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00:00:01 --> 00:00:04 Anna: Picture a black hole two and a half billion
00:00:04 --> 00:00:07 times the mass of our sun. Now stop
00:00:07 --> 00:00:09 picturing it as a drain, because the one
00:00:09 --> 00:00:11 we're opening with today isn't just
00:00:11 --> 00:00:14 swallowing, it's blowing. And the
00:00:14 --> 00:00:16 blast it drives reaches across
00:00:16 --> 00:00:18 300 light years,
00:00:19 --> 00:00:22 stirring an entire cluster of galaxies.
00:00:22 --> 00:00:24 Avery: 300 light years.
00:00:25 --> 00:00:27 That's roughly three times the width of the
00:00:27 --> 00:00:29 Milky Way. The reach of a single single black
00:00:29 --> 00:00:30 hole.
00:00:30 --> 00:00:33 Anna: That's our lead. Then, dead stars
00:00:33 --> 00:00:36 that hide their meals. A, uh, Metal World
00:00:36 --> 00:00:38 mission using Mars as a rehearsal studio.
00:00:39 --> 00:00:41 And the growing problem of traffic on the
00:00:41 --> 00:00:42 road to the Moon.
00:00:42 --> 00:00:45 Avery: And, uh, because it's the 30th, there are two
00:00:45 --> 00:00:46 meteor showers peeking over your head.
00:00:46 --> 00:00:49 Tonight. We'll tell you exactly where to
00:00:49 --> 00:00:50 look. North and South.
00:00:50 --> 00:00:53 Anna: It's Thursday, the 30th of July,
00:00:53 --> 00:00:55 2026. I'm Anna.
00:00:55 --> 00:00:57 Avery: And I'm Avery. This is Astronomy Daily.
00:00:58 --> 00:01:00 Anna: So let's start with a question that sounds
00:01:00 --> 00:01:03 simple and isn't. What does a black
00:01:03 --> 00:01:06 hole actually do to the space around it?
00:01:06 --> 00:01:09 Avery: The cartoon answer is it eats
00:01:09 --> 00:01:11 anything that gets too close, falls in, and
00:01:11 --> 00:01:12 never comes back.
00:01:12 --> 00:01:15 Anna: Right? And that part's true, but it's only
00:01:15 --> 00:01:18 half the story. When a supermassive black
00:01:18 --> 00:01:21 hole is feeding hard, it doesn't swallow
00:01:21 --> 00:01:24 everything cleanly. It's a messy eater.
00:01:24 --> 00:01:27 Enormous amounts of energy pour out of the
00:01:27 --> 00:01:30 region around it. Radiation and powerful
00:01:30 --> 00:01:32 outflowing winds of gas. And
00:01:32 --> 00:01:34 astronomers have a name for the way those
00:01:34 --> 00:01:37 winds push back on the wider universe.
00:01:37 --> 00:01:38 They call it feedback.
00:01:39 --> 00:01:42 Avery: Feedback, as in, um, the black hole feeds and
00:01:42 --> 00:01:43 the galaxy gets a response?
00:01:44 --> 00:01:46 Anna: Exactly. And it matters
00:01:46 --> 00:01:49 enormously because feedback is one of the
00:01:49 --> 00:01:51 ways galaxies keep themselves in check.
00:01:51 --> 00:01:54 Here's the puzzle. It at the center of a big
00:01:54 --> 00:01:57 galaxy cluster, there's a huge reservoir of
00:01:57 --> 00:02:00 hot gas, millions of degrees glowing in
00:02:00 --> 00:02:03 X rays. By all rights, that gas should be
00:02:03 --> 00:02:05 cooling, sinking to the center and collapsing
00:02:05 --> 00:02:08 into vast numbers of new stars.
00:02:08 --> 00:02:09 Avery: And it doesn't.
00:02:09 --> 00:02:12 Anna: And it doesn't. These cluster cores are far
00:02:12 --> 00:02:14 quieter than the simple physics predicts.
