Latest / Space News Today / Equinox Auroras, Ancient Stars, and a Satellite Resurrection

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Equinox Auroras, Ancient Stars, and a Satellite Resurrection · Space News Today

• 0:00
  Happy first day of spring, everyone. At
• 0:02
  least if you're in the northern
• 0:04
  hemisphere. I'm Anna.
• 0:06
  >> And I'm Avery. And what a day for the
• 0:08
  cosmos to celebrate with us. Because
• 0:11
  right now, as we're recording, the sun
• 0:13
  has fired three enormous blasts of
• 0:16
  charged particles straight at Earth. A 7
• 0:19
  ton space rock just lit up the skies
• 0:21
  over Ohio. A satellite that went silent
• 0:24
  for a full month has finally phoned
• 0:26
  home. And astronomers have found a star
• 0:29
  so old it carries the direct
• 0:31
  fingerprints of the very first stars
• 0:33
  that ever existed.
• 0:35
  >> Plus, we're going to explain exactly why
• 0:38
  the equinox and those solar storms are
• 0:40
  connected. It's one of the most
• 0:42
  fascinating quirks of Earth's orbit
• 0:44
  around the sun. And today is literally
• 0:46
  the best day of the year to talk about
• 0:48
  it.
• 0:49
  >> This is Astronomy Daily, season 5,
• 0:52
  episode 68. Let's get into it. Okay,
• 0:54
  Avery, before we even get into the
• 0:56
  equinox itself, we have to talk about
• 0:59
  what the sun has been doing this week
• 1:01
  because it has been busy.
• 1:03
  >> Extremely busy. So, here's a situation.
• 1:06
  As of today, Friday the 20th of March.
• 1:09
  Earth is being targeted by not one, not
• 1:11
  two, but three separate coronal mass
• 1:14
  ejections, CMEs, all fired off within
• 1:17
  the last few days. So, for anyone who
• 1:20
  needs a quick refresher, a CME is
• 1:22
  essentially a massive eruption of plasma
• 1:25
  and magnetic field from the sun. When
• 1:27
  these hit Earth's magnetic fields, they
• 1:29
  compress it, cause geomagnetic storms,
• 1:32
  and most visibly for us down here, they
• 1:34
  trigger auroras.
• 1:36
  >> The first of the three CMEs was expected
• 1:38
  to arrive today. Forecasters at Noah's
• 1:41
  Space Weather Prediction Center have
• 1:43
  issued a geomagnetic storm watch with
• 1:46
  conditions potentially reaching G2.
• 1:48
  That's moderate with a chance of G3 or
• 1:51
  strong. And that second level, G3, is
• 1:55
  where things get really interesting
• 1:56
  >> because G3 conditions could push aurora
• 2:00
  visibility well into mid latitudes as
• 2:02
  far south as Illinois, Oregon,
• 2:05
  potentially even lower under the right
• 2:07
  conditions. So, if you're in the
• 2:09
  northern US, northern Europe, Canada,
• 2:12
  tonight is a night to keep an eye on the
• 2:14
  sky.
• 2:14
  >> And there's more to come. A second CME
• 2:17
  is expected to deliver a glancing blow.
• 2:19
  And the third, triggered by an M2.75
• 2:22
  flare from sunspot region AR4392
• 2:27
  is expected to arrive around March 21st.
• 2:30
  So, this isn't a one-day event. The
• 2:32
  space weather picture remains active
• 2:34
  through the weekend.
• 2:35
  >> We should also mention we're currently
• 2:37
  near solar maximum, the peak of the
• 2:40
  sun's 11-year cycle, which is part of
• 2:42
  why we're seeing this kind of activity.
• 2:44
  Peak activity is expected to continue
• 2:47
  through the second half of 2026. So get
• 2:50
  used to these kinds of alerts.
• 2:51
  >> Worth bookmarking Noah's space weather
• 2:54
  prediction center, spaceweather.gov,
• 2:56
  for live aurora forecasts. And on our
• 2:59
  website at astronomydaily.io,
• 3:01
  we'll link to some recommended aurora
• 3:03
  apps for your phone.
• 3:04
  >> Okay, so let's talk about the actual
• 3:07
  astronomical event that is happening
• 3:09
  today, the vernal equinox. The 2026
• 3:14
  March equinox falls at 14:46
• 3:17
  UTC this afternoon.
