Recently we acquired a really exciting new exhibit at Science North. It’s called a diffusion cloud chamber, and it allows us to see trails made by high-energy particles in real time!Cosmic rays are highly energetic particles, mainly protons, electrons, and helium nuclei (known as alpha-particles). They come from distant sources such as supernova explosions. Some of the sources of cosmic rays are actually still a mystery to scientists today. These highly energetic particles are always around us, and many actually go right through us. We cannot directly see these particles but they do leave a trace in the right environment. Our cloud chamber is filled with alcohol vapour. When a highly energetic particle (a particle moving at a speed very close to the speed of light) passes through it leaves a trail of ions. The alcohol then condenses on these ions, creating a trail! This is similar to the condensation trails made by airplanes as they fly through the air. So we can see trails forming continuously in real time. It’s really amazing to look at this exhibit and realize how we are always surrounded by these particles from distant places in the universe – we are part of the universe. SNOLAB and Laurentian University have generously donated the cloud chamber to us through a grant from the City of Greater Sudbury. I hope you have a chance to come see the cosmic trails in it for yourself, but also have a look at the video here to see what it looks like!

We have an exciting new exhibit in Space Place called a diffusion cloud chamber. The clouds that it creates help us see tracks left behind by high-energy particles as they travel through the air.Watch this video to see how to make clouds of your own. Send us pictures and videos of your clouds!How do clouds form? When a liquid like water evaporates, the water vapor mixes with air. Cold air can’t hold as much water vapor as warm air. So if warm air containing lots of water vapor cools off, it can’t hold on to the water vapor anymore. The water vapor condenses into tiny droplets that stick to dust, soot, or any other particles in the air. These clusters of water droplets are clouds!In the experiments below, we will use pressure to change the temperature of air. When a gas is suddenly compressed, its temperature increases. When a gas is quickly expanded, the temperature drops.

Canadian astronaut Chris Hadfield is scheduled to blast off for a 5-month mission to the International Space Station on December 19th, 2012. He will get there in a Russian Soyuz rocket. In March he will take over as the first Canadian Commander of the space station. Rather than give you lots of details about the mission that you can find out about in many places, including on the Canadian Space Agency website, I thought I would take the opportunity to share some cool space exploration facts with you that you might not know about yet. So here we go: Did you know that Canada was the third nation in space? We accomplished this with the launch of Alouette-1, which studied the ionosphere, in 1962. NASA astronauts came to Sudbury in the 1970s to become familiar with shatter cones, a rock formation that can be found in impact craters. Today, scientists use Canada’s arctic to simulate missions to Mars with astronauts and rovers.Canada has set foot on the Moon (literally), having built the feet of the Apollo Lander. Chris Hadfield’s mission is the 16th time a Canadian astronaut has launched into space.The force of gravity on the international space station is 90% of what it is at the surface of the Earth. Astronauts only feel weightless because they are in orbit – which is in essence a free fall around the Earth. You feel weightless in any free fall, for example when you ride the Drop Tower at Canada’s Wonderland. The space station is about the size of a football field. The pressurized compartments add up to more than the size of a five-bedroom house. At an altitude of 400 km above us, the ISS is in space but there is still enough drag from the Earth’s thin atmosphere that it loses about 100 meters of altitude per day. The ISS therefore has to be “boosted” by a visiting spacecraft from time to time. While on the space station Chris Hadfield will experience a sunrise every 90 minutes! The station orbits around the Earth that fast. Astronauts contribute to osteoporosis research, as in space their bones degrade 10 times faster than in osteoporosis patients. The Canadian experiment eOsteo was designed to study this.Canada built a weather station for the 2008 Phoenix mission to Mars. The Curiosity rover has a Canadian instrument that uses x-rays to study the surface of the red planet.Space exploration related work contributes over 3.5 billion dollars and over 8000 jobs to the Canadian economy annually.

