SPACE -- There’s a visitor coming to town -- an eccentric member of the sun’s family who, after this visit, won’t be back for another 106,000 years.
The comet PanSTARRS, is making an appearance in the western sky at sunset this week and next, having arrived from the far reaches of the solar system.
After it has given its viewers a slight thrill, it will depart, on its way around the sun and back into its elliptical orbit toward Pluto and beyond.
The comet was recently discovered by an observatory in Hawaii through the use of digital and reflecting telescopes, according to local astronomy enthusiast, author and former earth-science teacher Helen Martin of West Marlborough Township.
She said her research indicates that it should be visible as of Monday and will continue to be present in the sky until March 24.
“But comets are so unpredictable. Some blow up before they can be seen; some are so bright they shine in the day,” she said, adding that no one is quite sure how bright this heavenly body will be.
One report said it will be about the brightness of Polaris -- the steady star at the end of the Little Dipper’s handle.
But it will be more than interesting than a star because it will have a tail -- one that will always point away from the sun.
Martin said the object will be steady in the sky, unlike a meteor which zips through the atmosphere and is visible for only about a second.
For those who want to see and perhaps attempt to photograph PanSTARRS, go to a place that has a clear view of the western sky on a cloudless night and look just above where the sun just set. On March 12 it was near the crescent moon.
PanSTARR travels in an elliptical orbit under the control of the sun, so, as such it is part of our solar system. But it doesn’t take the route of the eight (or nine) planets. Rather, it zooms in from the farthest reaches, circles the sun, and then goes on its way. It won’t return for more than 100,000 years, Martin said.
Martin said she is interested in seeing PanSTARRS, but is about twice as excited about a comet that is due to arrive in Comet ISON, which is due to arrive near the end of the year. That one has the potential to be so bright, it might be visible during the day.
Comets are sometimes referred to as “dirty snowballs,” Martin said. That’s why they heat up to glow or alternatively shed pieces of themselves. They are interesting as a study because scientists can examine the spectrum of their light and determine what they are made of.
Scientists can also use spectrography that same way to examine the makeup of planets from afar, as well as meteorites that have landed. The examination of bodies from outer space have brought scientists to the conclusion that some meteors are actually cast off pieces of the other planets like Mercury, Venus and Mars. Martin said she learned this from talking to scientists who were involved with the Apollo space mission.
Planets return on a regular basis, but some may take a long time to return. The famous Haley’s Comet returns about every 75 years, and is due here in 2061. Martin said that studies of ancient pictures and texts indicate that skywatchers have been aware of Haley’s Comet since 200 B.C.
Martin has been interested in astronomy and weather since her youth and has currently spent years studying the life and works of Sir Isaac Newton, who formulated the laws of motion that provide man’s understanding the attraction between objects and how they move.