00:02:15 --> 00:02:18 Something is reheating that gas, keeping it
00:02:18 --> 00:02:20 stirred up, stopping the runaway cooling.
00:02:20 --> 00:02:23 For years, the leading suspect has been the
00:02:23 --> 00:02:25 central black hole. That its outbursts
00:02:25 --> 00:02:28 dump energy back into the gas and hold
00:02:28 --> 00:02:31 the whole system in balance. But there's been
00:02:31 --> 00:02:34 a stubborn gap in the evidence, which is
00:02:35 --> 00:02:38 we could see black holes driving winds on the
00:02:38 --> 00:02:40 scale of their own galaxy. What we couldn't
00:02:40 --> 00:02:43 show was those winds reaching much beyond the
00:02:43 --> 00:02:45 galaxy, out into the space between
00:02:45 --> 00:02:48 galaxies. On the scale of the whole cluster.
00:02:49 --> 00:02:51 That's the part that stayed Theoretical until
00:02:52 --> 00:02:52 this study.
00:02:53 --> 00:02:55 Avery: So who did it and, um, how?
00:02:55 --> 00:02:57 Anna: A team led by Satoshi Yamada at
00:02:57 --> 00:03:00 Tohoku University in Japan with colleagues
00:03:00 --> 00:03:03 from Kanazawa, Tokyo Metropolitan and
00:03:03 --> 00:03:06 Kyoto Universities. It's published in
00:03:06 --> 00:03:08 Nature Astronomy this week on the 28th.
00:03:09 --> 00:03:11 And their target is a genuinely special
00:03:11 --> 00:03:13 object, a quasar called
00:03:13 --> 00:03:14 H1821
00:03:15 --> 00:03:16 643.
00:03:17 --> 00:03:19 Avery: Quasar, meaning a black hole that's feeding
00:03:19 --> 00:03:22 so ferociously it outshines its entire
00:03:22 --> 00:03:23 galaxy.
00:03:23 --> 00:03:25 Anna: That's it. Some of the most luminous
00:03:25 --> 00:03:28 single objects in the universe. This one sits
00:03:28 --> 00:03:31 in the Constellation Draco, about
00:03:31 --> 00:03:33 3.4 billion light years away. And
00:03:33 --> 00:03:36 its black hole weighs in around 2.6
00:03:36 --> 00:03:39 billion solar masses. But here's what makes
00:03:39 --> 00:03:42 it the perfect laboratory. It's the nearest
00:03:42 --> 00:03:44 quasar that lives right at the heart of a
00:03:44 --> 00:03:47 galaxy cluster. So you've got a raging black
00:03:47 --> 00:03:50 hole and a giant reservoir of hot
00:03:50 --> 00:03:52 cluster gas in the same place, close enough
00:03:52 --> 00:03:55 to study in detail. That almost never
00:03:55 --> 00:03:56 happens.
00:03:56 --> 00:03:59 Avery: And to study it, uh, they used xrism, which
00:03:59 --> 00:04:01 longtime listeners will remember.
00:04:01 --> 00:04:03 Anna: We've talked about it before. Yes,
00:04:03 --> 00:04:06 Xrism M, the X Ray Imaging and
00:04:06 --> 00:04:09 Spectroscopy mission is the Japanese led
00:04:09 --> 00:04:12 X Ray Observatory with NASA and the European
00:04:12 --> 00:04:15 Space Agency aboard. Uh, and its superpower
00:04:15 --> 00:04:17 is a kind of spectroscopy so precise
00:04:17 --> 00:04:20 it can read the motion of hot gas from the
00:04:20 --> 00:04:21 light it gives off.
00:04:22 --> 00:04:24 Avery: Explain how that works, because this is the
00:04:24 --> 00:04:25 clever bit.
