April 4, 2026
No Course Correction Needed: Artemis II Day 3 Update + Comet MAPS Perihelion Report
Artemis II, Comet MAPS, and Mercury: Your Space Week Just Got Very Busy
It's Day 3 of the Artemis II mission, a sungrazer comet is emerging from the solar corona, an Atlas V just set a payload record, and Mercury is at its best of the year. Here's everything you need to know from today's episode of Astronomy Daily. Artemis II Flight Day 3: Orion Doesn't Even Need a Course Correction Four humans are on their way to the Moon, and everything is going better than planned. Flight controllers cancelled the first of three scheduled trajectory correction burns today — Orion is already on such a precise path that the burn simply wasn't needed. As Howard Hu, NASA's Orion program manager, noted, this reflects exceptional navigation performance throughout the mission. The crew — Commander Reid Wiseman, Pilot Victor Glover, Mission Specialist Christina Koch, and CSA astronaut Jeremy Hansen — spent Day 3 on medical readiness drills, practising CPR in weightlessness and checking out the spacecraft's medical equipment. They also successfully tested Orion's optical communications system, transmitting HD video back to Earth from deep space. On Monday, April 6th, Orion will swing around the lunar far side at its closest approach — briefly out of radio contact with Earth — and at the mission's farthest point will travel 252,757 miles from home. That breaks the human spaceflight distance record set by Apollo 13 in 1970. Fifty-six years. We're finally going further. Comet MAPS: The Solar Plunge Is Done — Now Comes the Wait At 14:22 UTC on April 4th, Comet C/2026 A1 (MAPS) reached perihelion — passing just 161,000 kilometres from the surface of the Sun, skimming through the lower solar corona. Whether it survived that encounter is still being determined from spacecraft imagery, as the comet remains in the Sun's glare for ground-based observers. If MAPS emerges intact, the Southern Hemisphere viewing window opens April 6th to 10th. Look west after sunset, low on the horizon, near Venus. Brightness predictions range from magnitude -5 (comparable to Venus) to extraordinary scenarios even brighter. Even a nucleus breakup could leave a spectacular dust tail — what's known as a 'headless wonder.' Either way, this story is not over. Atlas V Sets a Record: 29 Amazon Leo Satellites, Heaviest Payload Ever At 1:45 a.m. Eastern Time on April 4th, a ULA Atlas V 551 lifted off from Cape Canaveral carrying 29 Amazon Leo satellites — the heaviest payload in the rocket's 102-mission history. Mission LA-05 continues Amazon's build-out of its 3,200-satellite internet constellation (formerly Project Kuiper), with around 241 satellites now on orbit. Amazon faces an FCC deadline to have half its constellation operational by July 2026. Blue Ghost Challenges a Fundamental View of the Moon New data from Firefly Aerospace's Blue Ghost lander — which operated on the lunar surface for two weeks in March 2025 — is shaking up decades of lunar science. Scientists expected Blue Ghost's landing site at Mare Crisium, well outside the Moon's 'hot zone,' to show significantly cooler interior temperatures than Apollo landing sites. It didn't. The near-side/far-side temperature divide may be far less pronounced than previously thought, suggesting heat-producing elements are more widely distributed beneath the surface. 'We may have to abandon that binary,' said principal investigator Seiichi Nagihara. Pulsars Broadcast Further Than Anyone Knew — With Australian Science Behind the Discovery A study led by Professor Michael Kramer (Max Planck Institute) and Dr Simon Johnston (CSIRO) has found that about one third of millisecond pulsars emit radio waves from two completely separate regions — including a distant zone at the very edge of their magnetic reach called the current sheet. This overturns decades of received wisdom and suggests pulsars should be detectable from a wider range of directions than previously thought — with implications for gravitational wave detection using pulsar timing arrays. Mercury Is at Its Best All Year — And Southern Hemisphere Skywatchers Win Mercury reached greatest western elongation on April 3rd — the year's best opportunity to see the innermost planet. From Australia and New Zealand, this is specifically the best morning apparition of Mercury in 2026. Look east about 30-40 minutes before sunrise for a steady point of light at around magnitude 0.4, just above Mars. Through binoculars or a small telescope, Mercury is currently showing a half-illuminated quarter phase. And on April 18th, Mercury, Saturn, Mars, and Neptune will gather in a tight morning-sky cluster — three of them visible to the naked eye.
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Language: en
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Welcome back to Astronomy Daily, the
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show that gets you caught up on the
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cosmos every single day. I'm Anna.
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>> And I'm Avery. And friends, what a day
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to be a space fan.
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>> It is day three of the Aremis 2 mission.
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Four humans are right now hurdling
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toward the moon, and we have a lot to
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cover. A record-breaking rocket launch,
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brand new lunar science, a stunning
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discovery about dead stars, and the best
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chance all year to spot the planet
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Mercury with your naked eye.
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>> Plus, we promised you an update on comet
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maps yesterday, and we are delivering.
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The solar plunge has happened. The
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verdict is still coming in. Stay with
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us.
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>> Let's get into it.
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>> Trajectory so perfect, NASA canled its
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own burn. We are now into day three of
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the Aremis 2 mission and the headline
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today is honestly almost too good to
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believe. NASA had planned a trajectory
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correction burn for this evening. A
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small engine firing to nudge Orion onto
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the perfect path to the moon and they
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didn't need it.
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>> Flight controllers in mission control at
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Johnson Space Center looked at the data
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and made the call. Cancel the burn.
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Orion is already on the precise
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trajectory it needs. As Howard Hu, the
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Orion spacecraft program manager put it,
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"It's really good to see that we don't
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need these minor correction burns. It
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shows that our navigation performance
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and our ability to get ranging has been
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outstanding." This was the first of
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three planned trajectory correction
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burns. The others are still on the
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schedule if needed, but this is a
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genuine vote of confidence in the
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precision of the entire mission so far.
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Meanwhile, what were Reed Wiseman,
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Victor Glover, Christina and
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Jeremy Hansen actually doing today?
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Mission control woke them up playing in
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a Daydream by the Freddy Jones band,
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which is a great alarm clock choice. And
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then they got to work.
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>> Day three was all about medical
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readiness. The crew demonstrated CPR
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procedures in weightlessness and checked
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out Orion's on board medical kit, a
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thermometer, blood pressure monitor, a
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stethoscope, and odoscope. They also
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tested Orion's optical communication
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system, successfully transmitting
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highdefinition video back to ground
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stations in the United States.
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>> But the really exciting part, the lunar
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science team back on Earth is already
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building what they call the lunar
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targeting plan. They're selecting
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specific geological features on the
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moon's surface. craters, ancient lava
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flows, ridges that the crew will observe
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and photograph during their 6-h hour
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flyby window on Monday.
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>> And Avery has been doing the math on
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what Monday actually means.
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>> Well, it's history. On Monday, April
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6th, the Aremis 2 crew will swing around
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the far side of the moon, briefly out of
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contact with Earth entirely. And at
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their farthest point, they will be
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252,757
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mi from home. That breaks the all-time
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human spaceflight distance record set by
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the crew of Apollo 13 back in April
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1970. 56 years. We've been waiting 56
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years to break that record.
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>> And it gets better. During the lunar
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flyby, Orion will enter a solar eclipse,
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the sun moving behind the moon from the
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crew's perspective. The crew will use
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that window to look for meteoroid
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impacts flashing on the lunar surface
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and to try to photograph the deep space
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sky without the sun in the way.
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>> We'll have full day four and Monday
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flyby coverage in Monday's episode.
