Calvin Observatory Set for Venus Transit

May 17, 2004 == MEDIA ADVISORY

On June 8 skygazers will see something nobody alive has ever witnessed: a
transit of Venus.

And what exactly is the transit of Venus?

Simply put: a leisurely pass across the face of the Sun by Venus, an event
that the Chronicle of Higher Education recently described as "creating a small
black period that will punctuate the fiery solar disk."

The last transit happened in 1882 and created a worldwide sensation. Back
then the transit was seen as a way to measure the distance between the Earth
and the Sun. In 1882, said the Chronicle of Higher Education, nations spent
the equivalent of millions of dollars mounting transit expeditions. It was the
19th century version of today's space race.

This time around the event is not so significant scientifically. But it is
still important.

And among those who will turn their eyes to the heavens on June 8 will be
Calvin College professor of astronomy Larry Molnar. Calvin plans to have an
open house in its Observatory that morning (assuming clear weather), beginning
with sunrise at 6:03 am and ending with the transit's conclusion at 7:25 am.

Molnar says the transit of Venus is worth watching.

"The event is unusual," he says. "The last was 122 years ago. Interestingly
the next (transit) will be in eight years, but then there is another 120-year
gap after that. So some people get two shots at it in their lifetime; many
others get zero."

Molnar says in 1882 the transit was a very big deal.

"Given the state of astronomy the last time around," notes Molnar, "it was a
golden opportunity to determine accurately the size scale of the solar system
using accurate timing of the Venus transit. This scale has now been well
determined by other means, so this year's transit is more of a spectator sport
with historic interest than a scientifically valuable event. Still it will be
fun."

Calvin's Observatory is equipped with a one-year-old telescope from Optical
Guidance Systems, featuring a 16-inch-diameter mirror and precision computer
pointing which allows long-time exposures of faint stars and galaxies,
resulting in clear images of planets at the edge of the solar system and
galaxies in the distant reaches of the universe. The imaging techniques used
are the same as those used by professional astronomers at major observatories.

The transit will be viewed at the observatory with the 16-inch scope, which
will be equipped with a solar filter, and with two other telescopes, which will
project images on screens.

Molnar says those wishing to view the early morning event from their homes can
create satisfactory images with easily constructed pinhole devices. The
simplest approach, he says, is to put a pinhole in one piece of paper and
project the sunlight that passes through the hole onto a second sheet about a
foot away. A slightly fancier approach is to use the cardboard tube from a
roll of wrapping paper as a framework. Place tin foil over one end and white
paper over the other. Poke a tiny pinhole in the center of the tin foil to
allow sunlight in, and the image will form on the paper at the other end. The
tube blocks scattered light, enhancing the contrast, and the longer the tube
the bigger the image. To view the image, cut a small peephole in the side of
the tube near the paper end.

Molnar also says people need to be sure that they have an unobstructed view of
the horizon just north of east, where the sun will rise. And for safety sake,
do not look directly at the sun.

See http://www.calvin.edu/academic/phys/observatory/
Contact Molnar at 616-526-6341 or lmolnar@calvin.edu

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Received on Mon May 17 16:08:42 2004