Sentences with phrase «as impact craters»

Hubble resolves Martian surface features with a level of detail only exceeded by planetary probes, such as impact craters and other features as small as 30 miles (50 kilometers) across.

Extraterrestrial sample analysis and terrestrial field work on fundamental geological processes such as impact cratering, and their implications for the origin and evolution of life.

Not exact matches

[241] The attractions and major tourist destinations of Ghana include a warm, tropical climate year - round; diverse wildlife; exotic waterfalls such as Kintampo Waterfalls and the largest waterfall in west Africa, Wli Waterfalls; Ghana's coastal palm - lined sandy beaches; caves; mountains, rivers; meteorite impact crater and reservoirs and lakes such as Lake Bosumtwi or Bosumtwi meteorite crater and the largest man - made lake in the world by surface area, Lake Volta; dozens of castles and forts; UNESCO World Heritage Sites; nature reserves and national parks.

Many scientists think these permanently shadowed regions, such as the floors on impact craters in the Moon's polar regions, could hold large deposits or water ice.

By examining the craters that formed on top of it, researchers estimate that Rembrandt formed in an impact some 3.9 billion years ago, near the end of a barrage of impacts in the inner solar system known as the Late Heavy Bombardment.

The impact melted the surface that it hit and gouged out a 77 - kilometre - wide basin known as King crater.

Key to the basin's identification as a potential impact crater are the decrease in the strength of Earth's gravity over the site, indicating a large basin filled with younger low - density sediments, and a strong increase in the strength of Earth's magnetism at the site.

Each grainy image took eight hours to receive, but the payoff was huge: Surprising evidence of deep impact craters banished the popular idea of Mars as a chillier version of Earth.

The chance of a giant impact producing a crater so precisely aligned with Charon is vanishingly slim, Keane says, so he and his team (as well as Nimmo's) went searching for another explanation.

At the same time, the impact would have plastered preexisting river and swamp deposits onto the flanks of the impact crater, where they would later be imaged as the chaotic deposits in our acoustic - echo profiles.

In this instance, researchers have been able to use new imaging techniques to measure the atomic nanostructure of ancient crystals at impact locations, using the 150 - kilometre - wide crater at Sudbury as a test site.

If that upwelled material is denser than what was blasted away by the impact, the crater ends up with the same mass as it had before the impact happened.

This is more than double previous estimates and, if correct, places the Alamo crater as one of the largest marine impacts in the last 550 million years, conservatively larger than the well - studied Chesapeake Bay impact crater (about 35 million years old) on the eastern shore of North America.

The crater was filled - in with fragmented rock, and later with more typical ocean deposits, as the energy from the impact lessened and the environment returned to normal.

As the drill approaches the crater, 800 meters down, scientists expect to find fewer species of the shell - producing animals that make up the limestone, because life was just recovering from the impact.

The shapes seen both in the models and in reality are similar to other funnel - shaped impact craters, such as those seen on NASA's Stardust spacecraft, which collected space dust particles in aerogel.

The impact that produced the crater was two million times more powerful than the largest nuclear device ever tested, a 58 - megaton hydrogen bomb known as Tsar Bomba, detonated by the Soviet Union in 1961.

Not a single impact crater is to be seen in this region, so the surface must be very young — reshaped by some sort of geological activity such as faulting or icy volcanism.

Some surface features, such as volcanoes and impact craters, are self - evident, but the images give only indirect clues to the all - important internal processes.

Although no very ancient terrestrial impact structures are preserved, the Sudbury basin provides a unique opportunity to study the sediment that filled the basin as a guide to what the earlier impact craters would have looked like.

The spherules, known as microtektites, are droplets of molten rock that were melted and thrown out of the impact crater by the energy of the projectile, or condensed from rock that was vaporized upon impact.

The cratering record on the moon provides a proxy for similar impacts by interplanetary debris such as comets and asteroids on Earth, the effects of which have largely been erased by billions of years of erosion and geologic activity.

The kind of asteroid needed to form the Martian dichotomy would fall in between that size and those of the rocks that formed other large craters, such as the South Pole — Aitken impact basin on the moon and the Hellas Basin in Mars's southern hemisphere, both more than 1,30 miles (2,000 kilometers) wide.

They reasoned that without continual renewal, the surfaces of such bodies should have become densely covered with craters as a result of impacts by meteorites and comets over the 4.5 billion years that they have existed.

The impact that formed a large basin known as Orientale in the western area of the moon's near side, which the group investigated in detail, obliterated all prior craters within the basin itself, an area of nearly 700,000 square kilometers.

Project scientists were so unsure of the impact's effects that they had a betting pool as to how large the crater would be — one of the most important indicators of the structure of the comet nucleus.

