I'm not saying it's aliens ... but
March 19, 2015 8:50 PM   Subscribe

"What is amazing, is that you can see the feature while the rim is still in front of the line of sight". Unreleased images of "feature number 5" aka the bight spots on Ceres suggest it might be an ice plume. Also we're naming everything after agriculture deities and festivals.
posted by Long Way To Go (20 comments total) 8 users marked this as a favorite
Dibs on Lacus Juturnae.
posted by clavdivs at 9:01 PM on March 19, 2015

For the curious, here's a big old list of astrogeological naming schemes.

Most of the themes are derived from classical literature and mythology, but Titan seems to have been given over to the nerds. Titan has straits, plains, ravines, hills and mountains named after characters and places from Asimov, Herbert, and Tolkien, including the impressive peak called Doom Mons.
posted by Iridic at 9:35 PM on March 19, 2015 [6 favorites]

The ice may occasionally squirt up in towering ‘cryovolcanoes’, thanks to internal pressures within the asteroid.

Whoa. Cryovolcanoes!
posted by isthmus at 9:38 PM on March 19, 2015 [2 favorites]

If it's two cryovolanoes, why only two? Weakest spot in the "crust" at that location maybe because of the impact?

When the spacecraft settles into an orbit (and makes closest approach) this is gonna get really interesting.
posted by InsertNiftyNameHere at 10:02 PM on March 19, 2015

If it's two cryovolanoes, why only two?

Ok, let's be honest, we're all hoping the bright spots are a beacon to a stele that's a perfect mineralogical match to the surviving copy of Hammurabi's code and that reads:
posted by Blue Jello Elf at 10:08 PM on March 19, 2015 [18 favorites]

IsCon-Agra an agricultural deity?
posted by Cranberry at 11:54 PM on March 19, 2015

IsCon-Agra an agricultural deity?

Only for tidally-locked planetary bodies that have a permanent dark side.
posted by traveler_ at 12:33 AM on March 20, 2015 [3 favorites]

"feature number 5"

Could this be Lou Bega's big comeback opportunity?
posted by fairmettle at 3:12 AM on March 20, 2015 [2 favorites]

If it's two cryovolcanoes, why only two?

It's not only two; you can see more in the rotating image in the fantastic 2nd link by Emily Lakdawalla (who's a treasure of a science writer). In a previous article linked in the last Ceres thread she specifically noted, "There are other bright spots elsewhere within craters."

Her explanation in the new article of why we think the bright spot is a plume is clear and interesting, too:

What he is saying is that as Ceres' globe rotates and the 80-kilometer crater's rim rotates into view, that rim should block our ability to see the bright feature on the floor of the crater. However, the bright feature is already visibly bright as the crater begins to rotate into view. Therefore, it must be vertically above the rim of the crater: it must be some kind of plume. "During the day," Nathues went on, "the feature evolves: it brightens. At dusk it gets fainter; at late dusk it disappears completely. We see this for cometary activity."

Don't miss her take on the ridiculous attempt at an embargo from the scientist who started his public talk with "Bloggers, please do not blog about this talk." Have I said yet I think she's a treasure?

posted by mediareport at 3:22 AM on March 20, 2015 [7 favorites]


would be much more fun
posted by Devonian at 3:28 AM on March 20, 2015 [13 favorites]

Also Lakdawalla says some of the images NASA is releasing are stretched to make Ceres look spherical (it's actually fairly oblate, like Saturn without rings). Frustrating in the age of Cassini, Spirit/Opportunity etc. not to have the raw images to look at.
posted by gubo at 4:23 AM on March 20, 2015 [1 favorite]

That's no planetoid. What we are seeing are rocket exhaust plumes.
posted by Renoroc at 5:06 AM on March 20, 2015 [1 favorite]

So exciting! Cryovolcanism on smaller bodies has been one of the coolest (ahem) surprises in planetary science the last 10 years or so.
posted by BrashTech at 5:48 AM on March 20, 2015

If it's two cryovolanoes, why only two?

Obvious. Cryovolcanoes are monogamous.

Weakest spot in the "crust" at that location maybe because of the impact?

Possible. Also, the crater floor is lower, if you have a "dust" covered iceball, then the lower spots are where you'd see ice. Ice has much higher albedo than the otherwise *very* dusky Ceres, average albedo is under 10%.

