0:00
Tyler Reddick here from 2311 Racing.
0:03
Yeah, it's even better with Chamba by my side.
0:06
Race to chumpacaceno.com.
0:09
No purchase necessary, VTW Group.
0:11
Void we're prohibited by law.
0:12
CT and C's, 21 plus sponsored by Chamba Casino.
0:15
Welcome to Astronomy Daily.
0:19
It is Thursday the 19th of February, 2026.
0:23
And we are recording this episode
0:25
while NASA is literally fueling a rocket
0:28
at this very moment.
0:29
And we cannot wait to tell you about it.
0:32
That's right, this is one of those days
0:34
where space news isn't just something
0:36
that happened somewhere out there in the universe.
0:39
It is happening right now on a launch pad in Florida.
0:44
Today, we're also asking what lurks in the darkness
0:48
between us and our nearest cosmic neighbors?
0:51
Could there be a cosmic clock ticking next
0:53
to the most extreme object in our galaxy?
0:56
And brace yourselves, is the universe actually going to end?
1:01
Plus, we have a story that will make you
1:03
want to check the sky tonight.
1:05
A warning from NASA that is genuinely a little unsettling.
1:09
And we're going to space with the music video.
1:11
All of that is coming up on Astronomy Daily.
1:14
Let's start with the big one.
1:16
And I mean big in every sense of the word.
1:19
As we speak, NASA's space launch system,
1:22
the most powerful rocket ever built,
1:25
is being loaded with more than 700,000 gallons
1:28
of cryogenic propellant at Launch Complex 39B
1:32
at Kennedy Space Center in Florida.
1:35
This is the second wet dress rehearsal for Artemis II,
1:38
the mission that will carry four astronauts
1:40
on a loop around the moon.
1:42
The first time humans have ventured to lunar distance
1:44
since Apollo 17 back in 1972.
1:48
The crew are Commander Reed Weisman, Pilot Victor Glover,
1:52
Mission Specialist Christina Cokes from NASA,
1:55
and Jeremy Hansen from the Canadian Space Agency.
1:58
Now, the reason they're doing this rehearsal
2:01
and the reason there have been so many eyes on it today
2:04
is that the first attempt back on the second
2:06
and third of February did not go as planned.
2:09
Engineers detected a liquid hydrogen leak during fueling,
2:13
which forced them to halt the test
2:15
before they could complete the full countdown sequence.
2:18
In the week since, technicians have replaced seals
2:21
around two fueling lines, swapped out a filter
2:24
and the ground support equipment,
2:25
and added an extra hour of buffer time
2:27
into the countdown to allow more room for troubleshooting.
2:31
It's the kind of painstaking, un-glamorous engineering work
2:34
that rarely makes headlines,
2:36
but it's exactly what keeps astronauts alive.
2:39
Today's rehearsal targets a simulated launch window opening
2:42
at 8.30 this evening, Eastern time.
2:45
The test is expected to run until around 12.30 Friday morning
2:49
and the stakes are high.
2:51
NASA has said it won't set a formal launch date
2:54
until after a successful wet dress rehearsal campaign.
2:58
March 6th remains the earliest possible crude launch date.
3:02
NASA Administrator Jared Isaacman put it well
3:04
when he said, we anticipated encountering challenges
3:08
that is precisely why we conduct a wet dress rehearsal.
3:11
These tests are designed to surface issues before flight.
3:14
The safety of the crew comes first.
3:17
So tonight, we watch and we wait.
3:19
We will be keeping a close eye on this one
3:22
and will bring you the results in tomorrow's episode.
3:25
Fingers crossed for a clean test.
3:27
No leaks and a March launch that puts humans
3:30
back in the vicinity of the moon
3:32
for the first time in over 50 years.
3:35
All right, from a rocket at Kennedy Space Center
3:37
to the absolute heart of our galaxy.
3:40
And this story is one of those discoveries
3:42
that if it's confirmed, could fundamentally change
3:45
how we understand the universe.
3:48
Researchers from Columbia University
3:50
working with the Breakthrough Listen Initiative,
3:52
which is best known for searching
3:54
for signs of intelligent life beyond Earth,
3:56
have announced the detection of a candidate millisecond pulsar
4:00
very close to Sagittarius A star.
4:03
That's the supermassive black hole sitting
4:06
at the center of the Milky Way,
4:08
roughly four million times the mass of our own sun.
4:11
So let's unpack what a pulsar is
4:14
because it's one of the most extraordinary objects
4:19
When a massive star reaches the end of its life
4:21
and explodes as a supernova,
4:23
what's left behind is an incredibly dense core
4:26
called a neutron star.
