Hesiodus A -- Concentric Ringed Crater on the Moon
The Donut Crater
Donut or Concentric craters are not common on the moon. Most of them occur near mare
edges and are small (2 to 20 km) in size. Slightly over 50 of them are known, with
Hesiodus A considered the easiest of them to observe. They are interesting craters that
are deep in mystery.
Charles Wood in his 2003 book “The Modern Moon” writes, “The inter doughnuts cannot
be impacts that just happened to be centered on preexisting craters. They must be formed
by some sort of volcanic extrusions or annual intrusions, neither of which have many
analogues on Earth.”
Hersiodus A is small (14.5 km). It is located on the southwest rim of the crater Hersiodus.
Hespsidus is adjacent to the large crater Pitatus which rests on the southern edge of
Mare Nubium.
The weather forecast on the night of the drawing was questionable. Also having a bright
gibbous moon kept me from setting up my usual telescope. Instead, I pulled out the
3.5-inch Questar and with a moon map decided to enjoy the moon for an hour or so. After
a while, the skies were still holding, and I decided to try and push the little telescope and
see what it could do. Hersiodus A was small in the eyepiece even at the highest powers
the little scope would let me use. Still with some effort details within the crater materialized
-- a test to the quality of the Questar optics with help from a somewhat stable atmosphere.
edges and are small (2 to 20 km) in size. Slightly over 50 of them are known, with
Hesiodus A considered the easiest of them to observe. They are interesting craters that
are deep in mystery.
Charles Wood in his 2003 book “The Modern Moon” writes, “The inter doughnuts cannot
be impacts that just happened to be centered on preexisting craters. They must be formed
by some sort of volcanic extrusions or annual intrusions, neither of which have many
analogues on Earth.”
Hersiodus A is small (14.5 km). It is located on the southwest rim of the crater Hersiodus.
Hespsidus is adjacent to the large crater Pitatus which rests on the southern edge of
Mare Nubium.
The weather forecast on the night of the drawing was questionable. Also having a bright
gibbous moon kept me from setting up my usual telescope. Instead, I pulled out the
3.5-inch Questar and with a moon map decided to enjoy the moon for an hour or so. After
a while, the skies were still holding, and I decided to try and push the little telescope and
see what it could do. Hersiodus A was small in the eyepiece even at the highest powers
the little scope would let me use. Still with some effort details within the crater materialized
-- a test to the quality of the Questar optics with help from a somewhat stable atmosphere.