• 3:20
  >> At that moment, the sun crosses the
• 3:22
  celestial equator, the imaginary line in
• 3:25
  the sky directly above Earth's equator,
• 3:28
  moving from south to north. And at that
• 3:30
  precise moment, every point on Earth
• 3:33
  receives roughly equal amounts of
• 3:35
  daylight and darkness.
• 3:36
  >> The word equinox comes from the Latin
• 3:39
  for equal night.
• 3:41
  It's the astronomical beginning of
• 3:43
  spring in the northern hemisphere and
• 3:45
  autumn in the southern. So if you're
• 3:47
  listening from Australia or New Zealand,
• 3:50
  happy autumn to you.
• 3:51
  >> And here's the thing that connects this
• 3:53
  equinox directly to the aurora story we
• 3:56
  just told. There's a phenomenon called
• 3:58
  the Russell McFaran effect named after
• 4:00
  the two scientists who identified it.
• 4:02
  And it specifically amplifies aurora
• 4:05
  activity around the equinoxes.
• 4:07
  >> Right? Basically around the equinoxes,
• 4:10
  Earth's magnetic field orientation is
• 4:12
  particularly favorable for coupling with
• 4:14
  the solar wind. The geometry of our
• 4:16
  planet's tilt relative to the sun means
• 4:19
  incoming charged particles from CMEs
• 4:22
  interact more efficiently with our
• 4:24
  magnetosphere. So what this means in
• 4:26
  practice is the equinoxes are
• 4:28
  historically the best times of year to
• 4:30
  see auroras even when the sun isn't
• 4:33
  being especially active. When you
• 4:35
  combine a natural peak in aurora
• 4:37
  probability with three incoming CMEs on
• 4:39
  the same day, well, today is genuinely a
• 4:43
  special aurora opportunity. And there's
• 4:46
  a lovely bonus for sky watchers this
• 4:48
  evening. After sunset today, look to the
• 4:51
  west southwest and you'll be able to
• 4:53
  spot a thin 5% lit waxing crescent moon
• 4:57
  glowing just above Venus. Spring
• 5:00
  evenings don't get much more beautiful
• 5:02
  than that. Equinox, auroras, crescent
• 5:05
  moon, Venus. Anna, I feel like the
• 5:08
  universe planned this episode.
• 5:11
  >> I am starting to think so, too. Check
• 5:13
  astronomyaily.io
• 5:15
  for skywatching links for tonight.
• 5:18
  >> Okay, shifting from things you need to
• 5:20
  look up for to something that came down
• 5:22
  from above rather dramatically on
• 5:25
  Tuesday, St. Patrick's Day. Thousands of
• 5:28
  people across the American Midwest
• 5:30
  experienced quite the green tinged
• 5:32
  morning. And not just from the holiday.
• 5:34
  >> At around 8:57 in the morning, a 7 ton
• 5:38
  asteroid roughly 6 feet in diameter
• 5:41
  entered the atmosphere above Lake Erie
• 5:44
  near Lraine, Ohio, and moved southeast
• 5:47
  at around 40,000 mph before fragmenting
• 5:51
  about 30 m above Valley City. The
• 5:55
  explosion had the energy equivalent of
• 5:57
  250 tons of TNT, and it produced
• 6:01
  multiple sonic booms that were heard and
• 6:03
  felt across northeast Ohio, and into
• 6:06
  Pennsylvania, New York, and beyond. Some
• 6:09
  reports came in as far as Ontario and
• 6:12
  Canada.
• 6:13
  >> People were flooding 911 lines thinking
• 6:15
  it was an earthquake or an explosion, or
• 6:18
  actually, there was quite a creative
• 6:20
  range of theories on social media. But
• 6:23
  NASA's Meteoroid Environments Office
• 6:25
  confirmed the meteor quickly and tracked
• 6:28
  its trajectory precisely.
