MessageToEagle.com - The Earth constantly captures small objects from (to) the NEO population and scientists construct a
steady-state model of the Earth’s temporary satellites.
According to their studies, at any given time there is at least one one-meter-diameter object orbiting the Earth and
the average satellite makes about 3 revolutions around the Earth in 9 months.
Their results agree with Earth’s single verified temporary satellite known to date.
Earth usually has more than one moon, according to a team of astronomers from
the University of Hawaii at Ma-noa, the University of Helsinki, and the Paris Observatory.
The 2,000-mile-diameter Moon, so beloved by poets, artists and romantics, has been orbiting Earth for over 4
Its much smaller cousins, dubbed “minimoons,” are thought to be only a few feet across and to
usually orbit our planet for less than a year before resuming their previous lives as asteroids orbiting the Sun.
Mikael Granvik (formerly of UH Ma-noa and now at the University of Helsinki), Jeremie Vaubaillon (Paris Observatory)
and Robert Jedicke (UH Ma-noa) calculated the probability that at any given time Earth has more than one moon.
They used a supercomputer to simulate the passage of 10 million asteroids past Earth. They then tracked the trajectories
of the 18,000 objects that were captured by Earth’s gravity.
They concluded that at any given time there should be at least one asteroid with a diameter of at least one meter
Of course, there may also be many smaller objects orbiting Earth, too.
According to the simulation, most asteroids that are captured by Earth’s gravity would not orbit Earth in neat circles.
Instead, they would follow complicated, twisting paths.
Click on image to enlarge
Earth captures a minimoon. The path of a simulated minimoon that is temporarily captured by Earth.
The object approaches Earth from the right along the yellow line and continues on its trajectory along
the orange path and finally escapes capture along the red path to the upper right. The size of Earth and the
Moon are not to scale but the size of the minimoon’s path is to scale in the Earth-Moon system.
Inset: Radar image of near-Earth asteroid 1999 JM8 made with NASA’s Goldstone Solar System Radar in California
and the Arecibo Observatory in Puerto Rico by a team of astronomers led by Dr. Lance Benner of NASA’s Jet Propulsion
Laboratory in Pasadena, California. Minimoons are captured from the much larger population of near-Earth asteroids
that pass close to Earth. This two-mile-diameter asteroid is more than a thousand times larger than the biggest
minimoons, but it shows the irregular shape and pockmarked surface expected on the much smaller minimoons.
This is because a minimoon would not be tightly held by Earth’s
gravity, so it would be tugged into a crazy path by the combined gravity of Earth, the Moon and the Sun.
A minimoon would remain captured by Earth until one of those tugs breaks the pull of Earth’s gravity, and the Sun
once again takes control of the object’s trajectory. While the typical minimoon would orbit Earth for about nine months,
some of them could orbit our planet for decades.
“This was one of the largest and longest computations I’ve ever done,” said Vaubaillon.
“If you were to try to do this on your home computer, it would take about six years.”
In 2006, the University of Arizona’s Catalina Sky Survey discovered a minimoon about the size of a car.
Known by the unimaginative designation 2006 RH120, it orbited Earth for less than a year after its discovery,
then resumed orbiting the Sun.
“Minimoons are scientifically extremely interesting,” said Jedicke. “A minimoon could someday be brought back
to Earth, giving us a low-cost way to examine a sample of material that has not changed much since the beginning
of our solar system over 4.6 billion years ago.”
The team used the Jade supercomputer at the National Computer Center for Higher Education (Centre Informatique
National de l’Enseignement Supérieur, or CINES) at Montpelier, France.
The team’s paper, “The population of natural Earth satellites,” appears in the March issue of the journal Icarus.
Why Do We See The Man In The Moon?
There’s something poetic about gazing up at the night sky, seeing the familiar face of the “Man in the Moon” who faithfully accompanies us through life.
The synchronous rotation of the Moon - it takes the same amount of time to spin around its own axis as it does to revolve around Earth -
is what causes the Moon to "lock eyes" with Earth.
This results in one of its hemispheres constantly facing us.
Alien Species Living In The Inner Milky Way Could Be In Danger
Few people doubt there is intelligent alien life in the Milky Way galaxy, but where can we expect to find it?
Astronomers think that while the inner sector of the MIlky Way Galaxy may be the most likely to support habitable worlds.
Unfortunately some of these places are also most dangerous to all life-forms.
Black Holes With No 'Table Manners' Eat Two Courses At Once!
It is still unknown how the supermassive black holes (SMBH) in galaxy centres accrete gas and grow.
Researchers from the University of Leicester (UK) and Monash University in Australia have investigated how some black holes got so big so fast that they are billions of times heavier than the sun.
Mercury Surprises Scientists
On March 17, MESSENGER (MErcury Surface, Space Environment, GEochemistry, and Ranging) completed its one-year primary mission, orbiting Mercury, capturing nearly 100,000 images, and recording data
that reveals new information about the planet's core, topography, and the mysterious radar bright material in the permanently shadowed areas near the poles.
Living Earth Simulator - Supercomputer Predicting The Future
In Douglas Adams book the Hitchhikers Guide to the Galaxy we encounter a machine called Deep Thought. It is the most powerful computer ever built. Deep Thought is capable of answering questions
concerning life, the Universe, and simply everything. Now scientists are planning to create a similar machine. It is called the Living Earth Simulator (LES).
Warp-Speed Planets Are Some Of The Fastest Objects In The Milky Way
Warped planets are some of the fastest objects in the Milky Way and they zoom through space near the speed of light.
Some years ago astronomers were astonished when they they found the first runaway star flying out of our Galaxy at a speed of 1.5 million miles per hour.
The discovery intrigued theorists, who wondered: If a star can get tossed outward at such an extreme velocity, could the same thing happen to planets?
Though the universe is filled with billions upon billions of stars, the discovery of a single variable star in 1923 altered the
course of modern astronomy. And, at least one famous astronomer of the time lamented that the discovery had shattered his world view.