00:04:25 --> 00:04:28 Anna: It is the hot gas in a cluster
00:04:28 --> 00:04:31 contains iron atoms. And those iron atoms
00:04:31 --> 00:04:33 emit X rays at very specific
00:04:33 --> 00:04:36 sharp energies, like a particular note.
00:04:36 --> 00:04:39 Now, if that gas is churning and swirling,
00:04:39 --> 00:04:42 some of it moves towards us and some away.
00:04:43 --> 00:04:45 And just like a siren changes pitch as it
00:04:45 --> 00:04:48 passes you, the motion smears that sharp
00:04:48 --> 00:04:51 X ray note out, it broadens the line.
00:04:51 --> 00:04:54 Measure how broad the line is and you've
00:04:54 --> 00:04:56 measured how violently the gas is moving.
00:04:56 --> 00:04:59 Avery: So the iron lines become a speedometer for
00:04:59 --> 00:05:01 gas you can't otherwise see.
00:05:01 --> 00:05:04 Anna: A speedometer for turbulence. And when they
00:05:04 --> 00:05:06 pointed xrism
00:05:06 --> 00:05:07 m@h1821
00:05:08 --> 00:05:11 643 and read those lines,
00:05:11 --> 00:05:13 the gas was full of far more turbulent than
00:05:13 --> 00:05:16 anyone expected. Compared with a calm,
00:05:16 --> 00:05:19 well behaved cluster like Perseus, the motion
00:05:19 --> 00:05:22 here is dramatically more violent. And
00:05:22 --> 00:05:25 it's violent across a huge span of space.
00:05:25 --> 00:05:26 Avery: How huge?
00:05:27 --> 00:05:29 Anna: The disturbance reaches out to something like
00:05:29 --> 00:05:32 300 light years from the black
00:05:32 --> 00:05:35 hole, well beyond the host galaxy, out
00:05:35 --> 00:05:38 into the cluster itself. And the energy tied
00:05:38 --> 00:05:40 up in that turbulence is on the order of a
00:05:40 --> 00:05:43 hundred times greater than earlier estimates.
00:05:44 --> 00:05:47 Avery: Hundred times. So this isn't A tweak to the
00:05:47 --> 00:05:49 model. It's a different order of magnitude.
00:05:49 --> 00:05:52 Anna: It really is. What they've shown is that this
00:05:52 --> 00:05:55 black hole is pumping something like a few
00:05:55 --> 00:05:58 to 10% of its radiative energy
00:05:58 --> 00:06:01 straight into the surrounding cluster. Gas on
00:06:01 --> 00:06:03 scales of tens to 100
00:06:03 --> 00:06:05 kiloparsecs. That's the missing link.
00:06:06 --> 00:06:08 That's direct evidence of a black hole
00:06:08 --> 00:06:11 heating and stirring its cluster from the
00:06:11 --> 00:06:13 inside. Exactly the process theorists
00:06:13 --> 00:06:16 needed to explain why all that gas
00:06:16 --> 00:06:18 isn't collapsing into stars.
00:06:18 --> 00:06:21 Avery: Yamada had a nice way of putting it, didn't?
00:06:21 --> 00:06:24 Anna: Hm, he, he did. He said black holes
00:06:24 --> 00:06:27 are famous for sucking matter in, but they
00:06:27 --> 00:06:29 also eject gas in powerful winds.
00:06:30 --> 00:06:33 And this study says those winds are immensely
00:06:33 --> 00:06:35 stronger than we understood. For the first
00:06:35 --> 00:06:38 time, he says, we've shown a black hole
00:06:38 --> 00:06:40 influencing the broader cosmos through a
00:06:40 --> 00:06:42 shockwave of astonishing power.
00:06:43 --> 00:06:46 Avery: And the reason to care beyond wow, big
00:06:46 --> 00:06:48 number is that this is really a story about
00:06:48 --> 00:06:50 how galaxies grow up.