• 6:30
  >> And here's the exciting follow-up that's
• 6:32
  still unfolding. NASA confirmed
• 6:34
  meteorites, actual fragments that
• 6:37
  survived the journey to the ground,
• 6:39
  landed in the vicinity of Medina County,
• 6:41
  Ohio. And the meteorite hunting
• 6:43
  community has mobilized in a spectacular
• 6:46
  fashion. Within days, hunters from
• 6:48
  Connecticut, South Carolina, and
• 6:50
  multiple other states were converging on
• 6:53
  a small town called Sharon Center. At
• 6:55
  least one hunter found a 12.2 g
• 6:58
  fragment. Another found pieces in a
• 7:01
  parking lot, and the hunt is still very
• 7:04
  much on. Daytime fireballs this bright
• 7:07
  are genuinely rare. An amateur
• 7:09
  astronomer in the area said something
• 7:11
  along the lines of, "To see a fireball
• 7:13
  in the daytime, it has to be
• 7:15
  extraordinarily bright." And the fact
• 7:17
  that it created multiple sonic booms
• 7:19
  over a populated area is something that
• 7:21
  happens perhaps once in a lifetime. If
• 7:24
  you're in the Medina County area and you
• 7:26
  spot a dark rock with a shiny exterior
• 7:29
  or a gray interior that looks slightly
• 7:32
  out of place, it might be worth a closer
• 7:34
  look. NASA's guidance is to photograph
• 7:37
  it without disturbing it and contact a
• 7:40
  local university geology department and
• 7:43
  absolutely do not pick it up without
• 7:45
  checking the rules. Meteorites have real
• 7:48
  scientific value.
• 7:49
  >> Happy hunting, Ohio.
• 7:51
  >> All right. From things falling to Earth
• 7:53
  to a star so old it predates almost
• 7:57
  everything we can see in the modern
• 7:59
  universe. This week in the journal
• 8:01
  Nature Astronomy, a team led by Anna
• 8:04
  Rude Chitty of Stanford University
• 8:07
  published a discovery that is being
• 8:09
  called, and I love this phrase, cosmic
• 8:11
  archaeology.
• 8:13
  >> So, let's set the scene. In the very
• 8:15
  early universe, the first stars were
• 8:18
  enormous and formed from just three
• 8:20
  elements: hydrogen, helium, and a tiny
• 8:23
  bit of lithium. That was it. Those were
• 8:25
  the only elements that existed. No
• 8:28
  carbon, no iron, no oxygen, none of the
• 8:31
  building blocks of chemistry as we know
• 8:33
  it.
• 8:33
  >> These first stars, called population 3
• 8:37
  stars, burned fast and hot. And when
• 8:40
  they exploded as supernova, they
• 8:42
  scattered the first heavy elements into
• 8:44
  the surrounding gas clouds. The next
• 8:47
  generation of stars, population 2,
• 8:49
  formed from that enriched material.
• 8:52
  >> And that's what makes this week's
• 8:54
  discovery so extraordinary. Astronomers
• 8:57
  have found a star called PIC 2-503
• 9:01
  sitting in a tiny ancient dwarf galaxy
• 9:04
  called Pictor 2, located about 150,000
• 9:09
  light years from Earth. And this star
• 9:11
  contains virtually no iron, less than
• 9:15
  140,000th of the iron in our sun.
• 9:18
  >> To put that in perspective, our sun is a
• 9:20
  third generation star. Picked 25503 is
• 9:24
  second generation. It formed from the
• 9:27
  direct debris of the universe's very
• 9:29
  first stars. It is quite literally
• 9:32
  carrying the chemical fingerprints of
• 9:34
  stars that no longer exist anywhere in
• 9:37
  the observable universe. The star also
• 9:40
  has an extraordinary overabundance of
• 9:42
  carbon, about 1,500 times more carbon
• 9:46
  relative to iron than our sun. And this
• 9:49
  is the key to unlocking a mystery that
• 9:51
  astronomers have puzzled over for years.
• 9:54
  There's a whole class of stars in the
• 9:56
  outer halo of our Milky Way called
• 9:58
  carbon-enhanced metal pore stars that
• 10:01
  show this same bizarre signature. High
• 10:04
  carbon, almost no iron. Scientists knew
• 10:07
  they were ancient, but they couldn't
• 10:09
  explain where they originally formed.
• 10:12
  Because our galaxy has been
• 10:13
  cannibalizing smaller galaxies for
• 10:15
  billions of years, scattering stars far
• 10:18
  from their birthplaces.
