00:00:00 --> 00:00:02 If you've been stepping outside after
00:00:02 --> 00:00:04 dark lately and wondering what that
00:00:04 --> 00:00:06 fuzzy smudge low on the horizon might
00:00:06 --> 00:00:09 be, stay tuned because by the end of
00:00:09 --> 00:00:10 today's show, you're going to know
00:00:10 --> 00:00:13 exactly what it is, exactly when to
00:00:13 --> 00:00:15 look, and exactly why you might only
00:00:15 --> 00:00:18 ever get one shot at seeing it. Welcome
00:00:18 --> 00:00:21 to Astronomy Daily. I'm Anna.
00:00:21 --> 00:00:24 >> And I'm Avery. This is season 5, episode
00:00:24 --> 00:00:27 91 of Astronomy Daily, your daily guide
00:00:27 --> 00:00:29 to everything happening in space and
00:00:29 --> 00:00:30 beyond.
00:00:30 --> 00:00:34 >> It is Thursday, the 23rd of April, 2026,
00:00:34 --> 00:00:37 and we have a cracking episode lined up.
00:00:37 --> 00:00:39 Six stories across the board today. From
00:00:39 --> 00:00:41 a gamechanging telescope that just
00:00:42 --> 00:00:44 locked in a launch date to a decad's old
00:00:44 --> 00:00:46 cosmic photograph getting a stunning
00:00:46 --> 00:00:49 update to a signing ceremony happening
00:00:49 --> 00:00:52 literally as we record this. And we'll
00:00:52 --> 00:00:53 close out with that comet you just
00:00:54 --> 00:00:55 teased, Anna, which our Southern
00:00:55 --> 00:00:58 Hemisphere listeners in particular are
00:00:58 --> 00:01:00 going to want to hear about. Trust us.
00:01:00 --> 00:01:02 >> Let's get into it.
00:01:02 --> 00:01:04 >> We touched on the Roman Space Telescope
00:01:04 --> 00:01:06 earlier this week when NASA hosted its
00:01:06 --> 00:01:08 big unveiling event at Gddard Space
00:01:08 --> 00:01:11 Flight Center. But since that story ran,
00:01:11 --> 00:01:13 something significant has become clear.
00:01:13 --> 00:01:15 The launch date. So, let's give this the
00:01:15 --> 00:01:16 update it deserves,
00:01:16 --> 00:01:18 >> right? And the headline here is
00:01:18 --> 00:01:21 genuinely exciting. The Nancy Grace
00:01:21 --> 00:01:24 Roman Space Telescope is now targeting a
00:01:24 --> 00:01:27 September 2026 launch. That's eight
00:01:27 --> 00:01:29 months ahead of its formal deadline of
00:01:29 --> 00:01:33 May 2027. 8 months. And it came in under
00:01:33 --> 00:01:35 budget. In government space projects,
00:01:35 --> 00:01:38 that is practically unheard of.
00:01:38 --> 00:01:40 >> To put this in perspective for anyone
00:01:40 --> 00:01:43 just catching up, Roman is NASA's next
00:01:43 --> 00:01:45 flagship space observatory. Think of it
00:01:45 --> 00:01:48 as Hubble's younger sibling. Same size
00:01:48 --> 00:01:51 mirror, about 2.4 4 m, but a field of
00:01:51 --> 00:01:54 view that is at minimum 100 times wider
00:01:54 --> 00:01:56 than Hubble's. The images it will
00:01:56 --> 00:01:59 capture are so large there is literally
00:01:59 --> 00:02:01 no screen currently in existence big
00:02:01 --> 00:02:03 enough to display them at full
00:02:03 --> 00:02:06 resolution. And NASA administrator Jared
00:02:06 --> 00:02:08 Isaacman made a striking comparison at
00:02:08 --> 00:02:10 this week's press event. What would take
00:02:10 --> 00:02:14 Hubble 2 years to survey, Roman can
00:02:14 --> 00:02:18 do in a single year. 2 years versus
00:02:18 --> 00:02:20 one. Let that sink in.
