Asteroid Flybys, Cosmic Mysteries, and the Search for the Universe's Ghost Signals

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Anna: Hello and welcome to Astronomy Daily.

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I'm Anna.

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Avery: And I'm avery. It's Monday, July 6th,

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and we've got a properly stacked show for you

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today.

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Anna: We're talking a, uh, nail biting asteroid

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flyby from Japan. A genuine

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cosmic mystery on two different worlds,

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and a hint that we might finally be hearing

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the universe's oldest ghost signal.

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Avery: Plus a black hole theory that could rewrite

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the rulebook. A, uh, look back at the

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weekend's aurora action, and a very long

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range weather forecast for the edge of the

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solar system.

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Anna: All that right after this.

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Avery: Let's kick off in Japan, where Mission

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Control had a genuinely nervous Sunday night.

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Anna: This is Hayabusa2. Yes, the

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same spacecraft that brought samples back

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from asteroid Ryugu in 2020. It's

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been on an extended mission ever since

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because it turned out to have fuel to spare.

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Avery: And on July 5, Japan time, it did

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something it was never really designed to do.

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A high speed flyby of a near Earth asteroid

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called Toroph, passing within about

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800 meters at, uh, more than 18,000

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kilometers an hour.

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Anna: 800 meters at that speed.

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Jaxa described it like trying to shoot a coin

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somewhere between Okinawa and Hokkaido.

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Avery: The spacecraft's cameras were never built for

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a flyby like this. Hayabusa 2 is a

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rendezvous spacecraft designed to hover close

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to an asteroid for months, not scream past

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one in a heartbeat.

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Anna: So this whole encounter is really an

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engineering demonstration first, science

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second.

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Avery: And the reason it matters, beyond the wow

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factor, is planetary defense. If

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humanity ever needs to nudge a hazardous

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asteroid off course, we need to know how

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these bodies behave up close. Do they act

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like solid rock? Or more like a loose pile of

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rubble? That changes everything about how

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you'd deflect one.

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Anna: JAXA confirmed the spacecraft is healthy.

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The flyby went to plan, and cameras captured

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imagery of Torophone's shape, texture and

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temperature that scientists are poring over

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now.

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Avery: Torophone itself is only about 450

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meters across. No sample returned this

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time. This one's, uh, a look and go.

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Hayabusa2's next big date is

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2031, when it rendezvous with a

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completely different target, the small, fast

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spinning asteroid 1998

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KY26.

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Anna: So think of Sunday as a dress rehearsal. A

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spacecraft already passed its day job, still

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finding ways to be useful.

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Avery: Our next story is one of those lovely we

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genuinely don't know what this is moments in

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astronomy.

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Anna: Researchers combing through James Webb Space

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Telescope data have found an unexplained

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absorption feature, basically a dick in the

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light spectrum, sitting at exactly

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5.11 micrometers uh, and

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Avery: they found it twice. Once on Saturn's big

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moon, Titan, and

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Anna: once on Pluto, which is odd, because

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Titan and Pluto are about as different as

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two icy worlds get. Titan has a thick

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nitrogen methane atmosphere, methane

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lakes, actual rain. Pluto has a

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wisp of an atmosphere and is bitterly cold

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and airbound in name only.

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Avery: The team led by Bruno Bizard at the Paris

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Observatory checked whether the signal could

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just be coming from the atmosphere rather

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than the surface. And on Titan at least, the

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absorption was actually weaker at the edge of

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the disk, where you'd expect an atmospheric

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signal to be stronger that points to the

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surface as the source.

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Anna: They've ruled out the usual common

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ices, straightforward hydrocarbons, the

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nitrogen photochemistry products you'd

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expect. The closest match so far is a class

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of molecules called Allenes, but it's not

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confirmed.

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Avery: And, and here's the twist.

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Anna: On Pluto, the same absorption line is

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about three times broader than on Titan,

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even though it sits at the same wavelength.

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So whatever it is, it's behaving differently

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on each world.

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Avery: This result is still a preprint, so it hasn't

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cleared peer review yet. But the researchers

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are calling it one of the more compelling,

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unassigned features they've seen. Solve this

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one, and you learned something new about

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organic chemistry happening in the deep

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freeze on two worlds at once.

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Next story three takes us underground,

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literally, to the Super Kamikande Neutrino

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Detector in Japan.

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Anna: Every second, somewhere in the universe, a

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massive star reaches the end of its life and

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collapses into a supernova. Each one of those

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explosions flood space with neutrinos,

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ghostly particles that barely interact with

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anything.

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Avery: Physicists have long predicted that all of

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those neutrinos from every supernova across

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the entire history of the universe should add

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up to a very faint, constant background

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hum. The diffuse supernova neutrino

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background, or DSNB, for short.

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Anna: It's never been detected until

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maybe now. The Super Kamikande

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collaboration presented results this week at

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the Neutrino 2026 conference in

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California. After combing through nearly

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5,000 days, that's about 13 and a

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half years of data.

