Once in a Comet's Lifetime

Every so often there is a celestial event so unique and rare that even the most jaded of people out there can't help but look to the heavens in awe of the displays that the cosmos deems us worthy of seeing. In the coming days, we'll have another one of those rare opportunities when the comet 17P/Holmes passes through the skies over the United States over the next day or so. Some people out there may be wondering what exactly a comet is. Well, put simply (and please bear in mind that I am in no way shape or form an astronomer so keep snide comments to yourself), you can think of a comet as a ball of cosmic ice and dust which is generally quite large and is on an orbital path that takes it around the sun and eventually back into space. As the ice approaches the sun (in relative terms) the ice is converted to gas and hence the long tails that appear behind the comets.

The picture above is not of the Holmes Comet but of the Hale-Bopp Comet that passed through the sky a few years ago. What makes the Holmes Comet unique is that it will be bright enough in the sky to be seen with the naked eye. Now when most people hear the term comet or think of what it must look like they believe that it will look like what you see in movies like "Armageddon" or "Deep Impact". That is massive chunks of rock that are on fire and pose an immediate threat to our livelihood. Fortunately (or unfortunately for some) this is not the case. The path of a comet rarely (if ever) brings it along a path that will impact on our planet's surface. What do impact on us from time to time are meteoroids which are actually pieces of the moon or other celestial bodies that have broken off and are on random paths that sometimes lead them to earth. Even then, there are rarely pieces as large as are shown in the movies that can lead to the utter and total devestation of man.

I remember the last time a comet similar to the Holmes Comet passed through our skies. This was not too long before Hollywood began making movies on killer meteors hitting us. At that time my parents, brother and I were returning from a dinner outing when we drove through a country road close to our home. We had heard the news about the comet being visible that night but we figured that without telescopes or any idea of where to look we'd probably not even see anything. We also figured with all of the ambient light in our neighborhood, we wouldn't see anything anyways. But along this country road we were astonished to see the comet right there in the sky. It didn't appear to be moving rapidly across the sky nor was it leaving a firey trail across the sky. In fact it was rather still and luminous. So much so that even after we got home, we could see it despite the surrounding lights in our neighborhood. We all stood quietly watching it and I wondered just how far this comet had traveled before passing this way. To think in simpler terms, this could be compared to your zooming past a house along the highway. Except that this highway was the endless sky and the speed of this comet may have appeared minimal due to it's distance from us but it was probably faster than any of us will ever travel.

The next morning at school I spoke with some of my friends and I was rather dismayed to hear their comments about the comet being 'boring' or the fact that it wasn't moving or was just sitting there. And on the one hand I could understand the disappointment or frustration. Thanks to Hollywood and pop culture, we often have incorrect visions of what an object like a comet is 'supposed to look like'. Not that I considered myself smarter or more appreciative of the comet but I have always tried to think of such things in different terms. From our vantage point on Earth the comet may not appear much larger than a jet we see travelling through the skies on occasion. Now compare those two.

Even when you see a jet in the sky leaving a vapor trail, it is high up enough that it can often appear no larger than a pin head. If it wasn't for the vapor trail we wouldn't even see it despite the fact that it's only a few thousand feet in the air. Now think about a comet which is a few million miles in the air. In order for us to see it, the comet has to be massive and for the tail to appear as long as it does, it needs to be quite massive as well. Given all those things and the relative size of the sky, you tend to have slightly more appreciation for just how grand this rare light show in the sky actually is. I'm hopeful that I will get a chance to see the Holmes Comet in the sky before it disappears again on the next leg of its voyage through space. Perhaps it's a slightly romantic notion or my overwhelming love for space travel and exploration but by having seen an object that will undoubtedly see parts of the universe I will probably never see in my lifetime, at least a part of me, in some small sense, will be on that journey too.