01:750:109 Lecture Notes - Lecture 20: Lunar Mare, Geology Of The Moon, Impact Crater
14 Nov 2018
School
Department
Course
Professor
Document Summary
Smooth, dark lunar maria are less heavily cratered than lunar highlands. Regions that are less cratered tend to be more recent. Maria were made by floods of runny lava. More of these areas on part of moon that faces earth. Pull from earth made it easier for lava to flow. Heat build-up allows lava to well up to surface. Cooled lava is smoother and darker than surroundings. Wrinkles arise from cooling and the contraction of a lava flood. Moon is considered geologically dead because geological processes have virtually stopped. Mercury has a mixture of heavily cratered and smooth regions like the moon. Smooth regions are likely ancient lava flows. Long cliffs indicate that mercury shrank early in its history. Sensitive measurements show that mercury and the moon have extremely thin atmospheres. Gas comes from impacts that eject surface atoms. Near polar regions of the moon and mercury. Might have been water from comets (ice compounds released)
