a Hero in my book.]

(Aside: It occurs to me that not everyone has enjoyed, if 'enjoyed' is the word for which I'm searching, the movie by Mel Brooks, "Spaceballs," a spoof on "Star Wars V," with Princess Vespa as Princess Lea. http://www.imdb.com/title/tt0094012/ )

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by Astronymus » Tue Aug 02, 2011 1:19 pm

Amazing pictures.

Maybe Vesta was part of a larger protoplanet which might explain the differnt hemispheres. Maybe the composition and density differs due to the position in the body of the hypothetical former protoplanet.

Or maybe Vesta was baked together from two different bodies in the young solar system.

Or maybe Vesta was once a moon of one of the greater planets with a fixed rotation so one side was more bombarded by space debris than the other.

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by orin stepanek » Tue Aug 02, 2011 12:28 pm

The first thing I noticed on today's picture was the crater with the black streaks; (what owlice calls a belly button. :ssmile: ) I wonder what the black substance is! I also noticed that on the rotation movie; that near the equator; there is a wide grove that seems to go all the way around the asteroid! I don't know if Vesta is round enough to be considered a planet! :roll:

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by neufer » Tue Aug 02, 2011 11:36 am


Asteroids are often thought to be the shattered remnants of planetesimals that never grew large enough to become planets because they were torn apart by giant baobab trees. Vesta is, in fact, the ancient core of one of those baobab trees.

  • Now there were some terrible seeds on the planet that was the home of the little prince; and these were the seeds of the baobab. The soil of that planet was infested with them. A baobab is something you will never, never be able to get rid of if you attend to it too late. It spreads over the entire planet. It bores clear through it with its roots. And if the planet is too small, and the baobabs are too many, they split it in pieces . . .

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by Indigo_Sunrise » Tue Aug 02, 2011 11:34 am

HOORAY!!!! for bystander, for keeping everybody straight! :D

I was going to say what you did, which is: this is NOT a repeated image. A little link-following will show that.
And I was just going to ask: who is 'princess vespa', and what does she have to do with asteroid Vesta?

Great - and interesting - image and links!
8-)

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by bystander » Tue Aug 02, 2011 10:51 am

bto wrote:... vespa has lots of features ...
liebencrantz wrote:named after princess vespa. huh? ...
It's Vesta, not Vespa!
wikipedia: Vesta wrote:Vesta was the virgin goddess of the hearth, home, and family in Roman religion. Vesta's presence was symbolized by the sacred fire that burned at her hearth and temples. Her closest Greek equivalent is Hestia

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by liebencrantz » Tue Aug 02, 2011 8:39 am

named after princess vespa. huh?
but really, i wonder if the grooves that circle this object are a result of smaller orbiting bodies whose orbits gradually decay to the point that they end up rolling along the surface.

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by nstahl » Tue Aug 02, 2011 8:09 am

Regarding the heavier cratering on the north side, I wonder if it doesn't just mean some bunch of stuff once came from that way. I presume the axis is pointing out of the plane of the solar system so that might mean some stuff was passing through the plane of the solar system. This is supposed to date a long way back.

Re: APOD: Asteroid Vesta Full Frame (2011 Aug 02)

by adrianxw » Tue Aug 02, 2011 6:45 am

The grooves surely indicate that Vesta was once part of a much larger and/or geologically active body. Great stuff this.

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