If you're still at work and reading this, you might want to walk outside and
look up this evening. Three planets and the Moon are again appearing in a
line. The alignment is, beginning in the west, Venus, Moon, Saturn, Jupiter.

Some people asked the last the time I mentioned this alignment (just about a
moonth ago) whether or not Kubrick and Clarke planned the movie this way for
the year 2001. The answer's no. These alignments are common. But it doesn't
make them any less pretty.

The planets, including the Earth, all formed themselves on a very flat plane,
called the Plane of the Ecliptic, which is also the rotational equator of the
Sun. The effect isn't surprising. If you covered a basketball with water and
then spun it in a gravitationless environment, the water would come off at
the basketball's equator in a similar flat plane. Because of this, when you
view the other planets from the Earth's perspective, they present themselves
in front of a very specific set of constellations, which were defined to be
the Zodiac several thousand years ago.

When the Earth-Moon system's tilt is appropriate, the Moon also swings right
along with the remainder of the planets, and that's approximately what's
occuring tonight and tomorrow night, although it is absolutely best on the
vernal and autumnal equinoxes (the Earth-Moon plane is coincident with the
Plane of the Ecliptic on those days).

All of these planets are bright enough so that you should be able to see them
from a brightly lit parking lot. It's not often that you can say that you can
see four planets in such a small section of sky (five, if you count the Moon
as separate planet, as some people do).

Wirt Atmar