00:02:20 --> 00:02:23 >> The science objectives are vast. Roman
00:02:23 --> 00:02:25 will hunt for exoplanets, potentially
00:02:25 --> 00:02:27 more than 100 new worlds in its
00:02:27 --> 00:02:30 first 5 years. It'll survey billions of
00:02:30 --> 00:02:33 galaxies, and critically it will probe
00:02:33 --> 00:02:35 two of the deepest mysteries in modern
00:02:35 --> 00:02:38 physics, dark matter and dark energy. We
00:02:38 --> 00:02:39 don't know what either of those actually
00:02:39 --> 00:02:42 are. And Roman's wide field infrared
00:02:42 --> 00:02:44 vision is designed specifically to pull
00:02:44 --> 00:02:47 back the curtain. It's also carrying the
00:02:47 --> 00:02:49 Coronograph instrument, a technology
00:02:49 --> 00:02:51 demonstrator that will attempt to
00:02:51 --> 00:02:53 directly photograph planets around
00:02:53 --> 00:02:55 nearby stars. That could be a
00:02:55 --> 00:02:57 transformative capability for the search
00:02:57 --> 00:02:59 for Earthlike worlds.
00:02:59 --> 00:03:02 >> Roman will travel to the Sun Earth L2
00:03:02 --> 00:03:04 point, the same orbital neighborhood as
00:03:04 --> 00:03:06 the James Webb telescope about a million
00:03:06 --> 00:03:09 miles from Earth. Once there, it begins
00:03:09 --> 00:03:12 a 5-year primary mission. If September
00:03:12 --> 00:03:14 holds, we could see first light before
00:03:14 --> 00:03:16 the end of this year.
00:03:16 --> 00:03:18 >> 16 years after astronomers ranked it as
00:03:18 --> 00:03:21 the single highest priority for the next
00:03:21 --> 00:03:23 decade of space science, four separate
00:03:24 --> 00:03:26 attempts to cancel the mission. And here
00:03:26 --> 00:03:29 we are 8 months ahead of schedule,
00:03:29 --> 00:03:31 watching it ship to Kennedy Space Center
00:03:31 --> 00:03:33 this summer. Some stories really do have
00:03:33 --> 00:03:34 a good ending.
00:03:34 --> 00:03:37 >> A feel-good story indeed.
00:03:37 --> 00:03:39 >> Right. Story two. And this one involves
00:03:39 --> 00:03:41 Uranus, which is having quite a moment
00:03:41 --> 00:03:43 scientifically lately.
00:03:43 --> 00:03:45 >> Uranus is the gift that keeps giving.
00:03:45 --> 00:03:47 The ice giant seven planets out from the
00:03:47 --> 00:03:50 sun, famously tilted on its side with 29
00:03:50 --> 00:03:54 known moons and a system of 13 rings.
00:03:54 --> 00:03:56 And it's those rings at the center of
00:03:56 --> 00:03:58 new research published this week in the
00:03:58 --> 00:04:00 journal of geoysical research, planets.
00:04:00 --> 00:04:03 A team led by Enke Deotter at UC
00:04:03 --> 00:04:06 Berkeley has combined data from three of
00:04:06 --> 00:04:09 the world's most powerful observatories.
00:04:09 --> 00:04:12 The WM KEKCK Observatory in Hawaii, the
00:04:12 --> 00:04:15 Hubble Space Telescope and the James Web
00:04:15 --> 00:04:18 Space Telescope to build the first
00:04:18 --> 00:04:20 complete reflectance spectrum of
00:04:20 --> 00:04:23 Uranus's two outermost rings known as
00:04:23 --> 00:04:26 the MU ring and the new ring. And what
00:04:26 --> 00:04:28 they found is that these two rings
00:04:28 --> 00:04:31 sitting side by side in the uranian
00:04:31 --> 00:04:33 system are made of completely different
00:04:33 --> 00:04:36 stuff. Which raises an obvious question.
