impact basin filled with basalt of
- Steptoe Butte Natural Area Preserve (dnr.wa.gov)
Steptoe Butte Natural Area Preserve (NAP) was established in 2018 to protect the largest known remaining occurrence of Palouse prairie in Washington. With an estimated 2% of its historic range remaining, the Palouse prairie is considered one of the most endangered ecosystems in the continental United States. The 437-acre preserve was identified by the Washington State Natural Heritage Program for NAP status to protect four rare plants, four priority plant associations, and one rare earthworm species.
- Lunar mare (Wikipedia)
The lunar maria (/ˈmæri.ə/ MARR-ee-ə; sg. mare /ˈmɑːreɪ, -i/ MAR-ay, MAR-ee) are large, dark, basaltic plains on Earth’s Moon, formed by lava flowing into ancient impact basins. They were dubbed maria (Latin for ‘seas’) by early astronomers who mistook them for actual seas.[citation needed] They are less reflective than the “highlands” as a result of their iron-rich composition, and hence appear dark to the naked eye. The maria cover about 16% of the lunar surface, mostly on the side visible from Earth. The few maria on the far side are much smaller, residing mostly in very large craters. The traditional nomenclature for the Moon also includes one oceanus (ocean), as well as features with the names lacus (’lake’), palus (‘marsh’), and sinus (‘bay’). The last three are smaller than maria, but have the same nature and characteristics.