You’ve likely heard a lot about the newest Mars rover, Curiosity, over the last few weeks. I thought this would be a great time to talk a bit more about the exploration of our closest planetary neighbour. Several rover missions have now visited Mars. For years now Spirit and Opportunity have explored the red planet. Most recently however the rover in the headlines has been Curiosity.You can find everything about Curiosity on their official mission website but I thought I’d highlight a few of the really neat things about this rover. It landed on Mars in a really unique way, by being dropped to the surface by a sky crane (see images below). The rover is powered, not by solar panels as previous rovers, but by the heat of decaying plutonium dioxide. The rover has many instruments on it to study the surface of Mars. Canada contributed the APXS, an x-ray device to determine the composition of rocks. Why are we so interested in Mars? Well, even though Mars is vastly different from Earth, it is highly interesting to us due to the fact that it had liquid water on it in the past and – who knows – maybe life! If we could confirm that life arose somewhere other than the Earth that would be a monumental discovery with tremendous implications. It would almost guarantee that we are not alone in the universe. It would also tell us about how different or similar life that came about somewhere else is from life on Earth. So far we have had no indication at all that life ever existed on Mars, but we know that it was once a wet planet. It had all the ingredients for life. Today it is very cold, and due to its thin atmosphere, water would immediately evaporate on the surface. We already know though that ice still exists just below the surface.Curiosity is going to study the geological history of Mars so we can build a better picture of the story of water on the red planet. Gale crater, where it landed, features a landscape that seems layered and was probably deposited over a long time. Just as geologists do on Earth, Curiosity can study these layers to get a clearer picture of the history of the planet. Even if it doesn’t find any evidence for life we will develop a better picture of what conditions are necessary for life.So I am looking to an exciting couple of years as this amazing robotic rover sends back its findings to us!

Get ready for launch! As we count down to the opening of the Canadian Space Agency’s Living in Space exhibit here at Science North, I’d like to share a design for a fun and simple rocket you can make. Like the name suggests, you launch a stomp rocket by stomping on a large bottle full of air connected to a hose. The air rushes through the hose to a smaller bottle, which increases the air pressure inside until the small bottle pops off the end of the hose.Watch this video to see how to build your own rocket and launcher. You can be as creative as you like with the design and decoration of your rocket. Send us pictures and videos of your rockets in action! How far can your rocket fly? Can you find ways to make it go even farther?Want more fun with rockets? To see instructions for another air-powered rocket, check out Simon’s Cool Science post.

If you’ve been holding onto a wish and waiting for a shooting star, your best bet is to look for one between August 9th and 14th! Intense streaks of light caused by small bits of interplanetary debris will be burning across the night sky in one of the best annual meteor showers seen on Earth.Meteor showers happen when the Earth passes into a cloud of dust and debris left over by a comet. These particles then enter our atmosphere at speeds up to 70 km/s. They glow because they collide with air molecules and are heated enough to produce light. While you may think that shooting stars are large bits of rock falling toward the earth, in actuality, most particles you see are only about the size of a grain of rice. This year's stellar light show is courtesy of the 2012 Perseid meteor shower, and fortunately for those of us living in the northern hemisphere we’ve got the best seat in the house. This year the light from the thin sliver of the crescent moon will create a bit of interference but the show will be much better than last year when the Perseids coincided with the bright full moon. Stargazers looking up to the sky may see up to 60 meteors per hour this year! Named after the constellation Perseus, the Perseid meteor shower is among one of the most reliable astronomy events in history, and has been observed for about 2,000 years.As the Earth orbits the sun each year, it passes through the same cloud of dust and debris left by the comet Swift-Tuttle on its orbit through the inner solar system. Specialized equipment is not necessary to be able to view the meteor shower; all you need are your eyes! Look to the northeast after midnight on August 12th as that will be the best time to view the Perseids. In this year’s shower, we expect a higher than average number of shooting stars. Binoculars may help to see fainter meteors.The best place to view the Perseids is far away from city lights where the night sky is not illuminated. If you are in the city, Science North will be hosting a free star party and public talk by staff scientist and astronomer Simon Strasser on August 12that Dynamic Earth. The talk will start at 8 p.m. and observing through telescopes will follow starting at 9 p.m., weather permitting. The Sudbury Astronomy Club and Science North staff will also set up telescopes to view many other objects visible in the night sky. You can also learn more about the night sky with a visit to Science North’s digital Planetarium, featuring the shows Wildest Weather in the Solar System and Earth, Moon & Sun! Visit sciencenorth.ca/planetarium for showtimes and admission.

