Picard - in Mare Crisium
- IAU page: Picard
(IAU Directions) PICARD.--The largest of the craters on the surface of the Mare Crisium, 21 miles in diameter. The floor, which includes a central mountain, is depressed about 2,000 feet below the outer surface, and is surrounded by walls rising some 3,000 feet above the Mare. A small but lofty ring-plain, Picard E, on the W., near the border of the Mare, is remarkable for its change of aspect under different angles of illumination. A long curved ridge running S. from this, with a lower ridge on the east, sometimes resemble a large enclosure with a central mountain. Still farther S., there is another bright deep crater, a, with a large low ring adjoining it on the S., abutting on the S.W. border of the Mare. Schroter bestowed much attention on these and other formations on the Mare Crisium, and attributed certain changes which he observed to a lunar atmosphere.
Depth data from Kurt Fisher database
- Pike, 1976: 2.32 km
- Westfall, 2000: 2.32 km
- Viscardy, 1985: 2.22 km
- Cherrington, 1969: 2.31 km
- Satellite crater Picard Z is on the ALPO list of bright ray craters.
- A thermal anomaly crater, implying a youthful age - Moore et al, 1980
Lunar Ellipse of Fire
Picard and Peirce (north of Picard) are (or were?) both number ten in the list of 12 localities in the Lunar Ellipse of Fire (see article from Farouk El-Baz in Sky and Telescope - June 1973).
- Jean-Felix Picard (July 21, 1620 – July 12, 1682) was a French astronomer. He was the first person to measure the size of the Earth to a reasonable degree of accuracy in a survey conducted 1669-70. Guided by Maurolycus' methodology and Snell's equipment design for doing so, Picard achieved this by measuring one degree of latitude along the Paris Meridian. His measurements produced a terrestrial radius of 6,328.9 km. The polar radius has now been measured at just over 6,357 km. This was an error only 0.44% less than the modern value. This was another example of advances in astronomy and its tools making possible advances in cartography.
- Not to be confused with Auguste Antoine Piccard.
- In the days of Hevelius (Johann Hewelcke), the crater Picard was called Insula Alopecia (Isle of Baldness?). See page 201 of Ewen A. Whitaker's Mapping and Naming the Moon (1999).- DannyCaes May 27, 2013