00:06:50 --> 00:06:53 Anna: That's the heart of it. Black holes and their
00:06:53 --> 00:06:56 galaxies grow together and feedback is the
00:06:56 --> 00:06:59 thermostat. Too little and the gas cools and
00:06:59 --> 00:07:02 the galaxy makes far too many stars. Too
00:07:02 --> 00:07:04 much and it blows the fuel away and star
00:07:04 --> 00:07:07 formation shuts down. Get it right and you
00:07:07 --> 00:07:10 build the galaxies we actually see. What
00:07:10 --> 00:07:12 Yamada's team has done is catch that
00:07:12 --> 00:07:15 thermostat in the act, working on a scale we
00:07:15 --> 00:07:18 could only assume before moving energy
00:07:18 --> 00:07:21 and eventually the chemical elements forged
00:07:21 --> 00:07:23 in stars out across the cluster.
00:07:24 --> 00:07:26 Avery: A black hole redecorating a whole
00:07:26 --> 00:07:28 neighborhood it never touches directly.
00:07:29 --> 00:07:31 Anna: More than three times the width of the Milky
00:07:31 --> 00:07:34 Way from a single point at the center. And
00:07:34 --> 00:07:36 this is really just the opening chapter.
00:07:37 --> 00:07:40 Xrism is still young and objects
00:07:40 --> 00:07:40 like
00:07:40 --> 00:07:43 H1821
00:07:43 --> 00:07:46 are, uh, rare and precious. Expect more of
00:07:46 --> 00:07:48 these hot cluster cores to get the same
00:07:48 --> 00:07:50 treatment. And expect our picture of how
00:07:50 --> 00:07:53 black holes shape the universe to keep
00:07:53 --> 00:07:55 getting bigger. Which is a lovely irony,
00:07:55 --> 00:07:58 isn't it? The more we look at the objects
00:07:58 --> 00:08:01 famous for pulling everything in, the more we
00:08:01 --> 00:08:02 find them reaching out.
00:08:03 --> 00:08:05 Avery: Reaching out. Good place to leave the giant.
00:08:05 --> 00:08:08 Let's bring it right down to a single dead
00:08:08 --> 00:08:10 star and a, uh, mystery about what it's been
00:08:10 --> 00:08:13 eating. So story two, A white
00:08:13 --> 00:08:16 dwarf is what our sun will become billions of
00:08:16 --> 00:08:18 years from now. The burnt out Earth sized
00:08:18 --> 00:08:21 core left behind when a star like ours runs
00:08:21 --> 00:08:23 out of fuel. And for a long time we've known
00:08:23 --> 00:08:26 these dead stars are a bit macabre. They're
00:08:26 --> 00:08:28 surrounded by the shredded remains of their
00:08:28 --> 00:08:31 old Planetary systems, asteroids, and even
00:08:31 --> 00:08:33 planets torn apart and pulled in.
00:08:33 --> 00:08:36 Anna: The star literally raining its old
00:08:36 --> 00:08:38 planets down onto itself.
00:08:39 --> 00:08:42 Avery: Beautifully grim. Yes, we can tell, because
00:08:42 --> 00:08:44 we see the metals from that debris polluting
00:08:44 --> 00:08:47 the star's atmosphere. But new research says
00:08:47 --> 00:08:49 we've been undercounting the meal, that white
00:08:49 --> 00:08:52 dwarfs are eating far more planetary material
00:08:52 --> 00:08:54 than we thought. And the reason we missed it
00:08:54 --> 00:08:55 is magnetism.
00:08:56 --> 00:08:58 Anna: Magnetic fields hiding the evidence.
00:08:59 --> 00:09:02 Avery: Exactly. Some white dwarfs are strongly
00:09:02 --> 00:09:04 magnetic. And when debris falls in, those
00:09:04 --> 00:09:07 magnetic field lines funnel the infalling
00:09:07 --> 00:09:09 material down to the star's magnetic poles,
00:09:10 --> 00:09:12 concentrating it into small patches instead
00:09:12 --> 00:09:15 of spreading it evenly. And patches at the
00:09:15 --> 00:09:17 poles are much easier to miss.