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Right now, four humans traveling toward
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the moon and everything is going exactly
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to plan.
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>> Next, the solar plunge has happened. Now
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we wait.
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>> All right, we promise you this and here
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it is. Your comet maps update. Yesterday
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we introduced you to comet C 2026A1
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known as MAPS, a rare CO sungrazer
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discovered in January by a team of
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French astronomers in Chile. We told you
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it was about to make one of the most
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dangerous journeys in the solar system,
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a pass within 161,000 km of the sun's
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surface, closer than most comets ever
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come. And we promise to bring you the
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latest today. So, here's where we are.
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At 14:22 UTC today, that's right in the
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middle of the day in Australia. Comet
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maps reached perihelion. It passed
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through the lower corona of the sun. The
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plunge is done.
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>> And the verdict? That is genuinely still
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coming in because right now, MAPS is in
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the sun's glare, basically invisible to
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groundbased observers. We're relying on
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spacecraft imagery, particularly from
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SOHO's Lasco Coronograph to track what
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happened.
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>> The big question has shifted. It's no
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longer just did it survive. It's what
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kind of show will it put on? There are
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several scenarios. If the nucleus
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survived intact, maps could emerge in
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the next day or two as a stunning naked
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eye comet. Some predictions put its
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potential brightness at magnitude
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minus5.
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brighter than Venus. Others suggest it
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could reach magnitude minus15,
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brighter than the full moon. At
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perihelion, it may have even been
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briefly visible in daylight.
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>> Even if the nucleus broke apart, which
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is what happens to most sun grazers, the
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story isn't necessarily over. A
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post-parelion breakup can produce what
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astronomers call a headless wonder, a
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bright glowing tail with no nucleus
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behind it. Sometimes those can be
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spectacular in their own right.
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>> Maps belongs to the Crutz sun graaser
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family, the same family as comet Ikea in
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1965.
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One of the brightest comets of the 20th
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century and comet Lovejoy in 2011, which
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survived its own brush with the corona
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and went on to dazzle southern
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hemisphere observers.
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>> And that is the key phrase, southern
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hemisphere. If maps emerges from the
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glare as expected, the window to see it
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from the ground opens around April 6th
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to 10th. Look west after sunset low on
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the horizon. In Australia and across New
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Zealand, you are perfectly placed for
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this. Venus will be your guide star,
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bright in the western evening sky, and
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maps, if it survived, should appear
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nearby.
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>> We will have the latest on Monday's
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episode. This story is very much not
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over. Atlas 5 lifts its heaviest payload
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ever, 29 Amazon LEO satellites.
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>> While all eyes were on the moon this
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morning, there was a rocket launch
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happening simultaneously that set a
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record of its own.
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>> In the early hours of this morning, 1:45
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a.m. Eastern time, a United Launch
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Alliance Atlas 5 rocket lifted off from
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Cape Canaveral Space Force Station in
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Florida. Its cargo, 29 Amazon LEO
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satellites. And that payload, 29
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satellites packed into one rocket, made
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history. It is the heaviest single
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payload the Atlas 5 has ever flown.
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>> This is mission LA05 for Amazon LEO, the
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satellite internet constellation
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previously known as Project Cooper.
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Amazon renamed the constellation in
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November last year, and they're building
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it at pace. With today's launch, they
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now have around 241 satellites on orbit
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out of an eventual constellation of more
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than 3,200.
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The Atlas 5 flew in its most powerful
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configuration, the 551 variant with five
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solid rocket boosters strapped on, and
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ULA engineers made specific
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modifications to the Centaur upper stage
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and its dispenser system to carry the
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extra load. These 29 satellites went up
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on a northeast trajectory to a low Earth
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orbit of around 450 km. Amazon has an
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FCC deadline looming. They need to have
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half of their constellation operational
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by July 2026, which puts them in a
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serious race. Multiple Atlas 5 and
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Vulcan Centaur launches are planned this
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year. Plus, missions on Aron 6, New
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Glenn, and Falcon 9. The Atlas 5 is one
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of the most reliable rockets ever built.
00:08:26.960 --> 00:08:29.670
This was its 102nd mission. And while
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the Vulcan Centaur is taking over as the
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primary heavy lift vehicle going
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forward, today proved the old workhorse
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has still got it.
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>> Okay, our next story. Moon's hot cold
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divide may be wrong. Blue Ghost rewrites
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lunar science. With the Aremis 2 crew
00:08:47.440 --> 00:08:49.430
heading toward the moon right now, this
00:08:49.440 --> 00:08:51.829
next story feels especially timely
00:08:51.839 --> 00:08:53.750
because new data from the moon's surface
00:08:53.760 --> 00:08:55.750
is challenging something scientists
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thought they understood for decades. A
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Firefly Aerospace's Blue Ghost lander
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touched down in the moon's Mari
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Chrysium, the Sea of Crises, back in
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March of 2025. It operated for a full
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lunar day, drilling into the surface and
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sending back over 110 gigabytes of data.
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And now a year on, scientists are
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presenting the first major scientific
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results. And they are surprising.
00:09:20.399 --> 00:09:22.389
>> The long-standing view of the moon has
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been this. The near side, the face we
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always see from Earth, is geologically
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hot. It's dominated by ancient volcanic
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plains. And beneath the surface, there's
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a concentration of heat producing
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radioactive elements, particularly
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thorium, in a region called the
00:09:40.320 --> 00:09:43.430
Proellarum creep terrain. The far side
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by contrast is cooler, older, more
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heavily cratered.
00:09:47.920 --> 00:09:50.470
>> Blue ghost was specifically sent to land
00:09:50.480 --> 00:09:53.509
outside that hot region and marchium
00:09:53.519 --> 00:09:56.150
well away from the creep zone precisely
00:09:56.160 --> 00:09:57.670
to test whether the temperature
00:09:57.680 --> 00:09:59.910
difference was as dramatic as scientists
00:09:59.920 --> 00:10:02.790
expected. The answer has upended the
00:10:02.800 --> 00:10:05.829
model. Lugos's heat probe found that the
00:10:05.839 --> 00:10:08.310
underground temperature at Mari Chrysium
00:10:08.320 --> 00:10:10.550
is not significantly different from what
00:10:10.560 --> 00:10:12.470
Apollo astronauts measured at their
00:10:12.480 --> 00:10:15.110
landing sites deep inside the supposed
00:10:15.120 --> 00:10:15.990
hot zone.
00:10:16.000 --> 00:10:18.870
>> As Seichi Nagihara, the principal
00:10:18.880 --> 00:10:21.350
investigator of Blue Ghost's heat probe
00:10:21.360 --> 00:10:24.310
at Texas Tech University put it, "We may
00:10:24.320 --> 00:10:26.150
have to abandon that binary."
00:10:26.160 --> 00:10:28.150
>> What does this mean? Heat producing
00:10:28.160 --> 00:10:30.710
elements like thorium may be more widely
00:10:30.720 --> 00:10:32.470
distributed beneath the lunar surface
00:10:32.480 --> 00:10:35.030
than anyone thought. And one possible
00:10:35.040 --> 00:10:37.350
explanation is that volcanic activity in
00:10:37.360 --> 00:10:39.430
some regions wasn't driven by those
00:10:39.440 --> 00:10:41.829
radioactive elements at all. It may have
00:10:41.839 --> 00:10:43.910
simply been easier for magma to break
00:10:43.920 --> 00:10:45.670
through in places where the crust was
00:10:45.680 --> 00:10:46.310
thinner.
