Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain
Speaker 1: Stuff learned Volga bam here. In November one, NASA's double
Speaker 1: Asteroid Redirection test robotic spacecraft, called DART for short, took
Speaker 1: off into space on a SpaceX Falcon nine rocket on
Speaker 1: a mission to intercept and change the orbit of an asteroid.
Speaker 1: Sometime in September or October, when DART is about seven
Speaker 1: million miles or eleven million kilometers from our planet, this spacecraft,
Speaker 1: weighing twelve thousand pounds or five fifty kilos and costing
Speaker 1: three five million dollars, will reach its target, Dimorphous, a
Speaker 1: small asteroid that orbits a second larger piece of space rock, Didimus,
Speaker 1: as the pair travels in an elliptical orbit around the Sun.
Speaker 1: While Dimorphous is not on course to hit the Earth,
Speaker 1: it does provide a nice safe target for testing technology
Speaker 1: that might someday helped he to the Earth from a
Speaker 1: catastrophic collision with a killer asteroid, as such as the
Speaker 1: one that wiped out the dinosaurs and plant and animal
Speaker 1: life some sixty six million years ago. When it reaches
Speaker 1: dim Morphous, DART will slam into the space rock at
Speaker 1: a speed of about six point six kilometers or four
Speaker 1: point one miles per second, hopefully giving the asteroid enough
Speaker 1: of a jolt to alter its orbit around its partner
Speaker 1: just slightly, but enough that the alteration might be observed
Speaker 1: by telescopes on Earth. For the article of this episode
Speaker 1: is based on How Stuff Works. Spoke by email with
Speaker 1: Linley Johnson, NASA's first ever planetary Defense officer, he said
Speaker 1: DART is a test of the effectiveness of the kinetic
Speaker 1: impact or technique for altering an asteroid's orbital path, and
Speaker 1: of the spacecraft technology used to deliver a kinetic impact
Speaker 1: or to the target asteroid. Crashing a spacecraft into an
Speaker 1: asteroid might sound easy, but it's not how stuff works.
Speaker 1: Also with Andy Rivkin, the DART investigation co lead from
Speaker 1: the Johns Hopkins Applied Physics Laboratory, which is leading the
Speaker 1: project for NASA, he said, Dimorphus is the smallest object
Speaker 1: that has ever been a mission target, and we're coming
Speaker 1: in very fast with a need to impact on the
Speaker 1: first try, without knowing fundamental things like dimorphous is shape
Speaker 1: or exact size. It's about three thousand, six hundred feet
Speaker 1: that's one thous from the center of Dinomus to the
Speaker 1: center of dimorphous and it's probably less than two thousand
Speaker 1: feet or six hundred meters from the surface of one
Speaker 1: to the surface of the other. We don't want to
Speaker 1: miss and we don't want to hit Didymus. Furthermore, the
Speaker 1: spacecraft has to overtake that target at such a high
Speaker 1: speed that there's very little margin for error the blink
Speaker 1: of an eye, according to the DART team. To achieve
Speaker 1: the necessary precision, the spacecraft will be guided by smart nav,
Speaker 1: a totally automated navigation system that require there's no human input.
Speaker 1: The spacecraft will also utilize an imaging instrument called the
Speaker 1: Denimus Reconnaissance and Asteroid camera for op NAV a k A.
Speaker 1: Draco to see where it's going, but it'll only be
Speaker 1: able to see its target in the last hour before impact.
Speaker 1: How Stuff works also spoke by email with Dark program
Speaker 1: scientist Tom Statler. He said, if we ever need to
Speaker 1: carry out a kinetic impact to prevent a natural disaster,
Speaker 1: we might need to do so quite far from Earth,
Speaker 1: which would make autonomous control by the spacecraft absolutely essential.