00:09:17 --> 00:09:20 Anna: And here's the part I love. The researchers
00:09:20 --> 00:09:22 point out it's essentially the same physics
00:09:22 --> 00:09:23 as an aurora.
00:09:23 --> 00:09:26 Avery: It is. Think about how our own auroras
00:09:26 --> 00:09:29 work. The sun throws charged particles at
00:09:29 --> 00:09:31 Earth. They follow our magnetic field lines
00:09:31 --> 00:09:34 down to the poles, and they light up a
00:09:34 --> 00:09:36 glowing patch in the atmosphere on a magnetic
00:09:36 --> 00:09:39 white dwarf. Swap the solar particles for the
00:09:39 --> 00:09:42 debris of a dead planetary system, and you
00:09:42 --> 00:09:45 get the same choreography material guided
00:09:45 --> 00:09:47 along field lines to a bright spot at the
00:09:47 --> 00:09:48 pole.
00:09:48 --> 00:09:50 Anna: An aurora made of ground up, uh,
00:09:50 --> 00:09:53 Avery: planets on the corpse of a star.
00:09:53 --> 00:09:56 And the practical upshot's real. If this
00:09:56 --> 00:09:58 magnetic funneling is common, then a lot of
00:09:58 --> 00:10:01 white dwarfs we've written down as clean may
00:10:01 --> 00:10:04 actually be feeding just quietly in a way
00:10:04 --> 00:10:07 our surveys don't catch. Which changes how we
00:10:07 --> 00:10:09 estimate what these old planetary systems
00:10:09 --> 00:10:10 were made of.
00:10:10 --> 00:10:13 Anna: A window into the guts of dead solar
00:10:13 --> 00:10:15 systems, including, one day, our own.
00:10:16 --> 00:10:18 Speaking of dress rehearsals for the future,
00:10:18 --> 00:10:20 let's go to Mars. Story 3.
00:10:20 --> 00:10:23 NASA's Psyche spacecraft is on its way to one
00:10:23 --> 00:10:26 of the strangest targets in the solar the
00:10:26 --> 00:10:29 asteroid 16 Psyche. A world that
00:10:29 --> 00:10:32 may be the exposed metal core of a shattered
00:10:32 --> 00:10:35 baby planet. Mostly metal, not rock or
00:10:35 --> 00:10:38 ice. We've never visited anything like it.
00:10:38 --> 00:10:40 Avery: And it doesn't get there until 2029.
00:10:41 --> 00:10:44 Anna: Not until 2029. That's right. But on the
00:10:44 --> 00:10:47 way back in May, it swung past Mars for a
00:10:47 --> 00:10:49 gravity assist, using the planet's pole to
00:10:49 --> 00:10:52 bend its path and pick up speed for free.
00:10:52 --> 00:10:54 And NASA's just shared with the team did with
00:10:54 --> 00:10:57 that flyby, which is the fun part. They
00:10:57 --> 00:10:59 treated Mars as a rehearsal studio.
00:10:59 --> 00:11:02 Avery: A chance to switch everything on and check.
00:11:02 --> 00:11:03 It works. Far from home.
00:11:03 --> 00:11:06 Anna: Exactly. They put the cameras, the
00:11:06 --> 00:11:08 magnetometer, and the particle instruments
00:11:08 --> 00:11:10 through their paces against a real world
00:11:10 --> 00:11:13 instead of empty space. They captured a
00:11:13 --> 00:11:15 striking time lapse of Mars sliding by.
00:11:16 --> 00:11:18 They even picked up neutrons coming off the
00:11:18 --> 00:11:20 planet. But the detail that jumped out at me.
00:11:20 --> 00:11:23 The imager managed to pick out Phoos and
00:11:23 --> 00:11:25 Deimos, the two tiny moons of Mars from a
00:11:25 --> 00:11:28 great distance, the little Martian moons.