00:10:46.320 --> 00:10:48.710
>> It's a fundamental rethink of how the
00:10:48.720 --> 00:10:51.350
moon formed and evolved. And it has
00:10:51.360 --> 00:10:53.509
direct implications for where future
00:10:53.519 --> 00:10:55.750
crude missions might land and what
00:10:55.760 --> 00:10:57.030
they'll find.
00:10:57.040 --> 00:10:59.829
Blue Ghost Mission 2, expected to launch
00:10:59.839 --> 00:11:02.310
later this year, will land on the lunar
00:11:02.320 --> 00:11:04.870
far side, giving scientists the next
00:11:04.880 --> 00:11:07.190
data point in this evolving picture.
00:11:07.200 --> 00:11:09.590
>> Onwards the story five. Let's simply
00:11:09.600 --> 00:11:12.790
call this one stellar science. Pulsars
00:11:12.800 --> 00:11:14.710
are broadcasting from the edge of their
00:11:14.720 --> 00:11:17.670
magnetic reach. Now to a discovery that
00:11:17.680 --> 00:11:20.550
overturns decades of thinking about some
00:11:20.560 --> 00:11:22.949
of the most extreme objects in the
00:11:22.959 --> 00:11:25.430
universe and it has an Australian
00:11:25.440 --> 00:11:26.870
fingerprint on it.
00:11:26.880 --> 00:11:29.590
>> Pulsars are the collaps remnants of dead
00:11:29.600 --> 00:11:32.150
stars. They're among the densest objects
00:11:32.160 --> 00:11:34.550
we know of. A teaspoon of pulsar
00:11:34.560 --> 00:11:36.949
material would weigh around 10 million
00:11:36.959 --> 00:11:40.310
tons on Earth. As they spin, they sweep
00:11:40.320 --> 00:11:42.790
beams of radio waves across the cosmos
00:11:42.800 --> 00:11:45.590
like cosmic lighouses. And a special
00:11:45.600 --> 00:11:48.710
class called millisecond pulsars spins
00:11:48.720 --> 00:11:51.350
hundreds of times per second. So
00:11:51.360 --> 00:11:53.829
regularly that they rival atomic clocks
00:11:53.839 --> 00:11:55.110
in their precision.
00:11:55.120 --> 00:11:57.350
>> For decades, the textbook answer to
00:11:57.360 --> 00:11:59.590
where those radio pulses come from was
00:11:59.600 --> 00:12:01.990
simple. Near the surface, close to the
00:12:02.000 --> 00:12:04.470
magnetic poles. That's where scientists
00:12:04.480 --> 00:12:06.470
assumed all the action happened.
00:12:06.480 --> 00:12:08.870
>> A new study published in monthly notices
00:12:08.880 --> 00:12:11.350
of the Royal Astronomical Society has
00:12:11.360 --> 00:12:13.750
just rewritten that. Professor Michael
00:12:13.760 --> 00:12:15.910
Kramer from the Maxplank Institute for
00:12:15.920 --> 00:12:18.389
Radio Aastronomy in Germany and Dr.
00:12:18.399 --> 00:12:22.069
Simon Johnson from Australia's own CSRO
00:12:22.079 --> 00:12:24.710
analyzed radio observations of nearly
00:12:24.720 --> 00:12:27.670
200 millisecond pulsars and compared
00:12:27.680 --> 00:12:29.829
them with gammaray data from NASA's
00:12:29.839 --> 00:12:31.350
Fermy Space Telescope.
00:12:31.360 --> 00:12:34.710
>> What they found about 1/3 of millisecond
00:12:34.720 --> 00:12:37.269
pulsars are broadcasting radio waves
00:12:37.279 --> 00:12:39.910
from two completely separate regions at
00:12:39.920 --> 00:12:42.949
once. not just the magnetic poles, but
00:12:42.959 --> 00:12:45.509
also from a distant swirling zone of
00:12:45.519 --> 00:12:47.829
charged particles called the current
00:12:47.839 --> 00:12:50.230
sheet, right at what's called the light
00:12:50.240 --> 00:12:52.710
cylinder. That's the boundary where the
00:12:52.720 --> 00:12:55.190
pulsar's magnetic field would need to
00:12:55.200 --> 00:12:57.509
travel faster than light just to keep
00:12:57.519 --> 00:12:59.030
pace with the spinning star.
00:12:59.040 --> 00:13:01.910
>> As Dr. Johnston put it, these tiny, fast
00:13:01.920 --> 00:13:04.389
spinning stars are even more complex and
00:13:04.399 --> 00:13:06.629
surprising than we thought. broadcasting
00:13:06.639 --> 00:13:08.949
from both their surfaces and from the
00:13:08.959 --> 00:13:11.110
very edge of their magnetic reach.
00:13:11.120 --> 00:13:13.430
>> The practical consequences are
00:13:13.440 --> 00:13:16.069
significant because the radio signals
00:13:16.079 --> 00:13:18.629
are spreading out over a wider range of
00:13:18.639 --> 00:13:21.350
directions than previously understood.
00:13:21.360 --> 00:13:23.750
More pulsars should be detectable than
00:13:23.760 --> 00:13:26.310
scientists thought. And that's good news
00:13:26.320 --> 00:13:29.269
for projects like pulsar timing arrays,
00:13:29.279 --> 00:13:32.230
networks of pulsars used as detectors
00:13:32.240 --> 00:13:35.110
for gravitational waves rippling across
00:13:35.120 --> 00:13:36.550
the universe.
00:13:36.560 --> 00:13:38.629
>> A great piece of science and a proud
00:13:38.639 --> 00:13:41.750
moment for CSRO, Australia's National
00:13:41.760 --> 00:13:43.269
Science Agency.
00:13:43.279 --> 00:13:46.230
>> And finally today, an invitation to go
00:13:46.240 --> 00:13:49.350
outside and look up because right now
00:13:49.360 --> 00:13:51.590
Mercury is putting on its best
00:13:51.600 --> 00:13:54.550
performance of the entire year. and we
00:13:54.560 --> 00:13:56.949
have the best seats in the house.
00:13:56.959 --> 00:13:59.189
>> Mercury reached what astronomers call
00:13:59.199 --> 00:14:02.150
greatest elongation on April 3rd, the
00:14:02.160 --> 00:14:03.910
point where it appears farthest from the
00:14:03.920 --> 00:14:06.470
sun in our sky. This is the year's
00:14:06.480 --> 00:14:08.710
greatest elongation for Mercury. Full
00:14:08.720 --> 00:14:12.629
stop. The best it will get all of 2026.
00:14:12.639 --> 00:14:15.430
Here's the key thing about Mercury. It's
00:14:15.440 --> 00:14:17.750
always close to the sun in our sky,
00:14:17.760 --> 00:14:19.910
which makes it genuinely difficult to
00:14:19.920 --> 00:14:22.629
spot. Most people have never actually
00:14:22.639 --> 00:14:25.670
seen it. Greatest elongation is your
00:14:25.680 --> 00:14:28.389
best window. The planet pulls as far
00:14:28.399 --> 00:14:30.949
from the sun's glare as it ever gets,
00:14:30.959 --> 00:14:33.509
giving you a brief, clear opportunity
00:14:33.519 --> 00:14:35.509
before it slips back.