Speaker 1: That's why we want to demonstrate and validate this technology
Speaker 1: with DART. The scientists don't really know what will happen
Speaker 1: when Dart hits the asteroid. Though. The thing is is
Speaker 1: that although they have a pretty good idea of what
Speaker 1: dimorphous is made up of, they're not sure how solidly
Speaker 1: that material is sewn together. If it's just a loose
Speaker 1: collection of rebel held together by gravity, that will impact
Speaker 1: the impact of how much material is broken off into
Speaker 1: space and how much Dimorphous budgets in its orbit. A
Speaker 1: dart is an early step in protecting human life from
Speaker 1: being wiped out by a space rock, but it also
Speaker 1: changes humanity's relationship to the cosmos. Up to this point,
Speaker 1: space has been something that we watch from afar and
Speaker 1: occasionally send brave souls to visit for brief periods. But
Speaker 1: now it's going to become something that humans can tinker with,
Speaker 1: just as we've altered our own planet. Has stuff works
Speaker 1: also spoke by an email with Martin Elvis, an astrophysicist
Speaker 1: at the Center for Astrophysics, Harvard and Smithsonian and author
Speaker 1: of the book Asteroids, How Love, fear Ingreed will determine
Speaker 1: our future in space. He said, perhaps the biggest point
Speaker 1: is that Dart will be humanity's first attempt to deliberately
Speaker 1: change the orbit of a solar system body. The amount
Speaker 1: we will change the orbital speed of dimorphous will only
Speaker 1: be by blessed than a snail's pace, literally four point
Speaker 1: six feet or one point four meters per hour. Yet
Speaker 1: it is not zero. The architecture of the solar system
Speaker 1: will be subtly altered. He says that while this doesn't
Speaker 1: have any immediate importance, it is symbolic. Quote. There are
Speaker 1: those who will thrill to this stepping out of humanity.
Speaker 1: There are others who will say, not again, must we
Speaker 1: repeat our environmental mistakes, only now on a far larger scale.
Speaker 1: Note that even an asteroid as small as di Morphus
Speaker 1: could do a lot of damage if it struck Earth.
Speaker 1: It's punique compared to the massive asteroid that wiped out
Speaker 1: the dinosaurs, whose size has been estimated at about six
Speaker 1: miles or ten kilometers across. But Johnson notes that di
Speaker 1: Morphus is three times the size and possibly five times
Speaker 1: the mass of the asteroid that created the Baringer Crater
Speaker 1: in eastern Arizona some fifty thou years ago. Johnson said
Speaker 1: it would impact with an estimated energy of roughly ten
Speaker 1: mega tons of t NT, larger than any nuclear bomb
Speaker 1: and create a crater of a few miles in diameter
Speaker 1: and a quarter mile in depth. Blast effects might extend
Speaker 1: for a hundred and fifty miles in all directions from
Speaker 1: the impact site, and the prospect of such disaster makes
Speaker 1: it conceivable that some future asteroid defense mission might need
Speaker 1: to target an object of dimorphous size. If dart Works
Speaker 1: is planned, Johnson said it will validate both the kinetic
Speaker 1: impact or technique for planetary defense purposes and that current
Speaker 1: technology enables our ability to perform the deflection, but that
Speaker 1: doesn't mean that NASA will rush to build more spacecraft
Speaker 1: that can perform the same feat Johnson explained a significant
Speaker 1: asteroid impact is an extremely rare natural disaster, and what
Speaker 1: techniques might be used to deflect one detected in advance
Speaker 1: would be very scenario dependent, especially on how many years
Speaker 1: in advance it was discovered. The decades may pass before
Speaker 1: the next major impact or is discovered, and the planetary
Speaker 1: defense program of that time in the future may want
Speaker 1: to use the more advanced technology that will likely be
Speaker 1: available by then. Today's episode is based on the article
Speaker 1: NASA's Dark Mission is humans first attempt to adjust the
Speaker 1: cosmos on how stuff works? Dot com written by Patrick J. Keiger.
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