By Professor Todd Brown / Contributor

Last Tuesday, I got to relive one of my “holy cow” moments in life. On a February evening in 1996, I was visiting one of my favorite restaurants of my graduate days enjoying helpings of my favorite food group: all-you-can-drink-caffeine-loaded-beverages. I was leafing through a newspaper because in those days we still had to read our news printed on paper as the Internet was in its early days.

A large article was dedicated to a comet that had been discovered the month before and was due to fly past the earth in late March. The comet, named Hyakutake after its discover, was a rather average comet as far as size was concerned but as real estate agents quote, it always about location, location and location to how spectacular a home, or in this case, a comet, will be.

As with all comets, Hyakutake’s story began with the formation of the solar system over 4.5 billion years ago. Most leftover materials were swept up by the sun, the planets or the moons during this period, but just like a construction site leaves a lot of debris from raising a new building, so did the making of our solar system. On the fringes of the sun’s domain, where its gravity was just strong enough to still rule, countless remnants were stored at the edge of interstellar space. In these cold depths were small objects that measured a few miles across and were made from a mixture of rock and frozen gases. They orbited the sun extremely leisurely but, on occasion, a large body such as distant star came just close enough to give a few comets a nudge towards the sun.

After billions of years contently observing the solar system from a safe distance, a nudged snowball started its thousand-year trek towards the inner solar system. Around the orbit of Jupiter, the temperatures due to the sun were high enough to start vaporizing some of the frozen gases under or on the surface of this comet-to-be. The dust and gas that were liberated formed an earth-sized cloud around the object. Fanned by a light but constant stream of particles coming from the sun dubbed the solar wind, the pieces were swept back to form the tail that could be millions of miles in length. Hence, a small, icy rock can quickly morph into the hairy star that we refer to as a comet.

As the gravitational pull of the sun on the comet grows, the comet speeds up and quickly rounds the sun only to head back out to the deep freeze that it came from. Once the temperatures drop to the point where the gases no longer erupt from the surface, the comet seems to turn off. Unless a chance encounter with a planet changes its orbit significantly, it will not return for several thousand years.

The former was the case with Comet Hyakutake. Returning after an absence of a few thousand years, the comet’s orbit passed about 35 times farther away than our Moon. In astronomy, this is a near-miss. Hence, the average comet was set to produce a dramatic show. Billed as a “comet of a lifetime,” it lived up to its name. For us in the Northern Hemisphere, it was placed well in the sky. Passing close to the North Star, it was easy to spot high overhead. Its tail seemed to stretch almost a sixth of the distance between horizons. You could see the bright head of the comet from the outskirts of Chicago. Driving to avoid the city glow was worth it many times over for me as I had never seen, nor have since, such a dominating sight. Comets are fickle things since their size and brightness depends on the gas eruptions that can quickly increase or fade. But choosing between being fooled into observing nine bursts to see only one that lived up to its hype would still make it worth it.

Fast-forward to last week. On Oct. 22, in the constellation Perseus, the dim comet Holmes continued its fanfare-less trek to a place beyond Jupiter after passing the sun and earth in early summer. Trapped in a short-term orbit of less than eight years, Comet Holmes has seen so many fly-bys of the sun that its gas supply has been depleted and hence it is a target for really large telescopes and observers that just want a challenge. Compound this with the fact that it is daily getting farther from the warming sun and the earth and one would not have high expectations for Holmes. But something happened to Comet Holmes in the late hours of Oct. 23. An eruption that contained, at least in part, a lot of dust occurred and the resulting particles spewed into space acted as tiny mirrors to the sun’s rays. The comet quickly increased in brightness almost a million-fold in less than 24 hours. What had been an afterthought had suddenly become a new “star” in Perseus.

Sadly, it seems to either have not developed a tail or else it is oriented as such relative to the earth to make it nearly impossible to see. But, its bright head can be seen to look star-like to the eye. With the aid of binoculars, a telephoto on a camera or a telescope, the comet appears as a bright, cotton-ball like apparition floating among the stars. At our distance, it appears to be significant portion of the apparent size of the moon. It’s not the comet of the century, nor do I hope it is the comet of my (remaining) lifetime. It is not the “holy cow” moment that Hyakutake or Hale-Bopp brought, but it is a comet that is visible to the unaided eye even in strong city glows. That makes it a rare jewel because we don’t know when the next frozen interloper from the outer fringes will make an appearance. So, if you have some optical aids, then take advantage of the show while it lasts.

What else is out there this week: