Science by Email 16 March 2012

	Having trouble reading this? Try the online version | Manage your subscription
	16 March 2012
News: Rain, rain go away By Patrick Mahony Cloud formation is often associated with low pressure systems. It has been a wet summer in many parts of Australia, reaching a dramatic climax with wild weather in February and March. The Todd River in Alice Springs started flowing for the first time in a year, major flooding affected the Wagga Wagga region, and Ivanhoe received almost its average annual rainfall in just one week. According to the Bureau of Meteorology the rain was caused by a slow-moving, low pressure trough. What does that mean? As a volume of air warms its density decreases, causing it to rise. The air pressure drops, creating what is called a low pressure system. As the air pressure drops it also cools, causing water vapour in the air to condense to form clouds. These systems are often associated with wet, rainy and windy conditions. In meteorology, a low pressure trough is a long, thin volume of air with higher air pressure on either side of it. The trough that caused the recent heavy rainfall extended from the Northern Territory down to Victoria. The weather system funnelled moist air from the tropics southwards into Victoria and New South Wales, creating humid conditions that fuelled the rain clouds. Australia is currently experiencing what is known as a La Niña event. La Niña and her brother, El Niño, are caused by variations in ocean temperatures and currents in the Pacific. La Niña events are associated with the wetter, cooler conditions that much of Australia has experienced recently. Climate science and predicting the weather are complicated fields. Scientists are continuing to monitor and observe atmospheric and ocean conditions in order to better understand the complex systems that drive the climate. More information Equal wettest week on record for New South Wales El Niño, La Niña and Australia's climate State of the Climate 2012 The Climatedogs: Influencers of Victoria's climate Careers link Graduate meteorologist
You will need these materials.   Carefully cut a hole in a piece of cardboard.   Place the cardboard around the telescope so that it casts a large shadow. Point the telescope towards the Sun.   Adjust the telescope and focus an image of the Sun onto the other piece of cardboard.   Try this: Solar viewer Safety: This activity involves a telescope and the Sun. Do not look at the Sun directly through the telescope, or leave the telescope unattended. You will need Telescope with a stand Cardboard Scissors Tape A friend What to do Set up the telescope on its stand and point it roughly towards the Sun. Do not look through the telescope. Carefully cut a hole in a large piece of cardboard so that it fits around the telescope and casts a large shadow. Depending on the time of day and your telescope, you may need to attach more cardboard. Have a friend hold another piece of cardboard in front of the eye piece of the telescope. Move the telescope so that you can see an image of the Sun projected onto the cardboard. You may need to move the cardboard to find out the optimum distance from the telescope. Adjust the focus until you have a clear image of the Sun on the cardboard. Due to the rotation of the Earth you may need to adjust the telescope to keep viewing the Sun. Do not leave the telescope unattended. What's happening? Telescopes can use lenses (a refracting telescope) or mirrors (a reflecting telescope). A refracting telescope has two lenses. The objective lens gathers the light and focuses it into a bright point. The second lens is the eyepiece lens. It takes the bright light and spreads it out. When you look through the eyepiece the image is projected onto the retina in your eye, allowing you to see a magnified image. A reflecting telescope does the same thing, only using mirrors. Light from the Sun is too intense to view directly. If you projected the light from the Sun onto your retina, it could damage the retina and cause blindness. Instead of projecting the image of the Sun onto the retina, we project it onto the cardboard. The light reflects off the cardboard, but scatters in many directions and is much less than intense than directly looking at the Sun. This is how we are able to view the Sun safely. Applications This method of projection is useful for viewing solar phenomena such as sunspots and eclipses. On 6 June 2012, the planet Venus will move between the Sun and Earth. This is known as a transit of Venus, and is a rare occurrence – the next one won't be for more than 100 years. You can use this method to safely view the transit from home. By Patrick Mahony Try another Science by Email activity to safely view the Sun More information How telescopes work CSIRO: Transit of Mercury and Venus Transit of Venus View the online version Quiz questions 1. Gentoo, little and rockhopper are all types of what? 2. What do ichthyologists study? 3. What causes an aurora? 4. 10-year-old Clara Lazen recently designed a new molecule – which three elements does it contain?      5. Durum is a variety of which grain? Did you know? The oldest known animal with a skeleton was discovered in South Australia. Named Coronacollina acula, it lived around 550 million years ago. Websites Read it! How many seasons are there? Check out this site and discover an Indigenous Australian perspective of the seasons. Watch it! What's involved in building a new chimpanzee enclosure? Find out in this video. Big Science Competition So you think you can think? Prove it by entering the Big Science Competition. The Big Science Competition gives you the opportunity to tackle science in a way that's relevant and challenging. It's more than just a test of your science knowledge. You'll find scientific answers to some of the riddles in the everyday world around us. Give it a go: there are great prizes up for grabs and you'll learn things even your science teacher doesn't know. Talk to your teacher today to register. Registrations close 18 April 2012. For more info go to the Australian Science Innovations website. Events Northern Territory: Double Helix Science Club events Want to learn about growing your own plants in the garden? Or how to make your own cosmetics? Check out these and other upcoming activities being offered by the CSIRO Education in the Northern Territory. Bookings are essential. For more information and bookings head over to the website. Birds, Saturday 17 March at 9.00 am on Network Ten They live on every continent of Earth. They can be found on the ground, in water or in the air. What are they? Birds! Join Dr Rob as he takes flight and SCOPES out all the science behind birds, as once again the ordinary becomes extraordinary, under the SCOPE. Next episodes: Thursday 22 March: Bees Saturday 24 March: Polymers Want to have your own episodes of SCOPE to watch whenever you feel like it? Click here to download them directly into your iTunes folder, or go here to download iTunes. Charges apply. Quiz answers 1. Gentoo, little and rockhopper are all types of penguin. 2. Ichthyologists study fish. 3. An aurora is caused by charged particles colliding with atoms in the atmosphere, releasing energy in the form of light. 4. Clara's molecule contained carbon, oxygen and nitrogen atoms. 5. Durum is a variety of wheat. CSIRO scientists have developed a variety of durum wheat with a salt-tolerant gene. Science by Email is a CSIRO publication. The Department of Agriculture, Fisheries and Forestry and bankmecu are proud partners of Science by Email. Editor: Mike McRae | Manage your subscription | FAQ

 

 

---