Last Saturday I had a fun experience: joining KGO 810 Talk Radio in San Francisco for a one-hour broadcast. Greg Gory invited me to stop by and talk about asteroids, meteors, fireballs and many other astronomy topics, and we had a fine time doing all of that and more! We entertained calls from listeners and ended the show on a high note, discussing why we go into space and explore in the first place. Click here to listen.
Mercury is the most elusive of the visible planets in the Solar System, never drifting far from the glare of the Sun, and always on the move. So you should take advantage of the upcoming weeks when Mercury will be well positioned in the sunset sky. Mercury is a small planet so it will not have the bold bright shine of Venus or Jupiter, but it will certainly stand out as a bright speck of light in the dusk sky. Look soon after sunset for a point of light that becomes increasingly bright as darkness sets in. You'll need a good, clear western horizon to see this. But take a minute some evening and spot it, since it won't be this easy again for a while.
This Friday, a small asteroid will pass quite close to Earth. 2012 DA14 is a 60 meter ('Olympic pool size') asteroid that will pass between the low-Earth orbit satellites and geostationary satellites, at a distance of about 17,000 miles, a close shave by astronomical terms, but not something that is posing any kind of threat to the planet.
Asteroids pass near to Earth all the time, and the largest of them are being closely tracked. At this time over 1300 potentially hazardous asteroids (PHAs) are being watched, but none of them are on a collision course with Earth. For the foreseeable future, we have nothing to worry about - - at least as far as asteroids go!
If you want to watch the fly-by, you can check out a number of websites that will have live video feeds of the asteroid. At closest approach, it will be daytime in California and not visible, but the video feeds will be delivered from the other side of the planet. It won't be overly dramatic -- just a spec of light moving against the backdrop of stars. As one website put it, the size and distance of 2012 DA14 will be, on the scale of a 12-inch globe of the Earth, a grain of sand 2 feet away from the surface of the Earth. That's a good reference.
Every month there are numerous opportunities to get involved with the fun and science of astronomy. The NASA Night Sky Network is a good place to start if you want to find a local event, and in this post I'll provide some local suggestions if you live in the San Francisco Bay Area.
I love presenting the sky at star parties and giving talks about astronomy, so I signed up to do this for the Marin County "One Book One Marin" celebration happening this year. Check the calendar for dates, and join me at different libraries in Marin for an introductory lecture on the Solar System and constellations, and star gazing (if weather permits). The first two events are on February 11th and 12th. The San Francisco Amateur Astronomers will also host star parties on different nights in February and March.
The Peninsula Astronomical Society and the always-excellent Dr. Andrew Fraknoi put on star parties and outstanding lectures in Los Altos Hills. And the wonderful Chabot Space & Science Center has very fine telescope nights featuring their giant telescopes on Friday and Saturday nights year-round.
This week, you will have a chance to spot elusive Mercury in the dusk sky, as the fast-moving planet gradually slides into the evening sky for a February showcase. In the first few days of Mercury's evening apparition, it moves past Mars, which itself is fading into the evening twilight. To spot these two planets in conjunction (close encounter) on February 7th and 8th, you will need binoculars or a telescope, and a clear western horizon. The two will form a very close pair for a couple days, and then Mars will continue its fade into the glare of sunset while Mercury will race eastward, appearing higher in the sky for the middle of the month. It will be work to find these two, but a fun challenge if you have clear western skies.
The image shows the view 30 minutes after sunset. The Sun sets in San Francisco around 5:40 pm this week.
In 2005 I began writing a column for the San Francisco Waldorf School newsletter called "The Urban Astronomer." I started this blog in 2007 as a place to archive my articles and to offer additional insights on the night sky - even if you live in a big city. In 2008 I became an occasional guest on the KFOG Morning Show, and more recently on KALW and KGO. Archived shows are posted on the blog.