Howdy stargazers, and welcome to this episode
of Star Trails. Drew here, and I'll be your guide
to the night sky for the week starting June 29th
through July the 5th. If you're in the US, many
of us will be out on the evening of July the
4th catching fireworks with friends or family.
But there's a cosmic fireworks show overhead
too. Also, last week seemed to bring a never
-ending array of wild astronomy news. From the
largest comet ever detected, the oldest galaxy
ever photographed, to discoveries in the weird
world of dark matter. We'll talk about all that
and even more in the second half of the show.
Whether you're tuning in from the backyard, the
balcony, or just your imagination, I'm glad you're
here. So find a cozy spot, let your eyes adjust,
and let's see what the sky holds for us this
week. Let's start with one of the prettiest pairings
of the week. Tonight, June 29th, look to the
western sky just after sunset. There you'll see
a delicate waxing crescent moon, only about 22
% illuminated, hanging out close to the planet
Mars. Nearby, you'll also spot Regulus, the brightest
star in the constellation Leo. If you have a
pair of binoculars, this little triangle of light,
the Moon, Mars, and Regulus, makes a perfect
early evening target. And, for those of you in
North and South America, there's a chance the
Moon might even briefly pass in front of Mars,
what astronomers call an occultation. We won't
all be able to see it. So check in on an astronomy
app such as Stellarium to see if the occultation
is visible in your area. Between now and July
the 5th, we're also catching the tail end of
the June boated meteor shower. This one's usually
pretty mellow, maybe a few meteors per hour,
but every now and then it surprises us with a
sudden outburst. If you're outside late in the
coming days, especially under dark skies, keep
an eye out for slow bright streaks drifting out
of the northern sky near the constellation Boötes.
There's a small planetary parade for early risers.
Just before sunrise, look toward the eastern
sky to catch Venus, shining like a cosmic spotlight.
It's the brightest thing in the sky after the
moon right now. Further to the east, Saturn is
climbing higher each day. Jupiter is rising as
well, but it's just ahead of the morning sun
and lost in the glare. Uranus is hanging out
around the Pleiades, but as usual, you'll need
a telescope to see it. Back in the evening sky,
Mercury is peeking out of the twilight haze.
Between now and June 30th, it passes near the
Beehive Cluster. also known as Messier 44 in
the constellation Cancer. Grab a pair of binoculars
and try to catch this pairing in the northwest
right after sunset. The beehive cluster looks
like a soft sprinkling of stars, and Mercury
will be just nearby, like a bright pearl in a
field of fireflies. It will set quickly, and
you'll need a clear view to the western horizon.
Now is also the perfect time to get reacquainted
with the Summer Triangle. This asterism made
up of the bright stars Vega, Deneb, and Altair
dominates the southern sky by 10pm and leads
you right into the rich star fields of the Milky
Way. Look higher overhead and you'll find Cygnus
the Swan flying along the Milky Way's path. while
Boötes and its bright orange star Arcturus glide
westward. If the sky is clear, you'll be able
to see the Milky Way as a faint misty band stretching
across the sky from northeast to southwest. It's
one of the best times of the year to see our
galaxy from the inside. The new moon just passed
us on June 25th, which still means we're getting
darker skies earlier in the week. The first quarter
moon lands around July 2nd and will rise near
sunset, staying bright until past midnight. It's
a good opportunity to study lunar craters with
a small telescope. Some weeks it feels like the
universe is just showing off, and lately it's
been putting on a real show. Whether it's ancient
galaxies turning up in the deep field, mysterious
matter finally stepping into the light, the largest
comet ever spotted, or an asteroid on a moonshot
trajectory, there's been no shortage of cosmic
headlines to catch our eye this week. Oh, and
I almost forgot, down south in my neck of the
woods, we had a giant daytime meteor light up
the summer skies a few days ago. complete with
a sonic boom. It was caught by everything from
security cameras to dash cams across the southeast
states. Before we dig into our big story about
one of the most powerful telescopes ever built
finally opening its eye on the universe, let's
take a quick spin through some of the quirkiest
and most fascinating space news of the week.
