Crater Euclides and Montes Riphaeus

Crater Euclides and Montes Riphaeus
Sketch and details by Frank McCabe

In southern Oceanus Procellarum not far from mare Cognitum you can locate a bright little Copernican era crater that formed after the last of the dark lava had solidified. This little 12 kilometer crater wearing the bright ejecta blanket is Euclides. The bright ejecta makes it easy to pick out at high sun and with a little bit of shadow and high magnification the nearby Riphaeus mountains also show some fine relief. In the upper left of the sketch note the front range of these mountains which date back 4 billion years. These mountains are likely the remains of a very large crater rim that was not completely buried in the lava flooding. Other similar sized and smaller craters in the region also reveal some bright ejecta betraying their young ages. To learn more read the LPOD caption for May 24, 2006.

Sketching:

For this sketch I used: black Canson paper 10″x 12″, white and black Conte’
pastel pencils , and Conte’crayons, a blending stump, plastic and gum erasers. Brightness was decreased -2 and contrast increased +2 using the scanner for this sketch
Telescope: 10 inch f/ 5.7 Dobsonian with 6mm (241x) eyepiece
Date: 11-28-2009 4:15-5:40 UT
Temperature: 0°C (32°F)
Clear becoming partly cloudy, calm
Seeing: Antoniadi II -III
Co longitude 44°
Lunation 11.4 days
Illumination 80.7%

Frank McCabe