Sentences with phrase «giant asteroid impacts»

New research shows that more than four billion years ago, the surface of Earth was heavily reprocessed — or mixed, buried and melted — as a result of giant asteroid impacts.

While researchers estimate accretion during late bombardment contributed less than one percent of Earth's present - day mass, giant asteroid impacts still had a profound effect on the geological evolution of early Earth.

Almost simultaneous with the birth of discover, physicist and Nobel laureate Luis Alvarez (along with his son, Walter Alvarez of the University of California, Berkeley) proposed that a giant asteroid impact killed off the dinosaurs by causing global firestorms and dust clouds that blotted out the sun.

A giant asteroid impact in the dwarf planet's past offers new insights into the possibility of an ocean beneath its surface.

Not exact matches

That's because the higher speed of comets and the high volatility of their constituents would create giant plumes on impact, so more of the iridium would escape into space, compared with impacts by rocky asteroids.

Like the dinosaurs themselves, giant marine reptiles, invertebrates and microscopic organisms became extinct after the catastrophic asteroid impact in an immense upheaval of the world's oceans, yet deep sea creatures managed to survive.

Almost nothing is known about the dinosaurs that lived in Africa at the end of the Cretaceous period 66 million years ago, just before they were wiped out by the impact of a giant asteroid.

Early detection is important because it increases the chance of being able to deflect a giant asteroid before impact.

Five gaping holes, created by giant impacts, dominate one side of Mathilde, and the asteroid is so lightweight, says Bell, that it must be either full of ice (but there's no sign of water) or a loosely packed pile of rocks held together by their own weak gravity.

Between now and then, humans will face plenty of other calamities: wars and pestilences, ice ages, asteroid impacts, and the eventual consumption of Earth — in about 5 billion years — as our sun expands into a red giant star.

Terrestrial planet formation models indicate Earth went through a sequence of major growth phases: accretion of planetesimals and planetary embryos over many tens of millions of years; a giant impact that led to the formation of our Moon; and then the late bombardment, when giant asteroids, dwarfing the one that presumably killed the dinosaurs, periodically hit ancient Earth.

Moons can form in one of three ways: accretion around a developing planet, capture by a planet's gravity or a giant impact from an asteroid or planet - size body that carves it out of a planet.

The giant crater at the centre of the image, called Herschel, was probably gouged out by an enormous asteroid impact.

Piecing those clues together, the two Alvarezes proposed a radical idea: The mass extinction that wiped out the dinosaurs 65 million years ago was caused by the impact of a giant asteroid, which unleashed a globe - spanning cloud of debris and plunged the planet into darkness for months.

The astronomers concluded there were no excess infrared emissions and therefore no sign of an asteroid belt collision, a giant impact on a planet or a dusty cloud of rock and debris.

Giant redwood trees shared the planet with the dinosaurs, yet somehow survived the asteroid impact.

Giant planet interiors are inaccessible to direct study from above, but oscillations excited by asteroid and comet impact can generate waves that are potentially observable.

However, if the measurements of the ancient ratios from SAM don't match up, this suggests that we may have to look at other ways the atmosphere could have been lost, such as giant impacts from asteroids,» says Mahaffy, who is Principal Investigator for SAM and Instrument Lead for the Neutral Gas and Ion Mass Spectrometer instrument on MAVEN.

But the extent / impact of the risk (if any) simply can not be evaluated, it's certainly no more of a «species - existential» risk than that of a giant asteroid collision, and the proposed «solutions» appear much more aimed at the modern happy lifestyle than really dealing with rising pCO2.