Comet L4 PANSTARRS looks better and better with each passing night as these two photos attest. The latest birghtness estimate made a day ago puts the comet at magnitude 2.6 or only a little fainter than the stars of the Big Dipper. Yuri Beletsky, who shot the image below from the Atacama Desert in Chile, reports it was easily visible to the naked eye low above the western horizon at dusk. In a week, PANSTARRS will creep over the western horizon for northern hemisphere sky watchers and we’ll finally get to see it ourselves. Expect the comet to become visible around March 7-8 in the west about a half hour after sunset.
How bright will the comet glow? It’s hoped between magnitude 1 and 2 or about as bright as Deneb in the Northern Cross. If haven’t got a pair of binoculars yet, now’s the time to get down to the store and pick them up. Anything in a 8×40, 7×50 or 10×50 size will do the job. I know I’ve said it before but avoid 20x (20-power) binoculars in small sizes. The narrow field of view and high magnification will make PANSTARRS difficult to find but also and tough to hold steadily. Super high quality glass is not essential. Moderation in binoculars will bring great celestial joy.
I’ll have more detailed maps and of course tons of photos once the PANSTARRS limited-engagement, once-in-a-lifetime show begins in earnest.
Comets aren’t the only thing happening lately. Late last night some of you may have been lucky enough to see Spica and the moon paired up. Clouds dogged my attempts. Giorgio composed a beautiful picture of them together over a rooftop in Trieste earlier this morning.
Aurora activity ramped up last night for arctic sky watchers when a high-speed stream of solar wind rammed Earth’s magnetic field. For a brief time, minor auroras may have been visible across the far northern U.S. Activity is expected to continue tonight and then decline on March 2-3. You can always check the space weather forecast for the latest update.
In a related story, NASA’s Van Allen probes discovered a third belt of radiation around Earth. We’ve known about the two Van Allen belts since 1958. They’re home to high-energy protons and electrons captured from the sun and cosmic rays from beyond the solar system and bottled up by Earth’s magnetic field. The inner belt is some 4,000 miles up; the outer belt extends from 13,000 to 37,000 miles high. Both belts swell and shrink in response to solar wind blasts and fluctuating amounts of cosmic rays.
The probes discovered a never-before-seen third belt just days after launch. Within a month it had disappeared. Exactly how, scientists are still trying to figure. If you’d like to read more about the discovery, click HERE.