00:11:28 --> 00:11:30 Avery: And that wasn't just for a nice photo.
00:11:30 --> 00:11:33 Anna: No, that was the whole point. Spotting two
00:11:33 --> 00:11:36 small faint moons against the glare is
00:11:36 --> 00:11:38 exactly the kind of needle in a haystack test
00:11:38 --> 00:11:40 they'll need when they arrive at asteroid
00:11:40 --> 00:11:43 Psyche and go looking for any little moonlets
00:11:43 --> 00:11:45 orbiting it. So Mars became a practice run
00:11:45 --> 00:11:47 for a search they'll do for real in a few
00:11:47 --> 00:11:50 years time, rehearsing the hardshot
00:11:50 --> 00:11:52 Avery: on a target you already know, so you're ready
00:11:52 --> 00:11:53 for the one you don't.
00:11:54 --> 00:11:56 Anna: Precisely. Every instrument checked,
00:11:56 --> 00:11:59 calibrated and confident three years before
00:11:59 --> 00:12:02 it matters. From one careful mission to a
00:12:02 --> 00:12:04 much messier problem closer to home.
00:12:04 --> 00:12:06 Avery the traffic on the road to the Moon.
00:12:08 --> 00:12:10 Avery: We spend a lot of time on this show talking
00:12:10 --> 00:12:12 about who's going to the moon now. NASA's
00:12:12 --> 00:12:15 Artemis program, China and Russia's planned
00:12:15 --> 00:12:18 research station, Europe's Argonaut landers,
00:12:18 --> 00:12:20 and the growing crowd of commercial missions.
00:12:21 --> 00:12:23 The next decade could see dozens of flights
00:12:23 --> 00:12:26 into what's called cislunar space. The whole
00:12:26 --> 00:12:27 region between Earth and the moon.
00:12:28 --> 00:12:30 Anna: And everywhere we've ever gone in space,
00:12:30 --> 00:12:32 we've left junk behind.
00:12:32 --> 00:12:35 Avery: That's the worry. We've made low Earth
00:12:35 --> 00:12:38 orbit crowded and cluttered. The question
00:12:38 --> 00:12:41 this new study asks is, are we about to do
00:12:41 --> 00:12:43 the same thing to the road to the Moon before
00:12:43 --> 00:12:46 we've even properly moved in? It's from a
00:12:46 --> 00:12:48 team at the Chinese Academy of Sciences, and
00:12:48 --> 00:12:51 they've looked at a specific clever kind of
00:12:51 --> 00:12:54 orbit out there, a, uh, distant retrograde
00:12:54 --> 00:12:55 orbit, which
00:12:55 --> 00:12:58 Anna: is one of those very stable parking spots in
00:12:58 --> 00:12:58 the Earth Moon system.
00:12:58 --> 00:13:01 Avery: Um, right. A wide stable loop
00:13:01 --> 00:13:03 that's attractive precisely because
00:13:03 --> 00:13:06 spacecraft can sit in it for a long time
00:13:06 --> 00:13:09 without much fuel. The catch is if a
00:13:09 --> 00:13:11 spacecraft in one of those orbits breaks up,
00:13:11 --> 00:13:14 an explosion, a, ah, collision, the debris
00:13:14 --> 00:13:16 doesn't just fall away and disappear the way
00:13:16 --> 00:13:19 it might near Earth. The team modeled how
00:13:19 --> 00:13:22 those debris clouds spread. And out there,
00:13:22 --> 00:13:24 the fragments can linger and drift in ways
00:13:24 --> 00:13:26 that are genuinely hard to predict.
00:13:27 --> 00:13:29 Anna: And unlike low Earth orbit, there's no
00:13:29 --> 00:13:32 friendly atmosphere out there to eventually
00:13:32 --> 00:13:34 drag the rubbish down and burn it up.
