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Archive for the ‘asteroid/comet impacts’ category: Page 4

Dec 19, 2020

Tunguska explosion in 1908 caused by asteroid grazing Earth

Posted by in categories: asteroid/comet impacts, existential risks

So we’ve had close calls before, huh?


In the early morning of June 30, 1908, a massive explosion flattened entire forests in a remote region of Eastern Siberia along the Tunguska River. Curiously, the explosion left no crater, creating a mystery that has puzzled scientists ever since — what could have caused such a huge blast without leaving any remnants of itself?

Now Daniil Khrennikov at the Siberian Federal University in Russia and colleagues have published a new model of the incident that may finally resolve the mystery. Khrennikov and co say the explosion was caused by an asteroid that grazed the Earth, entering the atmosphere at a shallow angle and then passing out again into space.

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Dec 9, 2020

Accessing the arches of chaos in the solar system for fast transport

Posted by in categories: asteroid/comet impacts, existential risks

Space manifolds form the boundaries of dynamic channels to provide fast transport to the innermost and outermost reaches of the solar system. Such features are an important element in spacecraft navigation and mission design, providing a window to the apparently erratic nature of comets and their trajectories. In a new report now published on Science Advances, Nataša Todorović and a team of researchers in Serbia and the U.S. revealed a notable and unexpected ornamental structure of manifolds in the solar system. This architecture was connected in a series of arches spreading from the asteroid belt to Uranus and beyond. The strongest manifolds were found linked to Jupiter with profound control on small bodies across a wide and previously unknown range of three-body energies. The orbits of these manifolds encountered Jupiter on rapid time-scales to transform into collisional or escaping trajectories to reach Neptune’s distance merely within a decade. In this way, much like a celestial highway, all planets generate similar manifolds across the solar system for fast transport throughout.

Navigating chaos in the solar system

In this work, Todorović et al. used fast Lyapunov indicator (FLI); a dynamic quantity used to detect chaos, to detect the presence and global structure of space manifolds. They captured the instabilities acting on orbital time scales with the sensitive and well-established numerical tool to define regions of fast transport in the solar system. Chaos in the solar system is inextricably linked to the stability or instability of manifolds forming intricate structures whose mutual interaction can enable chaotic transport. The general properties can be described relative to the planar, circular and restricted three-body problem (PCR3BP) approximating the motion of natural and artificial celestial bodies. While this concept is far from being fully understood, modern geometric insights have revolutionized spacecraft design trajectories and helped build new space-based astronomical observatories to transform our understanding of the cosmos.

Nov 23, 2020

How Werner Herzog learned to love Star Wars

Posted by in categories: asteroid/comet impacts, existential risks

“Herzog tells Inverse he’s less concerned than ever that a meteorite will destroy the Earth, but that doesn’t mean we shouldn’t still be worried about our own extinction. “It may be 100 million years to go until then,” Herzog says, before adding, “within the next thousand years, we may have done such stupid things that we are not around anymore to contemplate it.” The German filmmaker also explains what asteroids reveal about the universe, why he’s never watched Rick and Morty, even though it’s a “fiendishly intelligent show,” and lists the many things that could wipe out humanity before a meteorite ever arrives.”


The legendary director discusses his new film, ‘Fireball: Visitors From Darker Worlds,’ along with Star Wars, ‘Rick and Morty,’ and working with a co-director.

Nov 9, 2020

The Craters on Earth: New Atlas Presents and Explains the Impact Sites of Meteorites and Asteroids Worldwide

Posted by in categories: asteroid/comet impacts, existential risks, mapping, satellites

Prof. Dr. Thomas Kenkmann, geologist from the University of Freiburg’s Institute of Earth and Environmental Sciences, together with mineralogist Prof. Dr. Wolf Uwe Reimold from the University of Brasilia, Brazil, and Dr. Manfred Gottwald from the German Aerospace Center (DLR) published an atlas providing a comprehensive overview of all known impact craters on every continent. The authors present the more than 200 terrestrial impact sites in high-resolution topographic maps and satellite images, complete with detailed geological descriptions and photographs of the crater structures and their rocks. They also explain the essential details of each impact event.

The formation of craters by asteroid and comet impact has always been a fundamental process in the solar system, explains Kenkmann. As the planets developed along with their moons, these impacts played an important part in accreting planetary mass, shaping the surfaces of planetary bodies, and later also influencing their development. And larger meteorite impacts eventually affected the development of life on Earth.

