The night of Oct. 3 and 4 is not only a full moon, it is the harvest moon. Arousing nostalgic images of farmers with horse-drawn equipment working the fields by night, this year we may as well call it the demolition derby moon.

The night of Oct. 3 and 4 is not only a full moon, it is the harvest moon. Arousing nostalgic images of farmers with horse-drawn equipment working the fields by night, this year we may as well call it the demolition derby moon.

A few days after the full phase, as the shadows begin to appear in craters and lunar mountains along the western edge, NASA is about to crash a space probe and its Centaur rocket carrier into one of the craters just to see the fireworks display.

On Oct. 9, a spacecraft in orbit around the moon will send a spacecraft lander known as LCROSS smashing into a crater very close to the south pole of the moon. Permanently filled with shadow, scientists suspect that these perpetually darkened areas may contain water ice. The ice would have been deposited by the numerous comets believed to have crashed into the moon in millennia past. Ice from comets crashing where sunlight reaches would have quickly melted and vaporized.

Hopefully, like at a fairground grandstand, throngs of spectators will be cheering at this lunar demolition derby.

Astronomers back on Earth -- as well as well-equipped amateur astronomers and very-well-equipped orbiting telescopes -- will be watching closely for the resulting plume of dust and rock from the spacecraft’s crash, as well as what they hope will be vaporized water detectable back home with spectroscopes.

The orbiting spacecraft has been studying craters to choose one for the impact. The chosen crater is known as Cabeus, and it is 61 miles wide. A high concentration of hydrogen has been detected in the crater; hydrogen of course being the first part of water’s familiar compound H2O.

NASA TV is planning live coverage of the event, starting at 6:30 a.m. EDT, about an hour before the impact.

So how do astronomers see within a permanently darkened crater? One instrument being used actually uses starlight. Yes, starlight. So the crater isn’t totally dark after all, but the much nearer sun never shines there.

The Lyman-Alpha Mapping Project (LAMP) takes images using reflected ultraviolet light from the stars. The LAMPS instrument is aboard the satellite in orbit around the moon, known as the Lunar Reconnaissance Orbiter.

Hydrogen atoms are being detected on the moon using another instrument, the Lunar Exploration Neutron Detector (LEND). This instrument, aboard NASA’s orbiter, was built by the Russians. It has been a long time since the 1960s space race when the U.S.A. and U.S.S.R. were competing to land a man on the moon; they are on the same team for the demolition derby.

The crash occurs around 4:30 a.m., PDT, with the moon in a dark sky in western North America. You will need a telescope of at least 10 inches aperture to possibly detect the little and short-lived plume cloud. At that time, the sun will already be up in the eastern and central U.S.

Finding water on the moon would mean future astronauts would have a source of drinking water as well as a component for rocket fuel. Good for the lunar fair’s snow-cone stand too ... or to have a nice cold glass of comet water!

Meanwhile, enjoy the harvest moon and its lovely light for the few nights around that date, with bright moonlight bathing our fields and country roads. The best walks under the bright moon are definitely where you can walk safely without street and parking lot lights and neon signs.

Enjoy brilliant Jupiter well up in the south during the evening. A small telescope will easily show you its little disc and four bright moons. Early risers (or very late go-to-bed-ers) can see brilliant Venus low in the east during morning twilight. Look for planet Saturn a short distance below Venus, and planet Mercury very close by to Saturn. Binoculars will aid you in finding Saturn and Mercury, in the brightening dawn.

Comments and questions are welcome; e-mail pbecker@wayneindependent.com. Keep looking up!