Jump to content
House Price Crash Forum

Archived

This topic is now archived and is closed to further replies.

zugzwang

Bright Spots On Ceres

Recommended Posts

A Samsung death spy star? A bit like my television. The light comes on to tell you it's off! Only start worrying when the light goes off. :wacko:

Share this post


Link to post
Share on other sites

This is interesting.

Difficult to believe it is volcanic. Ceres is too small, and there are no nearby bodies to induce volcanic activity through tidal heating.

My guess is it is a recent impact that has uncovered an ice layer under a dusty surface.

There are several problems with that idea though. The one that strikes me as most obvious is the sheer coincidence of a 'recent impact' landing smack bang in the middle of a presumably 'ancient' crater. It would also have to be a really recent impact for the exposed ice not to have sublimated away or otherwise been obscured by mixing with dust from general turbation. The spots in question are really very bright indeed. Also, given that the area in question is close to the twilight zone at the time the photo was taken, how much sunlight would be reflected more or less vertically up to the Dawn craft, enough to make the spots so much brighter than any of the noonday part of Ceres?

The volcano theory makes sense of why the main bright spot is in the centre of a crater, namely that the crater was either somehow caused by a volcano or the event that caused the crater also triggered the eruption(s). It makes it much easier to see how the spot is that bright, because a cloud of ice crystals several km above the surface would both catch more of the sunlight and reflect more of it in Dawn's direction. It could also help explain the lesser but still bright spot a few km away, either as a nearby volcano in a broader area of weak crust, or as the main portion of the plume of said ice crystals falling back to Ceres, similar to the now well-known photos from Jupiter's Io and Saturn's Enceladus.

We need to keep this thread going till well past 6 March so that we get a close-up look (which may resolve the brightness into several distinct spots/areas) and also more of a lateral view which could help confirm or eliminate the hypothesis of plume fall-back. A further factor would be what the crater looks like at night: if the spots are surface ice the brightness should vanish, but if any glow remains it means some degree of heat from a volcano. Either way we're in for some interesting days just around the corner.

Share this post


Link to post
Share on other sites

There are several problems with that idea though. The one that strikes me as most obvious is the sheer coincidence of a 'recent impact' landing smack bang in the middle of a presumably 'ancient' crater. It would also have to be a really recent impact for the exposed ice not to have sublimated away or otherwise been obscured by mixing with dust from general turbation. The spots in question are really very bright indeed. Also, given that the area in question is close to the twilight zone at the time the photo was taken, how much sunlight would be reflected more or less vertically up to the Dawn craft, enough to make the spots so much brighter than any of the noonday part of Ceres?

The volcano theory makes sense of why the main bright spot is in the centre of a crater, namely that the crater was either somehow caused by a volcano or the event that caused the crater also triggered the eruption(s). It makes it much easier to see how the spot is that bright, because a cloud of ice crystals several km above the surface would both catch more of the sunlight and reflect more of it in Dawn's direction. It could also help explain the lesser but still bright spot a few km away, either as a nearby volcano in a broader area of weak crust, or as the main portion of the plume of said ice crystals falling back to Ceres, similar to the now well-known photos from Jupiter's Io and Saturn's Enceladus.

We need to keep this thread going till well past 6 March so that we get a close-up look (which may resolve the brightness into several distinct spots/areas) and also more of a lateral view which could help confirm or eliminate the hypothesis of plume fall-back. A further factor would be what the crater looks like at night: if the spots are surface ice the brightness should vanish, but if any glow remains it means some degree of heat from a volcano. Either way we're in for some interesting days just around the corner.

OK :

Doesn't look like it is right in the middle. Anyway, like all of these bodies the whole surface is crated, so it would not be that much of a co-incidence. I agree it would have to be fairly recent. I agree that it is extremely bright, so what could cause this is a mystery. I don't know what the spectral profile of the camera is though. Remember that not all space photos are taken in visible light and often have various enhancements.

I think the companion spot could be explained by a break up of the object that collided.

The big difference between Ceres and Io/Enceladus is that the latter are subject to large interior heating as a consequence of their orbits around the parent planet. This drives volcanic activity. If there is activity here it may be similar to that that occurs on triton :

http://en.wikipedia.org/wiki/Triton_(moon)

rather than io.

http://en.wikipedia.org/wiki/Tidal_heating

Still, the triton cryovolcanism may have been caused by tidal heating. I don't see where the evidence for any sort of tidal heating is on ceres.

These photos were taken on Feb 19th, so we can only assume NASA have much better photos available now. There is supposed to be a news briefing on Monday March 2nd.

Share this post


Link to post
Share on other sites

Interesting photo from the 4000km mapping orbit.

That crater looks quite fresh, the walls aren't rounded like they are on the other craters. Also there are no craters inside it, despite it being quite large. The field towards the bottom looks relatively devoid of craters, maybe this is because the ejecta from the main recent crater filled them in.

Anyway, the caption suggests ice.

http://www.nasa.gov/sites/default/files/thumbnails/image/pia19568_main-1041.jpg

Share this post


Link to post
Share on other sites

Its Goldmembers lair, someone left the sliding false bottom open.

Share this post


Link to post
Share on other sites

http://www.iflscience.com/nasa-releases-stunning-new-views-bright-spots-ceres

NASA has released stunning new views of those mysterious bright spots on the dwarf planet Ceres – but we’re still not any closer to working out what they are.

The images were taken by the Dawn spacecraft from a height of 1,470 kilometers (915 miles) above the surface. The resolution in them is about three times better than previous images returned in June, with about 140 meters (450 feet) per pixel.

The bright spots on show here (although there are others on Ceres) are in the Occator crater, the rim of which is as high as 1.6 kilometers (1 mile) and is even vertical in some places. The spots are so bright that the only way to see them was to combine two images – one exposed correctly for the surface, and one correctly for the spots themselves.

"Dawn has transformed what was so recently a few bright dots into a complex and beautiful, gleaming landscape," said Marc Rayman, Dawn's chief engineer and mission director based at NASA's Jet Propulsion Laboratory in Pasadena, California in a statement. "Soon, the scientific analysis will reveal the geological and chemical nature of this mysterious and mesmerizing extraterrestrial scenery."

Theories for the identity of the bright spots are numbered, but the two favored at the moment suggest they are either ice or salt flats exposed on the surface, possibly by an impact. As Dawn spirals closer and closer in the coming months, the images will get better and better, with an answer possibly on the horizon.

In its current orbit, Dawn is due to map the entirety of Ceres six times over two months. Imaging the dwarf planet at different angles also allows scientists to create 3D maps of the surface. The video below shows an animation created using this technique, revealing the topography of the Occator crater.

But for now, the mystery of what formed the bright spots remains.

Ceres%202.JPG?itok=sxjg6Hzl

Share this post


Link to post
Share on other sites

  • Recently Browsing   0 members

    No registered users viewing this page.

  • The Prime Minister stated that there were three Brexit options available to the UK:   211 members have voted

    1. 1. Which of the Prime Minister's options would you choose?


      • Leave with the negotiated deal
      • Remain
      • Leave with no deal

    Please sign in or register to vote in this poll. View topic


×

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.