00:14:35.519 --> 00:14:38.470
>> Right now, Mercury is sitting about 28°
00:14:38.480 --> 00:14:41.030
from the sun, rising in the eastern sky
00:14:41.040 --> 00:14:44.069
before dawn. Look east about 30 to 40
00:14:44.079 --> 00:14:46.230
minutes before sunrise. You're looking
00:14:46.240 --> 00:14:48.550
for a steady point of light, magnitude
00:14:48.560 --> 00:14:50.710
around 0.4, four, which is bright enough
00:14:50.720 --> 00:14:52.870
to see with the naked eye under decent
00:14:52.880 --> 00:14:54.870
conditions. It's sitting low on the
00:14:54.880 --> 00:14:56.870
horizon just above Mars in the
00:14:56.880 --> 00:14:58.870
constellation Aquarius.
00:14:58.880 --> 00:15:01.030
>> And here's the southern hemisphere
00:15:01.040 --> 00:15:04.230
advantage. This is specifically the best
00:15:04.240 --> 00:15:06.470
morning apparition of Mercury for the
00:15:06.480 --> 00:15:09.350
southern hemisphere in 2026 from
00:15:09.360 --> 00:15:11.910
Australia and New Zealand. The geometry
00:15:11.920 --> 00:15:14.629
of the ecliptic gives us a steeper angle
00:15:14.639 --> 00:15:17.269
to the horizon. Mercury climbs higher
00:15:17.279 --> 00:15:19.750
and stays out of the Merc longer than it
00:15:19.760 --> 00:15:22.470
does for northern hemisphere observers.
00:15:22.480 --> 00:15:24.230
>> If you have binoculars or a small
00:15:24.240 --> 00:15:26.949
telescope, there's a bonus. Mercury is
00:15:26.959 --> 00:15:28.949
currently showing a half illuminated
00:15:28.959 --> 00:15:31.350
face, what astronomers call a quarter
00:15:31.360 --> 00:15:33.269
phase. You can see it going through
00:15:33.279 --> 00:15:35.189
phases just like the moon, which is
00:15:35.199 --> 00:15:37.030
something a lot of people don't realize
00:15:37.040 --> 00:15:39.670
about Mercury. And keep watching the
00:15:39.680 --> 00:15:41.750
eastern sky over the next couple of
00:15:41.760 --> 00:15:45.110
weeks because Mercury, Mars, Saturn, and
00:15:45.120 --> 00:15:47.829
Neptune will gather in a tight cluster
00:15:47.839 --> 00:15:50.550
on the morning of April 18th. Three of
00:15:50.560 --> 00:15:52.550
those four will be visible to the naked
00:15:52.560 --> 00:15:54.790
eye, close enough to cover with three
00:15:54.800 --> 00:15:57.430
fingers held at arms length. A lovely
00:15:57.440 --> 00:16:00.310
little planetary alignment to chase.
00:16:00.320 --> 00:16:02.710
>> So this week, look east before sunrise
00:16:02.720 --> 00:16:05.670
for Mercury. Look west after sunset for
00:16:05.680 --> 00:16:07.990
any sign of comet maps emerging from the
00:16:08.000 --> 00:16:10.389
sun's glare. And keep an eye on Monday's
00:16:10.399 --> 00:16:12.230
episode for everything you need to know
00:16:12.240 --> 00:16:15.430
about the Aremis 2 lunar flyby. And that
00:16:15.440 --> 00:16:18.310
is your Astronomy Daily for Saturday the
00:16:18.320 --> 00:16:22.230
5th of April 2026. A crew heading to the
00:16:22.240 --> 00:16:24.949
moon. A comet that may be putting on the
00:16:24.959 --> 00:16:26.870
sky show of the decade. A
00:16:26.880 --> 00:16:29.269
record-breaking rocket launch. Science
00:16:29.279 --> 00:16:31.509
from the lunar surface. A pulsar
00:16:31.519 --> 00:16:34.230
discovery out of Australia. and Mercury
00:16:34.240 --> 00:16:36.310
waiting for you in the dawn sky.
00:16:36.320 --> 00:16:38.310
>> We'll be back Monday with day four and
00:16:38.320 --> 00:16:40.870
five of Artemis 2 and the latest on
00:16:40.880 --> 00:16:43.189
comet maps. If you're heading outside
00:16:43.199 --> 00:16:45.030
tonight, clear skies everyone.
00:16:45.040 --> 00:16:47.189
>> From all of us at Astronomy Daily, keep
00:16:47.199 --> 00:16:51.430
looking up. Astronomy day.
00:16:51.440 --> 00:16:59.430
Stories told.
00:16:59.440 --> 00:17:03.160
Stories to tell.
Kind: captions
Language: en
00:00:00.320 --> 00:00:02.550
Welcome back to Astronomy Daily, the
00:00:02.560 --> 00:00:04.070
show that gets you caught up on the
00:00:04.080 --> 00:00:06.869
cosmos every single day. I'm Anna.
00:00:06.879 --> 00:00:09.270
>> And I'm Avery. And friends, what a day
00:00:09.280 --> 00:00:10.709
to be a space fan.
00:00:10.719 --> 00:00:13.669
>> It is day three of the Aremis 2 mission.
00:00:13.679 --> 00:00:16.070
Four humans are right now hurdling
00:00:16.080 --> 00:00:18.310
toward the moon, and we have a lot to
00:00:18.320 --> 00:00:21.189
cover. A record-breaking rocket launch,
00:00:21.199 --> 00:00:24.070
brand new lunar science, a stunning
00:00:24.080 --> 00:00:27.269
discovery about dead stars, and the best
00:00:27.279 --> 00:00:29.109
chance all year to spot the planet
00:00:29.119 --> 00:00:31.349
Mercury with your naked eye.
00:00:31.359 --> 00:00:33.510
>> Plus, we promised you an update on comet
00:00:33.520 --> 00:00:35.750
maps yesterday, and we are delivering.
00:00:35.760 --> 00:00:38.069
The solar plunge has happened. The
00:00:38.079 --> 00:00:39.910
verdict is still coming in. Stay with
00:00:39.920 --> 00:00:40.790
us.
00:00:40.800 --> 00:00:42.150
>> Let's get into it.
00:00:42.160 --> 00:00:44.950
>> Trajectory so perfect, NASA canled its
00:00:44.960 --> 00:00:47.670
own burn. We are now into day three of
00:00:47.680 --> 00:00:49.750
the Aremis 2 mission and the headline
00:00:49.760 --> 00:00:52.389
today is honestly almost too good to
00:00:52.399 --> 00:00:54.869
believe. NASA had planned a trajectory
00:00:54.879 --> 00:00:57.110
correction burn for this evening. A
00:00:57.120 --> 00:00:59.830
small engine firing to nudge Orion onto
00:00:59.840 --> 00:01:02.229
the perfect path to the moon and they
00:01:02.239 --> 00:01:03.110
didn't need it.
00:01:03.120 --> 00:01:04.950
>> Flight controllers in mission control at
00:01:04.960 --> 00:01:06.950
Johnson Space Center looked at the data
00:01:06.960 --> 00:01:10.070
and made the call. Cancel the burn.
00:01:10.080 --> 00:01:11.910
Orion is already on the precise
00:01:11.920 --> 00:01:14.630
trajectory it needs. As Howard Hu, the
00:01:14.640 --> 00:01:17.270
Orion spacecraft program manager put it,
00:01:17.280 --> 00:01:19.190
"It's really good to see that we don't
00:01:19.200 --> 00:01:21.270
need these minor correction burns. It
00:01:21.280 --> 00:01:22.950
shows that our navigation performance
00:01:22.960 --> 00:01:25.350
and our ability to get ranging has been
00:01:25.360 --> 00:01:27.510
outstanding." This was the first of
00:01:27.520 --> 00:01:29.510
three planned trajectory correction
00:01:29.520 --> 00:01:31.510
burns. The others are still on the
00:01:31.520 --> 00:01:33.510
schedule if needed, but this is a
00:01:33.520 --> 00:01:35.350
genuine vote of confidence in the
00:01:35.360 --> 00:01:38.149
precision of the entire mission so far.
