Arandas (crater) km in diameter) they usually have a central peak. The peak is caused by a rebound of the crater floor following the impact. Sometimes craters expose layers that were buried. Rocks from deep underground are tossed onto the surface. Hence, craters can show us what lies deep under the surface. Arandas (crater) Arandas Crater is a crater in the Mare Acidalium quadrangle of Mars, located 42.77° North and 15.17° West. It is 24.76 km in diameter and is named after the town of Arandas in Mexico. South is the scalloped terrain of Cydonia Labyrinthus and further south is Cydonia Colles,
Obolon' crater Obolon' crater Obolon' crater is a diameter buried meteorite impact crater situated about southeast of Kiev in Ukraine (Poltava Oblast). The site has been drilled, which revealed the presence of shocked minerals and impact melt rock; the high chlorine content of the latter suggesting that the area was covered by shallow sea at the time of impact. One estimate puts the age at 169 ± 7 million years (Middle Jurassic). It has been suggested by Geophysicist David Rowley of the University of Chicago, working with John Spray of the University of New Brunswick and Simon Kelley of the Open University,