sexta-feira, dezembro 12, 2008
Oh, the Moon.
"Earth set for full moon close upThe moon will appear high in the night sky.
A full moon is set to occur closer to the Earth on Friday evening than it has done for the past 15 years. The Moon's elliptical orbit means its distance from the Earth is not constant.
It will be a little over 350,000km away as it passes over the northern hemisphere, which is about 30,000km closer than usual.
It will be a little over 350,000km away as it passes over the northern hemisphere, which is about 30,000km closer than usual.
If the sky is clear it will appear brighter and lighter than usual, say astronomers.
Friday's full moon could appear up to 14% bigger and 30% brighter than other full moons this year, Nasa said.
The Moon's orbit is elliptical, meaning it does not follow a circular but rather an oval path. It is currently approaching the point where this oval orbit is nearest to the Earth.
"It's only every few years that a full moon happens to coincide with the part of the Moon's orbit when its closest to the Earth," said Marek Kukula, an astronomer at the UK's Royal observatory.
"What people will see is a full moon that's really bright and a bit bigger than what they're used to."
The Moon is usually about 385,000km from Earth, but tonight it will be closer at around 363,000km. It will appear largest as it rises and sets, but this is a psychological illusion, Dr Kukula said.
The Moon's brightness varies throughout its annual cycle, during the mid-winter in the northern hemisphere it can appear brighter simply because it is higher in the sky."
Friday's full moon could appear up to 14% bigger and 30% brighter than other full moons this year, Nasa said.
The Moon's orbit is elliptical, meaning it does not follow a circular but rather an oval path. It is currently approaching the point where this oval orbit is nearest to the Earth.
"It's only every few years that a full moon happens to coincide with the part of the Moon's orbit when its closest to the Earth," said Marek Kukula, an astronomer at the UK's Royal observatory.
"What people will see is a full moon that's really bright and a bit bigger than what they're used to."
The Moon is usually about 385,000km from Earth, but tonight it will be closer at around 363,000km. It will appear largest as it rises and sets, but this is a psychological illusion, Dr Kukula said.
The Moon's brightness varies throughout its annual cycle, during the mid-winter in the northern hemisphere it can appear brighter simply because it is higher in the sky."
Fonte: BBC
Criado por Isménia @ 3:36 da tarde 
