Archive for the ‘Uncategorized’ Category

Unexpected pinhole effect

21 July, 2009

You could set a pinhole up to project the eclipse onto a makeshift screen but really, the pinhole camera essentially works with any tiny hole that can serve as an aperture.

One effect to look out for is the pinhole effect when sunlight filters through any tiny gaps, including those in trees in between leaves.

Photo: Juan Jaen

This could be anything from tiny gaps in between the leaves in a tree,

Photo: Ellywa

Or a gap in a fence of wall.

Photo: Nils van der Burg

Watch out for the ad hoc and unexpected pinhole effects around you next Wednesday during the eclipse. It might create a pretty sight that is as rare as the eclipse itself.

Less than 24 hours to go!

Eclipse from another world – Jupiter

6 July, 2009

You’ve seen what an eclipse, or transit, of the Sun looks like from Mars. Now here’s Jupiter.

Of the 63 natural satellites orbiting the largest planet in the solar system, five are capable of occulting the Sun. That is, they appear visually larger than the Sun.

They are Amalthea, Io, Europa, Ganymede and Callisto, the latter four being Jupiter’s four largest moons, also called Galilean moons since they were discovered by Galileo Galilei.

The rest are too small or too distant and transit the Sun.

Furthermore, since Jupiter is so large and there are five satellites capable of occulting the Sun, eclipses of the Sun from Jupiter are not particularly rare (unlike Earth!).

Shown in the computer generated picture below are the moons Io and Europa casting simultaneous shadows on the surface of Jupiter.

Author: Richard B