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Home My WebLink AboutThe Lucknow Sentinel, 2016-03-16, Page 11Wednesday, March 16, 2016 • Lucknow Sentinel 11 Star Column: Spacewatch and being on guard John Hlynialuk Bluewater Astronomical Society The best way to tick off an astronomer, amateur or oth- erwise, is to call them an astrologer. This raises the hackles immediately if it is done intentionally. If it is an inno- cent mistake, it gets a weary grin and the often -repeated explanation of the differ- ence. If you catch the astron- omer in a bad mood, you may get a quote from Shel- don Cooper: "Astrology is hokum!" The second best way to get an astronomer upset, to a lesser extent, is to mix up the terms meteor, meteoroid and meteorite. Pay attention class: here's what you need to know to impress your astronomy friends. Meteors are the streaks of light in the sky we call "shooting stars': If part of the space rock sur- vives the inferno of entry through the Earth's atmos- phere and lands on the sur- face of the Earth it is called a meteorite. Good examples of these are the small pieces of asteroid Vesta that came down Sept. 2, 2015 onto Bin- gol, Turkey and the large 650 kg piece (along with a few smaller ones) that survived from the Chelyabinsk super fireball on Feb 15, 2013. Meteoroid is the general term for the object in space nwmo that might produce these fiery events in the Earth's sky. These include asteroids, comets, and in the micro - meteoroid variety, the esti- mated 100 tonnes of space dust that falls onto Earth daily. The space debris that burns up in our atmosphere (meteors) consist partly of fine particles from the for- mation of the solar system, partly from collisions of asteroids over the billions of years our solar system has existed and partly from sand -grain sized particles trailing comets that orbit the Sun. When comets get near enough, the normally frozen "gravelly icebergs" experi- ence the heat of solar rays and the blasting of the solar wind and "grow" tails. Mete- ors from comet dust are what we see as yearly meteor showers when the Earth plows through these fine debris trails. The meteor shower that is observed every August, the Perseids, is from Comet Swift -Tuttle, first seen in 1862, and rarely has particles in its dust tail big- ger than a grape. Even that size would produce a bright streak of light as well as gasps and shouts of "WOW!" from observers. But what are the odds of something larger impacting the Earth? The Chelyabinsk fireball was estimated to be about 17 metres across and NUCLEAR WASTE SOCIETE DE GESTION MANAGEMENT DES DECHETS ORGANIZATION NUCLEAIRES massed about 10 000 metric tons. Peter Brown of the Meteor Group at Western University in London, ON, estimates the odds of such a large object hitting near a populated city at about 1 in 4,000. He adds that once every 80 years or so, a similar large object hits Earth in remote unpopulated areas like deserts, remote forests or oceans. Space-age records note that two dozen smaller objects (less than 10 m or so, i.e., a car -sized object) have burned up spectacularly, but harmlessly in Earth's atmos- phere in the last 15 years. For objects 10m or so and less, Earth's atmosphere does a good job of protecting us and only occasionally do a small number of fragments, i.e. meteorites, get through to be hunted down by mete- orite collectors. Objects bigger than 100 metres are much rarer but could do a lot more damage. The atomic explosions over Hiroshima and Nagasaki give an accurate picture of the effects (minus the nuclear radiation) of an impact from a 100m sized object. The best estimate of the odds of this event hap- pening from space are about one chance in 10,000 years. For objects bigger than a kilometre or so (call them meteoroids, asteroids or comet nuclei, they are all deadly), regional damage NWMO Learn More Centre The Township of Huron -Kinloss is one of nine communities involved in a process of learning about Adaptive Phased Management (APM), Canada's plan for the safe, long-term management of used nuclear fuel. The Nuclear Waste Management Organization is working collaboratively with the community to advance preliminary assessment studies. Learn about APM, meet NWMO staff, ask questions and offer your thoughts. Drop in to the NWMO community office and Learn More Centre in Ripley. Everyone is welcome. would occur and millions of people could be affected with death tolls like those in the world wars. Fortunately, the odds of an event this cat- astrophic are one chance in a million years or so. Impactors much larger than this, up to 100 km, are much, much rarer. The one that caused the dinosaur extinction 65 million years ago, and those that caused three or four other major extinctions of life on our planet over the last few bil- lion years would be world - changing events, and are very unlikely to happen in a human lifetime. That is not to say that they are impossible, but it is important to keep a sense of perspective. According to statistics from the National Safety Agency in the US, an individual human has a much larger chance of dying from heart disease or cancer (one in seven) or in a car crash (one in 112) or as a result of an airplane accident (1 in 8000). Even getting hit by lightning is a one in 165,000 chance. To further put your mind at ease, at least from the risk of potentially hazardous space objects, (PHO's) there are now many telescope - equipped searches going on to find the most hazardous objects out there. After a comet was observed to hit Jupiter in 1994, many NWMO Learn More Centre (Huron -Kinloss) 80 Huron Street, Ripley ON 519.386.6711 Wednesday Thursday Friday 10 a.m. to 3 p.m. 10 a.m. to 3 p.m. 10 a.m. to 3 p.m. Bluewater Astronomical Society Artist's impression of close pass of an asteroid to Earth. funding agencies from world governments (USA, Japan, UK, Italy, Germany and Can- ada) loosened their purse strings and put more money into funding observatories with telescopes and cameras devoted to searching for PHOs. Canada plays a leading role with its NEOSSat, the Near -Earth Object Surveil- lance satellite that was launched Feb 25, 2013, coin- cidentally only 10 days after the Chelyabinsk fireball. NEOSSat watches from 800 km up, continuously looking for any asteroids that are dif- ficult to spot from earth - based telescopes. The hun- dreds of images generated per day are examined for PHOs at the operations cen- tre at the University of Calgary. So far, thankfully, reports from NEOSSAT and the dozen other Spaceguard organizations indicate "All clear': Now, if they could only do something about these depressing February clouds. The website www.bluewa- terastronomy.com of the Bluewater Astronomical Society lists our coming events including first Wednesday of the month meetings, - the first of which was March 2. The public is welcome to attend. Pieces from Vesta will be on display. Our regular viewing ses- sions at the Fox Observatory commence in earnest for this year in March. Check our website for a list of upcoming dates and observing events as well as how to become a member (with observatory privileges.) For more information visit www.bluewaterastronomy. com PA.R K TEI E kTRF ba The svwt CODERICHI 519 524 1h 1: }T. l 1• 1 T r www.mavielinks.ca luta eauffe 1 -MO -265-343B SAUCEEN MOBILITY and REOIONAL TRAN sir SPECIALIZED PUBLIC TRANSIT MENTALLY & PHYSICALLY CHALLENGED RESIDENTS NON -EMERGENCY MEDICAL, SOCIAL & EMPLOYMENT LOCAL AND LONG DISTANCE 519-881-2504 1-866-981-2504 Please visit us at saugeenmobility.ca