Today, mapping of what can still be seen of the impact structures on the Earth’s surface can be done by satellites in low Earth orbit. From 2010 to 2016, the DLR successfully measured the Earth’s surface with the radar satellites of the TanDEM-X mission. The acquired data allowed, for the first time, to derive a worldwide terrain model with a height accuracy of up to one meter. From this global digital elevation model the authors have been able to produce this complete topographic atlas of 600 pages with information about all terrestrial impact craters known to date.

Continue reading “The Craters on Earth: New Atlas Presents and Explains the Impact Sites of Meteorites and Asteroids Worldwide” »

Nov 7, 2020

Asteroid the size of the Great Pyramid of Giza set to pass Earth tomorrow

Posted by in category: asteroid/comet impacts

An asteroid that could be almost 600 feet wide is set to fly by Earth on Saturday, passing us at a speed of more than 29,000 miles per hour.

The asteroid, named 2020 TY1, was first discovered in October. It is expected to pass at a distance of around 3.5 million miles, which is about 14 times the distance between Earth and the moon, meaning it poses no risk to our planet.

It is one of the largest asteroids to pass Earth in recent weeks, with the last of a similar size passing by on October 22. The space rock is estimated to be between 260 and 590 feet wide, making it around the size of the Great Pyramid of Giza, which is 455 feet tall.

Nov 4, 2020

Infamous asteroid Apophis is accelerating

Posted by in categories: asteroid/comet impacts, existential risks

Astronomers at the University of Hawaii issued a statement on October 26, 2020, revealing critical new findings linked to the large near-Earth asteroid 99942 Apophis, which is expected to pass close to Earth in 2029, 2036 and again in 2068. Dave Tholen and collaborators announced they have now detected a Yarkovsky acceleration on asteroid Apophis, arising from a minuscule push imparted by sunlight. This force is particularly important for asteroid Apophis, the scientists in Hawaii said, because it relates to the possibility of an Earth impact in 2068.

The 2021 lunar calendars are here! Order yours before they’re gone. Makes a great gift!

Tholen and colleagues used the 323-inch (8.2-meter) Subaru Telescope at Mauna Kea, Hawaii, to make the new observations. Their work suggests that the huge space rock – whose estimated diameter is between 1,115 and 1,214 feet (340 to 370 meters) – is drifting more than 500 feet (about 170 meters) per year from its expected position in its orbit.

Oct 28, 2020

“2068” –Massive Asteroid Apophis on Path for Earth Impact

Posted by in categories: asteroid/comet impacts, existential risks

Laser it o.o


Sixty Six million years ago a 14-kilometer long, Mount-Everest sized asteroid blasted a hole in the ground, when at the moment of impact, “the top of it might have still towered more than a mile above the cruising altitude of a 747,” writes Peter Brannen in Ends of the World. “In its nearly instantaneous descent, it compressed the air below it so violently that it briefly became several times hotter than the surface of the sun, hitting Earth with enough force enough to lift a mountain back into space at escape velocity, releasing the equivalent of 100 million megatons of TNT creating a 20-mile deep, 110-mile hole and sterilizing the remaining 170 million square miles of the ancient continent of Pangaea, killing virtually every species on Earth and, oddly, paving the way for the emergence of the human species.”

Magnified Preview of a Coming Attraction?

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Oct 19, 2020

Neil deGrasse Tyson warns asteroid could hit Earth day before election

Posted by in categories: asteroid/comet impacts, existential risks

That’s one way to rock the vote.

An asteroid with a diameter the size of a refrigerator could strike the Earth the day before the November election, according to celebrity scientist Neil deGrasse Tyson — but it’s not large enough to do any serious damage.

The famed astrophysicist said the space rock, known as 2018VP1, is hurtling towards Earth at a speed of 25,000 miles per hour and may clip the planet on Nov. 2.

Continue reading “Neil deGrasse Tyson warns asteroid could hit Earth day before election” »

Oct 14, 2020

When Asteroid Impacts Are a Good Thing

Posted by in categories: asteroid/comet impacts, existential risks

Meteorite impacts may be a good thing — but only sometimes.


Craters could create habitable conditions on many planets and moons.

Sep 29, 2020

Earth-skimming meteoroid dipped 56 miles into the atmosphere

Posted by in categories: asteroid/comet impacts, existential risks

A meteoroid skimmed Earth’s atmosphere for 19 seconds over the Netherlands and Germany. The object came in as low as 56 miles in altitude, covering a path of more than 466 miles.

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