Jupiter has lost its advantage over Saturn in terms of "most known moons"
after just a few short months.
With a total of 145 officially recognized moons, the ringed planet has once
again taken the lead thanks to the discovery of 62 previously undiscovered
satellites. This implies that in order for Big Jupe to reclaim the title
with its meager 92 known moons, it will need to execute some deft
maneuvers.
But more crucially, it shows the effectiveness of a method for finding tiny
moons around large planets.
A team led by astronomer Edward Ashton of the Academia Sinica Institute of
Astronomy and Astrophysics in Taiwan was able to locate Saturnian moons down
to a diameter of only 2.5 kilometers (1.55 miles) by moving and stacking
photographs of the moons acquired over a number of years.
Additionally, these recently found small moonlets are helping scientists
reconstruct Saturn's history.
Finding tiny moons that circle Jupiter and Saturn is actually rather
difficult. These two planets are the biggest in the Solar System, and from
Earth, where sunlight is constantly present, they seem quite brilliant in
the sky.
This implies that they considerably outshine anything in their immediate
vicinity, making it difficult to notice small, faint items.
It's interesting that there are a lot of different ways to define a moon or
natural satellite. The only prerequisite is that the item in issue must be
in a stable orbit around another, larger body that isn't a star. There is no
requirement for form, mass, diameter, or composition. Thus, moons may be
found on planets, dwarf planets, and even asteroids.
However, just observing an object close to a planet and proclaiming it to
be a new moon is insufficient. It is necessary to monitor the item, ideally
for several orbits, so that its trajectory may be examined to see if it is
stable. Shifting and stacking can therefore make dim objects visible, but
several such observations are required to prove the moon's status.
This is how it goes. At the same pace that the moon travels across the sky,
a collection of successive photographs is "shifted". Then, using a process
called stacking, these images are made brighter so that researchers may spot
signals that are too weak to be noticed in a single image.
In 2019, Ashton and his colleagues used the Canada-France-Hawaii Telescope
(CFHT) to scan the sky around Saturn and discovered what appeared to be
previously undiscovered objects in the space around Saturn. This shifting
and stacking technique had previously been used to look for moons orbiting
Uranus and Neptune.
They took observations for three hours at a time between then and 2021,
moving and stacking the resulting photos to determine whether the objects
they had discovered may be moons. One of the 63 new moons they chose will
occur in 2021. They have now thoroughly verified the remaining 62.
The kid's game Dot-to-Dot comes to mind while tracking these moons,
Ashton adds. "We have to connect the different appearances of these moons in our data
with a viable orbit, but with about 100 different games on the same page,
it's hard to tell which dot belongs to which puzzle."
The three groupings of Saturn's moons categorized as "irregular" include
all of the recently identified moons. These, which are grouped into the
Inuit, Gallic, and Norse moons, travel in vast, elliptical orbits around the
planet at an inclined inclination compared to Saturn's "regular"
moons.
The Norse group, which is the most populous and has the longest orbital
distance of the three, contains the majority of the new moons. Additionally,
it rotates in the opposite way from Saturn.
These clusters have been interpreted by astronomers as
proof of moon collisions
that occurred recently on Saturn and left behind swarms of smaller
moons.
Analysis suggests that the Norse group may be what remains after a somewhat
big irregular moon causes disruption. The recently found moons provide more
proof of this, according to the experts.
According to astronomer
Brett Gladman
of the University of British Columbia in Canada, "as one pushes to the limit
of modern telescopes, we are finding increasing evidence that a
moderate-sized moon orbiting backwards around Saturn was blown apart about
100 million years ago."
Jupiter, your turn.
