Monday, 9 December 2013

Bye-Bye Moon

It is thought that the Moon was formed when a proto-planet about the size of Mars collided with the early Earth around 4.5bn years ago. The debris left over from impact coalesced to form the Moon.
In the pre-moon days, the Earth wobbled so we never had the tilt like we have today where in summer the Northern Hemisphere is tilted towards the Sun and in winter the Northern Hemisphere is tilted away from the Sun giving us shorter days and cooler weather.
Having a huge Moon beside us steadied the wobble and we now how the seasons we get but boy would we be in trouble if the Moon ever moved away as we would experience much greater temperature swings than we are used to.
The good news is that the gravitational force of the Earth keeps the Moon where it is, the bad news is that the force is ever so slightly not enough to keep it there permanently and the moon is slowly creeping away from us.
The debris from the Earth that went into making the moon originally coalesced, out satellite sat much closer to the Earth, 14,000 miles away and over the past 4.5bn years it has shifted away to where it sits now, 250 million away from the Earth.
That averages out as the Moon spinning away from the Earth, at the rate of 3.78cm (1.48in) per year and as the Moon waves us good bye, the Earth's spin speeds up the faster it spins, the more it wobbles.
On early Earth, when the Moon was newly formed, days were five hours long, but with the Moon's braking effect operating on the Earth for the last 4.5bn years, days have slowed down to the 24 hours that we are familiar with now.
What all this means is that our early ancestors must have had a magnificent view of the moon but more importantly, has anyone checked if the Earth is wobbling anymore recently because i'm sure our seasons are completely out of whack, i was carrying my coat and shopping in a T-shirt today and it's the middle of December!


Anonymous said...

Maybe it is causing more extreme weather conditions


Lucy said...

The other way around apparently, from Wikipedia: 'two-thirds of the "wobble" was caused by fluctuating pressure on the seabed, which, in turn, is caused by changes in the circulation of the oceans caused by variations in temperature, salinity, and wind. The remaining third is due to atmospheric fluctuations.[4]'

Meat eaters fault yet again by which i mean you, the earth is wobbling because of you. Feeling guilty?

Anonymous said...

nah, i'm feeling hungry... for meat!


ps - the only that had fluctuated more in my 58 years is the scientists that say we are gonna have an ice age, no warming, no ice age, no wait, no arrrrrgghhhh.