Earth’s periodic passage through the galaxy’s disk could initiate a series of events that ultimately lead to geological cataclysms and mass extinctions.

By Michael R. Rampino 

Do geologists dream of a final theory?

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In an alternate reality playing out at this year’s international Planetary Defense Conference, a fictional asteroid crashes over Europe, ‘destroying’ a region about 100 km wide near the Czech Republic and German border. The scenario was imagined, but the people who took part are very real,

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Part of the world-wide effort to scan and identify near-Earth objects, the European Space Agency’s Test-Bed Telescope 2 (TBT2), a technology demonstrator hosted at ESO’s La Silla Observatory in Chile, has now started operating. Working alongside its northern-hemisphere partner telescope,

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JPL’s Center for Near Earth Object Studies will lead the hypothetical impact scenario to see how international agencies respond to an actual impact prediction. During the week of April 26, members of NASA’s Planetary Defense Coordination Office (PDCO) will participate in a “tabletop exercise”

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Planetary systems form out of the remnant gas and dust of a primordial star. The material collapses into a protoplanetary disk around the young star, and the clumps that form within the disk eventually become planets, asteroids, or other bodies.

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The effects of ancient asteroid impacts on Earth are still evident from the variety of impact craters across our planet. And from the Chelyabinsk event back in 2013, where an asteroid exploded in the air above a Russian town,

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The world’s first ground-based observations of the bare nucleus of a comet nearing the end of its active life revealed that the nucleus has a diameter of 800 meters and is covered with large grains of phyllosilicate; on Earth large grains of phyllosilicate are commonly available as talcum powder.

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A research team of international space scientists, led by Dr Matthias van Ginneken from the University of Kent’s School of Physical Sciences, has found new evidence of a low-altitude meteoritic touchdown event reaching the Antarctic ice sheet 430,000 years ago.

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The largest asteroid to pass by Earth this year has made its closest approach, posing no threat of a cataclysmic collision but giving astronomers a rare chance to study a rock formed during the beginning of our solar system.

The asteroid was two million kilometres (1.25 million miles) away at its nearest,

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In 2017, the first interstellar object from beyond our solar system was discovered via the Pan-STARRS astronomical observatory in Hawaii. It was named ‘Oumuamua, meaning “scout” or “messenger” in Hawaiian. The object was like a comet, but with features that were just odd enough to defy classification.

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