Howdy Star Gazers and welcome to this episode
of Star Trails. Drew here, and I'll be your guide
to the night sky for the week starting August
3rd to the 9th. This week brings us a bright
summer moon, planets in both the evening and
morning skies, and a few lingering meteors. Later
in the episode, we'll head to the frozen frontier
of the solar system to meet a brand new world,
nicknamed Ammonite, and explore what it means
for the ongoing mystery of Planet Nine. So let's
step outside and see what's happening overhead.
Our first stop is always the Moon. Tonight it's
a waxing gibbous, about 69 % illuminated. If
you head out shortly after sunset, you'll find
it sliding just beneath Antares, the bright red
heart of Scorpius, making a perfect binocular
target. Each night the moon grows fatter and
brighter. By Saturday, August the 9th, we reach
the full sturgeon moon. It rises already brilliant
in the early evening. The sturgeon moon is the
traditional name for the full moon in August,
and it comes from Native American and colonial
folklore, particularly from the Great Lakes and
northeastern North America. According to Algonquin
and other indigenous tribes in the northeastern
U .S. and parts of Canada, August was the time
of year when sturgeon were most readily caught
in the Great Lakes and other large bodies of
water. These massive ancient fish, some of which
can grow more than six feet long, would surface
in greater numbers during this time, making them
easier to harvest. As a result, tribes that relied
on fishing for sustenance saw August as a season
of abundance, and they marked the full moon of
this time with a name reflecting the height of
the sturgeon fishing season. Binocular and telescope
users will want to get in their observations
early this week, especially if you want to see
craters and mountain ranges along the lunar terminator.
This week's planets are split between evening
and dawn. Mars is fading into the western twilight,
a small orange ember low on the horizon. Saturn
rises in the east -southeast after sunset and
remains visible all night. Through a telescope,
its rings are stunning, and Neptune lurks nearby,
a faint bluish dot best seen with optics. Just
shift slightly up one to two degrees from Saturn
to locate Neptune. In the pre -dawn sky, the
real show begins. Venus dominates as the morning
star blazing over the eastern horizon. Jupiter
shines nearby, and the two planets inch closer
each morning heading toward a tight conjunction
on August 12. Uranus is faint but trackable just
below the Pleiades star cluster. This is a good
binocular challenge for dedicated early risers.
The Southern Delta Aquarid and Alpha Capricornid
meteor showers are tapering off this week. You
might catch a handful of lingering streaks early
in the week, with the Alpha Capricornids occasionally
producing a bright fireball. The Perseids are
already active and will peak next week around
August 12th or 13th, but a bright moon will wash
out many fainter meteors. Even so, pre -dawn
observers under dark skies can still spot some
early Perseids tracing long paths across the
sky. Looking deeper into the cosmos, check out
a few open clusters in Auriga, like M36, M37,
and M38. They're visible overhead in the early
evening. Auriga is high after dark and rich with
bright stars like Capella. Scorpius crouches
low in the southwest with Antares glowing red.
Early in the week, watch the moon drift past
it. In very dark areas, look along the Milky
Way from Cygnus through Sagittarius. This region
is rich with star clouds, dark nebula, and the
Sagittarius teapot asterism pointing to the galactic
center. Aim a small telescope or binoculars along
this Milky Way stretch, where open clusters like
M7 in Scorpius and M11 in Scutum sparkle amid
the star fields. Coming up, a distant relic of
the solar system is proving to be a bit of a
troublemaker, shaking up theories that point
to the existence of the fabled Planet Nine. That's
after the break. Stay with us. This week we're
venturing far beyond Neptune into the quiet frozen
frontier of the solar system, where astronomers
have discovered a mysterious new world. Its official
name is 2023 KQ14, but scientists call it Ammonite
after the coiled fossil. And its orbit is challenging
one of the most tantalizing ideas in planetary
science, the search for Planet Nine. Ammonite
was discovered in March 2023 by astronomers using
Japan's Subaru telescope on Mauna Kea. Recently
detailed in a Nature astronomy paper published
just last month, Ammonite's orbit is a highly
elongated, tilted trajectory, stretching from
66 AU at closest to more than 250 AU at farthest.
That's hundreds of times farther from the Sun
than Earth. Ammonite is estimated to be around
220 to 380 kilometers across, making it comparable
in size to other mid -sized trans -Neptunian
objects. Not Pluto -class, but substantial enough
to merit the dwarf planet tag. Interestingly,
its orbit has remained stable for roughly four
and a half billion years, making it a cosmic
fossil of the early solar system. What might
it look like? Well, picture a dark reddish -brown
icy world, like a charcoal -toned snowball. Its
surface is probably a mix of frozen water and
rock, cratered and rugged after billions of years
in deep freeze. In sunlight, a few patches of
bright frost might glimmer on its horizon. No
telescope on Earth can show us any details yet.
It's far too small and faint, but its orbit tells
its story. Ammonite is part of an elite family
of worlds called Sednoids. Only three others
are known, Sedna, Leila Kahuna, and one other
smaller object called 2012 VP. All of them live
beyond Neptune's influence, like fossils of the
early solar system, untouched for billions of
years. These objects suggest the presence of
the elusive Planet Nine, a hypothetical object
of maybe five to ten Earth masses orbiting hundreds
of AU from the Sun. Its gravity could shepherd
small icy bodies into similar orbits, creating
a cluster pointing in the same direction. But
here's the twist. Ammonite doesn't line up with
the cluster. Its orbit points almost the opposite
way, which weakens the main piece of evidence
for the existence of Planet Nine. Does that mean
Planet Nine isn't real? Well, maybe. Or maybe
it's farther out or on a different orbit than
we imagined. The good news is we're entering
a golden age for discoveries like this. Over
the next couple of years, the Vera C. Rubin Observatory
will begin the legacy survey of space and time.
creating a decade -long movie of the night sky.
It's expected to reveal hundreds of new distant
objects, giving us the numbers we need to confirm
or refute Planet Nine once and for all. No doubt
there are many more tiny frozen worlds like Ammonite
silently orbiting at the edge of our solar system.
They are fossils of our solar system's youth,
and each one whispers a story that might lead
us to the next great discovery. 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.