Now I have to report on celestial events? :)
Hale is on a working vacation, manning the Kitt Peak booth at the American Astronomical Society meeting in sunny Long Beach. (sounds grueling to me)
The following are excerpts from an interesting article I found this morning that explains stuff so even I can understand it: Be sure to take a peek on your way to the JTI PARTY tonight (if it isn't cloudy or snowing)
Saturday Night Special: Biggest Full Moon of 2009
If skies are clear Saturday, go out at sunset and look for the giant moon rising in the east. It will be the biggest and brightest one of 2009, sure to wow even seasoned observers.
Earth, the moon and the sun are all bound together by gravity, which keeps us going around the sun and keeps the moon going around us as it goes through phases. The moon makes a trip around Earth every 29.5 days.
But the orbit is not a perfect circle. One portion is about 31,000 miles (50,000 km) closer to our planet than the farthest part, so the moon's apparent size in the sky changes. Saturday night (Jan. 10) the moon will be at perigee, the closest point to us on this orbit.
It will appear about 14 percent bigger in our sky and 30 percent brighter than some other full moons during 2009, according to NASA. (A similar setup occurred in December, making that month's full moon the largest of 2008.)
A full moon rises right around sunset, no matter where you are. That's because of the celestial mechanics that produce a full moon: The moon and the sun are on opposite sides of the Earth, so that sunlight hits the full face of the moon and bounces back to our eyes.
At moonrise, the moon will appear even larger than it will later in the night when it's higher in the sky. This is an illusion that scientists can't fully explain. Some think it has to do with our perception of things on the horizon vs. stuff overhead. Try this trick, though: Using a pencil eraser or similar object held at arm's length, gauge the size of the moon when it's near the horizon and again later when it's higher up and seems smaller. You'll see that when compared to a fixed object, the moon will be the same size in both cases.
More lunacy... If you have other plans for Saturday night, take heart: You can see all this on each night surrounding the full moon, too, because the moon will be nearly full, rising earlier Friday night and later Sunday night.
Interestingly, because of the mechanics of all this, the moon is never truly 100 percent full. For that to happen, all three objects have to be in a perfect line, and when that rare circumstance occurs, there is a total eclipse of the moon.
A departing fact: The moon is moving away as you read this, by about 1.6 inches (4 centimeters) a year. Eventually this drift will force the moon to take 47 days to circle our world.