Sentences with phrase «bombardment by comets»

«The planet has been through a lot worse than us... been through earthquakes, volcanoes, plate tectonics, continental drift, solar flares, sun spots, magnetic storms, the magnetic reversal of the poles, hundreds of thousands of years of bombardment by comets and asteroids and meteors, worldwide floods, tidal waves, worldwide fires, erosion, cosmic rays, recurring ice ages — and we think some plastic bags and some aluminum cans are going to make a difference?»

One hypothesis that has gained popularity among scientists is that the early Earth was subjected to a period of bombardment by comets and water - rich asteroids.

Not exact matches

Amy Barr and Robin Canup of the Southwest Research Institute in Boulder, Colorado, think they know why: the moons were pummelled to differing degrees by wayward comets during the «late heavy bombardment», a cataclysmic period that began 3.9 billion years ago.

Recent modeling along with previously published results from NASA's MESSENGER spacecraft — short for Mercury Surface, Space Environment, Geochemistry and Ranging, a mission that observed Mercury from 2011 to 2015 — has shed new light on how certain types of comets influence the lopsided bombardment of Mercury's surface by tiny dust particles called micrometeoroids.

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.

If there is life on any Earth - type planet orbiting youthful Vega, it is likely to be primitive single - cell, anaerobic (non-oxygen producing) bacteria under constant bombardment by meteorites and comets as Earth was for the first billion years.

If there is life on any Earth - type planet orbiting youthful Altair, it is likely to be primitive single - cell, anaerobic (non-oxygen producing) bacteria under constant bombardment by meteorites and comets as Earth was for the first billion years.

Even if it is possible for an Earth - type planet to orbit youthful Sirius A and develop life, it is likely to be primitive single - cell, anaerobic bacteria under constant bombardment by meteorites and comets as Earth was for the first billion years.

That led many scientists to suggest that water would have been introduced on Earth at a later time, when it was pummeled by comets and asteroids during the Late Heavy Bombardment period, 4.1 to 3.8 billion years ago.

If there is life on any Earth - type planet orbiting youthful EV Lac, it is likely to be primitive single - cell, anaerobic (non-oxygen producing) bacteria under constant bombardment by meteorites and comets as Earth was for the first billion years and massive stellar flares.