00:01:38.159 --> 00:01:40.149
Meanwhile, what were Reed Wiseman,
00:01:40.159 --> 00:01:42.310
Victor Glover, Christina and
00:01:42.320 --> 00:01:44.950
Jeremy Hansen actually doing today?
00:01:44.960 --> 00:01:46.950
Mission control woke them up playing in
00:01:46.960 --> 00:01:49.350
a Daydream by the Freddy Jones band,
00:01:49.360 --> 00:01:51.590
which is a great alarm clock choice. And
00:01:51.600 --> 00:01:52.950
then they got to work.
00:01:52.960 --> 00:01:54.950
>> Day three was all about medical
00:01:54.960 --> 00:01:57.590
readiness. The crew demonstrated CPR
00:01:57.600 --> 00:01:59.749
procedures in weightlessness and checked
00:01:59.759 --> 00:02:02.230
out Orion's on board medical kit, a
00:02:02.240 --> 00:02:04.469
thermometer, blood pressure monitor, a
00:02:04.479 --> 00:02:07.030
stethoscope, and odoscope. They also
00:02:07.040 --> 00:02:09.270
tested Orion's optical communication
00:02:09.280 --> 00:02:11.510
system, successfully transmitting
00:02:11.520 --> 00:02:13.670
highdefinition video back to ground
00:02:13.680 --> 00:02:15.589
stations in the United States.
00:02:15.599 --> 00:02:18.229
>> But the really exciting part, the lunar
00:02:18.239 --> 00:02:20.550
science team back on Earth is already
00:02:20.560 --> 00:02:22.309
building what they call the lunar
00:02:22.319 --> 00:02:24.309
targeting plan. They're selecting
00:02:24.319 --> 00:02:26.470
specific geological features on the
00:02:26.480 --> 00:02:29.430
moon's surface. craters, ancient lava
00:02:29.440 --> 00:02:32.070
flows, ridges that the crew will observe
00:02:32.080 --> 00:02:34.309
and photograph during their 6-h hour
00:02:34.319 --> 00:02:36.070
flyby window on Monday.
00:02:36.080 --> 00:02:38.229
>> And Avery has been doing the math on
00:02:38.239 --> 00:02:40.550
what Monday actually means.
00:02:40.560 --> 00:02:43.030
>> Well, it's history. On Monday, April
00:02:43.040 --> 00:02:45.509
6th, the Aremis 2 crew will swing around
00:02:45.519 --> 00:02:48.070
the far side of the moon, briefly out of
00:02:48.080 --> 00:02:50.390
contact with Earth entirely. And at
00:02:50.400 --> 00:02:52.150
their farthest point, they will be
00:02:52.160 --> 00:02:55.990
252,757
00:02:56.000 --> 00:02:58.790
mi from home. That breaks the all-time
00:02:58.800 --> 00:03:01.110
human spaceflight distance record set by
00:03:01.120 --> 00:03:04.229
the crew of Apollo 13 back in April
00:03:04.239 --> 00:03:08.790
1970. 56 years. We've been waiting 56
00:03:08.800 --> 00:03:10.790
years to break that record.
00:03:10.800 --> 00:03:13.110
>> And it gets better. During the lunar
00:03:13.120 --> 00:03:16.309
flyby, Orion will enter a solar eclipse,
00:03:16.319 --> 00:03:18.790
the sun moving behind the moon from the
00:03:18.800 --> 00:03:21.030
crew's perspective. The crew will use
00:03:21.040 --> 00:03:22.949
that window to look for meteoroid
00:03:22.959 --> 00:03:25.270
impacts flashing on the lunar surface
00:03:25.280 --> 00:03:27.750
and to try to photograph the deep space
00:03:27.760 --> 00:03:29.750
sky without the sun in the way.
00:03:29.760 --> 00:03:31.670
>> We'll have full day four and Monday
00:03:31.680 --> 00:03:34.070
flyby coverage in Monday's episode.
00:03:34.080 --> 00:03:36.630
Right now, four humans traveling toward
00:03:36.640 --> 00:03:39.509
the moon and everything is going exactly
00:03:39.519 --> 00:03:40.710
to plan.
00:03:40.720 --> 00:03:43.670
>> Next, the solar plunge has happened. Now
00:03:43.680 --> 00:03:44.630
we wait.
00:03:44.640 --> 00:03:46.630
>> All right, we promise you this and here
00:03:46.640 --> 00:03:49.830
it is. Your comet maps update. Yesterday
00:03:49.840 --> 00:03:53.910
we introduced you to comet C 2026A1
00:03:53.920 --> 00:03:57.110
known as MAPS, a rare CO sungrazer
00:03:57.120 --> 00:03:59.190
discovered in January by a team of
00:03:59.200 --> 00:04:01.910
French astronomers in Chile. We told you
00:04:01.920 --> 00:04:03.830
it was about to make one of the most
00:04:03.840 --> 00:04:06.390
dangerous journeys in the solar system,
00:04:06.400 --> 00:04:10.630
a pass within 161,000 km of the sun's
00:04:10.640 --> 00:04:13.350
surface, closer than most comets ever
00:04:13.360 --> 00:04:15.670
come. And we promise to bring you the
00:04:15.680 --> 00:04:18.789
latest today. So, here's where we are.
00:04:18.799 --> 00:04:22.710
At 14:22 UTC today, that's right in the
00:04:22.720 --> 00:04:25.110
middle of the day in Australia. Comet
00:04:25.120 --> 00:04:27.909
maps reached perihelion. It passed
00:04:27.919 --> 00:04:30.710
through the lower corona of the sun. The
00:04:30.720 --> 00:04:32.469
plunge is done.
00:04:32.479 --> 00:04:35.670
>> And the verdict? That is genuinely still
00:04:35.680 --> 00:04:38.469
coming in because right now, MAPS is in
00:04:38.479 --> 00:04:41.110
the sun's glare, basically invisible to
00:04:41.120 --> 00:04:43.670
groundbased observers. We're relying on
00:04:43.680 --> 00:04:45.990
spacecraft imagery, particularly from
00:04:46.000 --> 00:04:48.870
SOHO's Lasco Coronograph to track what
00:04:48.880 --> 00:04:49.830
happened.
00:04:49.840 --> 00:04:52.070
>> The big question has shifted. It's no
00:04:52.080 --> 00:04:55.670
longer just did it survive. It's what
00:04:55.680 --> 00:04:58.469
kind of show will it put on? There are
00:04:58.479 --> 00:05:00.629
several scenarios. If the nucleus
00:05:00.639 --> 00:05:03.430
survived intact, maps could emerge in
00:05:03.440 --> 00:05:05.909
the next day or two as a stunning naked
00:05:05.919 --> 00:05:08.390
eye comet. Some predictions put its
00:05:08.400 --> 00:05:10.629
potential brightness at magnitude
00:05:10.639 --> 00:05:12.150
minus5.