There are a few other notably bright spots, all in craters -- none quite as dramatic as the Eyes of Ice-Sauron there, but still, there's something with very high albedo.

Also Lakdawalla says some of the images NASA is releasing are stretched to make Ceres look spherical

A couple have, because they're corresponding to maps, which we draw on perfect circles. There are plenty of images showing the oblateness. Indeed, one of the biggest evidence that Ceres has a relativity soft layer is the oblateness. Saturn (and all the gas giants, and the sun) are markedly oblate because they're basically gaseous, and the rotation sends material outwards at the equator and inward at the pole. In truth, most planets are like this, including Earth, but where the Earth and Moon have less that 1% oblateness, Ceres is closer to 7% and Saturn to 10%.

Frustrating in the age of Cassini, Spirit/Opportunity etc. not to have the raw images to look at.

You will. But one of the rules of the world is that the Primary Investigator gets to write his paper first. One big exception -- the Hubble Space Telescope reserves 10% of its image time in the cycle for "Director Discretion", which allows the HST Director to basically make the call. This is used for sudden events that didn't have a "trigger" proposal in place, or sometimes, explicitly to make a pretty picture. Data taken during DD time is considered public domain and released immediately. Otherwise, there's a one year embargo on that data unless the PI who requested the imagery releases it sooner.

The other problem is that the true raw data isn't very useful without the calibration info. These instruments are truly pushed to the edge to get the most data possible, but without the calibration, what you'll see in a camera image is over/under exposed with lots of noise, hot spots and whatnot. Until you reduce the data with dark frames, bias frame, hotspot maps, flat field corrections, fixed noise removal, and so forth, you get, at best, noise ridden photos, often underexposed.

Dawn has release the raw and calibrated (in case you don't want to reduce the raw data yourself) images for the Cruise, Mars, and Vesta phases of the mission, and, once they've had a good look at it, will release the Ceres imagery. But until the guys who've spent years working the mission, designing the instruments, etc., get a chance to write their papers, you have to wait.

You know, just like every other science.
posted by eriko at 6:14 AM on March 20, 2015 [6 favorites]

In case you're wondering, we won't get any more imagery in April. Dawn has actually gone behind Ceres for a bit as they fully match orbits, and they're now basically on the night side. While the ion thrusters on the spacecraft are capable of an amazing total ΔV, what they're lousy at is thrust, so burns take a very long time indeed.

We will get *much* closer images -- the point of the burn is first, orbital capture, then circulation for the first mapping pass, then lowering that orbit for the second mapping pass.

With chemical rockets, that orbital burn would be seconds to minutes. Of course, with those, Dawn would have run out of fuel/reaction mass long before reaching Ceres. With the ion thrusters, the capture burn is a few days (IIRC) and the circ burns will be hours.

By the time all is said an done, Dawn will have imparted about 10km/sec in ΔV, starting from LEO.
posted by eriko at 6:20 AM on March 20, 2015 [2 favorites]

I can not wait for later in the year, when Dawn gets much closer. In November, it'll begin a 3 month of investigation from an orbital height of 375mi, so hopefully we'll start seeing those photos in January or February of 2016.

In August, it'll be orbiting at 900mi high, so still plenty of good stuff before that time.
posted by Brandon Blatcher at 6:28 AM on March 20, 2015 [1 favorite]

Names for agricultural deities and festivals, fine.

Asari, Chahal, Dagau, Ebisu (sounds familiar - Sumer?), Gurcho, Rongo, Palo, Kumba (different transcription of the Indian Kumbha mela?), Hobnil, Siladi (would be nice to get the stories behind each of these, instead of having to transcribe them from an image), Taubewa, Wayu, and Zelus to round out the alphabetical arrangement.

But Yumyum? Yumyum? An agricultural festival called Yumyum? I'm having a hard time swallowing that.
posted by RedOrGreen at 9:19 AM on March 20, 2015 [1 favorite]

Why not, there's a planet in our solar system called MakeMake. The floodgates are open!
posted by Brandon Blatcher at 9:40 AM on March 20, 2015 [1 favorite]

I'm having trouble finding some of those deities. The only hits I get for Taubewa appear to be mis-scans and random word generators.
posted by tavella at 11:26 AM on March 20, 2015

RedOrGreen: " I'm having a hard time swallowing that."

Thats not what Mayans said.
posted by TheLittlePrince at 11:58 AM on March 20, 2015

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