You can scoop up bits of stishovite at the scene of meteorite impacts, such as a 50,000 - year - old meteor crater in Arizona that measures about 3 / 4 - mile across and about 570 feet deep.

Those results set the age boundary for the oldest terrains on Mercury to be contemporary with the so - called Late Heavy Bombardment (LHB), a period of intense asteroid and comet impacts recorded in lunar and asteroidal rocks and by the numerous craters on the Moon, Earth, and Mars, as well as Mercury.

The size and shape of the crater and the amount of material excavated depends on factors such as the velocity and mass of the impacting body and the geology of the surface.

This location was chosen because it is one of the most Mars - like locales on the face of the Earth: the island is completely uninhabited and unvegetated; it receives almost no precipitation, and is thus nearly as dry as Mars; temperature extremes approach those of Mars; the impact crater where the station is located is similar to many such craters on Mars.

Recently, geologists suggested these grains may have formed in huge impact craters produced as chunks of rock from space, up to several kilometres in diameter, slammed into a young Earth.

As five impact craters on Mercury receive names, NASA's MESSENGER spacecraft is about to create another, since it has run out of propellant and is predicted to impact on the surface of the planet at 8:26 pm BST today.

The minerals could not have been formed in a local event, such as an impact into an ice - filled crater.

Some of this brighter material appears to have flowed further downslope to form the heart shape, as the small impact occurred on the ejecta blanket of a much larger impact crater.

In addition, the collision with a 372 - kilogram (820 - pound) projectile launched by NASA's Deep Impact probe in 2005 has created a 150 - meter - wide (490 - foot - wide) crater with a small mound in the center, as some of the ejecta of the impact apparently fell back down within the crater, but the crater's relatively soft outline indicates that its edges have undergone significant changes since the 2005 impact (NASA / STARDUST / NExT news release; Astronomy Picture of the Day; David Shiga, New Scientist, February 15, 2011; Jonathan Amos, BBC News, February 15, 2011; and Richard A. Lovett, Nature News, February 15, Impact probe in 2005 has created a 150 - meter - wide (490 - foot - wide) crater with a small mound in the center, as some of the ejecta of the impact apparently fell back down within the crater, but the crater's relatively soft outline indicates that its edges have undergone significant changes since the 2005 impact (NASA / STARDUST / NExT news release; Astronomy Picture of the Day; David Shiga, New Scientist, February 15, 2011; Jonathan Amos, BBC News, February 15, 2011; and Richard A. Lovett, Nature News, February 15, impact apparently fell back down within the crater, but the crater's relatively soft outline indicates that its edges have undergone significant changes since the 2005 impact (NASA / STARDUST / NExT news release; Astronomy Picture of the Day; David Shiga, New Scientist, February 15, 2011; Jonathan Amos, BBC News, February 15, 2011; and Richard A. Lovett, Nature News, February 15, impact (NASA / STARDUST / NExT news release; Astronomy Picture of the Day; David Shiga, New Scientist, February 15, 2011; Jonathan Amos, BBC News, February 15, 2011; and Richard A. Lovett, Nature News, February 15, 2011).

Bright features such as these are caused by the presence of freshly crushed rock material that was excavated and deposited during the highly energetic collision of a meteoroid with Mercury to form an impact crater.

Impact craters at many latitudes sometimes expose thin ice layers a foot or so beneath Mars» surface.132 «At polar latitudes, as much as 50 percent of the upper meter of soil may be [water] ice.»

As distinct from impact craters, these craters are not formed from the clashing of bodies or projectiles from space.

In another scene, mimicking the popular Absolut Vodka advertising of the time, GALA's ad featured a liquor - bottle shaped impact crater as damage to the Alfred P. Murrah Federal Building, site of the 1995 Oklahoma City Bombing, a domestic terrorist attack that killed 168 people.

The record of history, as written in the many impact craters on Earth and the moon, demonstrate that it is just a matter of time before astronomers discover a near Earth object (NEO) headed toward a collision with Earth.

Yet even if the Siberian craters do prove to be an unexpected mechanism of accelerated methane release, the best analogy here remains «boiling a frog» as impacts accumulate gradually, until eventually a tipping point is reached.

But then, you see, the impact crater cools, as the heat is radiated, convected, and conducted away.

Guest shoot - down by David Middleton Preface In my previous two posts on uniformitarian impact craters, we examined the pitfalls of drawing cartoons on Google Earth images without ever looking at the geology and how the Carolina Bays are as antithetical to impact features as any dents in the ground possibly could be.

The firestorms would have produce an enormous injection of CO2 as well as soot, and the impact crater in partially calcium carbonate rock would have produced direct CO2 from the reduction of that rock, but neither the «nuclear winter» not the subsequent global warming extinguished life.