MessageToEagle.com - 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.
But is there a reason why this particular half of the Moon locked with Earth, or was it pure coincidence that
it didn’t “turn its back” on us?
Through careful analysis and computer-generated simulations, Prof. Oded Aharonson of the Weizmann
Institute’s Center for Planetary Science (he began this research while still at the California Institute of
Technology), together with Prof. Peter Goldreich of the California Institute of Technology and Prof. Re’em
Sari of the Hebrew University of Jerusalem have shown that it is not coincidence but the Moon’s geophysical
properties that determine its orientation.
The near side of the Moon is low-lying and covered by craters filled with dense, dark volcanic material,
giving us the Man in the Moon.
In contrast, the far side is predominately made up of higher mountainous regions. “Intuitively,
we might actually have expected the far side to be facing us as the high mountains would have brought the Moon closer
to Earth, putting the system in a lower energy state,” says Aharonson.
Nature usually prefers lower energy states, so why isn’t this the case?
The motion of the Moon is a bit like the motion of toy train circling around a track with two hills and two valleys.
The hills and valleys represent the different energy levels of the orientation of the geophysically asymmetric Moon.
Friction causes the train to slow down until it doesn’t have enough energy to climb over the hill, and settles
into one of the valleys.
The choice of valleys is governed not by the depth of valleys, but rather by the height of the hill it crossed
for the last time.
Similarly for the Moon, its maxima energy (the hills in our analogy) governs the ultimate state of the Moon,
not its minima energy (the valleys).
The lunar nearside (left) is a contrast between dark (craters) and light (mountains) surfaces that has been
fancied as the Man in the Moon. Lunar terrain types are still designated
by their 17th century name maria and terra (brighter features also known as uplands or highlands; right).
Images by NASA.
According to the scientists’ simulations, the energy values calculated for the current geophysical characteristics
of the Moon favor locking it in the current orientation.
"In fact, by designing different models of the Moon
– moving its mass around, and altering various other parameters that affect its gravitational properties – we are
able to have complete control over which ‘valley’ the Moon settles into," says Aharonson.
Some might argue that the Moon would have locked with Earth very early in its existence, when its properties were
much different to those of today's moon, and so these findings might not explain the actual events.
The scientists, and indeed some evidence, suggest that the other side of the Moon could have been facing Earth at
some point, but was hit out of sync and then later relocked into the current orientation in the way described by
the new findings.
Aharonson: "For me, what is most interesting is not seeing the Man in the Moon, but the elegance of how the system works."
Prof. Oded Aharonson would like to acknowledge support from the Lunar Reconnaissance Project.
Abnormal Star Discovered In The 'Forbidden Zone'
A team of astrophysicists from Germany, France and Italy have discovered in the constellation Leo is an old star.
The star's existence raised at once many questions for scientists.
The object is definitely not as its "contemporaries" that appeared immediately after the Big Bang event.
Thermonuclear Burning In A Neutron Star Detected For The First Time!
It's a very important discovery!
For the first time, an international team of scientists have detected all phases of thermonuclear burning in a
neutron star, located close to the center of the galaxy in the globular cluster Terzan 5.
Possible Water In The Atmosphere Of A Super-Earth
Four CfA astronomers, Zachory Berta, David Charbonneau, Jean-Michel Desert, and Jonathan Irwin, together with six colleagues,
used the Hubble Space Telescope to probe the atmosphere around the transiting super-Earth known as GJ1214b.
This exoplanet has a mass of 6.5 Earth-masses and a radius of 2.7 Earth-radii, and it orbits a small M-dwarf star (its diameter
is only 21% of the Sun's).
Astronomical Mystery - Tremendous Explosion And Appearance Of Odd Rings
Twenty five years ago, on 1987 February 23, the brightest supernova of modern times was observed in the Large Magellanic Cloud.
The collision occurred at speeds near 60 million kilometers per hour and shock-heats the ring material causing it to glow.
Over time, astronomers have watched and waited for the expanding debris from this tremendous stellar explosion to crash into previously expelled material...
Doesn't Secret Dark Matter Exist?
The more scientists study dark matter they know lesser and are not particularly optimistic about their results.
After completing this study, we know less about dark matter than we did before," said Matt Walker, of the Harvard-Smithsonian Center for Astrophysics.
A mysterious and still unknown substance is totally invisible in the Universe and reveals its presence only through its gravitational pull...
Dwarf Irregular Galaxy That Forces Scientists To Re-Evaluate Old Theory
Astronomers from Center for Astrophysics of the University of Porto, Portugal and Oskar Klein Centre, Stockholm University, Sweden come up
with new findings regarding one of the most studied objects - the dwarf galaxy I Zw 18.
The results led the scientists to the conclusion that this enigmatic blue compact dwarf might force
astronomers to review current galaxy formation models and much of what is known about galaxy formation and evolution might need substantial revision.
Violent Dragon Clash Billions Of Years Ago
NGC 5907 is sometimes called the "Splinter" or Knife Edge Galaxy because of its unusual appearance.
It is a spiral galaxy lying in the Dragon constellation,
about 40 million light-years from Earth that could have been formed through a gigantic collision of galaxies, 8 to 9 billion years ago.
MessageToEagle.com - 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.
A team of astrophysicists from Germany, France and Italy have discovered in the constellation Leo is an old star.
The star's existence raised at once many questions for scientists.
The object is definitely not as its "contemporaries" that appeared immediately after the Big Bang event.
It's a very important discovery!
For the first time, an international team of scientists have detected all phases of thermonuclear burning in a
neutron star, located close to the center of the galaxy in the globular cluster Terzan 5.
Four CfA astronomers, Zachory Berta, David Charbonneau, Jean-Michel Desert, and Jonathan Irwin, together with six colleagues,
used the Hubble Space Telescope to probe the atmosphere around the transiting super-Earth known as GJ1214b.
This exoplanet has a mass of 6.5 Earth-masses and a radius of 2.7 Earth-radii, and it orbits a small M-dwarf star (its diameter
is only 21% of the Sun's).
Twenty five years ago, on 1987 February 23, the brightest supernova of modern times was observed in the Large Magellanic Cloud.
The more scientists study dark matter they know lesser and are not particularly optimistic about their results.
Astronomers from Center for Astrophysics of the University of Porto, Portugal and Oskar Klein Centre, Stockholm University, Sweden come up
with new findings regarding one of the most studied objects - the dwarf galaxy I Zw 18.
NGC 5907 is sometimes called the "Splinter" or Knife Edge Galaxy because of its unusual appearance.
It is a spiral galaxy lying in the Dragon constellation,
about 40 million light-years from Earth that could have been formed through a gigantic collision of galaxies, 8 to 9 billion years ago.