KGO Broadcast - February 16, 2013

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.

A Perfect Time to see Mercury

Mercury in February

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.

Image courtesy Sky & Telescope.

Asteroid Alert! 2012 DA14 swings by Earth

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.

Get Involved: Star Parties/Learn to Use a Telescope

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.

Star Party

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 San Francisco Amateur Astronomers (SFAA) club has an open monthly meeting, where anyone may attend to hear very topical lectures on a variety of subjects related to astronomy and space research. The upcoming lecture and calendar are found on the website. And on Saturday February 16th the SFAA is hosting a Star Party and New Scope Forum where you can dust off and bring out your old telescope for a primer on how to use it, and then a chance to put it to work looking into the heavens.

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.

Get involved! You won't be sorry.

Planetary Conjunction at Dusk: Mars and Mercury

Mars & Mercury

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.

Here's a helpful short video clip from Sky & Telescope's Tony Flanders showing how to find the two planets in conjunction, and how to find Mercury during the month of February.

Image courtesy of Sky & Telescope.

Seeing the International Space Station

International Space Station

The International Space Station, or ISS, is a wonderful sight to see. It is Earth's 2nd largest satellite (after the Moon, of course). The ISS shines brightly because of the reflective surfaces across its trusses that shine brightly in the sunlight, and make the ISS look like a bright planet that moves relatively quickly across the sky.

The ISS only appears in the sky for a short while after sunset, or before sunrise. It is in orbit about 225 miles above the surface of the Earth; for example, shortly after a sunset the ISS catches sunlight and shines as it travels across the sky. When you get a very good alignment and it passes nearly overhead, it can reach the same magnitude as a bright Venus, and therefore be easy to spot. On such a pass, it takes about 5 minutes to travel from horizon to horizon, covering over 1000 miles in that time.

ISS visibility depends upon your location on Earth, since the best times to see the ISS in one part of the globe won't be the same as another. NASA has an an excellent web resource for this; for ISS sightings in San Francisco, we have morning passes right now, and will soon have good visibility in the evenings starting on February 5th. The iPhone app ISS Visibility is quite helpful for locating the ISS, with maps and easy-to-follow directions.

Best of luck seeing this wonderful sight. Image courtesy of NASA.

Astronomy Events in 2013

Every year is full of special moments in the sky as planets and stars and the Moon align to create noteworthy patterns and special views. 2013 will be marked by many special moments, so here's a quick overview of them.

Comets

Comet Hale-Bopp

The event of the year could be the fly-by of Comet Ison, currently en route for a November 28th close encounter with the Sun, potentially lighting up the night (and even daytime) sky. More information on Comet Ison here.

Asteroids

Mark your calendar for February 15-16, when Asteroid DA14 will pass within 10,000-20,000 miles of the surface of the Earth. This is a big asteroid, at 125 feet, and could cause considerable damage if it was to impact. Lucky for us, we will not have anything to worry about. More here from Earth Sky.

Eclipses

Only one eclipse will be of significance for the West Coast, on October 18th when the Moon will pass within the Earth's penumbral shadow. This partial eclipse will start before moonrise in California, but once the Moon rises, should be a nice sight.

Occultations

Every month as the Moon slips past planets and stars in the night sky, there are moments when a distant object is blocked out by the Moon, called an Occultation. This year there are several close encounters that should be quite fun to watch from the Bay Area. Depending where you are on Earth, you can see more or less of these events. A few noteworthy ones: January 21 and March 17 when the Moon passes very close to Jupiter; and February 28-March 1 and July 15-16 when the Moon passes very close to the bright star Spica.

Be sure to check out the Year In Space calendar for 2013 which has fascinating facts and is a wealth of astronomy information for every day and month of the year. And happy viewing this year!

Image courtesy Wikimedia Commons.

Alignments in the City Sky

Jupiter, Orion, and Sirius

I am viewing the sky this evening from one of the most densely populated urban areas, Manhattan. Looking up at the night sky here, you can't see many faint stars, but you can still see plenty of the brighter ones. Tonight looking toward the south, I was easily able to spot the fantastic alignment of Orion's belt, pointing downward toward the brightest star in the sky, Sirius, and pointing upward to the brightest planet in the sky in the evening, Jupiter. As Jupiter gradually moves in its orbit around the Sun, it will soon move out of alignment with Sirius, Orion's belt, and the bright star Aldeberan in the constellation Taurus. By the middle of 2013, Jupiter will be well on its way to the next sign in the Zodiac, Gemini. But for the coming weeks, you can enjoy the bright celestial alignment that can been seen from just about any location on Earth, even in the middle of an urban jungle such as NYC.

Image courtesy of Sky Safari.