00:05:12.160 --> 00:05:15.110
brighter than Venus. Others suggest it
00:05:15.120 --> 00:05:17.909
could reach magnitude minus15,
00:05:17.919 --> 00:05:19.830
brighter than the full moon. At
00:05:19.840 --> 00:05:21.830
perihelion, it may have even been
00:05:21.840 --> 00:05:23.670
briefly visible in daylight.
00:05:23.680 --> 00:05:25.749
>> Even if the nucleus broke apart, which
00:05:25.759 --> 00:05:28.390
is what happens to most sun grazers, the
00:05:28.400 --> 00:05:30.870
story isn't necessarily over. A
00:05:30.880 --> 00:05:33.430
post-parelion breakup can produce what
00:05:33.440 --> 00:05:36.469
astronomers call a headless wonder, a
00:05:36.479 --> 00:05:38.790
bright glowing tail with no nucleus
00:05:38.800 --> 00:05:41.029
behind it. Sometimes those can be
00:05:41.039 --> 00:05:43.110
spectacular in their own right.
00:05:43.120 --> 00:05:45.670
>> Maps belongs to the Crutz sun graaser
00:05:45.680 --> 00:05:49.270
family, the same family as comet Ikea in
00:05:49.280 --> 00:05:50.870
1965.
00:05:50.880 --> 00:05:52.950
One of the brightest comets of the 20th
00:05:52.960 --> 00:05:56.790
century and comet Lovejoy in 2011, which
00:05:56.800 --> 00:05:59.110
survived its own brush with the corona
00:05:59.120 --> 00:06:00.950
and went on to dazzle southern
00:06:00.960 --> 00:06:02.550
hemisphere observers.
00:06:02.560 --> 00:06:05.430
>> And that is the key phrase, southern
00:06:05.440 --> 00:06:07.830
hemisphere. If maps emerges from the
00:06:07.840 --> 00:06:10.070
glare as expected, the window to see it
00:06:10.080 --> 00:06:12.390
from the ground opens around April 6th
00:06:12.400 --> 00:06:15.670
to 10th. Look west after sunset low on
00:06:15.680 --> 00:06:18.230
the horizon. In Australia and across New
00:06:18.240 --> 00:06:20.550
Zealand, you are perfectly placed for
00:06:20.560 --> 00:06:22.629
this. Venus will be your guide star,
00:06:22.639 --> 00:06:25.029
bright in the western evening sky, and
00:06:25.039 --> 00:06:27.189
maps, if it survived, should appear
00:06:27.199 --> 00:06:28.230
nearby.
00:06:28.240 --> 00:06:30.150
>> We will have the latest on Monday's
00:06:30.160 --> 00:06:32.790
episode. This story is very much not
00:06:32.800 --> 00:06:36.230
over. Atlas 5 lifts its heaviest payload
00:06:36.240 --> 00:06:39.830
ever, 29 Amazon LEO satellites.
00:06:39.840 --> 00:06:41.749
>> While all eyes were on the moon this
00:06:41.759 --> 00:06:43.430
morning, there was a rocket launch
00:06:43.440 --> 00:06:45.670
happening simultaneously that set a
00:06:45.680 --> 00:06:46.790
record of its own.
00:06:46.800 --> 00:06:49.909
>> In the early hours of this morning, 1:45
00:06:49.919 --> 00:06:52.550
a.m. Eastern time, a United Launch
00:06:52.560 --> 00:06:55.590
Alliance Atlas 5 rocket lifted off from
00:06:55.600 --> 00:06:57.909
Cape Canaveral Space Force Station in
00:06:57.919 --> 00:07:01.749
Florida. Its cargo, 29 Amazon LEO
00:07:01.759 --> 00:07:04.629
satellites. And that payload, 29
00:07:04.639 --> 00:07:07.510
satellites packed into one rocket, made
00:07:07.520 --> 00:07:09.830
history. It is the heaviest single
00:07:09.840 --> 00:07:12.870
payload the Atlas 5 has ever flown.
00:07:12.880 --> 00:07:17.029
>> This is mission LA05 for Amazon LEO, the
00:07:17.039 --> 00:07:19.189
satellite internet constellation
00:07:19.199 --> 00:07:21.990
previously known as Project Cooper.
00:07:22.000 --> 00:07:24.230
Amazon renamed the constellation in
00:07:24.240 --> 00:07:26.309
November last year, and they're building
00:07:26.319 --> 00:07:28.950
it at pace. With today's launch, they
00:07:28.960 --> 00:07:32.710
now have around 241 satellites on orbit
00:07:32.720 --> 00:07:35.110
out of an eventual constellation of more
00:07:35.120 --> 00:07:37.110
than 3,200.
00:07:37.120 --> 00:07:40.070
The Atlas 5 flew in its most powerful
00:07:40.080 --> 00:07:43.830
configuration, the 551 variant with five
00:07:43.840 --> 00:07:46.390
solid rocket boosters strapped on, and
00:07:46.400 --> 00:07:48.710
ULA engineers made specific
00:07:48.720 --> 00:07:51.589
modifications to the Centaur upper stage
00:07:51.599 --> 00:07:53.990
and its dispenser system to carry the
00:07:54.000 --> 00:07:57.670
extra load. These 29 satellites went up
00:07:57.680 --> 00:08:00.469
on a northeast trajectory to a low Earth
00:08:00.479 --> 00:08:04.869
orbit of around 450 km. Amazon has an
00:08:04.879 --> 00:08:07.589
FCC deadline looming. They need to have
00:08:07.599 --> 00:08:09.670
half of their constellation operational
00:08:09.680 --> 00:08:12.950
by July 2026, which puts them in a
00:08:12.960 --> 00:08:15.830
serious race. Multiple Atlas 5 and
00:08:15.840 --> 00:08:18.070
Vulcan Centaur launches are planned this
00:08:18.080 --> 00:08:20.950
year. Plus, missions on Aron 6, New
00:08:20.960 --> 00:08:24.309
Glenn, and Falcon 9. The Atlas 5 is one
00:08:24.319 --> 00:08:26.950
of the most reliable rockets ever built.
00:08:26.960 --> 00:08:29.670
This was its 102nd mission. And while
00:08:29.680 --> 00:08:31.990
the Vulcan Centaur is taking over as the
00:08:32.000 --> 00:08:33.750
primary heavy lift vehicle going
00:08:33.760 --> 00:08:36.310
forward, today proved the old workhorse
00:08:36.320 --> 00:08:37.829
has still got it.
00:08:37.839 --> 00:08:40.949
>> Okay, our next story. Moon's hot cold
00:08:40.959 --> 00:08:44.550
divide may be wrong. Blue Ghost rewrites
00:08:44.560 --> 00:08:47.430
lunar science. With the Aremis 2 crew
00:08:47.440 --> 00:08:49.430
heading toward the moon right now, this
00:08:49.440 --> 00:08:51.829
next story feels especially timely
00:08:51.839 --> 00:08:53.750
because new data from the moon's surface
00:08:53.760 --> 00:08:55.750
is challenging something scientists
00:08:55.760 --> 00:08:58.070
thought they understood for decades. A
00:08:58.080 --> 00:09:00.630
Firefly Aerospace's Blue Ghost lander
00:09:00.640 --> 00:09:02.310
touched down in the moon's Mari
00:09:02.320 --> 00:09:04.790
Chrysium, the Sea of Crises, back in
00:09:04.800 --> 00:09:07.829
March of 2025. It operated for a full
00:09:07.839 --> 00:09:10.150
lunar day, drilling into the surface and
00:09:10.160 --> 00:09:13.590
sending back over 110 gigabytes of data.