On Tuesday evening of May 8th 2012, the Laughing Buddha was packed with over 50 interested people to learn about and discuss the Science of SNOLAB. Moderated by Dr. Simon Strasser, the panelists, Dr. Nigel Smith, Corina Nantais, and Dr. Christine Kraus each provided their unique perspectives on the topics of converation and answered many great questions. The discussion ranged from questions about the specifics of the research to the value of funding fundamental research. The panelists also addressed some broader topics, such as what they consider to be the biggest unanswered questions. One of the highlights of the evening came when a young girl came up to ask what came before the big bang.Listen to the audiocast here: http://sciencenorth.ca/audio_2012/snolab-cafe-final.mp3

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!

I am very excited about the newest permanent exhibit to come to Space Place at Science North: the Human Gyro. The gyroscope allows a person to spin themselves in all three dimensions and experience the forces created by the rotation with their whole body. Any object that is spinning wants to keep spinning in that direction unless acted upon by a force. Try to push over a spinning top and you will see that it resists your push and stays upright. For this reason when you are in the gyroscope you can feel a strong resistance whenever you try to change the direction of spin. You can use this fact to exercise using a gyroscope. Of course it is also just plain fun to spin yourself in every which direction!NASA used a version of the human gyroscope called the “Multi Axis Spin Space-Test Inertia Facility” or MASTIF to train astronauts for the Mercury missions in 1960. The goal was for the astronaut pilots to learn how to stop a spacecraft from tumbling by controlling air jets mounted on the spinning rings. MASTIF was also used to evaluate instrument control systems for space flight and to test the physiological effects of spinning, such as eye oscillation and motion sickness.You can take a spin on the Human Gyro at 11 AM and 2 PM on weekends and holidays by obtaining a free ticket ahead of time from the staff in Space Place. Only a limited number of tickets are available each day. On quiet weekdays we run the gyro by request unless a school program is booked in Space Place. Check out what you’re in for by watching our video!

In one year the world will end!Or will it?Well according to one interpretation, the Mayan calendar predicts the end of an age on December 21st 2012 but not the end of the world. Nevertheless a number of claims exist out there of a cataclysmic astronomical event happening soon that could destroy life on Earth as we know. I thought it would be interesting to look at a few of these scenarios and see what evidence (if any) we have for each of them.  Magnetic Pole ReversalThis is a real effect. Over the Earth’s history its magnetic field has reversed many times – meaning if you had a compass needle that used point North it would point South after a reversal. This does not happen in a regular fashion but normally about every few 100,000 years to every few million years. We are not able to predict when it might happen again but it hasn’t happened for 780,000 years. As the magnetic field changes, its strength might be very low for a period of time allowing radiation from space to reach us that normally wouldn’t. Could this destroy life on Earth? Well most scientists agree that the historical data does not show any evidence of that. We have no evidence that a pole reversal is about to happen in 2012 (it also usually takes thousands of years to complete).  Solar StormYou have probably heard of the solar wind – a stream of particles constantly radiating away from the Sun. Could a massive storm happen on occasion and destroy life on Earth? The short answer is that we have no evidence for it. In fact the Sun currently seems to be entering a period of remarkably low activity with fewer flares and Sunspots than what is normal. We do not expect any unusually large solar storms in 2012.   Planet X or NibiruCould there be a planet in our solar system we don’t know about that is going to collide with Earth? Are astronomers trying to cover it up? As an astronomer I can tell you with certainty that the answer to both of those questions is “no”! We might certainly discover more objects similar to Pluto far out in the solar system but we do not expect any of them to pose any danger to us, as their orbits would never take them into the inner solar system. The myth of Nibiru is persistent but not based in any facts. Fear not in 2012!   NemesisNemesis is the name of a supposed small and faint companion star to the Sun. Some scientists believe that data show a 26 million year period between major extinction periods. According to their theory, a rain of comets might have hit us when Nemesis came closest to us in its elliptical orbit. I would have passed through the Oort cloud and sent these comets into the inner solar system. Most scientists however don’t agree that there is such a 26 million year pattern in the major extinction events on Earth and we have found absolutely no evidence to date of any object that could be the hypothetical Nemesis. I should also mention that Nemesis is not associated with theories regarding 2012.So in conclusion, astronomers have not found any evidence to suggest that 2012 will be in any way an unusual year. There is no evidence of an impending catastrophe. Having said that we also know that something unpredictable, like an impact by an unknown asteroid, could happen at any time. So you never know…(Images and diagrams featured in this blog post courtesy of NASA)

