Jupiter Rules the Night

Appropriately for the king of the planets, giant Jupiter dominates the night sky beginning this month (and well into the spring as well).  And as January opens, it gets off with a bang sky-wise with a meteor shower.  Throw in the bright winter constellations like Orion now in full view and you have a wonderful way to spend a clear cold evening!

You can’t miss it!  Blazingly bright Jupiter rivets your attention as soon as you step outside and look up.  It lies in the constellation Taurus near the glittering Hyades and Pleiades naked-eye star clusters.  Your steadily-held Edmund binoculars will clearly show its non-stellar-appearing disk and with attention you may glimpse one or more of its satellites.  (While here, be sure to take a peek at both star clusters with you glasses as well!) Even a small beginner’s telescope like the Scientifics’ 60mm refractor will give a beautiful view of both the planet itself and all four of its bright Galilean satellites (those discovered by Galileo).  As they waltz around the planet from night-to-night, they undergo a number of fascinating phenomena—the most striking of which are their disappearance and reappearance into and out of Jupiter’s huge shadow cone.  For much more about this see the July, 2009, installment of Sky Talk archived on our site.

On the evening of January 3rd into the morning of the 4th, the annual Quadrantid Meteor Shower reaches its maximum. The display’s radiant—that point in the sky from which the meteors appear to stream—lies in the obsolete constellation Quadrans Muralis (thus its unusual name), which is part of Bootes today.  For this reason, some observers prefer to call this display the “Bootids” rather than the Quadrantids.  Peak activity is expected sometime before dawn on the East Coast.  The Moon will be approaching Last Quarter on the 5th and so will definitely interfere with this year’s display once it rises.  Under dark skies observers can normally expect to see upwards of 100 or more “shooting stars” an hour at the peak.  While this number will be reduced due to moonlight, the brighter ones should still show through and make the shower worth watching. Although Bootes itself doesn’t fully rise until well after midnight in January, meteors can still be seen shooting from over the northeastern horizon after darkness falls on the 3rd with meteoric activity increasing throughout the night as the constellation climbs higher in the sky. And as we’ve discussed in the past, after midnight our spinning planet is turned in the direction of the radiant—causing the meteors to slam into the atmosphere at higher speeds and making them more visible.

Since meteor observing sessions usually run many hours, reclining on a lawnchair is normally recommended.  But on a frigid January night, you may prefere instead to remain standing and keep moving about to stay warm. (A thermos of hot chocolate or coffee will definitely help here too!)   And while this is basically a naked-eye activity in order to canvass as large an area of the sky as possible, using your Edmund binoculars is also encouraged for following the fascinating drifting “smoke” trails or trains left behind by many of the really bright meteors.

James Mullaney

Former assistant editor at Sky & Telescope magazine and author of eight books on stargazing.