00:09:13.600 --> 00:09:16.070
And now a year on, scientists are
00:09:16.080 --> 00:09:18.150
presenting the first major scientific
00:09:18.160 --> 00:09:20.389
results. And they are surprising.
00:09:20.399 --> 00:09:22.389
>> The long-standing view of the moon has
00:09:22.399 --> 00:09:25.350
been this. The near side, the face we
00:09:25.360 --> 00:09:28.150
always see from Earth, is geologically
00:09:28.160 --> 00:09:31.269
hot. It's dominated by ancient volcanic
00:09:31.279 --> 00:09:33.670
plains. And beneath the surface, there's
00:09:33.680 --> 00:09:35.910
a concentration of heat producing
00:09:35.920 --> 00:09:38.389
radioactive elements, particularly
00:09:38.399 --> 00:09:40.310
thorium, in a region called the
00:09:40.320 --> 00:09:43.430
Proellarum creep terrain. The far side
00:09:43.440 --> 00:09:46.630
by contrast is cooler, older, more
00:09:46.640 --> 00:09:47.910
heavily cratered.
00:09:47.920 --> 00:09:50.470
>> Blue ghost was specifically sent to land
00:09:50.480 --> 00:09:53.509
outside that hot region and marchium
00:09:53.519 --> 00:09:56.150
well away from the creep zone precisely
00:09:56.160 --> 00:09:57.670
to test whether the temperature
00:09:57.680 --> 00:09:59.910
difference was as dramatic as scientists
00:09:59.920 --> 00:10:02.790
expected. The answer has upended the
00:10:02.800 --> 00:10:05.829
model. Lugos's heat probe found that the
00:10:05.839 --> 00:10:08.310
underground temperature at Mari Chrysium
00:10:08.320 --> 00:10:10.550
is not significantly different from what
00:10:10.560 --> 00:10:12.470
Apollo astronauts measured at their
00:10:12.480 --> 00:10:15.110
landing sites deep inside the supposed
00:10:15.120 --> 00:10:15.990
hot zone.
00:10:16.000 --> 00:10:18.870
>> As Seichi Nagihara, the principal
00:10:18.880 --> 00:10:21.350
investigator of Blue Ghost's heat probe
00:10:21.360 --> 00:10:24.310
at Texas Tech University put it, "We may
00:10:24.320 --> 00:10:26.150
have to abandon that binary."
00:10:26.160 --> 00:10:28.150
>> What does this mean? Heat producing
00:10:28.160 --> 00:10:30.710
elements like thorium may be more widely
00:10:30.720 --> 00:10:32.470
distributed beneath the lunar surface
00:10:32.480 --> 00:10:35.030
than anyone thought. And one possible
00:10:35.040 --> 00:10:37.350
explanation is that volcanic activity in
00:10:37.360 --> 00:10:39.430
some regions wasn't driven by those
00:10:39.440 --> 00:10:41.829
radioactive elements at all. It may have
00:10:41.839 --> 00:10:43.910
simply been easier for magma to break
00:10:43.920 --> 00:10:45.670
through in places where the crust was
00:10:45.680 --> 00:10:46.310
thinner.
00:10:46.320 --> 00:10:48.710
>> It's a fundamental rethink of how the
00:10:48.720 --> 00:10:51.350
moon formed and evolved. And it has
00:10:51.360 --> 00:10:53.509
direct implications for where future
00:10:53.519 --> 00:10:55.750
crude missions might land and what
00:10:55.760 --> 00:10:57.030
they'll find.
00:10:57.040 --> 00:10:59.829
Blue Ghost Mission 2, expected to launch
00:10:59.839 --> 00:11:02.310
later this year, will land on the lunar
00:11:02.320 --> 00:11:04.870
far side, giving scientists the next
00:11:04.880 --> 00:11:07.190
data point in this evolving picture.
00:11:07.200 --> 00:11:09.590
>> Onwards the story five. Let's simply
00:11:09.600 --> 00:11:12.790
call this one stellar science. Pulsars
00:11:12.800 --> 00:11:14.710
are broadcasting from the edge of their
00:11:14.720 --> 00:11:17.670
magnetic reach. Now to a discovery that
00:11:17.680 --> 00:11:20.550
overturns decades of thinking about some
00:11:20.560 --> 00:11:22.949
of the most extreme objects in the
00:11:22.959 --> 00:11:25.430
universe and it has an Australian
00:11:25.440 --> 00:11:26.870
fingerprint on it.
00:11:26.880 --> 00:11:29.590
>> Pulsars are the collaps remnants of dead
00:11:29.600 --> 00:11:32.150
stars. They're among the densest objects
00:11:32.160 --> 00:11:34.550
we know of. A teaspoon of pulsar
00:11:34.560 --> 00:11:36.949
material would weigh around 10 million
00:11:36.959 --> 00:11:40.310
tons on Earth. As they spin, they sweep
00:11:40.320 --> 00:11:42.790
beams of radio waves across the cosmos
00:11:42.800 --> 00:11:45.590
like cosmic lighouses. And a special
00:11:45.600 --> 00:11:48.710
class called millisecond pulsars spins
00:11:48.720 --> 00:11:51.350
hundreds of times per second. So
00:11:51.360 --> 00:11:53.829
regularly that they rival atomic clocks
00:11:53.839 --> 00:11:55.110
in their precision.
00:11:55.120 --> 00:11:57.350
>> For decades, the textbook answer to
00:11:57.360 --> 00:11:59.590
where those radio pulses come from was
00:11:59.600 --> 00:12:01.990
simple. Near the surface, close to the
00:12:02.000 --> 00:12:04.470
magnetic poles. That's where scientists
00:12:04.480 --> 00:12:06.470
assumed all the action happened.
00:12:06.480 --> 00:12:08.870
>> A new study published in monthly notices
00:12:08.880 --> 00:12:11.350
of the Royal Astronomical Society has
00:12:11.360 --> 00:12:13.750
just rewritten that. Professor Michael
00:12:13.760 --> 00:12:15.910
Kramer from the Maxplank Institute for
00:12:15.920 --> 00:12:18.389
Radio Aastronomy in Germany and Dr.
00:12:18.399 --> 00:12:22.069
Simon Johnson from Australia's own CSRO
00:12:22.079 --> 00:12:24.710
analyzed radio observations of nearly
00:12:24.720 --> 00:12:27.670
200 millisecond pulsars and compared
00:12:27.680 --> 00:12:29.829
them with gammaray data from NASA's
00:12:29.839 --> 00:12:31.350
Fermy Space Telescope.
00:12:31.360 --> 00:12:34.710
>> What they found about 1/3 of millisecond
00:12:34.720 --> 00:12:37.269
pulsars are broadcasting radio waves
00:12:37.279 --> 00:12:39.910
from two completely separate regions at
00:12:39.920 --> 00:12:42.949
once. not just the magnetic poles, but
00:12:42.959 --> 00:12:45.509
also from a distant swirling zone of
00:12:45.519 --> 00:12:47.829
charged particles called the current
00:12:47.839 --> 00:12:50.230
sheet, right at what's called the light
00:12:50.240 --> 00:12:52.710
cylinder. That's the boundary where the
00:12:52.720 --> 00:12:55.190
pulsar's magnetic field would need to
00:12:55.200 --> 00:12:57.509
travel faster than light just to keep
00:12:57.519 --> 00:12:59.030
pace with the spinning star.