What would you do if you were told that an asteroid with a Torino rating of 1 is hurtling towards the Earth? Panic? Stock up on water and canned beans? In our age of technology, you would likely do an Internet search to find out what exactly a Torino rating is. You would then find out that a Torino rating of 1 essentially means a routine discovery that has an extremely low potential for any type of danger to the Earth. Time to stop panicking. If you have been following current news, by now you have probably heard of the 'potentially hazardous asteroid' known as 2005 YU55 (YU55). Although this asteroid was at a Torino level of 1, it was downgraded last year to a rating of 0, or essentially a near-zero chance of striking the Earth. YU55 is scheduled for its close approach on November the 8th, at a distance of 350,000 km. This distance seems so large it is almost unimaginable. However, it is quite close for a celestial object. It will be passing closer than the average distance to the Moon. Astronomers do not expect an asteroid of comparable size to approach this close to the Earth for another 17 years.  Although not the first asteroid to pass this close, YU55 is one of the first that we have known about well in advance. This will allow astronomers to study it very closely with an array of different instruments, determining its shape, spin rate and even composition. For someone who doesn't have access to a high powered telescope, it will be very difficult to locate in the night sky. YU55 is large, but because of its distance, it will be faint and moving very fast. Even though astronomers have just about 100% guaranteed this object is not a danger, let's imagine it was. Following your hypothetical Torino level search we opened with, your next Internet stop might be to find out how scared you should be. Purdue University has set up a website where you can play 'sim-asteroid' to find the effects of an Earth impact... ... and you came here to smash some asteroids, so let's try it out. Links:Impact Earth!:http://www.purdue.edu/IMPACTEARTHSolar System Dynamics:http://ssd.jpl.nasa.gov/sbdb.cgi?sstr=2005%20YU55;orb=1;cov=0;log=0;cad=1

Craters are all around us. If you live in Sudbury you are actually living inside the second largest crater we know of in the world (the largest is the Vredefort crater in South Africa). About 1.8 billion years ago an asteroid roughly 10 to 15 km across hit this area and created a crater that was about 200 km wide! Due to erosion and geological activity it is actually quite hard to see the crater today but it’s still here in the form of the Sudbury basin.We also have a second crater nearby – Lake Wahnapitae, which is about 37 million years old. In fact, if it wasn’t for erosion, we would be able to see craters covering the Earth just like the Moon. In the early history of the solar system, large impacts were common on Earth. But even now, we continue to be the target of a large object from time to time.We can do a number of simple experiments to create craters and learn about the physics of crater formation. All you need are a few materials you will most likely find around the house.Things to look for:How is it the crater affected by the speed, trajectory angle, and the material of the impact object?Does the crater look very different depending on the material the object hits? What does it look like in slow motion?Observe the ejecta (the material from inside the crater that lands around it). How is it distributed?If you have a telescope or binoculars take a look at the Moon at night and compare your craters to the ones on the Moon. Can you see the ejecta around any of them?

Today (November 4th, 2011) six men are opening the hatch of their simulated spaceship that they just spent 520 days in. The mission took place in Russia and simulated a trip to Mars and back, including exploring the red planet. They did experiments on living in confined quarters for long durations of time and without sunlight. They lived without live television, fresh food, or any communcation with the outside world other than email. This mission is an attempt to better understand some of the challenges an eventual crew on a trip to Mars might face. There are no concrete plans as of yet for a mission to Mars but the goal is to send  humans to this neighbour planet of ours in about 20 years to 30 years.  If you would like to see the opening of the hatch and other videos from the mission you can see it here: http://www.esa.int/SPECIALS/Mars500/

