Sentences with phrase «impact crater about»

A surface feature of great interest to scientists is the Caloris basin, an impact crater about 1300 km in diameter, one of the biggest such craters in our solar system.

Not exact matches

The team hopes to find new clues about how these large craters form and what made the impact so deadly.

Furthermore, Schultz's work suggests fragments from these giants could account for a many of the impacts that occurred during a period called the Late Heavy Bombardment, which occurred from about 3.8 billion years ago to around 4 billion years, when scientists think most of the craters we see on the Moon and Mercury were formed.

A massive impact on the Moon about 4 billion years ago left a 2,500 - mile crater, among the largest known craters in the solar system.

Earth bears the scars of a few twin - asteroid impacts: the Clearwater Lakes near Hudson Bay in Canada, for instance, are craters that formed together about 290 million years ago.

The titanic force of the impacts that formed those two craters deformed the entire asteroid, nearly splitting it apart, and created broad troughs that encircle about two - thirds of its surface.

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.

Their results indicate that only about half of the Alamo impact crater and its related deposits are now exposed within the region, and they estimate its total diameter to be between 111 and 150 km.

And by drilling into a circular ridge inside the 180 - kilometer - wide crater rim, scientists hope to settle ideas about how such «peak rings,» hallmarks of the largest impact craters, take shape.

Work by B.C. Johnson and T.J. Bowling predicts that only about four of the craters produced by these impacts could persist until today, and geologists have already found three such craters (larger than 170 km in diameter).

For more than 30 years, scientists have argued about a controversial hypothesis relating to periodic mass extinctions and impact craters — caused by comet and asteroid showers — on Earth.

One of the craters considered in the study is the large (180 km diameter) Chicxulub impact structure in the Yucatan, which dates to about 65 million years ago — the time of a great mass extinction that included the dinosaurs.

Similarly, they are surprisingly free from impact craters, which reveals a great deal about their age, researchers added.

«For reasons that we're not totally sure about, the same properties can arise from the scattering of rocky ejecta on the blocky terrain of young impact craters on the moon,» Campbell notes.

One of the new craters, called Earhart, is about 200 kilometres across and is almost completely masked by a later impact and subsequent lava flooding.

Vesta also grew large enough to survive a massive battering about a billion years ago that formed the 500 - kilometer - wide Rheasilvia impact crater and its 22 - kilometer - high central mound (above).

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.

The expedition is helping answer important questions about the Chicxulub impact event and peak - ring crater formation on planetary bodies.

«By comparing the measured craters to the number and spatial distribution of large impact basins on Mercury, we found that they started to accumulate at about the same time, suggesting that the resetting of Mercury's surface was global and likely due to volcanism,» said lead author Dr. Simone Marchi, who has a joint appointment between two of NASA's Lunar Science Institutes, one at the SwRI in Boulder and another at the Lunar and Planetary Institute in Houston.

Studying the gravity anomalies created by an impact is a powerful way to find out more about a crater — particularly one that is now buried, like the Chicxulub crater.

The Vredefort impact crater, about 100 kilometers (60 miles) from Johannesburg, South Africa, was formed just a little over 2 billion years ago.

He started out studying impact craters, but a hunch about Antarctica reshaped his career.

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.

Astronomers think the impact that caused the crater was about 3.84 billion years ago.

Ten years before the 1990 discovery of the Chicxulub crater, physicist Luis Alvarez and geologist Walter Alvarez, a father - son team, proposed a theory about the impact that created it.

«The most striking thing about this image is, we have not yet found a single impact crater on this region,» Spencer said, adding that the smooth terrain suggests it is much younger than the 4.5 - billion - year - old solar system.

Vesta's south polar basin is dominated by two overlapping craters, where the younger Rheasilvia impact obliterated most of the slightly smaller Veneneia crater about a billion years ago (more).

Since the hole was spotted in mid-July by a helicopter pilot, conjecture has abounded about how the 30 - metre - wide crater was formed — a gas or missile explosion, a meteorite impact and alien involvement have all been suggested.

Where is the severe ice age that should have followed the Dinosaur - killer meteor impacts at Chicxulub crater, Silverpit crater, and Boltysh crater about 65 million years ago?