00:12:59.040 --> 00:13:01.910
>> As Dr. Johnston put it, these tiny, fast
00:13:01.920 --> 00:13:04.389
spinning stars are even more complex and
00:13:04.399 --> 00:13:06.629
surprising than we thought. broadcasting
00:13:06.639 --> 00:13:08.949
from both their surfaces and from the
00:13:08.959 --> 00:13:11.110
very edge of their magnetic reach.
00:13:11.120 --> 00:13:13.430
>> The practical consequences are
00:13:13.440 --> 00:13:16.069
significant because the radio signals
00:13:16.079 --> 00:13:18.629
are spreading out over a wider range of
00:13:18.639 --> 00:13:21.350
directions than previously understood.
00:13:21.360 --> 00:13:23.750
More pulsars should be detectable than
00:13:23.760 --> 00:13:26.310
scientists thought. And that's good news
00:13:26.320 --> 00:13:29.269
for projects like pulsar timing arrays,
00:13:29.279 --> 00:13:32.230
networks of pulsars used as detectors
00:13:32.240 --> 00:13:35.110
for gravitational waves rippling across
00:13:35.120 --> 00:13:36.550
the universe.
00:13:36.560 --> 00:13:38.629
>> A great piece of science and a proud
00:13:38.639 --> 00:13:41.750
moment for CSRO, Australia's National
00:13:41.760 --> 00:13:43.269
Science Agency.
00:13:43.279 --> 00:13:46.230
>> And finally today, an invitation to go
00:13:46.240 --> 00:13:49.350
outside and look up because right now
00:13:49.360 --> 00:13:51.590
Mercury is putting on its best
00:13:51.600 --> 00:13:54.550
performance of the entire year. and we
00:13:54.560 --> 00:13:56.949
have the best seats in the house.
00:13:56.959 --> 00:13:59.189
>> Mercury reached what astronomers call
00:13:59.199 --> 00:14:02.150
greatest elongation on April 3rd, the
00:14:02.160 --> 00:14:03.910
point where it appears farthest from the
00:14:03.920 --> 00:14:06.470
sun in our sky. This is the year's
00:14:06.480 --> 00:14:08.710
greatest elongation for Mercury. Full
00:14:08.720 --> 00:14:12.629
stop. The best it will get all of 2026.
00:14:12.639 --> 00:14:15.430
Here's the key thing about Mercury. It's
00:14:15.440 --> 00:14:17.750
always close to the sun in our sky,
00:14:17.760 --> 00:14:19.910
which makes it genuinely difficult to
00:14:19.920 --> 00:14:22.629
spot. Most people have never actually
00:14:22.639 --> 00:14:25.670
seen it. Greatest elongation is your
00:14:25.680 --> 00:14:28.389
best window. The planet pulls as far
00:14:28.399 --> 00:14:30.949
from the sun's glare as it ever gets,
00:14:30.959 --> 00:14:33.509
giving you a brief, clear opportunity
00:14:33.519 --> 00:14:35.509
before it slips back.
00:14:35.519 --> 00:14:38.470
>> Right now, Mercury is sitting about 28°
00:14:38.480 --> 00:14:41.030
from the sun, rising in the eastern sky
00:14:41.040 --> 00:14:44.069
before dawn. Look east about 30 to 40
00:14:44.079 --> 00:14:46.230
minutes before sunrise. You're looking
00:14:46.240 --> 00:14:48.550
for a steady point of light, magnitude
00:14:48.560 --> 00:14:50.710
around 0.4, four, which is bright enough
00:14:50.720 --> 00:14:52.870
to see with the naked eye under decent
00:14:52.880 --> 00:14:54.870
conditions. It's sitting low on the
00:14:54.880 --> 00:14:56.870
horizon just above Mars in the
00:14:56.880 --> 00:14:58.870
constellation Aquarius.
00:14:58.880 --> 00:15:01.030
>> And here's the southern hemisphere
00:15:01.040 --> 00:15:04.230
advantage. This is specifically the best
00:15:04.240 --> 00:15:06.470
morning apparition of Mercury for the
00:15:06.480 --> 00:15:09.350
southern hemisphere in 2026 from
00:15:09.360 --> 00:15:11.910
Australia and New Zealand. The geometry
00:15:11.920 --> 00:15:14.629
of the ecliptic gives us a steeper angle
00:15:14.639 --> 00:15:17.269
to the horizon. Mercury climbs higher
00:15:17.279 --> 00:15:19.750
and stays out of the Merc longer than it
00:15:19.760 --> 00:15:22.470
does for northern hemisphere observers.
00:15:22.480 --> 00:15:24.230
>> If you have binoculars or a small
00:15:24.240 --> 00:15:26.949
telescope, there's a bonus. Mercury is
00:15:26.959 --> 00:15:28.949
currently showing a half illuminated
00:15:28.959 --> 00:15:31.350
face, what astronomers call a quarter
00:15:31.360 --> 00:15:33.269
phase. You can see it going through
00:15:33.279 --> 00:15:35.189
phases just like the moon, which is
00:15:35.199 --> 00:15:37.030
something a lot of people don't realize
00:15:37.040 --> 00:15:39.670
about Mercury. And keep watching the
00:15:39.680 --> 00:15:41.750
eastern sky over the next couple of
00:15:41.760 --> 00:15:45.110
weeks because Mercury, Mars, Saturn, and
00:15:45.120 --> 00:15:47.829
Neptune will gather in a tight cluster
00:15:47.839 --> 00:15:50.550
on the morning of April 18th. Three of
00:15:50.560 --> 00:15:52.550
those four will be visible to the naked
00:15:52.560 --> 00:15:54.790
eye, close enough to cover with three
00:15:54.800 --> 00:15:57.430
fingers held at arms length. A lovely
00:15:57.440 --> 00:16:00.310
little planetary alignment to chase.
00:16:00.320 --> 00:16:02.710
>> So this week, look east before sunrise
00:16:02.720 --> 00:16:05.670
for Mercury. Look west after sunset for
00:16:05.680 --> 00:16:07.990
any sign of comet maps emerging from the
00:16:08.000 --> 00:16:10.389
sun's glare. And keep an eye on Monday's
00:16:10.399 --> 00:16:12.230
episode for everything you need to know
00:16:12.240 --> 00:16:15.430
about the Aremis 2 lunar flyby. And that
00:16:15.440 --> 00:16:18.310
is your Astronomy Daily for Saturday the
00:16:18.320 --> 00:16:22.230
5th of April 2026. A crew heading to the
00:16:22.240 --> 00:16:24.949
moon. A comet that may be putting on the
00:16:24.959 --> 00:16:26.870
sky show of the decade. A
00:16:26.880 --> 00:16:29.269
record-breaking rocket launch. Science
00:16:29.279 --> 00:16:31.509
from the lunar surface. A pulsar
00:16:31.519 --> 00:16:34.230
discovery out of Australia. and Mercury
00:16:34.240 --> 00:16:36.310
waiting for you in the dawn sky.
00:16:36.320 --> 00:16:38.310
>> We'll be back Monday with day four and
00:16:38.320 --> 00:16:40.870
five of Artemis 2 and the latest on
00:16:40.880 --> 00:16:43.189
comet maps. If you're heading outside
00:16:43.199 --> 00:16:45.030
tonight, clear skies everyone.
00:16:45.040 --> 00:16:47.189
>> From all of us at Astronomy Daily, keep
00:16:47.199 --> 00:16:51.430
looking up. Astronomy day.
00:16:51.440 --> 00:16:59.430
Stories told.
00:16:59.440 --> 00:17:03.160
Stories to tell.