00:04:36 --> 00:04:37 How?
00:04:37 --> 00:04:40 >> The Mu ring, it turns out, is composed
00:04:40 --> 00:04:43 of water ice particles. Tiny frozen
00:04:43 --> 00:04:45 grains being knocked loose from a small
00:04:45 --> 00:04:48 moon called Mab by micrometeorite
00:04:48 --> 00:04:52 impacts. M is only about 12 km across,
00:04:52 --> 00:04:55 barely a pebble on cosmic scales, but
00:04:55 --> 00:04:57 it's generating an entire ring of ice
00:04:58 --> 00:04:59 debris as it orbits.
00:04:59 --> 00:05:02 >> Interestingly, the only other blue ring
00:05:02 --> 00:05:03 like this in our solar system is
00:05:04 --> 00:05:06 Saturn's E-ring, produced by volcanic
00:05:06 --> 00:05:09 activity on Enceladus. The mechanism is
00:05:09 --> 00:05:11 different, but the result is remarkably
00:05:11 --> 00:05:14 similar. Major finding the same solution
00:05:14 --> 00:05:17 twice. Now, the new ring is where things
00:05:17 --> 00:05:20 get really strange. It's not made of
00:05:20 --> 00:05:23 ice. Instead, it's composed of rocky
00:05:23 --> 00:05:26 material laced with organic compounds,
00:05:26 --> 00:05:29 carbonri molecules. And crucially,
00:05:29 --> 00:05:31 there's no known moon nearby that could
00:05:31 --> 00:05:32 be the source.
00:05:32 --> 00:05:34 >> The researchers believe there must be
00:05:34 --> 00:05:37 unseen rocky bodies, possibly small moon
00:05:37 --> 00:05:39 lids tucked between the known moons,
00:05:39 --> 00:05:42 getting bombarded by micrometeorites and
00:05:42 --> 00:05:44 feeding material into the ring. In other
00:05:44 --> 00:05:47 words, Uranus likely has more moons than
00:05:47 --> 00:05:48 we know about.
00:05:48 --> 00:05:51 >> Mark Shoalter from the SETI Institute, a
00:05:51 --> 00:05:53 co-author on the study, was pretty
00:05:53 --> 00:05:55 direct about it. He said solving the
00:05:55 --> 00:05:57 full mystery will probably require a
00:05:57 --> 00:06:00 spacecraft mission to Uranus, and one is
00:06:00 --> 00:06:02 in the planning stages. It was the top
00:06:02 --> 00:06:04 priority in the most recent National
00:06:04 --> 00:06:07 Academy of Scienc's planetary science
00:06:07 --> 00:06:09 decadal survey, though funding remains
00:06:09 --> 00:06:11 the critical question.
00:06:11 --> 00:06:12 >> There's one more wrinkle worth
00:06:12 --> 00:06:15 mentioning. The MU ring appears to be
00:06:15 --> 00:06:17 changing in brightness over time, subtly
00:06:17 --> 00:06:20 but measurably. What's causing that?
00:06:20 --> 00:06:23 Nobody knows. Another mystery for a
00:06:23 --> 00:06:25 mission that, fingers crossed,
00:06:25 --> 00:06:27 eventually gets off the ground.
00:06:27 --> 00:06:29 >> Uranus. Deeply weird, deeply
00:06:30 --> 00:06:32 fascinating, and apparently still full
00:06:32 --> 00:06:35 of secrets. This story is going to keep
00:06:35 --> 00:06:36 developing.
00:06:36 --> 00:06:38 >> Story three. And this one's a treat for
00:06:38 --> 00:06:40 anyone who loves cosmic imagery with a
00:06:40 --> 00:06:43 sight of time-lapse astronomy. The
00:06:43 --> 00:06:45 Hubble Space Telescope has gone back to
00:06:45 --> 00:06:47 one of its classic targets, the Triffid
00:06:47 --> 00:06:50 Nebula, and the comparison between the
00:06:50 --> 00:06:52 original image and the new one is
00:06:52 --> 00:06:54 genuinely remarkable.
