No Reason to Get Excited...

A comet makes a close (87,000 miles) approach to Mars today.
How does it affect our lives? Not at all. Most of the world's population will not know it happened. And their lives will be no better or worse for it.
So, why is it interesting?
Well, it is quite literally a once-in-a-lifetime event. Maybe once in the entire human life span.
We humans take a great deal of interest in such events. Earthquakes, tsunamis, volcanic eruptions, floods, avalanches, and any other natural event of large proportion, even if, as is often the case, we only know of it because of the news coverage. If not for news coverage, I would not now be aware of the Ebola outbreak. I only know Mars is there because I read. How many people on Earth never heard of Mars? Wouldn't know a comet if it smacked into their house?
But it is fascinating. I watched live streaming from a South African observatory. See, even if I had a large enough telescope at my house, I couldn't have seen it from here.
So here is the thing: We (humans) have several satellites, rovers, and telescopes that can be tuned to watch this event. First time in history this could be done.
I have read several accounts and watched several videos about this comet. It is somewhere between .5 and 5 miles in diameter. Hopefully, after all these instruments watch it, someone will get an accurate assessment of its size. Why? Because if it, or another one later, were to hit Earth, the difference is significant. Half a mile? Tungusta, Siberia, 1908. Devastation over a few square miles. Depending on where it hit Earth, maximum death toll, 10,000,000. A large number. Insignificant compared to world population of 7 billion. Five miles across. Yucatan, 65,000,000 years ago. Totally changed the climatic conditions of the entire planet. Likely death toll, everyone.
So it is interesting as an event for which it would be wise to be prepared. Right now, if this were aimed at us, all we could do is hope for the half mile size, and take comfort in knowing that it is statistically likely to hit unoccupied ocean.
So, anyway, I find it interesting. It left the Oort Cloud, another thing I don't need to know about, maybe a million years ago. It has been falling, unimpeded, into the Sun's gravitational pull all that time. Now, Mars, a relatively small, insignificant hunk of rock will totally change its trajectory, sending it back toward deep space. Mathematicians are now calculating the odds that these two objects would have interacted. Then they will calculate how far the comet will be flung before it once again succumbs to the Sun's gravity. Or, if its encounter with Mars will tear it to pieces. Or, whatever.
And you and I will live our lives the same. Regardless.
But this is as much fun as going to a movie. And costs less.