• 10:19
  >> Picked 25503 is the missing link. It
• 10:23
  shows that these mysterious halo stars
• 10:26
  were born in tiny primitive dwarf
• 10:28
  galaxies like picture 2. Galaxies that
• 10:31
  formed early in cosmic history and
• 10:33
  haven't changed much since. The
• 10:35
  discovery was made possible by the magic
• 10:37
  survey. That stands for DAM mapping the
• 10:40
  ancient galaxy in CHK. A 54night
• 10:44
  observing program using the dark energy
• 10:46
  camera in Chile combined with a followup
• 10:49
  from the very large telescopes and the
• 10:51
  Mellan telescopes.
• 10:53
  >> The lead researcher described it as
• 10:55
  being at the edge of what we thought
• 10:56
  possible. And I think that phrase
• 10:58
  captures it perfectly because this star
• 11:01
  isn't just old. It's a direct record of
• 11:04
  chemical processes that happened when
• 11:05
  the universe was less than a billion
• 11:07
  years old. It's a time capsule.
• 11:10
  >> The paper is in Nature Astronomy this
• 11:12
  week. We'll link to the Nor lab press
• 11:14
  release on the website. They have some
• 11:16
  spectacular images of Pictor 2.
• 11:19
  >> Now, this one is a followup to a story
• 11:21
  we covered a few weeks ago, and it is
• 11:24
  very much a good news update. You'll
• 11:26
  remember that Europe's proba 3 mission,
• 11:29
  issa's ingenious two satellite formation
• 11:32
  flying solar science mission ran into
• 11:35
  serious trouble in midFebruary when the
• 11:38
  coronagraph spacecraft went completely
• 11:40
  silent. For those who need the
• 11:42
  refresher, proba 3 consists of two small
• 11:45
  satellites flying in exquisitly precise
• 11:48
  formation about 150 m apart with
• 11:52
  positioning accuracy of 1 mm. The
• 11:55
  oultter spacecraft blocks out the bright
• 11:57
  disc of the sun, while the coronagraph
• 12:00
  photographs the sun's outer atmosphere,
• 12:02
  the corona. It's basically a spacecraft
• 12:05
  that manufactures artificial solar
• 12:08
  eclipses on demand in orbit. The science
• 12:11
  potential is enormous because the corona
• 12:14
  is normally invisible from Earth except
• 12:16
  during the few minutes of a total solar
• 12:19
  eclipse. But in midFebruary, an anomaly
• 12:22
  on the coronagraph triggered a cascade
• 12:24
  of failures. It lost its attitude, its
• 12:27
  orientation in space, and failed to
• 12:30
  enter safe mode as expected. ESA spent
• 12:33
  weeks attempting to regain contact,
• 12:35
  working through ground stations around
• 12:37
  the world. And the great news confirmed
• 12:40
  on March 19th, issa's ground station in
• 12:43
  Vafrana, Spain, received a data packet
• 12:46
  from the coronagraph. The satellite is
• 12:48
  alive. It's in safe mode. Its solar
• 12:51
  panel is facing the sun, powering the
• 12:53
  electronics and charging the battery.
• 12:55
  >> Proba 3 mission manager Damian Galano
• 12:58
  said, and this is a direct quote from
• 13:00
  the ESA statement. Hearing back from the
• 13:03
  coronagraph is amazing news and a great
• 13:05
  relief.
• 13:06
  >> Now, we should be clear, the mission
• 13:08
  team isn't popping champagne just yet.
• 13:11
  The satellite has spent a month floating
• 13:13
  in space, exposed to the deep cold of
• 13:17
  orbital night, and its systems need time
• 13:19
  to warm up before any major actions are
• 13:22
  taken. Health checks are underway to
• 13:24
  assess whether any damage occurred.
• 13:27
  >> But the spacecraft is stable. The
• 13:29
  hardware is powered, and if those health
• 13:31
  checks come back clean, Proba 3 could
• 13:33
  resume its artificial eclipse science
• 13:36
  program. We'll be following this one
• 13:37
  closely.
• 13:38
  >> What a relief is right. We'll link to
• 13:41
  the full ESA update at
• 13:42
  astronomydaily.io.
• 13:45
  >> And finally, a story that is both a
• 13:47
  scientific mystery solved and a lovely
• 13:49
  reminder for why sample return missions
• 13:51
  matter so much. You'll remember NASA's
• 13:54
  Osiris Rex spacecraft collected samples
• 13:56
  from asteroid Bennon back in 2020, and
• 13:59
  those samples arrived on Earth in 2023.