00:06:54 --> 00:06:56 >> For those unfamiliar, the Triffid Nebula
00:06:56 --> 00:06:58 is a star forming region in the
00:06:58 --> 00:07:01 constellation Sagittarius, about 5
00:07:01 --> 00:07:03 light years from Earth. Its name comes
00:07:03 --> 00:07:06 from the Latin for divided into three.
00:07:06 --> 00:07:08 It split into three distinct loes by
00:07:08 --> 00:07:11 dark dust lanes, giving it the striking
00:07:11 --> 00:07:13 trilobate appearance. It's one of
00:07:14 --> 00:07:16 Hubble's most celebrated early targets.
00:07:16 --> 00:07:19 Hubble first imaged the tripffid back in
00:07:19 --> 00:07:23 1997, nearly three decades ago. The new
00:07:23 --> 00:07:25 image captured with upgraded instruments
00:07:25 --> 00:07:28 covers essentially the same field. And
00:07:28 --> 00:07:30 by placing the two side by side,
00:07:30 --> 00:07:33 astronomers have been able to track real
00:07:33 --> 00:07:36 measurable changes in how young stars in
00:07:36 --> 00:07:39 the region behave and evolve. Now, 29
00:07:39 --> 00:07:42 years sounds like a long time to us. On
00:07:42 --> 00:07:44 cosmic scales, it's barely an eyelink,
00:07:44 --> 00:07:47 but young stars still in the process of
00:07:47 --> 00:07:49 forming, still shedding material, still
00:07:49 --> 00:07:52 igniting, can show perceptible changes
00:07:52 --> 00:07:54 on human time scales. And that's exactly
00:07:54 --> 00:07:57 what the comparison reveals. What Hubble
00:07:57 --> 00:07:59 is doing here is functioning as a kind
00:07:59 --> 00:08:02 of cosmic time-lapse camera. The same
00:08:02 --> 00:08:05 telescope returning to the same subject
00:08:05 --> 00:08:07 decades apart and documenting how the
00:08:07 --> 00:08:10 universe has shifted in the interim.
00:08:10 --> 00:08:12 It's one of the most powerful aspects of
00:08:12 --> 00:08:14 having a long lived observatory in
00:08:14 --> 00:08:15 space.
00:08:15 --> 00:08:18 >> And of course, visually the new tripffid
00:08:18 --> 00:08:21 image is spectacular. The deep magentas,
00:08:21 --> 00:08:24 electric blues, and soft golden hues of
00:08:24 --> 00:08:26 active stellar nurseries. If you haven't
00:08:26 --> 00:08:28 seen it yet, it's worth seeking out.
00:08:28 --> 00:08:30 We'll link it in the show notes.
00:08:30 --> 00:08:33 >> The Triffid Nebula, 30 years older and
00:08:33 --> 00:08:36 if anything, more beautiful than ever.
00:08:36 --> 00:08:39 Proof that some things genuinely improve
00:08:39 --> 00:08:40 with age.
00:08:40 --> 00:08:42 >> Like us, maybe. Anna,
00:08:42 --> 00:08:45 >> story four now. And this one is
00:08:45 --> 00:08:48 happening today. Right now, as we record
00:08:48 --> 00:08:51 at NASA headquarters in Washington, DC,
00:08:51 --> 00:08:53 >> the Hashemite Kingdom of Jordan is
00:08:53 --> 00:08:55 signing the Artemis Accords, becoming
00:08:55 --> 00:08:58 the 63rd country to commit to the
00:08:58 --> 00:09:00 framework for peaceful and responsible
00:09:00 --> 00:09:02 space exploration. NASA administrator
00:09:02 --> 00:09:04 Jared Isaacman is hosting Ambassador
00:09:04 --> 00:09:07 Dena Cow for the ceremony.
