Dots on the sun and a Cosmic collision

On Tuesday June 5, just after 6 pm in the Eastern Time zone of North American, the planet Venus will track across the face of the sun, its called a transit. For most people, its not a big deal really. A tiny dot, Venus, will be seen (**if you wear protective eye coverings**) moving from left to right across the face of the sun. Astronomers have made a big deal about this for a long time. Back in the days of HMS Endeavour and James Cook, astronomers knew that such a transit could help them determine the size of our solar system, so James Cook was sent to gather the data. Today, transits are used to find new worlds around distant stars. The transit of Venus happens about every 120 years in pairs, eight years apart. This one is our last chance, the next one is in Dec., 2117, lets hope there are clear skies. Such are the vagaries of astronomy, a puff of condensed water vapour could obscure a once-in-a-lifetime event. Its happens a lot.
While I'm on the subject of missing big events, you're going to miss this one for sure. I heard about this first, decades ago, but astronomers are now convinced that its going to happen, a collision of galaxies. Its already happening, go out late at night, on crystal clear nights, and look between the great square of Pegasus and the W of Cassiopeia. If you have a sharp eye or a pair of binoculars, you can detect a fuzzy patch of light. That is M31, the Andromeda galaxy, and we in the Milky Way are heading straight for it fast, or its heading for us....both actually. The collision will be astronomical ;-), in 4 billion years.