First up, an asteroid dubbed 2024 YR4, a near
-Earth object roughly 250 meters across, has
made headlines for a pretty unusual reason. Unlike
most asteroids we worry about hitting us, this
one's projected to strike the Moon sometime in
late 2028. Scientists are actually taking it
seriously, not because it'll destroy the moon,
but because it could create a blast visible from
Earth and possibly threaten satellites orbiting
nearby. Even more fascinating, the impact would
provide an unplanned but valuable experiment
in lunar geology and space debris dynamics. Instruments
from NASA and the European Space Agency could
get real -time data on the effects of a mid -sized
asteroid collision on the moon's surface. So,
while it's technically a city killer, fortunately,
it's not aiming for us. Next up, let's meet Zhulong,
which means red dragon in Mandarin. This beauty
is the most distant grand design spiral galaxy
ever discovered, spotted by the James Webb Space
Telescope at an eye -watering 12 .3 billion light
-years away. Now remember, the universe is believed
to be around 13 .8 billion years old, so the
light from this galaxy has taken almost as long
to travel here as the universe has been in existence,
and that's absolutely mind -blowing when you
think about it. And here's the kicker, spiral
galaxies, those majestic pinwheels like our Milky
Way, aren't supposed to be this well -formed
so early in the universe. At this distance, we're
seeing Zhulong as it looked just 1 .5 billion
years after the Big Bang. That's a baby photo,
cosmically speaking. Most galaxies back then
were chaotic blobs, still in their awkward teenage
phase. But Zhulong is already posing for the
Hubble catalog. Its existence suggests galaxy
formation models may need some tweaking, or that
cosmic order arrived much sooner than we thought.
And speaking of cosmic giants, one of the solar
system's true leviathans is stirring out past
Saturn. Meet comet C2014UN271, also known as
Bernardinelli -Bernstein. a name almost as massive
as the object itself. This isn't your typical
icy visitor. Bernardinelli Bernstein is estimated
to be between 120 and 150 kilometers wide. That's
about 10 times the size of a typical comet and
roughly the size of the state of Rhode Island.
It's currently inbound from the Oort cloud, that
distant shell of icy bodies that surrounds our
solar system like a cosmic deep freezer. Even
though it's still more than 16 astronomical units
from the Sun, that's beyond the orbit of Uranus,
it's already active, venting gas and long frosty
jets. In fact, it was one of the most distant
comets ever observed with a visible coma. Its
closest approach will bring it only as near as
11 AU, and you may recall 1 AU is the distance
from the Earth to the Sun. It will remain well
outside Saturn's orbit by 2031, but its sheer
size and activity make it an incredible object
of study. It's basically a time capsule from
the solar system's earliest days, and we're getting
a front row seat. as it thaws out. And here's
one more quick news item. It's a true mystery
with a twist ending. For decades, astronomers
have known that the visible matter in the universe,
the stuff made of protons, neutrons, and electrons,
also known as baryonic matter, just didn't add
up. The math said it should be there, but when
we looked, only about half of it could be found
in stars, gas clouds, and galaxies. Enter fast
radio bursts, or FRBs, those strange ultra -short
flashes of radio waves from deep space. Scientists
realized they could use FRBs like X -rays, tracking
how much ordinary matter each signal passed through.
Using a network of these bursts, astronomers
found the missing baryons in long, wispy filaments
of gas stretched between galaxies. It's kind
of like finding socks that fell behind the dryer,
except on a cosmic scale. The science is evolving
as we speak, so hopefully we'll learn more in
the near future. And now for the big story this
week, the Vera C. Rubin Observatory, named after
the pioneering astronomer who helped discover
dark matter. It's finally awake and it's already
making waves. Last Monday, the Rubin team released
the telescope's first full -color, first light
image, taken with its 3200 -megapixel camera,
the largest digital camera ever built for astronomy.
This thing is an absolute monster in the best
possible way. Imagine a camera the size of a
small car, sensitive enough to detect a flashlight
from the moon, snapping the entire night sky
again and again for 10 years. The Rubin Observatory
is located in northern Chile, taking advantage
of some of the clearest skies on Earth. Its main
project is the legacy survey of space and time.
a decade -long scan of the southern sky that
will create the most detailed time lapse of the
universe ever made. Three things make Rubin stand
out from other observatories. One, its size and
speed. Rubin has an 8 .4 -meter mirror and can
image the entire southern sky every few nights.
Two, its resolution. With 3 .2 gigapixels per
image, Rubin can pick up faint, fast, and fleeting
objects, like asteroids zipping by or supernovae
popping off across the universe. And three, it's
collecting a massive amount of data. Over 10
years, Rubin will collect about 20 terabytes
of data per night, building a vast database of
how the sky changes over time. The first image
from Rubin is a beauty. The debut features regions
including the Virgo Cluster with hundreds of
galaxies packed into view, the Lagoon and Trifid
Nebula bursting with color and gas, and a segment
of the large Magellanic Cloud that looks like
a cosmic wave cresting. Even more impressively,
in just its first 10 hours of scanning, Rubin
detected more than 2 ,000 new asteroids, most
of which were unknown to previous sky surveys.
Eventually, Rubin is expected to detect billions
of galaxies, millions of supernovae, and track
hundreds of thousands of near -Earth objects,
all while helping scientists tackle the biggest
questions in astronomy. from dark matter and
dark energy to the origin of the Milky Way. And
with the data pouring in, who knows what surprises
the telescope might catch next? Rogue planets,
asteroid impacts, or the blink of a dying star?
where you can contact me and explore past episodes.
Be sure to follow us on Blue Sky and YouTube.
Links are in the show notes. Until we meet again
beneath the stars, clear skies everyone.