00:13:34 --> 00:13:37 Avery: That's the crux of it. Near Earth, the
00:13:37 --> 00:13:40 atmosphere slowly cleans up after us. In
00:13:40 --> 00:13:42 deep cislunar space, there's no such
00:13:42 --> 00:13:45 janitor. Debris can stay a hazard far
00:13:45 --> 00:13:47 longer. So the value of work like this is
00:13:47 --> 00:13:50 that it's preventative if we can map where
00:13:50 --> 00:13:52 the risky orbits and the lingering debris
00:13:52 --> 00:13:55 clouds are before the traffic arrives. We can
00:13:55 --> 00:13:57 design missions to steer clear and maybe keep
00:13:57 --> 00:13:59 the highway to the moon open for everyone who
00:13:59 --> 00:14:00 wants to use it.
00:14:01 --> 00:14:03 Anna: Cleaning up before we make the mess for once.
00:14:04 --> 00:14:06 Now let's get you outside because tonight the
00:14:06 --> 00:14:09 sky is putting on a show. And this one is
00:14:09 --> 00:14:11 genuinely for tonight, wherever you're
00:14:11 --> 00:14:14 listening. Two meteor showers are peaking at
00:14:14 --> 00:14:16 the same time, the night of the 30th into the
00:14:16 --> 00:14:19 early hours of the 31st. The southern delta
00:14:19 --> 00:14:20 aquariids and the alpha
00:14:20 --> 00:14:23 Avery: capricornids, two at once,
00:14:23 --> 00:14:25 tell us the difference between them.
00:14:25 --> 00:14:28 Anna: They've got very different personalities. The
00:14:28 --> 00:14:30 Southern Delta Aquariids are the steady
00:14:30 --> 00:14:33 workhorses. More meteors, a bit fainter,
00:14:33 --> 00:14:35 radiating from the constellation Aquarius.
00:14:35 --> 00:14:37 Their parent is thought to be a comet called
00:14:37 --> 00:14:40 96PMachholz. The alpha
00:14:40 --> 00:14:42 Capricornids are the opposite. Not many, but
00:14:42 --> 00:14:45 the ones you get are slow bright fireballs,
00:14:45 --> 00:14:48 real showstoppers coming from the direction
00:14:48 --> 00:14:50 of Capricornus from a comet called
00:14:50 --> 00:14:51 16.9pmeet.
00:14:52 --> 00:14:55 Avery: So quality versus quantity sharing
00:14:55 --> 00:14:55 the same night.
00:14:56 --> 00:14:59 Anna: Exactly. Now the honest catch this year,
00:14:59 --> 00:15:02 the moon. We had the full buck moon just last
00:15:02 --> 00:15:04 night, so tonight it's still around 98%
00:15:04 --> 00:15:07 lit. And that glare will wash out the fainter
00:15:07 --> 00:15:10 meteors. But, and this is the saving grace,
00:15:10 --> 00:15:13 those bright Capricornid fireballs can punch
00:15:13 --> 00:15:15 right through moonlight. As one astronomer
00:15:15 --> 00:15:18 put it, one bright one is worth 20 faint
00:15:18 --> 00:15:18 ones.
00:15:19 --> 00:15:21 Avery: So how do people actually watch? And um, this
00:15:21 --> 00:15:24 is where north and south really difference.
