Comment »Posted on Friday 12 December 2008 at 2:27 pm by Jacob Aron
In Space & Astronomy

If you’re wandering about outside this evening, you may notice your surroundings feel a bit brighter than usual. No, I’m afraid the council haven’t sprung for additional street lamps. Look up at the sky, and you’ll see the Moon, closer to Earth than it has been for the past 15 years.

Assuming clouds don’t obscure the view (from where I’m sitting, that might unfortunately be the case) the Moon could potentially appear 14% bigger and 30% brighter than other full moons this year, according to NASA. The effect is due to the elliptical orbit of our satellite friend. This oval-shaped path varies the distance between the Moon and ourselves. Normally, it orbits at around 385,000km from Earth, but tonight it will close the gap to around 363,000km.

A lovely full moon.
A lovely full moon.

According to Dr Marek Kukula, an astronomer at the UK’s Royal Observatory, this astronomical event only occurs every so often:

“Its 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,

“What people will see is a full moon that’s really bright and a bit bigger than what they’re used to.”

Interestingly, a psychological illusion actually makes the Moon appear even bigger when it rises and sets, says Dr Kukula:

“When it’s close to the horizon, our brain interprets it as being bigger than it actually is, this is called the moon illusion,

Dr Robert Massey of the UK Royal Astronomical Society cautions against expecting too much of a sight, however:

“The Moon may be brighter and may appear somewhat larger, but it’s really quite hard for the eye to notice the difference; the eye will compensate for the extra brightness, it’s not like going from night to day.”

Still, for all you amateur astronomers out there, look to the skies tonight!


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