Mark June 5th 2012 on your calendar! This is the date of the second only, and last, transit of Venus in our lifetime.  It is one of the rarest regular astronomical events. A transit of Venus happens only twice within 8 years every 105.5 or 121.5 years. Another one won’t happen again until 2117!What is a Transit of Venus? A transit of Venus happens when our closest planetary neighbour, Venus, is aligned with the Earth and Sun so closely that we see it pass in front of the Sun. Over the course of several hours observers on Earth can see the dark disk of Venus cross the Sun from one edge to the other. It is similar to a solar eclipse by the Moon, but of course because Venus appears much smaller it doesn’t cover the entire Sun. We won’t even notice a dimming of the Sunlight. Being prepared so you don’t miss this event is therefore crucial!A transit of Venus was first predicted by the famous astronomer Johannes Kepler and observed by the English astronomer Jeremiah Horrocks in 1639. Observing the next transits in 1761 and 1769 became extremely important when it scientists realized that it could be used to determine the size of the solar system. Back then nobody knew how large the distances between planets are. From different places on Earth the transit begins and ends at slightly different times. By accurately timing this difference we can triangulate the distance to Venus. This then gives us a scale for the solar system. Captain James Cook, for example, sailed halfway around the world from England to Tahiti to observe the event in 1769. His data combined with other observations led to the first estimates of the size of our solar system.For your only chance to see this event you need to prepare so you can do it safely. You should never look at the Sun without a proper filter. You will need special dark glasses, welding goggles, a pinhole camera, or a telescope equipped with a special solar filter. You can obtain dark glasses at http://www.canadiantelescopes.com/Astronomers-Without-Borders-Safe-Solar-Glasses_2. If you can come to Science North on June 5th we will set up several telescopes, and provide dark glasses free of charge. Our event will start at 5 PM with a presentation, followed by observing once the transit starts at about 6 PM. From Sudbury, we will unfortunately miss the end of the transit as the Sun sets.Don’t miss this event!

Did you know that right outside of Sudbury, at Vale’s Creighton Mine, we have one of the worlds most famous physics research facilities? That’s right – two kilometres underground you will find SNOLAB. There, scientists build experiments to detect tiny particles called neutrinos and dark matter.   Visiting SNOLAB is an amazing experience. After walking through dirty dark mining drifts deep underground you suddenly come into one of the cleanest places on Earth. Everyone has to shower and change into clean clothes before entering the lab. The lab is a network of tunnels and huge caverns where giant experiments are taking shape.   The first experiment built there was called SNO, or the Sudbury Neutrino Observatory.  It consisted of a huge acrylic sphere, 12 metres in diameter, filled with heavy water. The whole sphere was suspended in an even larger cavern filled with water. It was surrounded by thousands of light detectors, looking for the faint glow a neutrino would make from time to time.   Even though over a billion neutrinos pass through your thumbnail every second, you would never know. They go right through you and even through the Earth. That is why a huge tank of water is needed to detect just a few of them. The lab is so deep under the Earth to get away from the radiation at the surface that would interfere with these extremely sensitive experiments. Many neutrinos come from the Sun; they are emitted in the nuclear burning of hydrogen into helium. SNO was one of the first experiments to confirm that we receive the expected amount of neutrinos from the Sun, that we understand the physics of the Sun!Today SNOLAB is gearing up to look for even more elusive particles – dark matter. Nobody has every captured a dark matter particle even though we know that it makes up over 80% of the matter in the universe. Sudbury could be the place where we prove what makes up most of our universe!On May 8th we are hosting a Science Café in collaboration with SNOLAB at the Laughing Buddha Cafe. We will explore the science of SNOLAB, why it’s important, question if it’s worth spending time and money on it, and exchange our views on how this science affects our view of the world.  You will be able to listen to and question Dr. Nigel Smith, the director of SNOLAB, as well as Corina Nantais and Dr. Christine Kraus, scientists who work on experiments there.  Come join us for the discussion!