What does NASA’s asteroid DART mission mean for the future of humanity

At 7:14 p.m. EDT Monday night, something historic happened to the human race — and it happened more than 7 million miles from our planet.

NASA’s DART spacecraft successfully collided with the asteroid moon Demorphos, which orbits the larger asteroid Didymos (hence the “double asteroid”). The 1,250-pound DART spacecraft hit the asteroid at 14,760 miles per hour — in the coming days, NASA scientists will be studying the data to see how much Demorphos’ momentum changed due to the collision, with initial estimates suggesting it came 1 percent close to the collision. Didymus.

So why is this such a big deal? For one thing, hitting an asteroid just 560 feet wide — or about half the length of the Eiffel Tower — with a tiny spacecraft launched from Earth nearly a year ago is a victory for very difficult astrophysics.

Until the time of the impact, which was shown around the world on NASA TV, mission controllers were not sure they would hit the target. Greetings, steel-eyed bombers and women at NASA’s Jet Propulsion Laboratory! It literally moved the sky!

Far from honoring our nation’s leading space experts, the DART mission marks the first time humanity has successfully demonstrated that it may be able to directly protect itself from a major natural existential threat, which is as important as you can get.

What helped wipe out the dinosaurs from the face of the Earth, and which may threaten us with extinction in the future, is now under watch. Humanity has the beginnings of a real defense of the planet.

The universe is trying to kill you

Asteroids, if they collide with your planet, can be very bad news.

About 66 million years ago, an asteroid 6 to 10 miles wide slammed into the waters off the Yucatan Peninsula, near what is now Chicxulub, Mexico. The energy released by the resulting explosion was as strong as 100 trillion tons of TNT, which is equivalent to 10 billion Hiroshima nuclear bombs. A massive tsunami swept the surrounding coasts, and more than 1,000 cubic miles of vaporized rock flew into the sky.

Thermal radiation from hot air has led to fires all over the world. Brian Tun, an atmospheric researcher at the University of Colorado Boulder, told me about my book The End Times: A Brief Guide to the End of the World.

A cloud of debris filled with sulfur droplets blanketed the atmosphere, preventing much of the sun’s heat and light from reaching the Earth’s surface. Global temperatures have dropped by as much as 50 degrees Fahrenheit above Earth, and photosynthesis has almost stopped.

In general, it was a very bad day to be a dinosaur, or, for that matter, anything else that lived on Earth. More than 75 percent of the planet’s species will eventually die – so far, at least – from the planet’s five major extinction events.

The good news is that an asteroid collision of the size and size of Chicxulub is extremely rare, and the odds of it happening in a year, a century or thousands of years are extremely unlikely.

But it can happen, and even much smaller asteroids can do significant damage, especially if they collide near a densely populated area. In 1908, a relatively small meteorite, perhaps less than 100 feet in diameter, exploded above the Earth’s surface near Tunguska, Siberia. (Asteroids are asteroids when they’re in space and orbiting the sun, meteorites when they hit Earth’s atmosphere—most of which burn up as meteors—and meteors have to reach the surface.)

The energy released by the Tunguska explosion was the equivalent of 15 megatons of TNT – 1,000 times more powerful than the Hiroshima bomb. The shock wave destroyed trees over an area of ​​830 square miles. Fortunately, as now, trees were the main concern for Siberia, but if a meteorite the size of Tunguska exploded over a city the size of New York, millions could die.

Once in 1980 geologists Walter Alvarez and his father Luis W. Alvarez discovered the underwater Chicxulub impact crater and identified it as the likely cause of the extinction of the dinosaurs, it was clear that space influences could pose an existential threat to life on Earth. In July 1994, astronomers witnessed comet Shoemaker-Levy 9 colliding with Jupiter, causing a visible curvature in the gas giant and pushing the threat of space objects home.

As astrophysicist Neil deGrasse Tyson once said, “The universe is a deadly place. At every opportunity, it tries to kill us.” Which raises the question: What are we going to do about it?

watch the sky

Even before the Shoemaker-Levy 9 collision, concern about the threat posed by near-Earth objects (NEOs) such as asteroids was beginning to emerge. In 1991, a House bill directed NASA to study impact and defense risks — how to track them and how to stop them.

But when then-Vice President Dan Quayle endorsed an idea for the federal government to purchase telescopes to track potentially dangerous asteroids and use SDI-modified anti-missile weapons in orbit to destroy them, the concept was largely mocked. (In defense of the critics, Coyle was considered a very unserious politician, although by today’s standards, he would essentially be George Washington.)

However, the sight of Shoemaker-Levy 9 blowing a hole into the biggest and worst planet in the solar system had a sobering effect. In 1998 – not entirely coincidentally, the same year that Hollywood turned to the world of asteroids deep effect And the disaster NASA created the Near-Earth Object Program and significantly expanded its participation in the Spaceguard Survey, which is tasked with detecting and tracking at least 90 percent of potentially hazardous NEOs greater than 1 kilometer (0.62 miles).

These were rocks that could theoretically kill a city or even the human race if they were big enough – and if they collided at the right time and place.

Such planetary observation was a resounding success. Scientists believe they have identified 95 percent of the potentially dangerous NEOs, none of which are on a collision course with Earth. (Because asteroids, like other celestial bodies, follow predictable paths through space, their motion can be predicted with high accuracy decades into the future.)

But there’s always a small chance we’ll miss a big chance, and only roughly two-thirds of asteroids larger than 140 meters (459 feet) have been identified and tracked. Obviously, we can’t move the Earth if someone is detected on a collision course. But Newtonian physics says that if we could exert enough force on the asteroid, we could push it like a billiard ball and keep it out of the way. We just had to try.

Planetary Defense Office

Enter the DART task. NASA chose Demorphos – which poses no threat to Earth – as a target because its small size made it possible for even a small spacecraft, if moving fast enough, to change its orbital course.

(The bigger an asteroid, the more force you’ll need to exert on it. It’s something Hollywood doesn’t always understand – scientists once calculated that the bomb Bruce Willis and his brave team of astronauts/astronauts used to blow up an asteroid the size of Texas in disaster It would have required at least 50 billion megatons of kinetic energy, a billion times more powerful than the largest nuclear bomb ever built. So disaster He got it wrong, along with the idea that it would be easier to teach oil prospectors to be astronauts than astronauts to be oil prospectors, which even Ben Affleck realized was wrong.)

After the successful mission, Laurie Glaese, director of NASA’s Planetary Science Division, said.

There is a huge difference between the deflection of an asteroid 560 feet high and one large enough to reasonably threaten humanity. Despite this, DART shows us that this method can work, which brings us one step closer to eliminating the asteroid threat once and for all.

Humanity is facing an increasing number of existential threats, and unfortunately not all of these threats can be defeated by hitting something really hard. But at least we’ve made it clear that without anything more than vigilance, math, and a SpaceX Falcon 9 rocket — oh, thanks Elon Musk — we can protect ourselves from a universe that often wants us dead.

A version of this story was originally published in the Future Perfect newsletter. Register here to subscribe!

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