修饰名词"impact crater"用形容词,所以用know的形容词known,意为"已知的"。故填known。(2)考查动词时态和语态。句意:陨石坑,顾名思义,是小行星撞击地球等天体时形成的。这里为本句谓语动词,根据从句时态可知,主句时态为一般现在时;主语"an impact crater",为名词单数,和动词form之间存在...
Impact ejecta from the crater can be found in the Flinders Range 185 miles (300 km) to the east, among rocks with fossils of the first complex life forms on Earth. Chesapeake Bay crater Chesapeake Bay crater (Image credit: WHOI/USGS) Buried under seafloor muds, Chesapeake Bay Crater off...
1. The largest impact crater on Earth, the Vredefort crater in South Africa, is 99 miles (160 km) wide and was likely created about 2 billion years ago, according to NASA's Earth Observatory. The crater has largely eroded, but based on what's left of the rim, scientists have estimated...
Discovery of the largest impact crater field on Earth in the Gilf Kebir region, Egypt. Comptes Rendus Geoscience 336, 1491-1500.Paillou P, El Barkooky A, Barakat A, Malezieux JM, Reynard B, Dejax J, Heggy E (2004) Discovery of the largest impact crater field on Earth in the Gilf ...
1. Barringer Crater Mouser NerdBot / Flickr Barringer Crater is the best known and best preserved impact crater on Earth. The crater is named after Daniel Barringer who was first to suggest that it was produced by a meteorite impact. The crater is still privately owned by his family and is...
The almost 15-million-year-old Nördlinger Ries is an asteroid impact crater filled with lake sediments. Its structure is comparable to the craters currently being explored onMars. In addition to various other deposits on the rim of the basin, the crater fill is mainly formed by stratified cl...
Figure 1: Ceres global large crater size-frequency distribution. (a) Cumulative crater counts on the whole surface for diameter >70 km (magenta). For a comparison, counts for the heavily cratered terrain (blue) are also reported: The drop-off at 70–80 km is due to the limited area...
The terrestrial planets, the Earth's Moon, Mars,Venus, Mercury and the asteroids Gaspra and Ida showstriking similarities in their production crater size distribution characteristics. The investigation of hte crater populations in Gaspra and Ida yield information on the crater size distribution in the...
Mars on Earth How much they resemble each other: Chiemgau impact and Mars impact. Top: The Aiching/Dornitzen semi-crater punched into the Inn Valley slope today, after the other half has been “shaved off” by the Inn River. Below: This image was taken by NASA’s Mars Reconnaissance ...
"Australia is a fantastic place for impact crater hunters because we have huge open space with nothing in it," said Dr O'Toole, adding that the size of the new impact zone was very significant. "It's huge. Most asteroid events are about 100m in diameter." ...