ScienceCasts: The Sun's Magnetic Field is About to Flip

Something big is about to happen on the sun, and it will have far reaching effects throughout the solar system. As we near the midpoint of Solar Cycle 24 and Solar Max, the magnetic field of the sun is about to reverse polarity. This is something solar physicists have studied since the 1970's so it's not a big deal, but it is interesting and it's bound to stir up some unsettled space weather in the very near future.

Here's a video from NASA that explains what's going on:





Comet ISON Under Perfoming

Recent observations by the Hubble Space Telescope team and ground-based astronomers are beginning to cast doubt on comet ISON's expected  "Comet of the Century" performance this fall.

Will the comet blossom as it approaches the sun? Astronomer's can't make any reliable predictions at this point, so we will have to wait and see.

Here's a link to a recent article by Nat Geo: Comet ISON: Pop or Fizzle?

Comet Pan-STARRS Makes an Appearance

Throughout the month of March, Comet PANSTARRS (C/2011 L4) barely peeked above the western horizon after sunset. While many observers around the world reported seeing its coma without a telescope, it never reached "naked eye" visibility from the suburbs of San Diego. Because it was so low in the sky it was difficult to locate using a small 60mm refractor telescope. With a little luck it might grow a little brighter in the next week or so as it climbs higher in the evening sky, but its predicted to fade as it heads out of the Solar System.

Here's a link to some star charts that might help you find this beautiful but somewhat elusive comet.

And here's an excellent video about Comet Pan-STARRS from NASA:

Chelyabinsk Fireball Catches Earth by Surprise

On February 14, 2013 residents of the Russian city of Chelyabinsk were rocked by a fireball air burst almost as powerful as the legendary Tunguska Event. A small asteroid estimated to be over 10,000 metric tonnes entered the atmosphere from the daylight side of the planet at a very shallow angle and exploded at an altitude of 79,000 feet, raining fragments of material over a wide area.  

Photo: Alex Alishevskikh via Wikimedia Commons

Residents who came out to see the amazing trains of vaporized material hanging in the sky were taken by surprise by a series of powerful sonic booms that blew out windows and caused wide spread damage to buildings in the Chelyabinsk area a little over three minutes after the fireball burned up in the atmosphere. If the object had entered the atmosphere at a steeper angle the damage would have been catastrophic. Thanks to Russian's wide use of dash mounted video cameras, this incredible event was captured by many different people from many different vantage points, which will help astronomers determine the exact trajectory of this object as it ripped through the sky. 

Annular Solar Eclipse May 20, 2012

Southern California sky watchers were blessed by a rare celestial event on Sunday, May 20, 2013 when the moon passed in front of the sun and created an annular solar eclipse. An annular solar eclipse happens when the moon and the sun align but the apparent diameter of the moon is less than the apparent diameter of the sun, creating a ring of light, or "annulus" around the sun instead of blocking it completely.

The geometry didn't favor viewing the eclipse from San Diego, so instead of seeing an annular eclipse, we got to see a partial eclipse. But it was a spectacular sight nonetheless with approximately 80% of the sun's disk covered by the moon at the peak of the event. The sun set before the moon could completely pull away from the sun, making the sunset even more beautiful. In retrospect, it was an incredible event that I was fortunate enough to share with my family and friends. Solar and lunar eclipses are like bookmarks of our lives -- we are only here for a short period of time, and most people can count how many eclipses they've seen over their life on one hand.

I succeeded in capturing a couple of "white light" images of the eclipse with my ETX 60 and Celestron Solar Filter, and I will post them soon. I was unable to capture any clear images with my Coronado PST Hydrogen Alpha solar telescope.

Here's a link to NASA's Eclipse Page detailing this incredible event:

http://eclipse.gsfc.nasa.gov/SEgoogle/SEgoogle2001/SE2012May20Agoogle.html

And here's a Quicktime simulation video I made using my trusty old Starry Nights astronomy program. This video simulates the 2 hour 15 minute eclipse as seen from San Diego in 3 minutes and 52 seconds.

Total Lunar Eclipse: December 10, 2011

Southern Californian sky watchers were blessed with an amazing total lunar eclipse just before sunrise on Saturday, December 10, 2011. This will be the last total lunar eclipse visible from the west coast until 2014.

The timing of this particular lunar eclipse produced an extremely interesting event known as selenelion. In order to appreciate the unique circumstances that produce a selenelion, it's important to first understand the basic geometry that creates a total lunar eclipse.

A lunar eclipse can only occur when the full moon and the sun are aligned 180 degrees apart with the Earth in between. The Earth's shadow temporarily blocks the light of the sun, causing the full moon to darken, and as the moon passes deeper into the the Earth's shadow, sun light refracted by the Earth's atomosphere causes the moon to glow orange. On December 10th southern California sky watchers witnessed the rare sight of a fully eclipsed moon setting in the west as the sun rose in the east - a selenelion. This event lasted only a few minutes, but it was a spectacular sight to see.