by Scotty Hendricks
massive clouds of dust
in orbit around
discussed for years
proven to exist...
astronomers have proven the existence of two
"pseudo-satellites" in orbit around the earth.
clouds were first discovered in the sixties, but
are so difficult to spot that scientists have
debated their existence since then.
findings may be used to decide where to put
satellites in the future and will have to be
considered when interplanetary space missions
After more than fifty years of stargazing, debate, and
controversy, scientists have confirmed the existence of two "moons"
or "pseudo-satellites" made of dust orbiting the Earth.
Though the clever use of
mathematics, they also argue that the location of these dust clouds
gives them some unique characteristics.
What are they?
Kordylewski cloud in the night sky
its brightness greatly enhanced)
time of the observations.
Kordylewski clouds are two dust
clouds first observed by Polish astronomer Kazimierz Kordylewski
They are situated at two
Lagrange points in Earth's orbit.
These points are
locations where the gravity of two objects, such as the Earth and
the Moon or a planet and the Sun, equals the centripetal required to
orbit the objects while staying in the same relative position.
There are five of these
spots between the Earth and Moon.
The clouds rest at what
are called points four and five, forming a triangle with the
clouds and the Earth at the three corners.
The clouds are enormous, taking up the same space in the night sky
as twenty lunar discs; covering an area of 45,000 miles. They are
roughly 250,000 miles away, about the same distance from us as the
They are entirely
comprised of specks of dust which reflect the light of the sun so
faintly most astronomers that looked for them were unable to see
them at all.
The clouds themselves are probably ancient, but the model that the
scientists created to learn about them suggests that the individual
dust particles that comprise them can be blown away by solar wind
and replaced by the dust from other cosmic sources like comet tails.
This means that the
clouds hardly move but are
How did they
"In this picture the
central region of the Kordylewski dust cloud is visible (bright
red pixels). The straight tilted lines are traces of
In their study (Part
Part II) published in the
Monthly Notices of the Royal Astronomical Society, Hungarian
...described how they
were able to find the dust clouds using polarized lenses.
Since the clouds were expected to polarize the light that bounces
off of them, by configuring the telescopes to look for this kind of
light the clouds were much easier to spot.
What the scientists
observed, polarized light in patterns that extended outside the view
of the telescope lens, was in line with the predictions of their
mathematical model and ruled out other possible sources.
Why are we
just learning this now?
"Mosaic pattern of
the angle of polarization around the L5 point (white dot) of the
Earth-Moon system. The five rectangular windows correspond to
the imaging telescope with which the patterns of the Kordylewski
cloud were measured."
The objects, being dust
clouds, are very faint and hard to see. While Kordylewski observed
them in 1961, other astronomers have looked there and given mixed
reports over the following decades.
This discouraged many
astronomers from joining the search, as study co-author Judit
clouds are two of the toughest objects to find, and though they
are as close to Earth as the Moon are largely overlooked by
researchers in astronomy.
It is intriguing to
confirm that our planet has dusty pseudo-satellites in orbit
alongside our lunar neighbor."
Will this have
any impact on space travel?
Lagrange points have been put forward as excellent locations for a
space station or satellites like the
James Webb Telescope to be put
into orbit, as they would require little fuel to stay in place.
Knowing about a massive
dust cloud that could damage sensitive equipment already being there
could save money and lives in the future.
While we only know about
the clouds at Lagrange points four and five right now, the study's
authors suggest there could be more at the other points.
While the discovery of a couple of dust clouds might not seem all
that impressive, it is the result of a half-century of astronomical
and mathematical work and reminds us that wonders are still hidden
in our cosmic backyard.
While you might never
need to worry about these clouds again, there is nothing wrong with
looking at the sky with wonder at the strange and fantastic things
we can discover.