Haystack Vallis
Encyclopedia
Haystack Vallis is a valley at 4.7° N, 46.2° W on Mercury
. It superficially resembles a graben
but is actually a chain of overlapping secondary crater
s. It was named after Haystack Observatory
.
Mercury (planet)
Mercury is the innermost and smallest planet in the Solar System, orbiting the Sun once every 87.969 Earth days. The orbit of Mercury has the highest eccentricity of all the Solar System planets, and it has the smallest axial tilt. It completes three rotations about its axis for every two orbits...
. It superficially resembles a graben
Graben
In geology, a graben is a depressed block of land bordered by parallel faults. Graben is German for ditch. Graben is used for both the singular and plural....
but is actually a chain of overlapping secondary crater
Secondary crater
Secondary craters are impact craters formed by the ejecta that was thrown out of a larger crater. They sometimes form radial crater chains.-External links:*...
s. It was named after Haystack Observatory
Haystack Observatory
Haystack Observatory is a group of astronomical observatories owned and operated by Massachusetts Institute of Technology. It is located in Westford, Massachusetts . It is the home of the Millstone Hill Observatory....
.