Astronomy Picture of the Day -- The Regolith of Asteroid Eros

NASA ^ | June 19, 2011 | (see photo credit)

[SunkenCiv]

Explanation: From fifty kilometers above asteroid Eros, the surface inside one of its largest craters appears covered with an unusual substance: regolith. The thickness and composition of the surface dust that is regolith remains a topic of much research. Much of the regolith on 433 Eros was probably created by numerous small impacts during its long history. In this representative-color view taken by the robot spacecraft NEAR-SHOEMAKER that orbited Eros in 2000 and 2001, brown areas indicate regolith that has been chemically altered by exposure to the solar wind during micrometeorite impacts. White areas are thought to have undergone relatively less exposure. The boulders visible inside the crater appear brown, indicating either that they are old enough to have a surface itself tanned by the solar wind, or that they have somehow become covered with some dark surface dust. This July, NASA's Dawn spacecraft will orbit giant main belt asteroid Vesta.

[SunkenCiv]

[Credit: NEAR Project, JHU APL, NASA]

[SunkenCiv]

I freely admit I'm kind of a weirdo, but this is my favorite shot since the revival of the APoD list.

join or quit list APoD 'blog post new APoD topic Astronomy Picture of the Day topic & keyword Astronomy Chat, Bloggers & keyword Science Chat, Bloggers & keyword NASA's APoD archive Calendar 1995-present APoD on your desktop

[PeaceBeWithYou]

BTTT.

Regolith ( ) n. The layer of loose rock resting on bedrock, constituting the surface of most land. Also called mantle rock.

[SunkenCiv]

Very cool, an impact crater on Eros, close-up.

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[SunkenCiv]

Thanks PBWY.

[SatinDoll]

You’re not a weirdo.

I have a poster, a composite view of the surface of Ganymede taken many years ago on a flyby, and it is definitely out of this world!

[dr_lew]

I followed this mission closely. It was something to watch a nondescript blob grow into a complex object. I was most impressed by the mpeg movies taken from "near" orbit.

[alexander_busek]

I could use some scale to better appreciate this image. How big is, e.g., the largest boulder in the middle of the image?

Is it really correct to refer to regolith as "unusual?" After all, the Martian moons Deimos and Phobos are covered with it, our moon Luna is largely covered with it - wouldn't it be expected even here, on a celestial body the size of Eros?

Regards,

[Rudder]

Does it imply that Eros has gravity sufficient to hold on to its regolith?

[COBOL2Java]

It'll be very exciting when Dawn Mission visits Ceres in 2015. All we have right now is a fuzzy image from Hubble.

Depiction of Dawn firing its ion thruster en route to Ceres

[left that other site]

I wonder who will be the first one to build timeshares on the site.

[bert]

The process of compacting regolithic deposits into brick like building blocks is currently under study anticipating the possible real estate boom

[left that other site]

LOL! Don’t go on the tour! You’ll never get out without buying in!

[SunkenCiv]

Too late, I bought Eros online, very reasonable.

[left that other site]

Hoo Boy!

Your first Invoice for your maintenance fee, taxes, Timeshare Membership, HOA Fee, and Club membership will come next month!

[bigheadfred]

weirdo

Ya shoulda been with us on the 5 day roadtrip to Portland (Oregon). You think I wasn't gonna spend that extra bit of time to drive over to the coast, strip to my boxers, and run into that freezing cold ocean? Not a chance.

[bigheadfred]

weirdo

Ya shoulda been with us on the 5 day roadtrip to Portland (Oregon). You think I wasn't gonna spend that extra bit of time to drive over to the coast, strip to my boxers, and run into that freezing cold ocean? Not a chance.

[bigheadfred]

weirdo

Ya shoulda been with us on the 5 day roadtrip to Portland (Oregon). You think I wasn't gonna spend that extra bit of time to drive over to the coast, strip to my boxers, and run into that freezing cold ocean? Not a chance.

[dr_lew]

This Discover Magazine site has a version of this same photo, identifying it as the crater Psyche. ( If you imagine Eros as a ballet slipper, Psyche is on the center of its arched sole. ) Another illustration shows the layout of Eros with a 5km scale. I think the width of the APOD photo is about 3km. That puts the boulder maybe in the 100 meter range.

[mowowie]

Civ could you add me to your APOD ping list?
Thanks.

I was on the old one but that sort of disappeared a while back...