On July 8th, 2011, history was made when Atlantis became the last space shuttle to launch into space. On July 21, it returned to Earth, marking the official end to the space shuttle program. While many of us here in Sudbury watched the launch at Science North on the IMAX screen or at home on our computers, a lucky group of Laurentian University students got to travel to Florida to see the launch from the VIP area. You may well remember this group of students when they were in the news a few weeks ago after winning the international Lunabotics competition in Florida by scooping a record amount of simulated lunar material with their rover. The invitation to see the launch of Atlantis live was part of their prize. Watching a shuttle launch is an awe-inspiring experience unlike any other. We are fortunate that Jeff Pagnutti, one of the members of the Laurentian University Lunabotics team, sent us a report of how he experienced it. Here is the launch of the final space shuttle in his words: “It's not that it wasn't exciting, but it wasn't what I had expected.”Titusville is a city of about 50,000 people. The people are very kind and inviting. A million people were visiting during the shuttle launch so it was a little crowded at times.We were headed 'pretty far from Kansas' to see the launch. There was a lot of hope for no delays; the slightest change in weather or a bird flying in the wrong place might just hold up the mission. The wait was a little nerve-wracking. You're really hoping the sky will clear so they can light the fuse on this rocket.The astronauts are really taking a plunge here, pretty much entrusting their lives to other people. When you hammer a nail, it's usually not so scary when you have the hammer and the nail. Now hammer the same nail, but you hold it and give someone else the hammer: suddenly the task becomes a little scarier. Everyone who worked on this operation deserves a pat on the back.With an hour to lift off, the sky cleared up, and things looked good.  We made it to T-minus four minutes and there was a failure; they must have forgotten to put the gas cap back on or something. I'm sure you can imagine the united sigh from a million people. We're blasting off into space though; let's be sure our mirrors are properly adjusted before blast-off.A few seconds before lift-off, the thrusters on the glider (that's the black and white ship) fire up. There's smoke barrelling out from the base of the shuttle and the countdown descends to the declaration, "We have lift-off!"This is a spectacular moment. This vehicle is charging away from Earth's crust. It looks just like in the videos and photographs. The thing about a photograph is that it's an image on a piece of paper. When the shuttle is ripping through the air, the flames coming out from the thrusters are as bright as the sun. The sound of the rockets carries for miles. The smoke stream lays frozen in the sky for minutes. This thing is alive.I had the opportunity to hear Canadian astronaut Chris Hadfield speak a year ago, and he put it into perspective when he said, and I'll paraphrase, "The space shuttle has about five hundred controls; an F18 Fighter jet has about three." What a phenomenal event. "We are just an advanced breed of monkeys on a minor planet of a very average star. But we can understand the Universe. That makes us something very special."- Stephen HawkingIf you missed the launch or would just like to see it one more time, here is the official YouTube video: http://www.youtube.com/watch?v=3deA3BXAnHs

This Friday, July 8th, will be the last time a Space Shuttle launches into space. After 30 years and 135 total missions, the space shuttle program is coming to an end. While the space shuttle is an American rocket, Canada has been heavily involved in its history; eight of our astronauts have flown into space with one of the shuttles. Canada also contributed the Canadarm to the space shuttle program. The robotic arm was vital in helping in the construction of the International Space Station and many other missions.Why is the Space Shuttle program ending?Over the last few years it has become increasingly clear that we need a new rocket to help us accomplish our future goals. The space shuttle program has become increasingly expensive and the shuttles are aging. The shuttles also can’t take humans to the moon, to an asteroid, or to any other planetary bodies. With the aim of eventually exploring Mars, the United States decided to develop a new rocket to replace the space shuttles. Over the years the Space Shuttle program has seen many highlights. Among them the launch and repair of the Hubble Space Telescope, the building of the International Space Station, and many missions to conduct scientific research. Tragedy also struck the program twice of course, with the loss of Challenger in 1986 and Columbia in 2003. So this Friday, Space Shuttle Atlantis will be the last shuttle to launch into space. Its destination will be the International Space Station, to which it will deliver supplies, logistics and spare parts. Seeing a shuttle launch brings into perspective how strongly bound to the Earth we are like almost no other event can. It is a tremendous display of energy, the human quest for knowledge and exploration, and the achievements of technology.   To mark this historic event, we are showing the IMAX® classic “The Dream is Alive” on Friday morning starting at 10 a.m. This will be followed by a presentation on the Space Shuttle and Canadian space exploration (with many prizes to give away!). And of course, if the launch goes ahead as planned, we will be showing it live at 11:26 a.m. in the IMAX theatre to participants of the event. For more information, visit the Events page.

