Millions may shine pointers at moon
By Chris Oliver
Advertiser Staff Writer
"Paint the Moon," an effort to get millions of people across North America to "paint" a red spot on the dark portion of the moon by using laser pointers, is set for Oct. 27. James Downey, of Columbia, Miss., is calling his idea "a collaborative work of celestial art," and hopes the red dot will be visible from earth during the five-minute period.
www.paintthemoon.org
"It's an artistic experiment to see if we can create a temporary visible field of color on our nearest celestial neighbor," he said.
The idea is to produce a laser-red spot on a dark part of the lunar surface. Possible? Who knows?
At a pre-arranged time (5 p.m. Hawai'i time), Downey asks that everyone with a laser pointer aim it at the terminator (the line where sunlight stops) and continue for five minutes.
Downey, a fortysomething writer, artist and bookbinder, talked about his idea on National Public Radio in August: "I honestly don't know if it will work, but if we can get a few million people to attempt it, it just might. Think what an awesome sight it would be."
He notes that he's not the first person to shoot lasers at the moon. "NASA has been doing it for years as part of a range-finding effort."
Scientists are skeptical. "It would be very difficult for people to aim all of their laser pointers carefully enough to effectively add the light together," said James Armstrong, a graduate student at the University of Hawai'i's Institute for Astronomy. "The diameter of the moon is about half a degree."
To get an idea of how tricky the aim is, Armstrong suggests taping a quarter to a wall to represent the moon. "From a distance of about nine feet, aim the laser pointer at the quarter without turning it on. When you think you've got the aim down, turn on the laser and see how close you are to hitting the target."
•
'On the Web: www.paintthemoon.org
Armstrong adds, "Remember that even if 'painting the moon' could work, you wouldn't know if you were hitting the target."
Another difficulty, he says, is that there wouldn't be enough energy reflected back from the moon for us to see the results from Earth. "The laser travels away from the pointer in a very narrow beam. When it hits something — a wall, or the moon — the light reflected is spread over a larger and larger area the farther away it gets from the reflecting surface."
Armstrong said that laser pointers have a power of about 5 milliwatts. "Even if 2 million laser pointers were aimed at the same place on the moon at the same time, that would only be a combined power of 10 watts. Most people have a 75-watt light bulb somewhere in their house. Do you think you could see a 10-watt bulb from the surface of the moon? ...
"The moon is 240,000 miles from Earth. Shining two million laser pointers at an object that distance compares to shining a single laser at a point 170 miles away ... say from the top of Diamond Head to the top of Haleakala, on Maui. And that is assuming everyone hits the moon at the same time."
Though Armstrong says the experiment will be a dud, he thinks it's a neat idea. "It's not a waste of time, only a waste of batteries. What phase is the moon in right now? Chances are most people don't know. There's a lot of really neat things to see in the night sky. Too often we forget to look."
