So I was flipping through the “Cosmos: A Field Guide” book tonight and decided to stop on the comets page while I ate my dinner. I read over the text and checked out the photos, saving the captions for last. There’s a large (read: 17″x14″) full page image of a comet that is quite a nice shot, which I admired it for a while as I finished up my sandwich. I read over the captions for the other 5 comets pictured, which had orbital periods ranging from 5.5 years (Comet Tempel, the target of the Deep Impact Spacecraft) up to 76 years (Halley’s Comet). Cool. Then moved over to read the caption for the full page image. It’s name (awesomely) is Comet “Neat”! Hah! Here is the photo:
Then I read the caption. Orbital period for this comet? THIRTY-SEVEN-THOUSAND YEARS. I had to double check the number–did that really say 37,000 years?… oh. I guess that’s right.
That’s wild. The last time this thing plunged into the inner solar system, mankind had just migrated to Australia and Europe for the first time. And we were at the Cro-Magnon stage in our evolution. The next time this comet will return to our inner solar system? Humans will have long ago evolved into something new. Thirty Seven Thousand is such a bafflingly large timescale.
How many historical figures can you name from over a thousand years ago? Three thousand? Five? Fifteen? In 37,000 years, us, and everyone we ever met will be completely forgotten about, and the particles which made up our bodies will long ago have decayed and been recycled into Earth, possibly even having been incorporated into several new organisms by then. If there are some descendants of today’s homo sapiens that have survived, they wont’ call it the year 39,xxx AD–today’s popular mythologies will all have died out long ago. Just like today’s date is not measured in years related to Zeus, Odin, or Ra, the ancient Egyptian sun god. I wonder what gods the Cro-Magnons worshiped?
Check out NASA’s site with this cool interactive ‘orbit diagram’ that shows the positions all the planets and the comet as it traveled through space. If you line up the solar system on it’s axis and hit play to watch the comet slide by, you’ll notice that it doesn’t even pass through the orbits of any planet. In it’s moment closest to the sun it picks up a lot of speed for a brief moment too. We should’ve gone all ‘deep-impact’ and launched a satellite to travel to the comet… it could have landed and rode along for the ride out to the oort cloud. What a journey?!
Wave goodbye kids!