Tomorrow finds three celestial objects all in a row: Mercury directly in between the Sun and the Earth. The diagram above shows what you would see from the North American west coast, Pacific time.
The famous Polish astronomer Copernicus reportedly never saw the planet Mercury. I’ve only seen it twice in my life. My first time was during the 1974 transit when my friend Stephen and I set up his telescope and projected the sun’s image onto a large piece of white cardboard. Mercury showed up as a small dot.
A few cautions for tyro astronomers out there. Please do not look directly at the sun. It might have worked at Fatima, but you can cause permanent eye injury. Mercury’s dark disk will be too small to view, anyway. Also, be very careful with using a telescope to project the sun’s image. If you’re not careful, you might melt interior workings of your scope. If you’re in Africa, Europe, or Western Asia, you’re on the wrong side of the planet for this spectacle. Try again in 2016.
In other space news, the Messenger probe to Mercury has just completed its first Venus flyby on its way to Mercury orbit in 2011. Why so long? It is relatively easy to send a spacecraft past Mercury in flyby mode. But in order to achieve orbit with a minimum of fuel, repeated passes of Earth, Venus, and Mercury have been designed to ease the weighty demands of propellant and maximize scientific instruments. Click here to see the whole mission design.