March 21st at 45 minutes after sunset.
I would try looking for Comet PanSTARRS 30 minutes after sunset towards the west-northwest with binoculars and then try just with your eyes roughly 50 minutes after sunset. The moonlight, however, is beginning to interfere with finding the comet!
UPDATE March 20, 2013
Comet PanSTARRS is roughly 108,000,000 miles away from the earth right now. With that in mind, this comet is not very bright. Tonight it took me nearly 50 minutes (after sunset) before seeing the comet. The sky was very clear and very cold on this first day of spring! I could just barely see the comet with the naked eye. As usual, I needed binoculars to locate it first. I feel the comet is getting dimmer. I did find a star, Alpheratz, in the constellation of Pegasus about the same altitude above the horizon as the comet. This star of Pegasus is roughly 10° to the right of the comet. The brightness of Alpheratz is roughly second magnitude and very easy to see with the naked-eye. Comet PanSTARRS was more immersed in the twilight than the star, but not by much. The moon is very bright right now being that its first-quarter. I feel that the moon is contributing to the dimness of the comet. With the comet pulling further away from the earth each day, and the moon becoming brighter and fuller, the comet is going to naturally become less and less bright and harder to find.
UPDATE March 18, 2013
Finally clear, after a bout of numerous thunderstorms, possible tornadoes and a hard rain this morning with the clouds slowly dissipating by nightfall! I went outside forty-five minutes after sunset with some stray clouds lingering from the storms. Looking due west and a little to the right, I easily picked the comet up in my binoculars. Once I got my bearings, I could see the comet with the naked eye fairly easily. I believe I could see a hint of the tail, but I was still fighting the fragmented clouds this evening. Looking at the stars that make up the Pleiades open cluster in the constellation of Taurus, I found the faintest stars to be comparable in brightness to Comet PanSTARRS.
March 13, 2013 part two
I looked again on this Wednesday night. Now that I know what I am looking for, I can sum up this comet in one word... DIM! I started seeing the comet 30 minutes after sunset with binoculars. Forty-five minutes after sunset, it appeared very dim to the naked-eye. At the time, I had to use averted vision to pick up on Comet PanSTARRS. I looked at the Andromeda Galaxy nearby and the Orion Nebula for comparison. The tail of the comet, through binoculars, was of comparable brightness to these Messier objects, although the comet seem to have a slightly brighter, yellower sheen because of the dust in its tail reflecting the sunlight. The sky may have been clearer tonight for I could see the comet, mostly with binoculars, for about an hour. I hope to look at it with a telescope tomorrow night... stay tuned!
UPDATE March 13, 2013
I finally saw Comet PanSTARRS last night near the moon in middle Tennessee. I had to use binoculars to see it. It was a good forty minutes after sunset before I could see it without binoculars. Seeing it with the naked-eye lasted for roughly ten minutes before the atmosphere soaked up its light near the horizon. The tail was apparent with the binoculars, but I just could not see it with my eyes. Interesting comet but no "knock your socks off" moment. I found the moon many times more interesting with its super thin crescent! As it getsfurther away from the horizon, hopefully it will become more apparent! (I did take photos, but I am still using dinosaur technology... FILM.)
UPDATE March 10, 2013
This comet is hard to see (I still haven't seen it yet, and I was looking through clouds again last night.) Look at the photo below that is on spaceweather.com... not an easy find! You will have to have a clear view of the western horizon, and you will need binoculars. Weather again for me today, on Sunday, is socked in with clouds and rain later today.
UPDATE March 8, 2013
The western horizon was cloudy in Clarksville, TN for me this evening. I don't believe anyone is seeing it yet from the mid-northern latitudes!
I just found this at Sky & Telescope's website a short time ago: March 8: North to Florida. Longtime amateur astronomer Jim Brant writes from Homestead, Florida, latitude 25° N: "I spotted the comet naked eye at 7 p.m. tonight (March 7th). It is much fainter than recent photos from the Southern Hemisphere, which is expected as they are time exposures. It looks like a faint straight jet contrail, about a degree long and fainter than I expected. It's a pretty sight in my f/6.25 80mm University Optics refractor at 11x."
UPDATE March 7, 2013
Tonight will be the first night I will try looking for the comet, because it is clear here. I will let you know one way or another if I see anything or not.
Addendum - I checked this evening and saw nothing. I used binoculars as well. The clouds had moved out of the area earlier today, but the sky seemed somewhat milky towards the west. I will try again tomorrow. I know the twilight is killing the view of it right now. Once the comet pulls further away from the horizon, we should see something. Also, it is suppose to be at it's brightest on the 10th. Patience is a virtue!
C/2011 L4 ( PanSTARRS ) animated
Updated on March 20, 2013