00:09:07 --> 00:09:09 >> Now, we should explain what the Artemis
00:09:09 --> 00:09:11 Accords actually are for anyone who
00:09:11 --> 00:09:14 joined us more recently. The accords
00:09:14 --> 00:09:16 were established in 2020 during the
00:09:16 --> 00:09:19 first Trump administration by NASA and
00:09:19 --> 00:09:21 the State Department initially with
00:09:22 --> 00:09:24 seven other founding nations including
00:09:24 --> 00:09:27 Australia. They're a set of practical
00:09:27 --> 00:09:29 principles covering how countries should
00:09:29 --> 00:09:32 conduct themselves in space.
00:09:32 --> 00:09:34 transparency, interoperability,
00:09:34 --> 00:09:38 data sharing, protecting historic sites,
00:09:38 --> 00:09:41 safe zones around operations, and the
00:09:41 --> 00:09:43 responsible extraction of resources.
00:09:43 --> 00:09:46 >> They're built on top of the 1967 Outer
00:09:46 --> 00:09:48 Space Treaty, but they add specificity
00:09:48 --> 00:09:50 that the original treaty lacked. And
00:09:50 --> 00:09:52 critically, they're open to any nation
00:09:52 --> 00:09:54 that wants to participate in the broader
00:09:54 --> 00:09:57 Artemis program of moon exploration.
00:09:57 --> 00:09:59 What's interesting about the timing here
00:09:59 --> 00:10:02 is that just 3 days ago on Monday,
00:10:02 --> 00:10:06 Latvia signed as the 62nd nation, though
00:10:06 --> 00:10:09 we've seen two signitories in one week,
00:10:09 --> 00:10:11 right on the heels of Artemis 2's
00:10:11 --> 00:10:14 successful return to Earth.
00:10:14 --> 00:10:16 >> There is a momentum story here. Artemis
00:10:16 --> 00:10:19 2 returns from the moon and within days,
00:10:19 --> 00:10:21 the international community is literally
00:10:21 --> 00:10:23 lining up to join the framework. Jordan
00:10:23 --> 00:10:26 notably has genuine aspirations in the
00:10:26 --> 00:10:28 space sector. The country has invested
00:10:28 --> 00:10:30 in satellite technology and space
00:10:30 --> 00:10:32 science education in recent years. This
00:10:32 --> 00:10:36 isn't just symbolic. 63 nations. The
00:10:36 --> 00:10:39 list now spans every inhabited continent
00:10:39 --> 00:10:43 with 29 European nations, 15 across
00:10:43 --> 00:10:45 Asia, and representation from the
00:10:45 --> 00:10:48 Americas, Africa, and Oceanania. The
00:10:48 --> 00:10:51 Aremis program is increasingly a
00:10:51 --> 00:10:53 genuinely global endeavor.
00:10:53 --> 00:10:55 >> Congratulations to Jordan. Welcome to
00:10:55 --> 00:10:57 the coalition.
00:10:57 --> 00:10:59 >> Before we move on to our next story,
00:10:59 --> 00:11:01 I'll just jump in and give you a
00:11:01 --> 00:11:04 reminder about our sponsor, NordVPN.
00:11:04 --> 00:11:05 They're the ones who are helping us keep
00:11:05 --> 00:11:07 the lights on this week. But if you're
00:11:07 --> 00:11:09 looking to make your online presence
00:11:09 --> 00:11:12 really secure from snooping eyes, and
00:11:12 --> 00:11:15 that includes governments, then you need
00:11:15 --> 00:11:18 NordVPN. They're the one we use and can
00:11:18 --> 00:11:20 highly recommend. Check them out via the
00:11:20 --> 00:11:22 link in the show notes and I think
00:11:22 --> 00:11:24 you'll be amazed at the incredible deals
00:11:24 --> 00:11:27 they have in place for Astronomy Daily
00:11:27 --> 00:11:28 listeners.