• 14:02
  Well, this week, scientists published
• 14:04
  results in Nature Communications that
• 14:06
  finally solve one of Bennu's most
• 14:08
  puzzling features. So, here's the
• 14:11
  mystery. Back in 2007, NASA's Spitzer
• 14:14
  Space Telescope measured what's called
• 14:16
  low thermal inertia on Bennu, meaning
• 14:19
  the asteroid surface heats up and cools
• 14:22
  down rapidly as it rotates. on Earth.
• 14:24
  That's what sand does, which led
• 14:27
  astronomers to expect Bennu's surface
• 14:29
  would be sandy and smooth, a bit like a
• 14:31
  beach.
• 14:32
  >> And then Osiris Rex arrived in 2018 and
• 14:35
  found the opposite. The surface was
• 14:38
  covered in enormous boulders, rough,
• 14:40
  rocky, definitely not sandy. And these
• 14:43
  boulders should behave like blocks of
• 14:45
  concrete thermally, holding heat for
• 14:47
  hours after the sun goes down. But they
• 14:50
  weren't. They were losing heat rapidly,
• 14:52
  just like the original observation
• 14:54
  suggested.
• 14:55
  >> Scientists scratched their heads for
• 14:57
  years. The boulders were porous. That
• 15:00
  explained some of the heat loss, but not
• 15:02
  all of it. The numbers still didn't add
• 15:04
  up.
• 15:05
  >> And then they put the actual return
• 15:07
  samples into an X-ray CT scanner. And
• 15:10
  that's when everything clicked into
• 15:11
  place. The boulders aren't just porous.
• 15:13
  They're riddled with an extensive
• 15:15
  internal network of fine cracks, like a
• 15:18
  shattered windshield that's still in one
• 15:20
  piece. The cracks dramatically alter how
• 15:22
  heat moves through the rock. When
• 15:24
  scientists ran computer simulations
• 15:27
  scaling those cracked boulder properties
• 15:29
  up to the full size of Bennu's actual
• 15:31
  surface, the numbers matched perfectly,
• 15:34
  right down to what the spacecraft had
• 15:36
  measured from orbit.
• 15:37
  >> The lead researcher, Andrew Ryan, from
• 15:39
  the University of Arizona put it simply.
• 15:42
  It turns out they're really cracked,
• 15:44
  too. And that was the missing piece of
• 15:46
  the puzzle. The full citation is in the
• 15:48
  show notes.
• 15:49
  >> And the implications go way beyond
• 15:51
  Bennu. This work means scientists can
• 15:54
  now use the thermal properties of an
• 15:55
  asteroid measured from a telescope on
• 15:58
  Earth to make much more accurate
• 16:00
  inferences about its internal structure.
• 16:02
  You no longer need to go there and pick
• 16:04
  it up to understand it,
• 16:06
  >> which matters enormously for planetary
• 16:08
  defense. The more accurately we can
• 16:10
  model asteroid composition and structure
• 16:12
  from a distance, the better we can
• 16:14
  predict trajectories, deflection
• 16:16
  responses, and potential impact hazards.
• 16:18
  Osiris Rex keeps on delivering. What an
• 16:22
  episode to celebrate the first day of
• 16:24
  spring in the northern hemisphere and
• 16:26
  autumn in the southern hemisphere. We
• 16:28
  had solar storms, an aurora opportunity,
• 16:31
  a meteorite hunt in Ohio, one of the
• 16:33
  oldest stars ever discovered, a
• 16:36
  satellite that came back from the dead,
• 16:38
  and an asteroid mystery finally cracked.
• 16:41
  Not bad for a Friday.
• 16:43
  >> If you're in aurora territory tonight,
• 16:45
  get outside, find a dark spot, look
• 16:47
  north. The sky may reward you.
• 16:49
  >> You can find show notes, source links,
• 16:52
  and skywatching guides at
• 16:53
  astronomyaily.io.
• 16:55
  Follow us on X, Instagram, Tik Tok,
• 16:58
  YouTube, and Tumblr, all at Astro Daily
• 17:01
  Pod.
• 17:02
  >> If you're enjoying the show, please
• 17:04
  leave us a review wherever you get your
• 17:05
  podcasts. It genuinely helps new
• 17:07
  listeners find us.
• 17:09
  >> Until next time, keep looking up. I'm
• 17:11
  Anna
• 17:12
  >> and I'm Avery. Happy Equinox, everyone.
• 17:26
  Stories told.