You’ve probably heard that the Apollo astronauts came to Sudbury to train for their missions to the Moon. You might have also heard that the reason was Sudbury’s supposedly Moon-like landscape. That is not true; the Sudbury area was chosen for training the Apollo astronauts because the landscape was shaped by an impact crater, the second largest known crater on Earth. For this same reason, scientists are again in our area to gain experience for a possible future mission to the Moon!For the next two weeks, Sudbury is playing host to a team of scientists and engineers from a number of Canadian institutions. They were contracted by the Canadian Space Agency (CSA) to conduct an “analogue” mission with a lunar rover. This is a simulated mission to the Moon with scenarios similar to those that would occur in a real mission. One of the goals of the mission is to collect samples of rock with the rover and return them to scientists to be further analyzed.The eventual goal is to send a real lunar mission to the Moon’s South Pole Aitken basin. While Sudbury’s crater is the second largest known crater on the Earth, measuring about 30 km by 60 km in diameter, the Aitken basin is the second largest known crater in the entire solar system. It measures an incredible 2900 km, equivalent to the distance between Ottawa and Calgary! Still, our local crater provides a unique landscape for the team to simulate a mission to the Moon.Why are impact craters so interesting?Well, not only are they striking features (no pun intended) on all larger rocky objects in the solar system, but they also give us access to material normally buried deep under the surface. After an impact, this buried material can end up at the surface and can therefore be studied without drilling down. For this mission to Sudbury, some scientists remain in mission control at The University of Western Ontario in London. They will make decisions on what to look at with the rover, and which samples to collect. The team here in Sudbury controls the rover to accomplish these instructions. One of the challenges the team has to consider is that in any real mission to the Moon the amount of data that can be sent back to Earth is limited. The real landing site will be on the far side of the Moon so data can only be collected by a satellite that periodically passes overhead. So the team will follow the same limitations, communicating only during certain intervals.Are you interested in learning more?On Saturday June 18th, 2011, Science North is hosting the lead scientist for the mission, Dr. Gordon Osinski from The University of Western Ontario, at Dynamic Earth. He will give a free presentation to the public about the mission and what they were able to learn by coming to Sudbury. The lunar rover will also be available for viewing. The presentation takes place at 7:00 p.m. in the Atlas Copco theatre at Dynamic Earth. Throughout the mission the team will also provide updates on their official website or you can follow the mission on Facebook and Twitter.

I recently had the opportunity to sit down with Sheepy, the star of Science North’s newest object theatre, The Changing Climate Show. He excitedly told me about one of his farm’s most recent endeavors in the fight against climate change: biodigestion.  Farm animals have been getting some of the blame for the change in the world’s climate for doing what they do best, and that’s eating.  Of course, what goes in must come out.  So every time ruminants like sheep, goats, cows, and horses eat grass, the microorganisms in their guts digest the plant material into a noxious gas called methane.  Methane is expelled from their bodies when they burp, fart, and, um, poop.   Around the world, humans and farms are creating an energy slurry by mixing water with manure from farm animals and, in some places, human manure.  Food and crop wastes and old frying oils from restaurants can also be added.  This slurry is then put into biodigesters.  The biodigester is like a big bath full of microorganisms similar to the ones found in a sheep’s and other grass-eating animal’s guts.  If these microorganisms are kept at a temperature between 30-60 degrees Celsius, and are fed enough watery slurry, after 20 to 45 days in an anaerobic (low oxygen) environment, they start to produce three products: methane, liquid fertilizer, and composted biosolids. Sheep are very happy with this process because the liquid fertilizer and dried compost go back onto the crop fields and pasture to help increase plant yields.  This means more grass for the sheep, more cash crops to sell and less need to purchase artificial fertilizer, putting money back into farmers’ pockets. Also, by burning the methane in a combination heat and power unit (CHP - a generator that heats water and uses the steam to turn a turbine), the barn is a warmer place to sleep at night, baths can now be taken in warm water, and enough electricity is generated to run the farm without having to rely completely on the local power grid.  In fact, many farms are generating enough electricity to sell back to the grid to support the electricity needs of hundreds more homes. But even more importantly, methane happens to be a very potent greenhouse gas.  In fact, it is approximately 21 times more potent then carbon dioxide.  It is also chock full of energy that until recently was sent floating up into the atmosphere. The only waste products from the burning of methane are carbon dioxide, heat and water.  This carbon dioxide is less scary than that from fossil fuels because it is already active in the Earth’s carbon cycle.  It has not been mined from carbon dioxide trapped in the Earth long ago, which messes with the current stable cycle.  The use of biodigestion on farms also has several more advantages:  that famous barnyard smell is reduced, and the risk of pathogens and nutrient run-off polluting waterways and drinking water supplies is significantly diminished.  Cleaner drinking water means less need for antibiotics and dewormers, therefore healthier and happier sheep and neighbours. I had already heard about the use of methane for electrical generation because here in Sudbury, the city’s landfill currently mines for methane.  They find the methane in the mounds of decomposing waste at the dump.  This methane produces 1.2 Megawatts of electricity to meet the needs of 3,000 households across the region. You can check out Sheepy and his friends as they further help us pull the wool off of our eyes about the science of climate change in The Changing Climate Show.  This brand-new experience can be found on the fourth floor of Science North.

