Still Looking for Pan-STARRS?
Comet PanSTARRS is still with us for 30 to 45 minutes immediately following sunset. Look for it due west 20 degrees below the crescent moon Thursday, March 14. Shining around second magnitude, PanSTARRS at first appears as a modest star. Binoculars — and with ideal viewing conditions, even the unaided eye — will reveal a wispy tail pointing almost straight up. It appears a little higher above the horizon as it nears its peak on the 24th, edging to the northwest, or right, night by night.
This chunk of ice and rock has resided in the Oort Cloud at the farthest edge of the solar system since its formation billions of years ago. For whatever reason, perhaps a collision with another interstellar object, its usual course changed, bringing it toward the sun for the first time ever. That approach has cost PanSTARRS much of its heft, which we see melting off in the tail. By the time it returns to the outer solar system, there will not be enough left for another visit to our neck of the woods.
This comet was discovered in the summer of June 2011 by the automated Pan-STARRS sky survey in Hawaii, which was set up to find comets and asteroids on possible collision courses with earth — none of which will prove a threat. Come December, we’ll have another, possibly brighter visitor in Comet ISON.
The moon draws toward Jupiter at week’s end, culminating Sunday when the waxing crescent’s upper tip is less than two degrees below Jupiter. The planet is brighter than any star, so don’t confuse it with Aldebaran, just a few degrees to the left of the moon.
Saturn is the only other visible planet, rising in the east-southeast before midnight and high in the south before dawn.
Wednesday, March 20, at 7:02 in the morning, the sun passes to the north of the equator, marking the onset of spring for us in the Northern Hemisphere.