ちょっと気分転換ね。...火星のクレーターの記事。
Mars’s mysterious elongated crater / Space Science / Our Activities / ESA
Orcus Patera is an enigmatic elliptical depression near Mars’s equator, in the eastern hemisphere of the planet. Located between the volcanoes of Elysium Mons and Olympus Mons, its formation remains a mystery.
http://www.esa.int/esaSC/SEMDV9BO3DG_index_2.html