Over the last few weeks something that astronomers have known for thousands of years has suddenly hit the news headlines: you may not be the sign of the zodiac you think you are! Let me explain.“Your Sign”The Earth travels around the Sun once a year. Now imagine looking at the solar system from above. The sky that you can see at night from the Earth will be in the direction opposite from the Sun, and the daytime sky is in the direction of the Sun (as shown in Figure 1). Six months later the Earth is on the other side of the Sun, as it has completed half of its orbit around the Sun. What was the night sky is therefore now visible in the daytime and vice-versa. If we could see the stars the Sun is in front of, they would be different now.The constellations that the Sun appears to travel through during the course of one year are called the signs of the zodiac. Your sign is the one the Sun was in front of when you were born (so it would be up during the daytime). If your birthday falls between January 21 and February 19 you are an Aquarius, right? Actually you are most likely not!The Signs of the Zodiac ShiftThe signs that astrologers currently use were correct about 2000 years ago. At that time, the Sun really was in front of the sign Aquarius in February. Now as it turns out, the Earth’s axis slowly changes direction (just the way a spinning top turns really fast, but you may also see how its axis goes around in a circle at a much slower pace - especially when the spinning top starts to lose balance). It takes the Earth’s axis 25765 years to make one circle. This is called precession. But what does that have to do with your sign? Well, it’s winter when the Earth’s axis is pointing away from the Sun (see Figure 2).So if the orientation of the Earth’s axis slowly changes, the seasons will also slowly occur at a different part along the Earth’s orbit. In other words, different stars will be visible in the sky at the same time of year thousands of years from now or thousands of years ago.As I mentioned, astrologers refer to the signs of the zodiac as they were about two thousand years ago. Since then the Earth’s axis has rotated slightly so the Sun is no longer between us and the constellation Aquarius in February. That time has gradually shifting towards March.The Age of AquariusYou might have heard that we are entering the Age of Aquarius. As I described above, the Sun gradually is between Aquarius and us more in March. On the date of the spring equinox, about March 20th most years, the Sun is currently still in the constellation Pisces. When the sky has shifted enough due to precession that the Sun is in Aquarius on the date of the spring equinox, some people say we will enter the Age of Aquarius. You might remember the famous song referring to this, “This is the age of Aquarius!”. This is of no scientific significance however.

Have you ever wondered how to build a rocket? Well here are some simple instructions to build your own bottle rocket launcher. It will allow you to launch a 2-litre pop bottle using only air pressure.In the video below I demonstrate Science North’s own bottle rocket launcher. The one I present here is a little less complicated than that, but it will work just as well. The key to a bottle rocket launcher is really how you attach the rocket so that it gets pumped full of air and then released. There are many ways to do it and you can be creative, but you might like the simplicity of our suggestion.Let us now if you decide to take on this project. We’d love to see the results! Record a video, post it online and add your link in the comments below. Happy launching!

