Comets

The newly discovered comet Neowise has been in the sky recently. Our state has been blessed with good weather, so everyone who wants to can see it. Well, everyone except for those of us who live on the coast. We get clouds every night. But Friday night it looked like we might get a break. There were high, wispy clouds but we thought it might be possible. My wife and I went outside just after sunset and walked around the block. Too much light. We walked around it again. Too much light. We walked around again. I got my binoculars out and scanned the northwest sky. All total, we were out there about 45 minutes, but we found nothing. My wife went to bed and about 15 minutes later I tried again. Now it was certainly dark enough. I could see the Big Dipper (one of the landmarks for finding the comet) but only faintly. This close to the ocean, there is always a haze that rises up from the west. The dipper was barely peaking out through the haze and that did not bode well for the comet. Indeed, the comet did not make an appearance to me.

Comets are bodies composed of ice, dust, and rock. Scientists sometimes refer to them as dirty snowballs to help people visualize them. They are generally in orbit around our sun. They have a highly elliptical orbit and come in two flavors:  short-period comets which return to the sun in tens to hundreds of years, and long period comets which return in thousands to millions of years. As a comet gets close to the sun the solar radiation causes the ice and other volatiles to turn to gas. This, and the dust that gets released, produces the tail of the comet. Regardless of what direction the comet is moving, the tail is always pointing away from the sun. that is because it is pushed away from the comet by the solar wind. Comets actually have two tails, one of gas and one of dust. The dust tail is somewhat less affected by the solar wind so it points away at a slightly different angle than the gas tail. Tails can be millions of miles long.

Comets that can be seen with the naked eye are pretty rare. I remember when comet Kohoutek came along in 1973 and it was supposed to be the “comet of the century”. Kohoutek was a dud. That is one problem with comets: How visible they will be is hard to predict. Both Kohoutek and another one that they had high hopes for this spring (I forget the name), both looked promising in early observations, but they partially disintegrated as they got close to the sun.

Despite this, I have seen comets before. In 1986 I saw the most famous one of all, Halley’s comet. There wasn’t a lot to see as the geometry was not good for Earth viewing. But given good directions on where to find it in the sky, my wife, and I went out with binoculars and found the fuzzy spot that was the comet. I even tracked its progress against the backdrop of stars for a few nights.

In 1996, I got to see comet Hayakutake. This was a naked eye comet which we could see without aid. Then in 1997 I got to see comet Hale-Bopp. That was two comets visible to the naked eye in two years. We were starting to feel like this was a regular thing. Then, nothing until 2020. Well, actually there have been a lot of comets between 1997 and 2020. Comets come all the time, it is just that most of them are not very visible.

We went out again on Saturday to look for Comet Neowise. My wife and I looked for a while. Eventually she gave up and went to bed. I tried again about 10:15, scanning the sky with my binoculars. The weather was clear, and it just felt like I should be able to find it. Then, there it was! I couldn’t exactly see it with the naked eye, but it was clear in the binoculars. I tentatively went into the bedroom to see if my wife was still awake. She said, “is it there?” I said yes, and she said, “I’m coming.” She got dressed and we went outside. I pointed out where to look with the binoculars. She was satisfied and went back to bed (she's a trooper). 

One of my ‘what do you want to be when you grow up’ items when I was a kid was: astronomer (along with astronaut, race car driver, Olympic athlete, actor, chemist, politician, and naval officer). Most of those dreams had changed by the time I grew up, but that doesn’t mean I lost my love of the stars.

(My science fiction novel Star Liner, is now available in paperback or as an e-book through Amazon and other online sources).

Link to Star Liner