00:11:28 --> 00:11:29 >> All right, story five. And if you're
00:11:29 --> 00:11:32 wondering how quickly NASA moves after a
00:11:32 --> 00:11:34 successful mission, wonder no more.
00:11:34 --> 00:11:37 >> It was just 10 days ago that the Aremis
00:11:37 --> 00:11:40 2 crew splashed down in the Pacific.
00:11:40 --> 00:11:43 Four astronauts home safe after the most
00:11:43 --> 00:11:46 distant human space flight in history.
00:11:46 --> 00:11:48 And NASA is already rolling out the
00:11:48 --> 00:11:50 hardware for the next one.
00:11:50 --> 00:11:52 >> On April 20th, just a week and a half
00:11:52 --> 00:11:54 post splashdown, engineers at NASA's
00:11:54 --> 00:11:57 Mish assembly facility in New Orleans
00:11:57 --> 00:11:59 loaded the core stage of the Aremis 3
00:11:59 --> 00:12:02 space launch system rocket onto the AY's
00:12:02 --> 00:12:04 Pegasus barge. It's currently on route
00:12:04 --> 00:12:06 to Kennedy Space Center in Florida,
00:12:06 --> 00:12:08 where final integration and outfitting
00:12:08 --> 00:12:11 will take place. The core stage is
00:12:11 --> 00:12:14 enormous. When fully integrated, it'll
00:12:14 --> 00:12:19 stand 212 ft tall, around 65 m. What
00:12:19 --> 00:12:21 rolled onto the barge is the top four
00:12:21 --> 00:12:24 fifths of that structure. The liquid
00:12:24 --> 00:12:26 hydrogen tank, liquid oxygen tank,
00:12:26 --> 00:12:29 intertank, and forward skirt. The engine
00:12:29 --> 00:12:33 section with its four RS25 engines will
00:12:33 --> 00:12:35 be attached at Kennedy. Now, Artemis P's
00:12:35 --> 00:12:37 mission profile has evolved since the
00:12:37 --> 00:12:39 program was first announced. The
00:12:39 --> 00:12:41 original plan, landing astronauts at the
00:12:41 --> 00:12:43 lunar south pole, has been pushed back
00:12:43 --> 00:12:46 to Artemis 4, now targeting the first
00:12:46 --> 00:12:49 half of 2028. Artemis 3, scheduled for
00:12:49 --> 00:12:52 2027, will instead test rendevous and
00:12:52 --> 00:12:54 docking procedures in Earth orbit. With
00:12:54 --> 00:12:56 the Orion spacecraft linking up with one
00:12:56 --> 00:12:59 or both of the contracted lunar landers
00:12:59 --> 00:13:01 from SpaceX and Blue Origin,
00:13:01 --> 00:13:04 >> it's a sensible reconfiguration. test
00:13:04 --> 00:13:06 the systems in Earth orbit first where
00:13:06 --> 00:13:08 rescue is possible if something goes
00:13:08 --> 00:13:11 wrong, then send people to the moon.
00:13:11 --> 00:13:13 >> And there's an added layer of
00:13:13 --> 00:13:15 significance here. One of those landers,
00:13:15 --> 00:13:18 Blue Origins Blue Moon, was supposed to
00:13:18 --> 00:13:20 launch on a new Glenn rocket. That
00:13:20 --> 00:13:23 rocket is currently grounded following
00:13:23 --> 00:13:25 last week's upper stage mishap. So,
00:13:25 --> 00:13:27 there's some pressure on Blue Origin to
00:13:27 --> 00:13:30 resolve that situation quickly. NASA
00:13:30 --> 00:13:32 administrator Isaac men has expressed
00:13:32 --> 00:13:34 confidence publicly, but the clock is
00:13:34 --> 00:13:35 ticking.
