Intense Cratering
The complex terrain of is captured in this view of its southern hemisphere. Most of the surface consists of intensely terrain transected by and graben.
CRATERING RATES
In addition to the bombardment by meteoroids with masses of a gram or more, ...
Cratering on the Moon
Craters in the Tycho-Clavius region of the Moon.
Cratering in your Classroom
Impact cratering is a process found everywhere in the solar system except on the giant gaseous planets. Earth has been heavily impacted but erosion has removed most of the craters.
Impact cratering involves high velocity collisions between solid objects, typically much greater than the velocity of sound in those objects.
Impact cratering is a common occurrence on many solar system bodies. Much of Enceladus's surface is covered with craters at various densities and levels of degradation.
Impact cratering on Earth
Lists by region
Africa Â- Asia Â- Australasia and Antarctica Â- Europe Â- Canada Â- USA and Central America Â- South America ...
"Impact Cratering On The Earth" by Richard A. F. Grieve, SCIENTIFIC AMERICAN, April 1990, 66:73.
"Dinosaurs & Friends Snuffed Out?" by Richard A. Kerr, AAAS SCIENCE, 11 January 1991, 160:162.
Extensive cratering is seen on both types of terrain. The density of cratering indicates an age of 3 to 3.5 billion years, similar to the Moon.
This experiment yielded information on the petrologic properties of the surface material on the moon, as well as giving images useful for morphologic studies and cratering statistics.
Impact Cratering (PDF, 274 KB): Model and examine the impact cratering process.
Grade Level: K-4
Impact Craters: Holes in the Ground (PDF, 274 KB): Participants model and examine the impact cratering process.
Grade Level: 5-8, 9-12 ...
Cratering Density
The amount of cratering is usually an indication of the age of a geological surface: the more craters, the older the surface, because if the surface is young there hasn't been time for many craters to form.
Every highland region has been subjected to repeated large impacts, as evidenced by heavy cratering. The maria, on the other hand, show much less cratering and thus are significantly younger.
PSEUDOTACHYLITE - Rock formed by frictional melting of rocks during faulting and impact cratering as a result of high rates of deformation and nearly total transformation of kinetic energy to heat.
This assumes, of course, that the cratering rate has been fairly constant for the last few billion years. The heavy bombardment of about 3.8 billion years must be taken into account when using the crater age dating technique.
If you look at the northern hemisphere, you'd see that it is relatively smooth with very little cratering. This is also where you tend to see volcanoes. In the south there are many more craters and some large impact basins.
Cratering on Mercury triggered volcanic eruptions that filled much of the surrounding area. Mercury does have a magnetic field (probably generated by a partly-liquid iron core).
SIZE
Mercury is about 3,031 miles (4,878 km) in diameter.
The findings rekindle a much debated topic in impact cratering that concerns the Moon's bombardment history, and whether there was an apparent spike in the rate of impacts 3.9 billion years ago.
Callisto shows the most cratering and probably shows us the oldest surface. Ganymede shows large fault systems which look like features on the Earth, such as the San Andreas fault in California.
Their work remained controversial, but the American Apollo Moon landings, which were in progress at the time, provided evidence of the rate of impact cratering on the Moon.
The clays probably formed during an intense cratering period in Mars' early history known as the Noachian Era. That time period lasted from from the planet's birth around 4.5 billion years ago to about 3.8 billion years ago.
Surface evolution was characterized by differentiation, cratering, flooding, and surface erosion and uplift. The volatile elements H, He, C, and N are extremely depleted in the Earth.
The remaining planetesimals collide with the newly formed planets causing extensive cratering. Eventually the planetesimals are used up and the cratering dies out to today's low rate. The result is the solar system we see today.
Large, fast objects release a lot of energy and form large, complex craters. Very large impacts can even cause secondary cratering, as ejected material falls back to the ground, forming new, smaller craters, or a series of craters.
Radar experiments have established that the surface is somewhat smoother than the Moon, but there are mountains and there is extensive cratering. Atmospheric pressure 92-95 atm.
are the M-type objects, corresponding in composition to the meteorites known as "irons". Consisting of an iron-nickel alloy, they may represent the cores of melted, differentiated planetary bodies whose outer layers were removed by impact cratering.
The trailing hemisphere is more heavily cratered than the leading hemisphere, which is the reverse of the cratering on most of the other Saturnian satellites.
that of a society with zero growth, where the number of children born in the year is equal to the number of individuals that have passed away. For the NEO population, the existence of a steady state is suggested by the observation that the cratering ...
The surface of Mercury has been shaped by three processes: impact cratering where large objects struck the surface resulting in crater formation, volcanism where lava flooded the surface, ...
and their satellites resemble miniature solar systems.
The planets are well-spaced in their orbits.
Comets come from a region out beyond Pluto (known as the Oort Cloud).
All bodies with solid surfaces show evidence of craters and cratering.
ejecta (NASA Thesaurus) Matter ejected during impact cratering processes, usually meteoritic. ejection capsule (NASA SP-7, 1965) 1.
 See also: Crater, Earth, Orbit, Moon, Planet
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