Astro Bob blog: Another fireball update plus a Saturnian sunNew rumbles from last week's fireball plus a planet update
By: Bob King, Duluth News Tribune
Another fireball update plus a Saturnian sun
The sun near sunset yesterday was draped in a wreaths of clouds that mimicked the rings of Saturn. Hazy air scattered much of the sun's shorter wavelength light away -- the blues, greens and even some yellow -- leaving the disk a deep red. Photo: Bob King
Mercury and Jupiter were in conjunction only about a degree apart a short distance west of the sun yesterday evening. Unfortunately only the coronagraph on board the SOHO spacecraft could see the event, because the planets were so close to the sun they were lost in its glare. A coronagraph uses a metal disk (dark blue circle) to artificially eclipse the sun so astronomers can study its outer atmosphere called the corona. Jupiter will reappear in the morning sky in just a couple weeks; Mercury makes one of its best appearances of the year at dusk later this month. More information on current planets is at bottom.
The coronagraph in the Solar and Heliospheric Observatory (SOHO) took this photo at 6:42 p.m. yesterday when the two planets were in conjunction (at their closest). The lines are electronic artifacts while the many white dots are stars. Credit: NASA/ESA
I've been in touch the past couple days with meteorite hunter Mike Bandli regarding the bright fireball seen over Duluth and region last Wednesday. Mike alerted me to the American Meteor Society's fireball sighting log. There I found more than a dozen additional reports on the meteor plus sightings of other recent fireballs. Most interesting, there were three reports of "distant rolling thunder" or rumblings associated with the Duluth fireball in the Stillwater-Lake Elmo-Hudson area east of the Twin Cities. Mike is now in the process of examining and interpreting NEXRAD (Next Generation Radar) Doppler data from the National Weather Service to look for possible detections of the fall. While rumblings are a good sign that pieces of the meteor may have survived, "the pressure wave is coming from much higher in the atmosphere and can be heard for much greater distances," according to Bandl. Translation: any potential fragments could be up to 100 miles from where the sounds were heard. I'll pass along more information as it comes to light.
Stars show as long trails during this 14-minute time exposure. Saturn (near top) is the brightest. Details: 70mm lens at f/2.8, ISO 200. Photo: Bob King
Yesterday evening was a perfect time to be out. We've grown so used to being cold while standing under the stars that I can't help but be amazed how relaxing and easygoing stargazing is when the temperature's in the 30s. I didn't even wear gloves. While peering through the telescope at Mars, comets and galaxies last night, my camera silently recorded the rotation of the Earth as revealed in the movement of the stars.
Tomorrow we'll revisit the constellation Monoceros the Unicorn and get acquainted with its brightest star cluster. Get your binoculars ready!
This week's planetary highlights include the improved visibility of Venus at dusk and Saturn coming into prominence in the evening sky. Illustration: Bob King