00:13:35 --> 00:13:37 >> The momentum of the Aremis program feels
00:13:37 --> 00:13:40 very real right now. One mission just
00:13:40 --> 00:13:42 returned. The next one is literally on a
00:13:42 --> 00:13:45 barge. The one after that is already in
00:13:45 --> 00:13:48 planning. This program is moving.
00:13:48 --> 00:13:51 >> Next, something for our sky watchers.
00:13:51 --> 00:13:53 >> That's right. The story I teased in the
00:13:53 --> 00:13:55 opener summary. And this one is
00:13:55 --> 00:13:56 especially for our listeners in
00:13:56 --> 00:13:59 Australia, New Zealand, and across the
00:13:59 --> 00:14:00 southern hemisphere.
00:14:00 --> 00:14:05 >> Comet C 2025 R3 pan stars. It's been
00:14:05 --> 00:14:07 generating buzz for months. Some corners
00:14:07 --> 00:14:09 of the internet have called it the
00:14:09 --> 00:14:12 potential great comet of 2026. And right
00:14:12 --> 00:14:14 now, this week, is when southern
00:14:14 --> 00:14:16 hemisphere sky watchers get their best
00:14:16 --> 00:14:17 shot at it.
00:14:17 --> 00:14:20 >> Let's set the scene. This comet was
00:14:20 --> 00:14:23 discovered in September 2025 by the Pan
00:14:23 --> 00:14:26 Star Survey Telescope in Hawaii. At that
00:14:26 --> 00:14:28 point, it was a faint 19th magnitude
00:14:28 --> 00:14:31 spec visible only to the most sensitive
00:14:31 --> 00:14:33 detectors. It's been brightening
00:14:33 --> 00:14:35 steadily ever since. It reached
00:14:35 --> 00:14:37 perihelion, its closest approach to the
00:14:37 --> 00:14:40 sun on April 19th, passing within about
00:14:40 --> 00:14:43 75 million km of the sun. And here's
00:14:44 --> 00:14:45 where it gets particularly interesting
00:14:45 --> 00:14:48 for our southern hemisphere listeners.
00:14:48 --> 00:14:50 While northern hemisphere observers have
00:14:50 --> 00:14:52 now largely lost it in the sun's glare,
00:14:52 --> 00:14:55 the geometry is turning in your favor.
00:14:55 --> 00:14:58 >> From late April through early May, the
00:14:58 --> 00:15:00 comet will appear in the evening sky for
00:15:00 --> 00:15:02 southern hemisphere viewers, moving
00:15:02 --> 00:15:05 progressively higher after sunset. At
00:15:05 --> 00:15:07 its brightest estimates, it could reach
00:15:07 --> 00:15:11 magnitude 3.5, comparable to the stars
00:15:11 --> 00:15:13 of the Southern Cross, and potentially
00:15:13 --> 00:15:15 brighter. There's even an optimistic
00:15:15 --> 00:15:18 scenario where it approaches magnitude
00:15:18 --> 00:15:20 zero, which would make it one of the
00:15:20 --> 00:15:23 most striking naked eye comets in years.
00:15:23 --> 00:15:26 Now, comets are famously unpredictable.
00:15:26 --> 00:15:28 We can model their orbits beautifully,
00:15:28 --> 00:15:30 but their brightness depends on how the
00:15:30 --> 00:15:33 icy nucleus responds to solar heating,
00:15:33 --> 00:15:35 and that's harder to forecast. The
00:15:35 --> 00:15:37 magnitude 3.5 estimate is a solid
00:15:37 --> 00:15:39 baseline, but don't be surprised if it
00:15:39 --> 00:15:42 over or underdelivers. The closest
00:15:42 --> 00:15:45 approach to Earth happens on April 26th,
00:15:45 --> 00:15:48 just 3 days from now, when it passes
00:15:48 --> 00:15:52 within about 73 million km. Look low in
00:15:52 --> 00:15:54 the western sky after sunset in the
00:15:54 --> 00:15:56 direction of the constellations Pisces
00:15:56 --> 00:15:59 and Pegasus. Binoculars will certainly
00:15:59 --> 00:16:02 help, but under dark skies, you might
00:16:02 --> 00:16:04 find it with the naked eye.