00:15:24 --> 00:15:27 Anna: It does. So let's do both properly. First,
00:15:27 --> 00:15:28 the good news for us here in the Southern
00:15:28 --> 00:15:31 hemisphere, this is our show. Both
00:15:31 --> 00:15:33 radiants ride high overhead from southern
00:15:33 --> 00:15:36 latitudes, so we get the best seats. The
00:15:36 --> 00:15:38 Southern Delta Aquarids can deliver something
00:15:38 --> 00:15:41 like 10 to 20 an hour from a dark site under
00:15:41 --> 00:15:44 a better moon. And even tonight with the moon
00:15:44 --> 00:15:46 bright, the south still comes out ahead
00:15:46 --> 00:15:47 Cygny
00:15:47 --> 00:15:50 Avery: and um, the east coast. When and where head
00:15:50 --> 00:15:51 out after the
00:15:51 --> 00:15:53 Anna: moon and sky settle late evening onward. But
00:15:53 --> 00:15:56 the best window is the small hours local
00:15:56 --> 00:15:59 time, roughly 1 to 4am when the
00:15:59 --> 00:16:01 radiance are highest. Look towards the north
00:16:01 --> 00:16:03 and east. Get as far from city lights as you
00:16:03 --> 00:16:06 can and give your eyes a solid 20 to 30
00:16:06 --> 00:16:09 minutes to adapt. Lie back and take in a
00:16:09 --> 00:16:12 wide patch of sky rather than staring at one
00:16:12 --> 00:16:12 spot.
00:16:12 --> 00:16:15 Avery: And for our North American listeners, our
00:16:15 --> 00:16:17 biggest audience who don't get the radiant
00:16:17 --> 00:16:20 Anna: as high, you can still absolutely
00:16:20 --> 00:16:22 catch this. You just work with lower numbers
00:16:22 --> 00:16:25 and lean on the fireballs. Your best time
00:16:25 --> 00:16:28 is Also the pre dawn hours. Think
00:16:28 --> 00:16:30 2 to 4am local, whether that's
00:16:30 --> 00:16:33 Eastern Central Mountain or Pacific time.
00:16:34 --> 00:16:36 Once the radiants have climbed as high as
00:16:36 --> 00:16:39 they'll get the pro tip for the moonlight
00:16:39 --> 00:16:42 Position yourself facing away from the moon
00:16:42 --> 00:16:45 with it at your back or blocked behind a
00:16:45 --> 00:16:48 building or a hill so its glare isn't in your
00:16:48 --> 00:16:51 eyes. Then watch a broad stretch
00:16:51 --> 00:16:54 of sky and wait for those slow Capricorned
00:16:54 --> 00:16:54 fireballs.
00:16:55 --> 00:16:57 Avery: No telescope, no binoculars.
00:16:57 --> 00:17:00 Anna: Done it all meteors are a naked eye
00:17:00 --> 00:17:03 whole sky event. Just you, a
00:17:03 --> 00:17:05 reclining chair, something warm and patience.
00:17:06 --> 00:17:08 And if tonight clouds you out, both showers
00:17:08 --> 00:17:11 stayed active for another week or two, so
00:17:11 --> 00:17:13 you'll get more chances as the moon thins out
00:17:13 --> 00:17:14 and conditions improve.
00:17:15 --> 00:17:18 Avery: Two comets worth of dust burning up over your
00:17:18 --> 00:17:20 head. Not a bad way to end the day.
00:17:21 --> 00:17:23 Anna: Not bad at all. Look up if you can.
00:17:24 --> 00:17:26 Avery: That's the lot for today. Every story with
00:17:26 --> 00:17:29 links and sources is over at astronomydaily
00:17:29 --> 00:17:32 IO. The new site has the full back
00:17:32 --> 00:17:34 catalog, a rolling news feed, and you can
00:17:34 --> 00:17:36 sign up for the newsletter or drop us a line
00:17:36 --> 00:17:37 right there.
00:17:37 --> 00:17:40 Anna: We love hearing from you. Tell us if you
00:17:40 --> 00:17:43 catch a Capricorned fireball tonight. Find us
00:17:43 --> 00:17:45 at astrodaily pod and on the
00:17:45 --> 00:17:47 bytes.com podcast network for
00:17:47 --> 00:17:49 Anna and for me.
00:17:49 --> 00:17:50 Avery: Thanks for listening.
00:17:50 --> 00:17:52 Anna: Until tomorrow. Clear skies.
00:18:01 --> 00:18:02 Avery: Mhm.
00:18:08 --> 00:18:09 Anna: You
00:18:11 --> 00:18:12 stories we told.