30 December 2010

Quadrantids Meteor Shower - January 3-4, 2011

2011 starts with an impressive meteor shower for those ready to brave a cold night. The Quadrantids take place the night of Monday January 3rd into the morning of Tuesday January 4th, and are made better by the fact that the Moon is new, meaning no interference from moonlight.

As always, the best viewing of any meteor shower is from a dark location, ideally away from city lights. But I have had some success right in my backyard in San Francisco by positioning myself away from direct lights such as streetlights and houselights, and allowing myself 5 to 10 minutes to adapt to the darkness. Once dark adapted, the winter sky shimmers and Quadrantids are readily visible. In dark skies outside of cities you can expect up to 2 meteors per minute, but in the City I am happy to see 1 meteor every few minutes. This year should be as good a show as any, and despite our rainy Northern California weather the outlook is good.

To see this shower, position yourself facing northeast but give yourself as much of a view of the sky as possible. A lawn chair is best (along with blankets and a hat), as the meteors appear to originate in the constellation Bootes in the northeast part of the sky, but the meteors radiate in every direction away from this point.

For some fun background and history of this meteor shower, check out Astronomy.com and NASA's "What's Up" blog series. Image is courtesy of NASA.

Stay warm, and here's to good skies!

26 December 2010

Shimmering Early Morning Sky

As we approach the latest sunrise of the year (January 4th at 7:25 am in San Francisco), the morning sky remains dark enough to see stars until well after 6:00 am. That means that the early riser is rewarded with some lovely sights to close out 2010 and welcome 2011. Brilliant Venus dominates the sky each morning, shining bright in the South-East well before dawn. This week the waning Moon presents a changing landscape as it moves past Saturn, the bright star Spica (see diagram on the right), and then later in the week Venus and Mercury. Following the Solstice-Total-Lunar-Eclipse, the Moon is tracking downward on the Ecliptic, meaning that each Morning it is following the planets from high in the sky on a steep angle toward the horizon.

If you are not an early riser, don't despair. I'll have a post about the Winter skies soon. All you have to do is look up (especially if you are up at midnight on New Year's Eve and have clear skies). The Winter is a fantastic time to enjoy the stars.

Image courtesy of Sky and Telescope Magazine.

14 December 2010

Total Lunar Eclipse of December 20, 2010

Monday night December 20th, we get to witness a very exciting astronomical spectacle, a Total Lunar Eclipse. This one promises to be a special one, capping the longest night of the year with the strange and beautiful view of the full Moon being blotted out by the shadow of the Earth. The geometry of an eclipse is fairly textbook, but the experience is quite dramatic.

This eclipse will be visible from the western hemisphere, meaning that anyone on the entire night side of Earth will have a view of the full Moon and will see the phases of the eclipse. In this particular eclipse, the Moon passes through the darkest part of the Earth's shadow (umbra) meaning that the entire surface of the Moon will no longer have direct sunlight shining on it, but because of the atmosphere of the Earth, refracted rays of sunlight will in fact bend around the Earth and illuminate the Moon, creating a trademark orange or reddish color on the Moon, an eerie effect indeed. The excellent NASA Eclipse Website has much more detailed information on the eclipse.

The event starts at 10:33 pm in San Francisco, as the partial phases of the eclipse take about an hour. The period of "totality" when the entire surface of the Moon is dark, lasts about an hour from 11:41 pm until 12:53 am, and then the Moon is slowly revealed again for another hour. Cross your fingers for good weather, dress warmly, and enjoy this fascinating spectacle of nature. And if you have binoculars or a telescope, use them - this is exactly the time to get a close-up look at one of the wonders of the sky.

Image courtesy of the Universe Today.

08 December 2010

Geminid Meteor Shower 2010

One of the best Meteor Showers of the year takes place in favorable conditions on Monday night December 13th into the morning hours of December 14th. The shower is called the Geminids, named after the constellation Gemini. The Geminids appear to originate from the constellation Gemini which rises shortly after sunset and is high in the sky around midnight. This point in the sky is called the radiant, and if you trace the paths of the meteors backwards, they will all converge in this point.

Meteor showers generally get better late into the night because the Earth is rotated in the direction of its orbit around the Sun and consequently we encounter a higher number of meteors, on average. This is certainly true for the Geminids, and in dark conditions after midnight you might see 1 or even 2 meteors a minute. Being winter, you have to really prepare for this by dressing extremely well for your local conditions. I plan to get up early and look for Geminids in the early morning hours of Tuesday 14th, since the Sun does not impact the viewing until after 6:00 am.

This year is particularly favorable for the Geminids because the Moon is at First Quarter and will not be a factor after midnight. Stay warm and enjoy the show!

Image courtesy of Earth Sky.

03 December 2010

KFOG Podcast - December 3, 2010

Today on the KFOG Morning Show Podcast with Irish Greg, we talked about the discovery of new stars in the galaxy, alien life forms right here on Earth, the upcoming Geminids Meteor Shower on December 13-14, the upcoming Total Lunar Eclipse on December 20-21, and Holiday Shopping including a special 10% discount on anything at Scope City in San Francisco (my favorite place to shop) if you mention KFOG or The Urban Astronomer. Click here to listen. And take advantage of the 10% offer while it lasts!