Howdy Star Gazers and welcome to Star Trails.
I'm Drew and I'll be your guide to the night
sky for the week of Sunday, August the 24th to
the 30th. This is a week that begins in darkness
and ends with a silver lantern in the sky, thanks
to a waxing moon. We'll take a look at what else
is up this week and in the second half of the
show, We journey out to Uranus where a tiny new
moon has just been discovered. More importantly,
we wonder, what would it be like to walk around
this tiny moon? 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. The new moon slipped
past us on August the 23rd, which means the first
half of this week belongs to deep -sky hunters,
galaxies, clusters, and nebula without the lunar
washout. But each evening, the waxing crescent
grows larger, rising higher in the west until
it becomes a bright beacon by Saturday night.
Try for the razor -thin crescent earlier in the
week low in the west 20 to 45 minutes after sunset.
By the week's end, the crescent is high enough
to sketch shadows along the terminator when viewed
with binoculars. Saturn is the planetary star
of the show this week. It lifts itself into the
southeastern sky by mid -evening. Its rings tilted
just enough to remind us why Galileo once called
them ears. A small telescope will reveal Titan
as a tiny golden companion. and with larger optics
you'll spot multiple moons strung like faint
pearls nearby. Look east before dawn and you'll
find a brighter spectacle, Venus blazing like
a spotlight with Jupiter tagging along. They've
been in conjunction recently, but even as they
drift apart they still share binocular fields
like two bright exclamation points in the morning
twilight. In the evening, Mars is hanging low
in the western twilight for about 45 -60 minutes
after sunset. It's small and faint now, so we
can treat it as a goodbye glance object this
week. Uranus rises around midnight, high before
dawn, in Taurus, drifting beneath the Pleiades
this month, which makes it an easy star -hop
target for 50 -70mm binoculars under dark skies.
Telescopes will reveal a tiny greenish disc.
Another meteor shower, the Aurigids, arrives
this week, active from August 28th into early
September. They're usually modest, maybe 10 streaks
per hour at their best, but they're quirky. The
shower is known for sharp, unpredictable bursts.
Their radiant lies in Auriga, climbing high before
dawn. So the best time to watch is the final
hours of darkness on Friday and Saturday morning.
With only a slim crescent moon, the sky is yours.
Now let's wander away from the summer triangle
and dip into some lesser traveled constellations
you can see this month. Lacerda the lizard is
a faint zigzag north of Cygnus, often overlooked.
Its pattern is delicate, more a whisper than
a shout. But sweep binoculars through and you'll
stumble across the open cluster NGC 7243, a loose
scattering of stars that looks like a spilled
box of jewels. Lacerda was only added to the
official sky maps in the 17th century, a relative
newcomer compared to the ancient Greek constellations.
Aquarius, the water bearer, sits lower in the
south, sprawling and hard to trace. In mythology,
Aquarius pours the life -giving waters onto the
Earth, but for observers it hides treasures of
a different sort. Look for the globular cluster
M2, a dense ball of stars about 37 ,000 light
-years away, so bright that even small telescopes
can resolve its grainy edges. The ancients saw
Aquarius as a bringer of floods. Astronomers
see him as a keeper of starry vaults. And then
there's Capricornus, the sea goat, straddling
myth's line between land and water. To the eye,
it's a pair of shallow triangles, almost like
a sideways smile, low in the southern sky. In
lore, the sea goat is tied to Pan. who leapt
into the Nile to escape a monster, half transformed
into a fish. Through the eyepiece, Capricornus
is a playground of doubles and patterns, a geometry
lesson written in stars. Scan slowly and you'll
find the planet Saturn parked here this season,
the mythic goat, sharing the stage with the Lord
of the Rings. These constellations may not command
the same fame as Orion or Scorpius, but they
reward patient eyes with quiet wonders. You may
have heard last week that a new moon has been
discovered around Uranus, thanks to careful observations
by the James Webb Space Telescope. This moon
is only about six miles across, which made me
wonder, is it possible to walk around it? That's
coming up after the break. Stay with us. Welcome
back! Astronomers have just added another body
to Uranus's family tree, a tiny moon barely 6
miles across whirling around the planet in less
than 10 hours per orbit. That bumps the official
moon count for Uranus to 29. The little moon
is currently only known by its placeholder name,
S -2025U1. But in keeping with tradition, it'll
possibly be given a literary name, perhaps a
character from Shakespeare or Alexander Pope.
