| |
 |
 |
 |
|
|
Random Game
Frogger
High Score: 5110
By: Trayan |
|
|
 |
|
 |
|
|
|
|
|
|
|
|
|
|
|
Why Moon looks Black and White |
|
Posted by Julia
|
 Edinburgh, Feb 06: Ever wondered why the Moon looks black and white.
Well Scottish researchers might have the answer now.
Scientists here have recreated a Moon rock in a
laboratory, mimicking the low-oxygen conditions found on the lunar
surface, and simulated the conditions of an asteroid explosion to learn
why our closest heavenly neighbour has a distinctive black and white
colouration.
According to them the tremendous heat released, as the Moon cooled, turned its surface white.
The Moon was formed 4.5 billion years ago when the Earth collided with
a massive comet. A large chunk of the debris was trapped in the earth`s
gravitational pull.
According to the research team, the collision released a
huge amount of energy, in the form of heat, which turned much of the
Moon`s surface into a lunar ocean of magma, or lava. The lava then
cooled and solidified, giving it a white appearance, even as its centre
remained black.
As part of their study, geologists at the Edinburgh University created
artificial pieces of Moon rock based on the chemical compositions of
samples brought back from the Apollo space missions.
The researchers then used a special furnace to heat the
artificial rock to 1,500 degrees Celsius, turning it to magma, and then
watched it cool.
They found that the white crystals were the first to form into magma,
floating on top of the black liquid, suggesting that during its
original formation, the Moon was covered by a perfect white sheen.
The centre of the sample remained black, much like the Moon.
According to the scientists, some 2.5 billion years ago, an asteroid
shower must have hit the Moon, rupturing its white exterior and causing
volcanic explosions of black lava.
The lava - dark in colour because of its high concentration of iron -
was slowly pulled by the Moon`s weak gravity into valleys, exposing
dark craters and white "lunar highlands".
This is why the Moon is white and black, said Dr Stephan Klemme, the lead researcher.
"When you look at rocks from the Moon and from the Earth, they are very
similar. The black rock on Arthur`s Seat in Edinburgh, for example, is
not much different from black Moon rock. However, there are crucial
differences that have baffled scientists," he said.
"Our experiments have shown that the minerals creating the
white rock - seen in the lunar highlands - would have crystallised
first, whereas the dark and heavy iron-rich minerals would have sunk in
the magma oceans, creating darker rock that would have been buried deep
inside the Moon.
"The reason that the darker rocks are now visible on the
surface of the Moon is proof of a later period of intensive meteorite
showers. The iron-rich minerals that were deep inside the Moon proved
to be especially high in hafnium and low in tungsten, and would have
erupted to the surface as molten rock, filling the valleys on the Moon
and leaving a darker shade we observe today," he added.
Bureau Report
http://zeenews.com/articles.asp?rep=2&aid=352391&ssid=27&sid=ENV
See also:
|
|
|
|
|
|
|
|
|
|
|
