Latest / Space News Today / Artemis, Pulsars, Big Crunch & City Killers

Transcript

Artemis, Pulsars, Big Crunch & City Killers · Space News Today

0:00
Welcome to Astronomy Daily. I'm Anna.
0:03
>> And I'm Avery. It is Thursday, the 19th
0:06
of February, 2026, and we are recording
0:09
this episode while NASA is literally
0:12
fueling a rocket at this very moment.
0:14
And we cannot wait to tell you about it.
0:17
>> That's right. This is one of those days
0:19
where space news isn't just something
0:21
that happened somewhere out there in the
0:23
universe. It is happening right now on a
0:26
launchpad in Florida. But that's not
0:29
all. Today, we're also asking what lurks
0:32
in the darkness between us and our
0:34
nearest cosmic neighbors. Could there be
0:36
a cosmic clock ticking next to the most
0:39
extreme object in our galaxy? And brace
0:42
yourselves, is the universe actually
0:45
going to end?
0:46
>> Plus, we have a story that will make you
0:48
want to check the sky tonight. A warning
0:50
from NASA that is genuinely a little
0:52
unsettling. And we're going to space
0:55
with a music video. All of that is
0:57
coming up on Astronomy Daily.
0:59
>> Let's start with the big one, and I mean
1:02
big in every sense of the word. As we
1:04
speak, NASA's Space Launch System, the
1:07
most powerful rocket ever built, is
1:10
being loaded with more than 700,000
1:13
gallons of cryogenic propellant at
1:15
launch complex 39B at Kennedy Space
1:18
Center in Florida. This is the second
1:21
wet dress rehearsal for Artemis 2, the
1:23
mission that will carry four astronauts
1:25
on a loop around the moon. The first
1:27
time humans have ventured to lunar
1:29
distance since Apollo 17 back in 1972.
1:33
The crew are commander Reed Weisman,
1:35
pilot Victor Glover, mission specialist
1:38
Christina Ko from NASA, and Jeremy
1:40
Hansen from the Canadian Space Agency.
1:43
Now, the reason they're doing this
1:45
rehearsal, and the reason there have
1:47
been so many eyes on it today is that
1:49
the first attempt back on the 2nd and
1:51
3rd of February did not go as planned.
1:54
Engineers detected a liquid hydrogen
1:56
leak during fueling, which forced them
1:59
to halt the test before they could
2:00
complete the full countdown sequence. In
2:03
the weeks since, technicians have
2:05
replaced seals around two fueling lines,
2:07
swapped out a filter and the ground
2:09
support equipment, and added an extra
2:11
hour of buffer time into the countdown
2:13
to allow more room for troubleshooting.
2:15
It's the kind of painstaking,
2:17
unglamorous engineering work that rarely
2:20
makes headlines, but it's exactly what
2:22
keeps astronauts alive. Today's
2:24
rehearsal targets a simulated launch
2:26
window opening at 8:30 this evening,
2:29
Eastern time. The test is expected to
2:31
run until around 12:30 Friday morning,
2:34
and the stakes are high. NASA has said
2:37
it won't set a formal launch date until
2:39
after a successful wet dress rehearsal
2:42
campaign. March 6th remains the earliest
2:45
possible crude launch date.
2:47
>> NASA administrator Jared Isaacman put it
2:49
well when he said, "We anticipated
2:51
encountering challenges. That is
2:53
precisely why we conduct a wet dress
2:55
rehearsal. These tests are designed to
2:57
surface issues before flight. The safety
3:00
of the crew comes first. So, tonight we
3:03
watch and we wait.
3:04
>> We will be keeping a close eye on this
3:06
one and we'll bring you the results in
3:08
tomorrow's episode. Fingers crossed for
3:11
a clean test, no leaks, and a March
3:13
launch that puts humans back in the
3:15
vicinity of the moon for the first time
3:17
in over 50 years. All right, from a
3:21
rocket at Kennedy Space Center to the
3:23
absolute heart of our galaxy. And this
3:25
story is one of those discoveries that
3:28
if it's confirmed, could fundamentally
3:30
change how we understand the universe.
3:33
>> Researchers from Columbia University
3:35
working with the Breakthrough Listen
3:36
Initiative, which is best known for
3:38
searching for signs of intelligent life
3:40
beyond Earth, have announced the
3:42
detection of a candidate millisecond
3:44
pulsar very close to Sagittarius A star.
3:48
That's the super massive black hole
3:50
sitting at the center of the Milky Way.
3:53
Roughly 4 million times the mass of our
3:55
own sun.
3:56
>> So, let's unpack what a pulsar is
3:59
because it's one of the most
4:01
extraordinary objects in the universe.
