Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff learned Volga bam here. In November one, NASA's double Asteroid Redirection test robotic spacecraft, called DART for short, took off into space on a SpaceX Falcon nine rocket on a mission to intercept and change the orbit of an asteroid.
Sometime in September or October, when DART is about seven million miles or eleven million kilometers from our planet, this spacecraft, weighing twelve thousand pounds or five fifty kilos and costing three five million dollars, will reach its target, Dimorphous, a small asteroid that orbits a second larger piece of space rock, Didimus, as the pair travels in an elliptical orbit around the Sun. While Dimorphous is not on course to hit the Earth,
it does provide a nice safe target for testing technology that might someday helped he to the Earth from a catastrophic collision with a killer asteroid, as such as the one that wiped out the dinosaurs and plant and animal
life some sixty six million years ago. When it reaches dim Morphous, DART will slam into the space rock at a speed of about six point six kilometers or four point one miles per second, hopefully giving the asteroid enough of a jolt to alter its orbit around its partner just slightly, but enough that the alteration might be observed by telescopes on Earth. For the article of this episode
is based on How Stuff Works. Spoke by email with Linley Johnson, NASA's first ever planetary Defense officer, he said DART is a test of the effectiveness of the kinetic impact or technique for altering an asteroid's orbital path, and of the spacecraft technology used to deliver a kinetic impact or to the target asteroid. Crashing a spacecraft into an asteroid might sound easy, but it's not how stuff works.
Also with Andy Rivkin, the DART investigation co lead from the Johns Hopkins Applied Physics Laboratory, which is leading the project for NASA, he said, Dimorphus is the smallest object that has ever been a mission target, and we're coming in very fast with a need to impact on the first try, without knowing fundamental things like dimorphous is shape
or exact size. It's about three thousand, six hundred feet that's one thous from the center of Dinomus to the center of dimorphous and it's probably less than two thousand feet or six hundred meters from the surface of one to the surface of the other. We don't want to miss and we don't want to hit Didymus. Furthermore, the spacecraft has to overtake that target at such a high speed that there's very little margin for error the blink
of an eye, according to the DART team. To achieve the necessary precision, the spacecraft will be guided by smart nav, a totally automated navigation system that require there's no human input. The spacecraft will also utilize an imaging instrument called the Denimus Reconnaissance and Asteroid camera for op NAV a k A. Draco to see where it's going, but it'll only be able to see its target in the last hour before impact. How Stuff works also spoke by email with Dark program
scientist Tom Statler. He said, if we ever need to carry out a kinetic impact to prevent a natural disaster, we might need to do so quite far from Earth, which would make autonomous control by the spacecraft absolutely essential. That's why we want to demonstrate and validate this technology with DART. The scientists don't really know what will happen
when Dart hits the asteroid. Though. The thing is is that although they have a pretty good idea of what dimorphous is made up of, they're not sure how solidly that material is sewn together. If it's just a loose collection of rebel held together by gravity, that will impact the impact of how much material is broken off into space and how much Dimorphous budgets in its orbit. A dart is an early step in protecting human life from being wiped out by a space rock, but it also
changes humanity's relationship to the cosmos. Up to this point, space has been something that we watch from afar and occasionally send brave souls to visit for brief periods. But now it's going to become something that humans can tinker with, just as we've altered our own planet. Has stuff works also spoke by an email with Martin Elvis, an astrophysicist at the Center for Astrophysics, Harvard and Smithsonian and author of the book Asteroids, How Love, fear Ingreed will determine
our future in space. He said, perhaps the biggest point is that Dart will be humanity's first attempt to deliberately change the orbit of a solar system body. The amount we will change the orbital speed of dimorphous will only be by blessed than a snail's pace, literally four point six feet or one point four meters per hour. Yet it is not zero. The architecture of the solar system will be subtly altered. He says that while this doesn't
have any immediate importance, it is symbolic. Quote. There are those who will thrill to this stepping out of humanity. There are others who will say, not again, must we repeat our environmental mistakes, only now on a far larger scale. Note that even an asteroid as small as di Morphus could do a lot of damage if it struck Earth. It's punique compared to the massive asteroid that wiped out the dinosaurs, whose size has been estimated at about six
miles or ten kilometers across. But Johnson notes that di Morphus is three times the size and possibly five times the mass of the asteroid that created the Baringer Crater in eastern Arizona some fifty thou years ago. Johnson said it would impact with an estimated energy of roughly ten mega tons of t NT, larger than any nuclear bomb and create a crater of a few miles in diameter
and a quarter mile in depth. Blast effects might extend for a hundred and fifty miles in all directions from the impact site, and the prospect of such disaster makes it conceivable that some future asteroid defense mission might need
to target an object of dimorphous size. If dart Works is planned, Johnson said it will validate both the kinetic impact or technique for planetary defense purposes and that current technology enables our ability to perform the deflection, but that doesn't mean that NASA will rush to build more spacecraft that can perform the same feat Johnson explained a significant asteroid impact is an extremely rare natural disaster, and what techniques might be used to deflect one detected in advance
would be very scenario dependent, especially on how many years in advance it was discovered. The decades may pass before the next major impact or is discovered, and the planetary defense program of that time in the future may want to use the more advanced technology that will likely be available by then. Today's episode is based on the article NASA's Dark Mission is humans first attempt to adjust the cosmos on how stuff works? Dot com written by Patrick J. Keiger.
Brainstuff is production of I heart Radio in partnership with houstff Works dot com and is produced by Tyler Klang with assistance by Ramsey Young. Four more podcasts from my heart Radio. Visit the I heart Radio app, Apple Podcasts, or wherever you listen to your favorite shows.