4:28
Some of those neutron stars spin rapidly
4:31
and emit beams of radio waves
4:33
like a cosmic lighthouse sweeping through space.
4:36
When those beams sweep past Earth,
4:38
we detect them as regular pulses, hence pulsar.
4:42
And what makes millisecond pulsar special
4:45
is their extraordinary precision.
4:47
They spin hundreds of times per second
4:49
with almost perfect regularity.
4:52
Scientists have called them the most accurate clocks
4:55
more stable than atomic clocks here on Earth.
4:58
This candidate, nicknamed BLPSR,
5:00
completes one full rotation every 8.19 milliseconds.
5:05
Now, here's why finding one near Sagittarius A star
5:10
A pulsar next to a 4 million solar mass black hole
5:14
would be operating in one of the most extreme
5:16
gravitational environments imaginable.
5:19
And Einstein's general theory of relativity
5:22
makes very specific predictions
5:24
about what happens to space and time
5:26
in such extreme environments.
5:28
Predictions that have never been tested
5:30
at this level of precision.
5:32
And if a pulsar is orbiting close to Sagittarius A star,
5:36
the black hole's gravity would warp space times so severely
5:39
that those precise pulsar pulses
5:41
would arrive at our telescopes with tiny,
5:44
but measurable distortions.
5:46
As researchers love co-bognav from Columbia put it,
5:49
any external influence on a pulsar
5:51
would introduce anomalies in the steady arrival of pulses,
5:55
which can be measured and modeled.
5:57
In other words, a confirmed pulsar next to a supermassive
6:00
black hole would be a natural laboratory
6:02
for testing Einstein's gearies
6:04
in the most extreme conditions possible.
6:07
It could also help us understand things
6:09
like the mass of Sagittarius A star,
6:11
the geometry of space time near a supermassive black hole,
6:15
and potentially even offer clues about dark matter.
6:18
Now, it's important to be clear,
6:20
this is still a candidate.
6:22
The team published their findings
6:23
in the astrophysical journal and breakthrough listen
6:26
has released all the observational data publicly.
6:29
So researchers around the world
6:30
can do independent analyses.
6:32
Confirmation will require extensive follow-up observations,
6:36
but the scientific community is buzzing.
6:38
This is the kind of discovery
6:40
that reshapes entire research programs if it holds up.
6:43
Keep watching the skies and the galactic center.
6:46
This story is far from over.
6:49
So we've talked about what's happening in Florida tonight
6:51
and what might be happening at the center of our galaxy.
6:54
Now let's zoom all the way out.
6:57
Farther than you've probably ever thought about,
6:59
and ask, how does the universe end?
7:02
For most of the past few decades,
7:04
the scientific consensus has been pretty clear.
7:08
The universe expands forever.
7:10
Dark energy, that mysterious force
7:12
making up roughly 68% of all the mass and energy
7:16
in the cosmos, was thought to be a constant,
7:19
relentlessly pushing everything apart.
7:22
Eventually, galaxies would drift so far from each other
7:25
that the night sky would go dark.
7:27
Stars would burn out.
7:29
Everything would fade into a cold, silent void.
7:33
Scientists call this the big freeze or heat death.
7:36
But new data is challenging that picture in a dramatic way.
7:40
Physicist Henry Tai at Cornell University
7:43
has published new calculations using data
7:45
from two of the world's most powerful dark energy
7:48
observatories, the dark energy survey in Chile
7:51
and the dark energy spectroscopic instrument in Arizona.
7:54
And his conclusion is striking.
7:57
The universe may be heading not for a freeze,
8:01
Here's how it works.
8:02
Both surveys are finding evidence
8:04
that dark energy isn't actually constant.
8:07
It appears to be weakening over time.
8:10
If that's true, then the force pushing the universe apart
8:13
is gradually fading.
8:15
And at some point, gravity takes over.
8:17
The expansion slows, stops, and then reverses.
8:21
Everything that has been flying apart
8:23
for billions of years begins falling back together.
8:27
A Tai's model introduces a hypothetical particle
8:30
called an ultralight axion,
8:33
combined with what's known as a negative cosmological constant
8:37
to explain how dark energy could behave this way.
8:40
The math suggests the universe is currently
8:43
about 13.8 billion years old and approaching
8:47
the halfway point of its total lifespan.
8:50
It would continue expanding for roughly
8:52
another 11 billion years, reach its maximum size,
8:56
and then begin to contract, ultimately collapsing
9:00
into a single point of unimaginable density.
