May 24, 2019

The Day the Dinosaurs Died

“If, on a certain evening about sixty-­six million years ago, you had stood somewhere in North America and looked up at the sky, you would have soon made out what appeared to be a star. If you watched for an hour or two, the star would have seemed to grow in brightness, although it barely moved. That’s because it was not a star but an asteroid, and it was headed directly for Earth at about forty-five thousand miles an hour. Sixty hours later, the asteroid hit. The air in front was compressed and violently heated, and it blasted a hole through the atmosphere, generating a supersonic shock wave. The asteroid struck a shallow sea where the Yucatán peninsula is today. In that moment, the Cretaceous period ended and the Paleogene period began.

A few years ago, scientists at Los Alamos National Laboratory used what was then one of the world’s most powerful computers, the so-called Q Machine, to model the effects of the impact. The result was a slow-motion, second-by-second false-color video of the event. Within two minutes of slamming into Earth, the asteroid, which was at least six miles wide, had gouged a crater about eighteen miles deep and lofted twenty-five trillion metric tons of debris into the atmosphere. Picture the splash of a pebble falling into pond water, but on a planetary scale. When Earth’s crust rebounded, a peak higher than Mt. Everest briefly rose up. The energy released was more than that of a billion Hiroshima bombs, but the blast looked nothing like a nuclear explosion, with its signature mushroom cloud. Instead, the initial blowout formed a “rooster tail,” a gigantic jet of molten material, which exited the atmosphere, some of it fanning out over North America. Much of the material was several times hotter than the surface of the sun, and it set fire to everything within a thousand miles. In addition, an inverted cone of liquefied, superheated rock rose, spread outward as countless red-hot blobs of glass, called tektites, and blanketed the Western Hemisphere.

Some of the ejecta escaped Earth’s gravitational pull and went into irregular orbits around the sun. Over millions of years, bits of it found their way to other planets and moons in the solar system. Mars was eventually strewn with the debris—just as pieces of Mars, knocked aloft by ancient asteroid impacts, have been found on Earth. A 2013 study in the journal Astrobiology estimated that tens of thousands of pounds of impact rubble may have landed on Titan, a moon of Saturn, and on Europa and Callisto, which orbit Jupiter—three satellites that scientists believe may have promising habitats for life. Mathematical models indicate that at least some of this vagabond debris still harbored living microbes. The asteroid may have sown life throughout the solar system, even as it ravaged life on Earth.”

Read more

JJ Editor's Daily Picks

"The results were surprising. The center-right coalition, led by Prime Minister Scott Morrison, remained in power against the opposition Labor party, which had led in every poll for years."

"Anger seldom works against Trump; he owns the currency and can always issue more of it. In addressing the rogue President directly, or speaking about him in the third person, Pelosi usually adopts a tone that is more sorrowful than angry..."

"I am Mizrahi, as are the majority of Jews in Israel today. We are of Middle Eastern and North African descent. Only about 30% of Israeli Jews are Ashkenazi, or the descendants of European Jews."

"Kids are exposed to plenty of controversial social issues on a daily basis. And if parents don’t want their kids to watch “Mr. Ratburn and the Special Someone,” they can turn off the TV."

"Are public-school teachers really underpaid? It’s a claim often made during teacher pay disputes, but the same data and statistical methods that produce the “teacher salary gap” lead to some ridiculous conclusions..."

"Tech companies are getting into the business of making cities. We need to stop Silicon Valley social engineering before things get even worse."

"Having a Library or Cafe Down the Block Could Change Your Life: Living close to public amenities—from parks to grocery stores—increases trust, decreases loneliness, and restores faith in local government."

"“What name . . . shall we give to the darkness of hell...?” The question of how we can name a place such as this is at the center of scholar Scott G. Bruce’s new anthology The Penguin Book of Hell."

"She had all six of her kids — ages 5, 4, 2 (twins) and 10 months (also twins!) in her 10-seater van. To get the kids a quick snack, Curry parked in front of the Cobbler’s Café."

"Nearly three-quarters of those surveyed said they grew up typically eating dinner at a kitchen table, but a little less than half said they do so now when eating at home."

"If you tied a rope tight around the Earth’s equator and then added a single yard of slack, would the extra material make any noticeable difference to someone standing on the ground?"

"While American Jewish women face attacks on our freedom and rising anti-Semitism, abortion opponents are appropriating Jewish history in order to push an agenda that hurts women."