Gee Whiz! Astronomy Trivia! Did you know that .....

If you watch the sun set on a clear, flat horizon (from the top of a tall
building, or from a boat at sea, for instance), you may see a momentary
"green flash" as the earth's atmosphere bends and disperses the sunlight,
prism-fashion.

If you made a model of the earth, 40 cm in diameter, the atmosphere would
be less than a mm thick.

As a result of human activity in space, there are over 10,000 large pieces
of debris up there, and millions of smaller pieces. You have to watch where
you are going!

The moon is as black as coal; it reflects only 6 per cent of the light which
falls upon it.

The full moon looks larger when it is near the horizon -- but it's just an
optical illusion.

You can remember the order of the planets Mercury, Venus, Earth, Mars, Jupiter,
Saturn, Uranus, Neptune and Pluto by remembering "my very educated mother
just showed us nine planets".

Saturn's rings -- which are made of chunks of rock and ice, orbiting above
the equator of the planet -- are 300,000 times wider than they are thick.
Relatively thinner than a sheet of paper! By the way: the average density
of Saturn is less than that of water, so Saturn would float in a very large
bathtub (but would leave a ring behind).

Uranus was the first planet to be "discovered" (by William Herschel in 1781).
It's pronounced UR'-a-nus, not the other way. Several of its moons have been
discovered by Canadian astronomers.

People argue about whether Pluto is a planet. It's smaller than earth's
moon, and it's just the largest of thousands of icy worlds in the outer
solar system. But for historical reasons, astronomers consider it a planet.

Comets are balls of ice. When they are near the sun, the ice evaporates
to form a cloud of gas. The sun's radiation pushes the gas into a "tail",
which always points away from the sun. So when a comet is moving away
from the sun, it's chasing its tail!

Our sun isn't an average star; it's more massive and powerful than 95 per
cent of its neighbours.

In five billion years, the sun will swell up to become a red giant, and
will engulf the inner solar system. But there are many things that
earthlings must worry about before that.

Betelgeuse, the reddish star in the upper left shoulder of the constellation Orion, is already so large that, if you put it where the sun is, its atmosphere
would stretch beyond the orbit of Mars.

A supernova is a stellar explosion which occurs when a dying star collapses,
releasing enough gravitational energy to blow the star apart. The brightest
supernova in 400 years was discovered, in 1987, by Canadian astronomer Ian
Shelton.

All the atoms in your body, with the exception of hydrogen and helium (there
isn't much of that) were created in stars, and blasted into space by stellar
explosions such as supernovas.

A black hole is an object whose gravity is so strong that nothing -- not even
light -- can escape. Very massive stars collapse, at the end of their lives,
to become black holes. The first example was co-discovered by Canadian
astronomer Tom Bolton.

There are enough ethyl alcohol molecules in interstellar space to make a
trillion bottles of whisky.

If there were aliens in our galaxy, as intelligent and technological as we are, we could communicate with them, using present-day radio technology.

Astronomer Edwin Hubble (the Hubble Space Telescope is named after him), went
to Oxford University on a Rhodes Scholarship. For that, you have to be
athletic as well as bright; he was a very good boxer. As an astronomer in
Los Angeles, he mixed with movie stars; he was a handsome fellow!

In the universe, you can look back in time. Since light travels at the fast
but finite speed of 300,000 km/s, we see the sun as it was 8 minutes ago, the
nearest other star as it was 4 years ago, the nearest large galaxy as it was
2 million years ago, and the most distant galaxy as it was 10 billion years
ago.

with files from J.R. Percy (2003), University of Toronto