4:03
When a massive star reaches the end of
4:05
its life and explodes as a supernova,
4:08
what's left behind is an incredibly
4:10
dense core called a neutron star. Some
4:13
of those neutron stars spin rapidly and
4:16
emit beams of radio waves like a cosmic
4:19
lighthouse sweeping through space. When
4:21
those beams sweep past Earth, we detect
4:24
them as regular pulses, hence pulsar.
4:27
>> And what makes millisecond pulsar
4:29
special is their extraordinary
4:31
precision. They spin hundreds of times
4:34
per second with almost perfect
4:35
regularity. Scientists have called them
4:38
the most accurate clocks in the
4:39
universe, more stable than atomic clocks
4:42
here on Earth. This candidate, nicknamed
4:44
BLPSR, completes one full rotation every
4:48
8.19 milliseconds. Now, here's why
4:51
finding one near Sagittarius A star is
4:54
such a big deal. A pulsar next to a 4
4:57
million solar mass black hole would be
4:59
operating in one of the most extreme
5:01
gravitational environments imaginable.
5:04
And Einstein's general theory of
5:06
relativity makes very specific
5:08
predictions about what happens to space
5:10
and time in such extreme environments.
5:13
Predictions that have never been tested
5:15
at this level of precision.
5:17
>> And if a pulsar is orbiting close to
5:19
Sagittarius a star, the black hole's
5:21
gravity would warp spaceime so severely
5:24
that those precise pulsar pulses would
5:27
arrive at our telescopes with tiny but
5:29
measurable distortions. As researcher
5:31
Slavo Bogdanov from Colombia put it, any
5:34
external influence on a pulsar would
5:36
introduce anomalies in the steady
5:38
arrival of pulses which can be measured
5:40
and modeled.
5:42
>> In other words, a confirmed pulsar next
5:44
to a super massive black hole would be a
5:46
natural laboratory for testing
5:48
Einstein's theories in the most extreme
5:50
conditions possible. It could also help
5:53
us understand things like the mass of
5:54
Sagittarius a star, the geometry of
5:57
space-time near a super massive black
5:59
hole, and potentially even offer clues
6:02
about dark matter.
6:03
>> Now, it's important to be clear this is
6:05
still a candidate. The team published
6:07
their findings in the Astrophysical
6:09
Journal, and Breakthrough Listen has
6:11
released all the observational data
6:13
publicly, so researchers around the
6:15
world can do independent analyses.
6:17
Confirmation will require extensive
6:19
follow-up observations, but the
6:21
scientific community is buzzing. This is
6:24
the kind of discovery that reshapes
6:26
entire research programs if it holds up.
6:28
>> Keep watching the skies and the galactic
6:31
center. This story is far from over.
6:34
>> So, we've talked about what's happening
6:35
in Florida tonight and what might be
6:37
happening at the center of our galaxy.
6:39
Now, let's zoom all the way out, farther
6:42
than you've probably ever thought about,
6:44
and ask, how does the universe end?
6:47
>> For most of the past few decades, the
6:50
scientific consensus has been pretty
6:52
clear. The universe expands forever.
6:55
Dark energy, that mysterious force
6:57
making up roughly 68% of all the mass
7:00
and energy in the cosmos, was thought to
7:03
be a constant, relentlessly pushing
7:05
everything apart. Eventually, galaxies
7:08
would drift. so far from each other that
7:10
the night sky would go dark. Stars would
7:13
burn out. Everything would fade into a
7:16
cold, silent void. Scientists call this
7:19
the big freeze or heat death. But new
7:22
data is challenging that picture in a
7:24
dramatic way. Physicist Henry Thai at
7:26
Cornell University has published new
7:29
calculations using data from two of the
7:31
world's most powerful dark energy
7:33
observatories. The dark energy survey in
7:35
Chile and the dark energy spectroscopic
7:38
instrument in Arizona. And his
7:40
conclusion is striking. The universe may
7:42
be heading not for a freeze, but for a
7:45
crunch.
7:46
>> Here's how it works. Both surveys are
7:48
finding evidence that dark energy isn't
7:51
actually constant. It appears to be
7:53
weakening over time. If that's true,
7:56
then the force pushing the universe
7:57
apart is gradually fading. And at some
8:00
point, gravity takes over. The expansion
8:03
slows, stops, and then reverses.
