December 25, 2000
"Timing is Everything - The Clouds of Magellan"
Nights aboard Odyssey, are among the loveliest I've known. On dark nights before the new moon appears and there is no moon, the sky is wonderfully dark, a kind of velvet black, an experience almost entirely missing for most of us in this modern world. So dark is it then, here in the Pacific, that we see the clouds of Magellan with perfect clarity. These usually faint puffs of light are, in fact, the closest galaxies to our galaxy. There is some evidence that they are companion galaxies to our milky way, perhaps even circling it. It seems unfair that in the northern hemisphere, where most people live, we should have no companion galaxies in our night sky, whereas those who live here in the southern hemisphere get to admire not just one, but two of them.
Although one of the clouds of Magellan is about twice the diameter of the other, both are unlike anything in the northern hemisphere in that they are both large features in the sky, their size looking roughly the size of the moon, and their overall appearance like fragments of the milky way that have drifted away from it and are now anchored off, by themselves. They were last in the news in November of 1987 when a supernova blew up in the large cloud of Magellan, giving scientists their best observations ever of that rarest of all astronomical events. After an initial brilliance millions of times that of any star (I was in the Seychelles at the time from which it just looked to me like an ordinary star), The supernova began its slow wane, which will end in about 100 years when the remnant rings that were ejected by the explosion are no longer visible.
I remember reading that it had taken the light from that explosion 170,000 years to reach our eyes (for that is the distance to the large Magellanic cloud-the small cloud is a further 30,000 light years away). This means that the way the large Magellanic cloud looks to us tonight is the pattern in which its millions of stars were fixed 170,000 years ago, and gives no hint at all as to its current form. (We'll have to wait another 170,000 years to know that.) Which means that the light from that supernova explosion left the large Magellanic cloud longer ago than the pyramids, longer ago than our ancestors made paintings in that cave at Lascaux, longer ago than the last Ice Age began, and longer even then the Ice Age before it began, in fact, about the same time that our species, Homo sapiens, first appeared. Which means, that throughout our entire history our species has sat beneath night skies from which the evidence of that single cataclysmic event was absent, though it was hurtling through the void towards us.
During that mind-boggling period of time, we have developed speech, society, writing, astronomy, physics, and mathematics. And only in the nick of time, when the rays of light from that supernova were already closer to our star than to any other in the universe, were we finally ready, or telescopes set up and pointing in the right direction (both on the ground and in space) to be able to capture the arrival of that event, and furthermore to understand its significance. What better evidence could we possibly need that timing, is everything?
This is Roger Payne speaking to you from the deep night of the Pacific.
© 2000 - Roger Payne