The discovery was made with the James Webb Space
Telescope with its jaw -dropping sensitivity
and ability to view the near -infrared. The new
moon was spotted tucked within Uranus's inner
ring system, a region previously blind to Voyager
2 and Hubble. It's kind of like spotting a pebble
from a hundred miles away. Uranus already has
a wonderfully eccentric entourage. There are
the five big rounded moons, Titania, Oberon,
Ariel, Umbriel, and Miranda. These are strange
places carved by canyons, cliffs, and perhaps
hiding briny underground seas. Then there's a
swarm of smaller inner moons that shepherd the
planet's delicate rings, and even more distant
irregular satellites looping in eccentric orbits.
Voyager 2 gave us our first and only close -up
look back in 1986, discovering many of these
worlds in a single flyby. Since then, telescopes
have slowly filled in the roster. But this new
web find fascinates me because of its size. Normally,
when we're talking about topics in astronomy,
we're measuring objects that are incomprehensible
in size and scale. We often need to resort to
exponents, 10 to some power, to describe distances,
mass, and so on. For example, something gigantic,
like the Milky Way galaxy, has a diameter around
10 to the 24th power in meters. That's a 1 followed
by 24 zeros, a nearly incomprehensible number.
But this newly discovered moon is really tiny
in a way that makes it relatable. Some of you
may know that I'm a walker. I try to get out
and walk every day if possible, and, in fact,
one of these late -night Constitutionals planted
the seed that resulted in this podcast. At just
10 kilometers across, this new moon is so small
you could, in theory, walk all the way around
it in a few hours. The idea intrigues me, a hiker's
circuit of an entire moon before lunch. The catch
is, of course, gravity. Does an object this small
produce enough gravity to keep an average human
rooted on its surface? So we did the math, and
the numbers are fascinating. Let's take a look
at some figures, and just know these are estimates.
The new moon is only about 10 kilometers across,
or roughly 6 miles. That means a radius of around
5 ,000 meters. If it's made of dark, icy or rocky
material like Uranus's other inner moons, perhaps
we can estimate the density around 1200 to 1800
kg per cubic meter. That means its surface gravity
works out to roughly 0 .00017 or thereabouts
to 0 .00026 g. That's around 4 ,000 to 6 ,000
times weaker than Earth's gravity. On Earth,
gravity is a firm tug. On S -2025U1, it's practically
a whisper. Surface gravity would be about 2 ten
-thousandths of Earth's. Put another way, if
you weigh 180 pounds here, you'd weigh less than
an ounce there. The escape velocity, that's the
speed you need to break free entirely, is only
around 10 miles per hour. That's a hard jog.
Trip and shove off too forcefully, and you wouldn't
come down, you'd be in orbit for a moment and
likely drifting away into space. So, would walking
even work? Well, not in the traditional sense.
Each step would act more like a little launch.
You'd move in slow arcs, spending most of your
time hovering above the surface before settling
back down. To stay grounded, you'd need a tether,
or something you can use to stay connected to
the ground, kind of like an ice climber using
a pick on a slippery slope. With care, you could
shuffle around, but it would feel like spelunking
on a giant trampoline in slow motion. Like the
Earth's moon, the new Uranian moon is tidally
locked, so it spins only once every time it orbits
Uranus, about every 9 .6 hours. So at the equator,
the ground slides under you at around 2 miles
per hour. That slightly reduces effective gravity
and escape speed at the equator by 5 to 10 percent.
For comparison, Mars's tiny moon, Deimos, which
is a bit larger than this object, has an escape
speed around jogging pace. People often point
out you can almost jump to orbit. This new moon
is in that same ballpark. There's another factor
at play here, and that's the tidal forces of
Uranus itself. If you're trying to walk on the
side of the moon facing Uranus, things get a
little ticklish. You'd be even floatier, thanks
to the massive influence of Uranus, which steals
about a quarter of your already light weight.
You won't be yanked into space while you're standing
still, but a gentle hop could send you flying.
I hope you enjoyed this little thought experiment,
or daydream, really. There's something beautifully
peculiar about Uranus. It's a sideways spinning
planet. hiding possible oceans and ring moon
chaos that defies typical orbits. Now Webb has
shown us that Uranus contains even more secrets
and reminds us that the solar system is a lot
less static than we sometimes think. If the stars
spoke to you this week or if a question's been
on your mind, I'd love to hear it. Visit our
website, StarTrails .Show, 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.