8:06
Everything that has been flying apart
8:08
for billions of years begins falling
8:11
back together. A TAI model introduces a
8:14
hypothetical particle called an ultra
8:16
light axion combined with what's known
8:19
as a negative cosmological constant to
8:22
explain how dark energy could behave
8:24
this way. The math suggests the universe
8:27
is currently about 13.8 billion years
8:30
old and approaching the halfway point of
8:33
its total lifespan. It would continue
8:36
expanding for roughly another 11 billion
8:39
years, reach its maximum size, and then
8:42
begin to contract, ultimately collapsing
8:45
into a single point of unimaginable
8:47
density, the big crunch. Total elapsed
8:51
time approximately 33 billion years.
8:54
>> Now, before anyone starts updating their
8:56
bucket list, this is one model. It's not
8:59
yet scientific consensus. There's
9:01
healthy debate about how to interpret
9:03
the dark energy data and upcoming
9:05
missions from the European Space ay's
9:07
Uklid telescope, NASA Spherex project
9:10
and the Vera C Ruben Observatory will
9:13
provide much better measurements over
9:14
the coming years. But the very fact that
9:17
two independent observatories, one in
9:20
the southern hemisphere, one in the
9:22
northern, are converging on similar
9:24
results about dark energy evolving.
9:27
That's significant. As Tai himself put
9:30
it, for the last 20 years, people
9:33
believed the universe would expand
9:35
forever. The new data may be telling us
9:38
something very different.
9:39
>> The universe might be mortal after all.
9:42
Quite the thought to sit with on a
9:44
Thursday evening.
9:45
>> And now, because apparently one
9:48
existential revelation isn't enough for
9:50
one episode, let's talk about city
9:53
killer asteroids.
9:55
>> Those two words together are doing a lot
9:57
of work. They really are. So, at the
10:00
American Association for the Advancement
10:02
of Science conference in Arizona this
10:04
week, NASA's Planetary Defense Officer,
10:08
and yes, that is a real job title, Dr.
10:11
Kelly Fast, gave a presentation that's
10:14
been making headlines ever since, and
10:16
for good reason.
10:18
>> Dr. Fast explained that when it comes to
10:20
asteroids, there are essentially three
10:22
categories of concern. At the small end,
10:25
things are hitting Earth all the time.
10:26
meteors burning up in the atmosphere,
10:29
the occasional fireball. We're not
10:31
particularly worried about those. At the
10:33
large end, the extinction level rocks,
10:35
the movie asteroid kind, scientists are
10:38
actually fairly confident about where
10:40
those are. We track them. We know their
10:42
orbits.
10:43
>> It's the middle ground that keeps Dr.
10:46
Fast up at night. Asteroids in the range
10:48
of 140 m and larger, large enough to
10:52
devastate an entire city or a wide
10:55
region. but small enough to be difficult
10:58
to detect with current telescopes. Her
11:00
estimate there are around 25,000 of
11:03
these objects in the vicinity of Earth's
11:06
orbit.
11:06
>> And how many have we found? About 40%.
11:10
Meaning there are potentially 15,000
11:12
city killing space rocks out there right
11:14
now that we simply do not know about.
11:17
>> To add some context to that and to the
11:20
challenge of actually doing something
11:22
about it if we did spot one, Dr. Nancy
11:25
Shabet, the planetary scientist who led
11:27
NASA's Dart mission, the spacecraft that
11:30
successfully changed the orbit of an
11:32
asteroid back in 2022, was also at the
11:35
conference. She pointed out that DART
11:38
was a breakthrough demonstration, but
11:40
there isn't another one sitting on a
11:42
launchpad ready to go. She specifically
11:45
referenced the asteroid Y R4 which
11:48
caused some anxiety earlier this year
11:50
with a small but not zero probability of
11:53
a lunar impact in 2032. She said if
11:57
something like Y4 had been headed
12:00
towards the Earth, we would not have any
12:02
way to go and deflect it actively right
12:04
now.
12:05
>> The hope on the horizon is the Near
12:07
Earth Object Surveyor Telescope which is
12:10
planned for launch next year. Unlike
12:12
conventional optical telescopes, it uses
12:15
thermal infrared signatures to detect
12:18
darker asteroids that are essentially
12:20
invisible to conventional instruments.
12:23
Potentially a gamecher for the detection
12:25
side of the problem.
12:26
>> But Dr. Shabau's point stands. Detection
12:29
is one thing. Having an active readyto
12:32
deploy deflection capability is another.
12:35
And that investment, she says, is simply
12:37
not being made at the level that needs
12:39
to be. Something worth thinking about
12:41
given that planetary defense is probably
12:43
the one area of space science that is
12:46
quite literally about survival.
12:48
>> Sobering stuff. Let's come back down to
12:50
Earth for a moment. Or rather, let's
12:52
look up from it.
