Saturday, April 19, 2014

Total Lunar Eclipse April 15, 2014

It's been a long time since we've been able to see a total lunar eclipse from the West Coast of North America, but the wait is finally over. The total lunar eclipse that took place on April 15, 2014 was the first of two total lunar eclipses in 2014, and the first in a tetrad (four total lunar eclipses in series). The subsequent eclipses in the tetrad will occur on October 8, 2014, April 4, 2015 and September 28, 2015. This eclipse was especially well placed for observers in San Diego, California.

A lunar eclipse can only occur during a full moon when the orbital geometry of the Earth, the Moon and the Sun align for a short period of time. The Earth’s shadow has two parts: a darker inner section called the umbra and a lighter outer region called the penumbra. When the Moon only passes through the penumbra, we experience a Penumbral Eclipse. When the Moon passes through part of the umbra, we see a Partial Eclipse. When the Moon passes completely through the umbra, we experience a Total Eclipse.

Friday, December 6, 2013

Comet ISON's Full Perihelion Pass

It's been a long wait, and many amateur astronomers have been biting their finger nails and hoping for some good news, but apparently comet ISON didn't survive its close pass by the sun on Thanksgiving Day.
 
As you can see in the video below, the comet dramatically brightened as it swung around the sun, but its brightness greatly diminished soon after. Astronomers now believe the comet fragmented during approach and most of it's ice was vaporized by the intense heat and radiation. Astronomers will continue to observe the remains of this amazing comet for as long as they can, but it will be extremely dim as it exits the solar system. Those of us hoping for a Great Comet will have to wait a while longer...


Monday, August 5, 2013

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:




Wednesday, July 31, 2013

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?

Saturday, March 9, 2013

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:





Friday, February 15, 2013

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. 

Sunday, May 20, 2012

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.