Astro Bob A look at celestial happenings in the Northland and beyond Bob King View my profile Click here to view previous posts or additional resources

Wrinkle in time

The fastidious will walk around their homes tonight setting all the clocks ahead one hour in anticipation of the changeover to daylight saving time Sunday morning. Most of us won't bother until well after we get up on Sunday. My clock meddling begins with the microwave and ends several days later with the LED on the car's dashboard. How many clocks do you change in your house? Our tally comes to seven. I wonder ... do we need that many clocks?

This map shows the sky as you face east tonight at 8. Arcturus will have just risen and Saturn will be up a little higher. Maps created with Stellarium

Since we "spring ahead" or advance an hour that means the sun will set an hour later Sunday. We welcome the evening light. It makes driving home from work easier and coaxes us outside after dinner. Tonight the sun sets at 6:11 p.m. in Duluth; tomorrow it sets at 7:13 p.m. Add in a little less than two hours for twilight, and the sky won't be truly dark Sunday until around 9 o'clock.

Now we're looking the same direction at the same time Sunday night. Because of the changeover to daylight time, Arcturus has yet to rise and Saturn scrapes the eastern horizon.

The changeover to daylight time also causes a one-hour shift in the stars' positions. If you look toward the east around 8 p.m. tonight and follow the arc of the handle of the Big Dipper you'll run into the brilliant star Arcturus. Three fists to the right of Arcturus and a little higher in the sky is the planet Saturn. Go our tomorrow night at the same time and Arcturus won't even be up yet while Saturn will have just risen. Not to mention that the sky will still be aglow with twilight. To see Saturn and Arcturus like you will tonight, you'll have to wait until 9 p.m. on Sunday -- one hour later than normal.

In the western sky, daylight time has the opposite effect. Stars that tonight are low in the sky at 8 p.m. will be an hour's worth of time higher up on Sunday. While advancing our clocks an hour ahead, we've artificially shifted the entire night sky an hour's worth of time to the east. In fall, we "fall back" and shift the sky an hour in the western direction.

Although most of us don't like losing that hour of sleep from changing our clocks there is one advantage. Sunrise is an hour later so the sky stays dark in the morning making it easier to stay asleep and finish off those pleasant dreams.

Here's a unique video of multiple comets diving into the sun made over the past three days -- ice meets fire!

Yesterday a comet -- or series of comets really -- brightened up briefly before plunging headlong into the sun. The video shows that most of the comets were tiny but one was larger and put on a good show before it dissipated. All of them were most likely fragments of a single larger comet that broke up more than 2000 years ago. The photos used in the video were taken by the coronagraph aboard the Solar Heliospheric Observatory (SOHO) which can observe the sun 24 hours a day.

Posted by: rking@duluthnews.com on 3/13/2010 at 12:19 PM | Comments (0) | Permalink | Edit

Tags: daily updates, daylight saving time, astro bob, life, time, arcturus, saturn, comet, sun, video