12:54
>> Here's something wonderful and
12:56
wonderfully timely because this one is
12:58
happening right now tonight as you
13:00
listen to this. Mercury, the innermost
13:03
planet of our solar system and the one
13:05
most people have never actually seen
13:07
with their own eyes, is tonight reaching
13:10
what astronomers call its greatest
13:12
eastern elongation. That's the point in
13:15
its orbit where it's at its maximum
13:17
angular distance from the sun as seen
13:19
from Earth. Meaning it appears as far
13:21
from the sun in our sky as it ever gets.
13:24
And why does that matter for observers?
13:26
Because Mercury is normally incredibly
13:29
difficult to spot. It's always close to
13:31
the sun in the sky, so you're either
13:33
trying to catch it just before sunrise
13:35
or just after sunset with very little
13:38
time before it follows the sun below the
13:40
horizon. But at greatest elongation, you
13:43
get the best window.
13:44
>> Tonight, look to the western horizon
13:47
shortly after sunset. Mercury will be
13:49
visible as a moderately bright point of
13:51
light, shining steadily rather than
13:54
twinkling like a star. You won't need
13:56
any special equipment, though.
13:57
Binoculars will give you a much nicer
14:00
view. This is Mercury's first greatest
14:02
elongation of 2026, and the best evening
14:06
viewing opportunity we'll get for the
14:07
year so far. There's also a bonus
14:10
tonight. The crescent moon, Saturn, and
14:12
Neptune are all gathering in the same
14:14
part of the sky, with Saturn and Neptune
14:17
very close together near the western
14:19
horizon. Now, Neptune will need a
14:21
telescope, and you'll need to wait until
14:23
the sun is fully set. Do not point any
14:26
optical instrument toward the horizon
14:28
until the sun has cleared it completely.
14:31
But the overall scene is really quite
14:33
beautiful this evening.
14:34
>> And for those of you keeping track of
14:36
the upcoming six planet parade on the
14:38
28th of February, Mercury reaching
14:41
greatest elongation tonight is actually
14:43
a key milestone in that buildup. By the
14:46
28th, Mercury will have improved its
14:48
position enough to join Venus, Saturn,
14:51
Jupiter, Uranus, and Neptune, all
14:53
visible in the same sky. We'll have a
14:56
full guide to that event closer to the
14:58
date, but tonight is your preview. Go
15:00
look west.
15:01
>> And now to close out the episode, we
15:04
have something that we absolutely love.
15:06
A reminder that even on a space station
15:08
in orbit, humans will find a way to
15:11
celebrate. The crew of China's Shenzhu
15:14
21 mission currently living and working
15:16
aboard the Tangong space station have
15:18
released a music video to mark the Lunar
15:20
New Year, the year of the horse. And
15:23
honestly, it is delightful. Filming a
15:26
music video in microgravity is, as you
15:28
might imagine, a unique creative
15:30
challenge. Everything floats. Hair
15:33
floats. Props float. But the crew
15:35
apparently embraced all of it. And the
15:38
result is one of those lovely, warm,
15:40
deeply human moments that cuts right
15:42
through all the geopolitical complexity
15:44
of the space race and reminds you that
15:47
the people up there are just people
15:49
celebrating a holiday with their
15:51
families watching from below. Pyong,
15:53
which means heavenly palace, currently
15:55
has a crew of three aboard following the
15:57
Shenzhu 21 mission. China has been
16:00
steadily expanding its space station
16:02
program. And moments like this one
16:04
shared with the world are a reminder of
16:07
why humans go to space in the first
16:09
place. Not just for science or national
16:12
prestige, but for the sheer joy of being
16:14
up there.
16:16
>> Dang fai to all of our listeners
16:18
celebrating the lunar new year. May the
16:20
year of the horse bring you good fortune
16:22
and hopefully fewer hydrogen leaks.
16:26
And on that note, that's your Astronomy
16:28
Daily for Thursday, February 19th, 2026.
16:33
What a lineup today. A live rocket
16:36
fueling test, a cosmic clock near a
16:38
black hole, the possible end of the
16:40
universe, city killing asteroids,
16:43
Mercury in the evening sky, and a music
16:46
video from orbit.
16:48
>> If you want to follow along with the
16:49
Aremis 2 fueling test tonight, NASA has
16:52
a live stream at nasa.gov. We'll link
16:55
everything in the show notes. And if you
16:57
spot Mercury tonight, tag us on social
16:59
media at Astro Daily Pod. We would love
17:02
to see your photos.
17:03
>> Subscribe, leave a review if you're
17:05
enjoying the show, and we will be back
17:07
tomorrow with the results of tonight's
17:09
fueling test. Until then, keep looking
17:12
up.
17:13
>> Clear skies, everyone.
17:25
Stories told.