9:03
The big crunch, total elapsed time,
9:06
approximately 33 billion years.
9:09
Now, before anyone starts updating their bucket list,
9:13
It's not yet scientific consensus.
9:16
There's healthy debate about how to interpret
9:18
the dark energy data and upcoming missions
9:20
from the European Space Agency's Euclid Telescope,
9:24
NASA's FIREX project, and the Veracirubin Observatory
9:28
will provide much better measurements over the coming years.
9:31
But the very fact that two independent observatories,
9:35
one in the southern hemisphere, one in the northern,
9:38
are converging on similar results
9:40
about dark energy evolving, that's significant.
9:44
As Tai himself put it, for the last 20 years,
9:47
people believed the universe would expand forever.
9:51
The new data may be telling us something very different.
9:55
The universe might be mortal after all.
9:57
Quite the thought to sit with on a Thursday evening.
10:00
And now, because apparently one existential revelation
10:04
isn't enough for one episode,
10:06
let's talk about city-killer asteroids.
10:10
Those two words together are doing a lot of work.
10:14
So at the American Association for the Advancement
10:17
of Science Conference in Arizona this week,
10:20
NASA's Planetary Defense Officer,
10:23
and yes, that is a real job title,
10:26
Dr. Kelly Fast gave a presentation
10:28
that's been making headlines ever since,
10:31
and for good reason.
10:33
Dr. Fast explained that when it comes to asteroids,
10:36
there are essentially three categories of concern.
10:39
At the small end, things are hitting Earth all the time.
10:41
Meteors burning up in the atmosphere, the occasional fireball.
10:45
We're not particularly worried about those.
10:48
At the large end, the extinction level rocks,
10:50
the movie asteroid kind,
10:53
scientists are actually fairly confident about where those are.
10:56
We track them, we know their orbits.
10:58
It's the middle ground that keeps Dr. Fast up at night.
11:02
Asteroids in the range of 140 meters and larger,
11:06
large enough to devastate an entire city or a wide region,
11:11
but small enough to be difficult to detect
11:13
with current telescopes.
11:15
Her estimate, there are around 25,000 of these objects
11:19
in the vicinity of Earth's orbit.
11:22
And how many have we found?
11:25
Meaning there are potentially 15,000 city-killing space rocks
11:29
out there right now that we simply do not know about.
11:32
To add some context to that,
11:34
and to the challenge of actually doing something about it,
11:37
if we did spot one, Dr. Nancy Shabbat,
11:40
the planetary scientist who led NASA's Dart mission,
11:44
the spacecraft that successfully changed the orbit
11:47
of an asteroid back in 2022, was also at the conference.
11:51
She pointed out that Dart was a breakthrough demonstration,
11:55
but there isn't another one sitting on a launch pad
11:59
She specifically referenced the asteroid YR4,
12:03
which caused some anxiety earlier this year
12:05
with a small but not zero probability
12:08
of a lunar impact in 2032.
12:11
She said, if something like YR4 had been headed towards the Earth,
12:16
we would not have any way to go and deflect it actively
12:20
The hope on the horizon is the near-earth object
12:23
surveyor telescope, which is planned for launch next year.
12:27
Unlike conventional optical telescopes,
12:29
it uses thermal infrared signatures
12:32
to detect darker asteroids that are essentially invisible
12:36
to conventional instruments, potentially
12:38
a game changer for the detection side of the problem.
12:41
But Dr. Shabbat's point stands.
12:44
Detection is one thing.
12:45
Having an active ready-to-deploy deflection capability
12:49
is another, and that investment, she says,
12:52
is simply not being made at the level that needs to be.
12:55
Something worth thinking about, given that planetary defense
12:58
is probably the one area of space science
13:00
that is quite literally about survival.
13:03
Sobering stuff, let's come back down to Earth for a moment,
13:06
or rather, let's look up from it.
13:09
Here's something wonderful and wonderfully timely,
13:12
because this one is happening right now,
13:14
tonight, as you listen to this.
13:17
Mercury, the innermost planet of our solar system,
13:20
and the one most people have never actually seen
13:23
with their own eyes, is tonight reaching
13:25
what astronomers call its greatest eastern elongation.
13:29
That's the point in its orbit,
13:30
where it's at its maximum angular distance
13:33
from the sun as seen from Earth,
13:35
meaning it appears as far from the sun in our sky
13:39
And why does that matter for observers?
13:41
Because Mercury is normally incredibly difficult to spot.