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Avery: They found a statistically significant excess

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of events in the expected energy range. The

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confidence level works out to about

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Anna: 99.5%, which sounds

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enormous, but in particle physics terms, it's

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still short of the gold standard five sigma

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threshold needed to call it a discovery. So

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the team is very deliberately calling this an

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indication, not a confirmation.

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Avery: Still, if it holds up with more data, this

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would be a whole new way of studying the

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history of the universe's. Supernovae. Using

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particles instead of light, it could tell us

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how often massive stars have exploded over

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cosmic time and how black holes and neutron

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stars formed a background

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Anna: hum from every dying star that ever

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lived.

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Not bad for a Monday Sticking with

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Avery: big theoretical ideas, Story four is

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a fresh attempt to solve one of physics's

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most stubborn headachesthe Black Hole

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Information paradox.

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Anna: Quick Refresher Stephen Hawking showed in the

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1970s that black holes very

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slowly radiate energy and in theory

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eventually evaporate completely. The

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paradox is what happens to all the

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information about everything that ever fell

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in. Quantum mechanics says information

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can't just vanish, so where does it go?

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Avery: A new theoretical study proposes an answer

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using a seven dimensional model of spacetime

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built on something called Einstein Cartan

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geometry with torsion basically letting

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spacetime twist as well as bending.

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Anna: The researchers found at extreme densities

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right at the Planck scale, that twisting

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produces a, uh, repulsive force strong enough

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to halt the final stage of Hawking in

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operation completely.

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Avery: Instead of vanishing, the black hole would

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freeze into a stable leftover object,

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a remnant with a predicted mass of around

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9 times 10 to the -41

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kilograms. Genuinely tiny.

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Anna: And the proposal is that this remnant acts

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like a permanent archive with the black

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hole's information encoded in long lived

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internal vibrations. Rather than being lost,

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it's squarely in

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Avery: fascinating but far from settled territory.

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This is a theoretical framework, not an

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observation, but it's a serious attempt to

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answer a 50 year old question. And it comes

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with a neat bonus. The same geometry might

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also help explain why fundamental particles

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have, uh, uh, mass in the first place.

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Anna: Two birds, one seven dimensional stone

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Next up, a quick check in on the sky show

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from the weekend for anyone who missed it or

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is still out chasing it.

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Avery: Saturday's X1 solar flare and its

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coronal mass ejection slammed into Earth's

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magnetic field as forecast, pushing

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geomagnetic activity up to G3.

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Strong storm levels through July 3rd and 4th.

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Anna: Aurora Borealis was reported as far south

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as Utah, Colorado and Nevada in the US

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with some lovely July 4th fireworks and

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Aurora combo shots doing the rounds online.

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Avery: NOAA AH Space Weather Prediction center says

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activity has been easing since with

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conditions dropping to unsettled to G1 levels

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through today the 6th as the effects of last

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week's CMEs fade out.

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Anna: So if you're in a high latitude spot,

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Southern Hemisphere included, tonight's still

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worth a glance skyward. But don't expect a

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repeat of Saturday's fireworks. The main

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event has passed.

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Avery: Our last story is a lovely bit of long

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range Weather forecasting Except the weather

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is solar wind and the destination is

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interstellar space.

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Anna: NASA's New Horizons, the

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spacecraft that gave us our first close up

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look at Pluto in 2015 and then

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flew past the Kuiper Belt object Arrokoth

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in 2019, is still out there, still

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working currently around, uh, 66

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astronomical units from M the Sun.

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Avery: Researchers at the Southwest Research

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Institute, led by Dr. Jonathan Gasser

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have combined solar wind forecasting with

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helios heliosphere models to predict when New

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Horizons will cross. Determination Shock the

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first plasma boundary marking the edge of the

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Sun's influence before the true edge of the

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heliosphere further out.

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Anna: Their answer? Somewhere between

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2029 and 2040, which

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is, let's be honest, a pretty wide window.

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Avery: But that's because the heliosphere isn't a

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fixed shell. It swells and shrinks with the

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solar cycle, expanding during solar maximum

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and contracting during solar minimum. New

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Horizons might even cross the boundary more

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than once if the shock front M moves back and

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forth across the spacecraft's path.

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Anna: For context, Voyager 2 crossed its

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termination shock back in 2007

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at 84 astronomical units and

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measured a sharp 46% drop

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in solar wind speed right at the boundary.

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Avery: If New Horizons gets there, it'll become only

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the third spacecraft in history to cross into

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that outer frontier after Voyager 1 and

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2. Not bad for a mission that was just

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supposed to visit Pluto.

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Anna: A whole new frontier. And we might get to

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watch it happen live sometime in the next

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decade or so.

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Avery: And that's a wrap on Today's episode.

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An asteroid 5i a, uh, shared mystery on

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two icy worlds, a possible whisper from

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every supernova that ever happened, a

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theoretical black hole afterlife, some

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leftover aurora, and a decade long forecast

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for the edge of the solar system.

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Anna: If you enjoyed the show, please do leave us a

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rating and review. It genuinely helps other

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space fans find us.

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Avery: I'm Avery.

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Anna: And I'm Ana. We'll see you next time on

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Astronomy Daily. Clear skies, everyone.

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Avery: Sam

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m.