crater
1. the bowl-shaped opening at the top or side of a volcano or top of a geyser through which lava and gases are emitted
2. a similarly shaped depression formed by the impact of a meteorite or exploding bomb
3. any of the circular or polygonal walled formations covering the surface of the moon and some other planets, formed probably either by volcanic action or by the impact of meteorites. They can have a diameter of up to 240 kilometres (150 miles) and a depth of 8900 metres (29 000 feet)
4. a large open bowl with two handles, used for mixing wines, esp in ancient Greece
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
Crater
(kray -ter) (Cup) A small inconspicuous constellation in the southern hemisphere near Leo, the brightest stars being of 3rd and 4th magnitude. Abbrev.: Crt; genitive form: Crateris; approx. position: RA 11.5h, dec –l5°; area: 282 sq deg.Collins Dictionary of Astronomy © Market House Books Ltd, 2006
crater
[′krād·ər] (geology)
A large, bowl-shaped topographic depression with steep sides.
A rimmed structure at the summit of a volcanic cone; the floor is equal to the vent diameter.
(mechanical engineering)
A depression in the face of a cutting tool worn down by chip contact.
(metallurgy)
A depression at the end of the weld head or under the electrode during welding.
Crater
[′krād·ər] (astronomy)
A constellation, right ascension 11 hours, declination 15°S. Abbreviated Crt. Also known as Cup.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.
Crater
a bowl- or funnel-shaped depression with a diameter measuring between dozens of meters and several kilometers and a depth from a few meters to hundreds of meters. Craters form during volcanic eruptions, as a result of the impact of meteorites, and as a result of large man-made explosions. Volcanic craters are usually located on the peaks or slopes of volcanoes. At the bottom of the crater are one or several vents through which lava and other volcanic products rising along an outlet channel from the magmatic center reach the surface. Sometimes the bottom of the crater is covered with a lake of lava or a small, newly formed volcanic cone.
The craters on the moon and Mars are round depressions surrounded by circular ridges; their diameters are up to 100–200 km and they are up to several kilometers deep. A distinction is made among them between craters formed during the impact of meteorites and asteroids and craters of volcanic origin (similar to the earth's volcanic craters and calderas).
Crater
(the Cup), a constellation of the southern hemisphere; its brightest star has a visual stellar magnitude of 3.6. The constellation is most easily viewed in March; it is visible from the central and southern regions of the USSR. (SeeSTELLAR SKY.)
The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.