NEAR spacecraft images 253 Mathilde

low density

data indicate that the dark rock has a low density, akin to that of a pile sand or ribble loosely bound by gravity.

darker than charcoal

It reflects the same amount of sunlight, half as much as a chunk of carcoal, even from regions where a projectile has dug deep into the rock.

carbonaceous material

The uniformity indicates that the rock, classified as a C-type asteroid because it contains carbonaceous material, is a pristine relic of the early solar system.

Science News, Vol 152, July 12, 1997, page 29, "Waltzing past Mathilde" and " Hidden comapnion"

Date: Sun, 03 Aug 1997 12:50:12 -0700
From: Pat Whitman
Organization: USL
Mime-Version: 1.0
To: Anthony Zuppero , Cc:,

It is a sandy body held together by gravity alone...
I have come across some new (to me) info in the July 12th issue of Science News. Two short articles on the same page that I will fax to you tomorrow. First is called Waltzing past Mathilde. reference is to the main belt asteroid 431 Mathilde passed by NEAR which spied 5 craters more than 20 km in diameter (431 Mathilde is a 50km across potato). The pic I saw shows only one. Question is how can this fellow still be there. An analysis of "radio waves" suggests the answer. It is a sandy body held together by gravity alone... Another interesting thought not expressed in the article concerns the distribution of rotational speeds. I have a memory of this too being consistant with objects being held together by gravity only. Do you know anything about this?

Second article is about asteroid 3753. It is loosely bound to the Earth and remains ~ 40 Earth-Moon distances from the Earth. It is on a stable orbit with probable loss from a perturbation by Venus in ~ 8000 years.

Also there was an interesting article on the Mars Lander. Seems web sites containing new pics scored 100 million hits in 5 days, a world record. So people are interested in such things as never before seen alien landscapes.