Harry’s Ramblings How Close Is The Moon
We are still here, so the asteroid that hurtled past the earth recently far faster than I can possibly comprehend has missed us. Again. But it will be back in 2029.
This is as big as The Shard, the London office block, and called 2002 NN4. Another way to compare is it is 1,000 ft across, larger than 90% of asteroids. It passed three million miles away, and the moon is on average approximately 239,000 miles, or 384,000 kms, away from us, depending on factors such as gravitational pull and the sun. That means when you look up into the sky at night, thinking you can touch that lovely bright moon, 2002 NN4 was about thirteen times further away than our own special moon. Putting in perspective, that was a little close for comfort. If I had been out that Saturday night stargazing, I would have likely felt the draft.
On researching this article, I didn’t appreciate that the moon had been part of the earth. When the earth was only young, a huge body about the size of Mars smashed right into it, and all the debris over a long period of time re-formed into our moon. They know this because when the Apollo mission returned it came back with over a third of a ton of moon formation. When they dissected they worked it out that its rocks were very similar to earth’s, which would not have occurred if both had formed separately in the solar system. I suppose they would have had to microscopes alongside each other, one eye on each, saying to white-suited colleagues ‘have a look at this, didn’t know that earth and moon DNA are so similar.’
You have heard the expression ‘dark side of the moon’. That is because as the moon is rotating at the same speed as us, it always shows the same side, so there’s the light side and the dark side. But if you land on the bright side, it’s dark. If you follow what I mean. Satellites have orbited round the dark side, weren’t too impressed because they couldn’t take too many decent photos as it was at night, but what they have seen is not much. I am attaching a photo of the dark side, as you can see, there’s not a lot to see apart from a lot of craters.
A solar eclipse occurs when the moon covers the sun. I might have simplified a little, but basically when you look at the sun, and then the moon, they both appear to be the same size, due to the distance between them, so when the moon precisely covers the sun, that’s when the lights go out for a little while. The moon is there all the time, it’s just we don’t see it very often during the day because it needs its brightness at night to be discernible. On rare occasions you can look up into the afternoon sky and see the shape of the moon, while the sun is shining brightly.
The moon is imperceptibly moving further away from earth, so there will come a time, not in my lifetime or yours, or your grandchildren’s, when solar eclipses don’t happen because the moon is too far away. You had better hope that you are not alive when this happens, because we need the moon to be precisely where it is to maintain civilisation as we know it. The pull of gravity from the moon, for example, means that we have a high tide every twelve hours and 25 minutes, which is good because we have all those fishes swimming in the active sea. No moon equals no tides, no tides equals static sea. Sea that doesn’t move means lots of smelly seaweed, nothing living in the sea, and 70% of the earth’s surface is dead. Nice water means clouds form, gathering water, which drops onto land. We need water, so we like the moon. Simples.
June 30th has been dedicated International Asteroid Day by the United Nations. I suppose it’s asking too much why any day should be devoted to something that poses a risk to humanity. One huge asteroid, called Ceres, is 600 miles across and is sufficiently large to be qualified as a dwarf planet. It’s so big it could have its own motorway all the way round, complete with service stations for men in little buggies.
There’s also meteoroids. They gain their name from their size – less than one metre across. They would make a dent in earth if they hit us, but the telescope has to be pretty sharp to be able to see them. An obvious point, but there is no human life on meteoroids. We hope. Because if there is, then if they are human-sized then there’s nowhere for them to pitch a tent.
So, there is our small part of the universe summed up as I see it.
Harry Pope has written some books, the most recent are Buried Secrets, which is a hilarious account of his time as a funeral director, full of amusing anecdotes, and Hotel Secrets, when he and his wife owned a 28 bedroom seaside hotel in disastrous partnership with a Californian businessman with feet of clay. Both on Amazon as either e-books or printed.