13:45
It's always close to the sun in the sky,
13:47
so you're either trying to catch it just before sunrise
13:50
or just after sunset, with very little time
13:53
before it follows the sun below the horizon.
13:56
But at greatest elongation, you get the best window.
13:59
Tonight, look to the western horizon
14:02
shortly after sunset.
14:03
Mercury will be visible as a moderately bright point of light,
14:07
shining steadily rather than twinkling like a star.
14:10
You won't need any special equipment,
14:12
though binoculars will give you a much nicer view.
14:15
This is Mercury's first greatest elongation of 2026,
14:19
and the best evening viewing opportunity
14:22
will get for the year so far.
14:24
There's also a bonus tonight.
14:25
The crescent moon, Saturn, and Neptune
14:28
are all gathering in the same part of the sky.
14:31
With Saturn and Neptune very close together
14:33
near the western horizon.
14:35
Now Neptune will need a telescope,
14:37
and you'll need to wait until the sun is fully set.
14:40
Do not point any optical instrument
14:42
toward the horizon until the sun has cleared it completely.
14:46
But the overall scene is really quite beautiful this evening.
14:49
And for those of you keeping track
14:51
of the upcoming six planet parade on the 28th of February,
14:55
Mercury reaching greatest elongation tonight
14:57
is actually a key milestone in that buildup.
15:00
By the 28th, Mercury will have improved its position
15:03
enough to join Venus, Saturn, Jupiter, Uranus, and Neptune,
15:08
all visible in the same sky.
15:10
We'll have a full guide to that event closer to the date.
15:13
But tonight is your preview.
15:17
And now to close out the episode,
15:19
we have something that we absolutely love,
15:21
a reminder that even on a space station in orbit,
15:25
humans will find a way to celebrate.
15:27
The crew of China's Shenzu 21 mission,
15:30
currently living and working aboard the Tiangong space station,
15:33
have released a music video to mark the lunar new year,
15:36
the year of the horse, and honestly, it is delightful.
15:40
Filming a music video in microgravity is, as you might imagine,
15:44
a unique creative challenge.
15:46
Everything floats, hair floats, props float,
15:50
but the crew apparently embraced all of it.
15:52
And the result is one of those lovely, warm, deeply human moments
15:56
that cuts right through all the geopolitical complexity
16:00
of the space race and reminds you
16:02
that the people up there are just people,
16:04
celebrating a holiday with their families watching from below.
16:07
Tiangong, which means heavenly palace,
16:10
currently has a crew of three aboard,
16:12
following the Shenzu 21 mission.
16:14
China has been steadily expanding its space station program,
16:18
and moments like this one, shared with the world,
16:21
are a reminder of why humans go to space in the first place,
16:25
not just for science or national prestige,
16:28
but for the sheer joy of being up there.
16:31
Dongxi Fachaie to all of our listeners
16:33
celebrating the lunar new year.
16:35
May the year of the horse bring you good fortune
16:37
and hopefully fewer hydrogen leaks.
16:41
And on that note, that's your astronomy daily
16:44
for Thursday, February 19th, 2026.
16:48
What a lineup today, a live rocket fueling test,
16:52
a cosmic clock near a black hole,
16:54
the possible end of the universe, city killing asteroids,
16:58
Mercury in the evening sky, and a music video from orbit.
17:03
If you wanna follow along with the Artemis II fueling test
17:06
tonight, NASA has a live stream at nasa.gov.
17:09
We'll link everything in the show notes.
17:11
And if you spot Mercury tonight,
17:13
tag us on social media at Astro DailyPod.
17:16
We would love to see your photos.
17:18
Subscribe, leave a review if you're enjoying the show,
17:21
and we will be back tomorrow with the results
17:23
of tonight's fueling test.
17:25
Until then, keep looking up.
17:28
Clear skies, everyone.
17:29
The astronomy day, the star is the toe.
17:35
The star is the toe.
17:43
The star is the toe.
17:50
The star is the toe.
17:53
Telloretic here from 2311 Racing.
17:55
Game night's fun until someone spends five minutes
17:58
lining up one shot.
17:59
Chalk, breathe, reach-shock, still aiming.
18:03
While they figure it out, I fire up Chamba Casino.
18:05
I can spin anywhere, anytime,
18:07
and there's always a new social casino game every week.
18:10
Spins happen way faster than that shot.
18:13
Play now at chambacasino.com.
18:16
Sponsored by Chamba Casino, no purchase necessary.
18:19
VGW Group, voidware prohibited by law,
18:21
21 plus terms and conditions apply.