Although the job represented a demotion for Johann, it gave him access to the new 27-inch (690 mm) refractor, the largest telescope in the world at that time.
The initial orbital elements of the asteroid were then computed by V. A. Lebeuf, another Austrian astronomer working at the Paris Observatory.
Mathilde is very dark, with an albedo comparable to fresh asphalt,[12] and is thought to share the same composition as CI1 or CM2 carbonaceous chondrite meteorites, with a surface dominated by phyllosilicate minerals.
[4] The density measured by NEAR Shoemaker, 1,300 kg/m3, is less than half that of a typical carbonaceous chondrite; this may indicate that the asteroid is very loosely packed rubble pile.
[5] The same is true of several C-type asteroids studied by ground-based telescopes equipped with adaptive optics systems (45 Eugenia, 90 Antiope, 87 Sylvia and 121 Hermione).
[11] The low interior density is an inefficient transmitter of impact shock through the asteroid, which also helps to preserve the surface features to a high degree.
The slow rate of rotation may be accounted for by a satellite orbiting the asteroid, but a search of the NEAR images revealed none larger than 10 km in diameter out to 20 times the radius of Mathilde.