The “blossom” of material around the sun is a cloud of plasma speeding toward us at 2.2 million mph. It arrives tonight. The picture was taken by the sun-blocking coronagraph on the Solar and Heliospheric Observatory. Credit: NASA/ESA

NOAA space weather experts forecast possible auroras tonight (Sept. 30) and tomorrow night from the arrival of a storm of electrons and protons from the sun. An Earth-directed coronal mass ejection blasted solar plasma in our direction last Thursday evening. Minor to major magnetic storms are likely as is the potential for auroras for the northern U.S. and higher latitudes.

Tonight’s bright moon may pose a problem with glare, but go out anyway to check the northern sky. I’ll post an update this evening if we get lucky.

The harvest moon rises within the blue-gray band of Earth’s shadow during twilight yesterday. Photo: Bob King

50 flybys in 13 minutes. That’s how many birds I saw winging across the full moon through my telescope from 9:13 to 9:27 p.m. last night. Most were very small and every one flew from east to west, crossing the moon’s face in 1-3 seconds. The anticipation of each brief avian appearance reminded me a lot of meteor shower watching. Late August through October is the best time to follow bird migration by moonlight. The period between waxing gibbous through waning gibbous moon is ideal.

Full moon rise is also a perfect time to notice Earth’s shadow. It’s a thick, dusky band spanning the horizon from northeast to southeast that appears around sunset and rises higher as twilight progresses. The pairing of moon and shadow last night was a delicious sight. If good weather holds, you’ll see the two together again tonight.

Amazing little comet 168P/Hergenrother shows a bright nucleus and short tail when this photo was taken on Sept. 16. At left is a small group of galaxies. Credit: Michael Jaeger

Comets have always been the apple of my observing eye. That’s why I wanted to share this beautiful picture taken by Michael Jaeger of Austria of 168P/Hergenrother. Besides, it’s just fun to pronounce the name: HER-gen-ROTH-er. The comet was discovered by American astronomer Carl Hergenrother in 1998 and returns every 7 years. Although its current predicted brightness is 15th magnitude (very faint), Hergenrother’s been considerably brighter the past month.

Recently it experienced an outburst of activity in its icy nucleus and now shines at magnitude 10.4 along the eastern side of the Great Square of Pegasus. An 8-inch or larger telescope will nab it.

I’d share a map showing how to find it if it weren’t for the bright moon nearby. Later next week, when the moon departs, the comet will be easier to see. I’ll post a finder chart then. Hergenrother flies nearest to the sun on Monday Oct. 1 but misses it by a healthy 131 million miles. Closest approach to Earth happened on September 25 at 39 million miles.

Jupiter is visible in the east around 11 p.m. in early October. To its right is the bright star Aldebaran and the V-shaped Hyades Cluster. Photo: Bob King

I’ve noticed that Jupiter rises above the trees in the northeast by 11 o’clock. If you’re out looking for aurora, take a look in that direction. It’s the brightest “star” you’ll see in the evening hours.

Stay up even later (or get up early) and you’ll see the space station make its final round of morning appearances this coming week. Starting October 9 the shiny bird returns to the evening sky. I’ve listed viewing times for the Duluth, Minn. region. To find out when to watch for your town, log in to Heavens Above or type in your zip code at Spaceweather’s Satellite Flyby site.

* Monday Oct. 1 starting at 5:12 a.m. Comes up from the west, waxes into brilliance and then fades when it enters Earth’s shadow near the top of the sky
* Tuesday Oct. 2 at 5:59 a.m. Nice pass below the constellation Orion
* Wednesday Oct. 3 at 5:12 a.m. Brief appearance when it pops of out Earth’s shadow east of Orion
* Thursday Oct. 4 at 5:59 a.m.  brief pass very low in the southern sky