00:16:04 --> 00:16:05 >> And here's the detail that gives this
00:16:05 --> 00:16:08 story real weight. The comet's orbit may
00:16:08 --> 00:16:11 be hyperbolic. That means it may have
00:16:11 --> 00:16:13 come from interstellar space, will swing
00:16:13 --> 00:16:16 past the sun once, and then head back
00:16:16 --> 00:16:19 out, never to return. If that's
00:16:19 --> 00:16:22 confirmed, April and May 2026 could be
00:16:22 --> 00:16:24 the only time in all of human history
00:16:24 --> 00:16:28 that anyone ever sees this object ever.
00:16:28 --> 00:16:31 >> So, get outside this week. Dark sky,
00:16:31 --> 00:16:34 western horizon, after sunset. You might
00:16:34 --> 00:16:36 be watching something no human has ever
00:16:36 --> 00:16:39 seen before and no human ever will
00:16:39 --> 00:16:40 again.
00:16:40 --> 00:16:42 >> Before we wrap up, time for your daily
00:16:42 --> 00:16:44 dose of cosmic trivia.
00:16:44 --> 00:16:47 >> Today's question, the Nancy Grace Roman
00:16:47 --> 00:16:50 Space Telescope shares its primary
00:16:50 --> 00:16:53 mirror size with a famous existing space
00:16:53 --> 00:16:55 telescope. Which one and where did the
00:16:55 --> 00:16:57 mirror originally come from?
00:16:57 --> 00:16:59 >> I'll give you a second or two to think
00:16:59 --> 00:16:59 about it.
00:16:59 --> 00:17:03 >> The answer, Roman's 2.4 4 meter mirror
00:17:03 --> 00:17:05 is the same size as the Hubble Space
00:17:05 --> 00:17:07 Telescopes. And here's the remarkable
00:17:07 --> 00:17:09 backstory. The mirror was actually
00:17:10 --> 00:17:12 donated to NASA by the National
00:17:12 --> 00:17:14 Reconnaissance Office. It was originally
00:17:14 --> 00:17:16 built for a classified intelligence
00:17:16 --> 00:17:20 satellite. NASA repurposed surplus spy
00:17:20 --> 00:17:22 satellite hardware into what will become
00:17:22 --> 00:17:24 one of the most powerful astronomical
00:17:24 --> 00:17:27 instruments ever launched. From watching
00:17:27 --> 00:17:29 Earth from above to watching the
00:17:29 --> 00:17:31 universe from afar. Not a bad career
00:17:31 --> 00:17:33 change for a mirror.
00:17:33 --> 00:17:35 >> And that is your astronomy daily for
00:17:35 --> 00:17:39 Thursday the 23rd of April 2026. Six
00:17:39 --> 00:17:42 stories, one extraordinary universe.
00:17:42 --> 00:17:43 Thank you so much for spending part of
00:17:44 --> 00:17:45 your day with us.
00:17:45 --> 00:17:47 >> Find us everywhere podcasts are found on
00:17:48 --> 00:17:51 YouTube and at astronomydaily.io.
00:17:51 --> 00:17:52 Leave us a review if you're enjoying the
00:17:52 --> 00:17:54 show. It genuinely makes a difference.
00:17:54 --> 00:17:57 and follow us on social media at Astro
00:17:57 --> 00:17:58 Daily Pod.
00:17:58 --> 00:18:00 >> And for our Southern Hemisphere
00:18:00 --> 00:18:02 listeners, get outside this week. That
00:18:02 --> 00:18:04 comet is waiting for you.
00:18:04 --> 00:18:06 >> Until tomorrow, keep looking up.
00:18:06 --> 00:18:11 >> Clear skies, everyone. Astronomy day.
00:18:11 --> 00:18:19 Stories be told.
00:18:19 --> 00:18:23 Stories told.