Every moment of our lives, we are under the influence of the force of gravity. Gravity does more than keep us from floating off into space. Without gravity, the Universe as we know it would not exist. That’s because the Sun and the Earth would not have formed, nor would any stars, so it would be very dark and cold.  There would be no light because stars can only shine once gravity has pulled the gas into a sphere with such high pressure and density at its centre that nuclear fusion can occur (hydrogen atoms fuse together to form helium). It is then gravity that holds the star together against the pressure from the tremendous amount of energy flowing out of the centre at all times. Gravity also keeps objects orbiting around each other. In our solar system, moons orbit around the planets; all the planets, comets, and asteroids orbit around the Sun; and the Sun orbits around the centre of our galaxy, the Milky Way.  A gravity well allows us to play with the force of gravity and see how it acts on objects. It is like a large funnel whose shape matches that of the mathematical formula of a gravitational field (dropping off as 1 over the radius squared). By releasing ball bearings (or other things like coins), we can create circular and elliptical orbits and even mimic the trajectory of a light beam that is bent as it passes by a massive object. A gravity well also demonstrates how matter may react around a black hole. Matter potentially spirals towards the event horizon, from beyond which it can never return.In the video I use our gravity well here at Science North to show you some really neat experiments with orbits – including what happens when I drop 100 ball bearings in at the same time.

The Canadian Space Agency has just launched an aurora webcam! The project is called AuroraMAX and allows visitors to view current aurora borealis, or northern lights, activity at any time. The camera, located in Yellowknife, has been installed in preparation for the next expected solar maximum in 2013. In addition to the live feed, the website links to an aurora forecast service provided by Astronomy North.For several years now, the Sun has been stuck in a solar minimum, with very little magnetic activity. This means that there have been few sunspots and solar flares. During a minimum, the solar wind is also much weaker, leading to fewer high energy particles streaming towards the poles of the Earth. It is the interaction between these particles and the gases in the Earth's atmosphere (in particular nitrogen and oxygen) that leads to the beautiful light displays of the aurora.So as the solar activity picks up in the coming months and years, we will see more frequent and spectacular northern lights. It should be a good show and thanks to AuroraMAX, we won’t have to miss any of it, even if we can't leave the bright city lights for the dark skies!

For thousands of years, humans saw themselves occupying the center of the universe with the celestial spheres, the Sun and all the other planets revolving around Earth. We now know that the Earth orbits the Sun, which is but an average star orbiting around the center of the Milky Way Galaxy. The Milky Way, in turn, is just one of billions of galaxies in the Universe. Still, as of today, our Earth is the only known place in the Universe where life exists. Since 1995, a new scientific horizon has gradually opened up to us that might soon lead us to discover worlds beyond our solar system that could harbour life. In the span of only 15 years, astronomers have now confirmed the existence of planets around over 400 other stars! Detecting such an extra-solar planet is extremely difficult. The most common method is to measure the small wobble a star undergoes due to the gravitational tug of an orbiting planet. This wobble is larger for a closer and more massive planet. For this reason, the vast majority of planets we have discovered to date are larger than Jupiter and orbit their star at a much closer distance than the Earth orbits the Sun. Life as we know it cannot exist in those conditions.We are getting ever closer to the first discovery of an Earth-like planet. On August 24th, 2010, European astronomers discovered a solar system with at least five planets orbiting the star HD 10180. Among them is possibly a planet with a mass only 1.4 times that of Earth. It is so close to its star though that it completes one orbit in only 1.18 Earth days (as opposed to the approximately 365 days the Earth takes to orbit the Sun) and would therefore be scorching hot! The video provided by the European Southern Observatory provides more detail on this exciting discovery.NASA also recently launched its Kepler Observatory, which is hunting for earth-like planets around over 100,000 stars. It measures the tiny drop in the star's brightness when a planet passes in front of it. Soon, we may indeed find the first world beyond our solar system where life could exist! We'll keep you posted.To find out more about space and astronomy visit Space Place and the Planetarium at Science North.References:Press Release: http://www.eso.org/public/news/eso1035/