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--------------------- 2595 - ASTEROID - Teacher’s Lesson Plan?
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- Go to http://faulkestelescope.com/education for more the information.
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- The amateur astronomer took CCD images of the asteroid with several exposures. He studied the brightness of the pixels as they rotated across the image. His calculations were that the asteroid was spinning one revolution per 42.7 seconds.
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- This is the fastest spinning asteroid measured to date. The amazing part was that he was in the United Kingdom and was using a telescope in Australia. Getting his images by remote control over the internet. Amazing!
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- The Faulkes Telescope project is opening this capability to everyone. Telescopes all over the world are signing up to let amateurs log in. The 2 meter telescope in Hawaii has come on line. The capability will be 24-7 because there will always be a telescope somewhere that is in the dark. You can be a student working with a $10 million telescope and camera. How better to learn astronomy.
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- The Faulkes Telescope project offers many other lesson plans for students. For example it tells students how to Google Earth and find dozens of meteor craters around the planet. Measure the diameter of the impact and calculate the amount of kinetic energy that crashed into the planet.
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- The Chicxulub Crater in the Yucatan, Mexico, is 100 kilometers in diameter. The density of rock was 2700 kilograms per cubic meter. The diameter of the asteroid that made this crater was 17.5 kilometers. That would put the volume at 2.81*10^12 cubic meters.
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- Mass = density * volume, therefore the mass was 7.6*10^15 kilograms.
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- Volume = 4/3 pi * r^3, radius = 17.5*10^3 meters / 2
- Mass = (2.7*10^3 kg/m^3) * (2.8*10^12 m^3) = 7.58*10^15 kilograms
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- Kinetic Energy = ½ mass* velocity^2. The velocity was 20,000 meters per second. The Kinetic Energy of the impact was 1.52*10^24 kilogram*meter^2 / second^2, or, 1.52*10^24 joules.
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- One ton, 2,000 pounds, of TNT releases 4.2*10^9 joules of energy. The impact was equivalent to 360 trillion tons of TNT.
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- A magnitude 7 earthquake is 10^15 joules. Therefore, this impact was equivalent to 5 magnitude 7 earthquakes going off all at once. An atomic bomb is 8*10^17 joules, therefore, the impact was equivalent to 2 million atomic bombs going off all at once. No wonder it killed off all the dinosaurs.
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- University of Maryland discovered the oldest asteroids to date. Visible and infrared data collected found 3 times as much calcium and aluminum as the oldest known meteorites. Scientists believe that calcium and aluminum were among the first elements to condense for the young Solar System’s swirling gas disk.
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- The older the asteroid the more calcium and aluminum it should contain. Their calculations put the age at 4,550,000,000 years. The names of the asteroids are 387 Aquitania, 980 Anacostia, and 234 Barbara.
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- If we could learn more from these asteroids we could better understand how the planets formed in our early Solar System.
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- An asteroid is going to hit our planet, Earth. It is not an if, it is a when. Astronomers are tracking Near Earth Asteroids, NEAs. There are many, and each one needs to be identified with an orbit trajectory to learn if it will be a threat.
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- So, what can we do about it? The first idea was to send a rocket to intercept it carrying a nuclear warhead. Blow the asteroid to smithereens. So, instead of a big rock heading towards us we have a million small one. Like buckshot from a shotgun there is still a lot of damage heading our way. What then?
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- Then, don’t us a big bomb use a small one. One just the right size to vaporize some of the surface on one side of the asteroid and deflect it off course. The trick is to get just the right size. The bomb could still launch some small rocks that are still heading our way even though the big rock is deflected off its trajectory.
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- Ok, then use a bunch of small bombs. Like shooting the asteroid with a pellet gun. Not enough to damage anything but repeated boosts that eventually redirect to asteroid’s trajectory. Calculations are that a one mile per hour impact could direct an asteroid 170,000 miles off course if we started hitting it 20 years before it got here.
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- Maybe we do not need bombs? Maybe the solar wind could do the job? Sunlight hitting a shiny white surface over a long period of time would redirect the asteroid. We could just paint one side of the asteroid a shiny white. Or, a matt black if we wanted sunlight absorption to be the redirecting force. White paint or black paint, whatever, sunlight could push the asteroid out of our path.
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- Painting may be messy. Why not just install a giant mirror on the asteroid. The Solar Wind pushing on the mirror would do the job of redirecting the rogue asteroid.. However, attaching anything to the surface of an asteroid might have the unintended consequence of dislodging boulders or smaller rocks that would still remain as buckshot heading our way.
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- What about replacing the solar sail with a solar net? A 550 pound carbon fiber mesh could wrap around the asteroid. The net material could absorb the amount of Sun radiation needed to redirect the asteroid off course. The net would keep any buckshot from escaping from the asteroid. The net would have to be installed at least 18 years in advance.
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- Or, instead of one giant mirror why not a number of mirrors in orbit about the asteroid. The could be focused to beam sunlight on to the asteroid like a magnifying glass. Vaporization on the surface would act as a thruster to send the asteroid off its course.
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- Some astronomers like the direct approach. Just attach a rocket to the surface and light it off. The giant rocket thrust will do the job. Again, landing, attaching, and restraining a giant rocket is risky business.
- Well the final suggestion is to just let it happen and use the time here on Earth to prepare for the impact. Just like preparing for a nuclear holocaust. Maybe a late redirect could cause the impact to be mid ocean instead of hitting a population center.
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- It is not if, it is when will we face these decisions and what will we do? Like dinosaurs we may give up the Earth and turn it over to the cockroaches, or, whatever survives the next mass extinction.
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- In 1908 an asteroid 60 meters in diameter exploded above the ground over the Tunguska River in Central Siberia, Russia.
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- An asteroid named “ Eros” , 33,000 meters in diameter came within 20,000,000 miles as it zipped by Earth.
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- An asteroid 1,000 meters across has the explosive power of 20,000 megatons of TNT. An asteroid that size is projected to hit Earth every few million years, on average.
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- Smaller asteroids are more numerous. A 100 meter rock ( 20 megatons TNT) is projected to hit us every 100 years, on average.
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- The Chicxulub Crater in the Yucatan, Mexico, is 100 kilometers across. It was caused by an asteroid impact 17,500 miles across.
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------------------ The Density of this rock was 2,700 kilograms / cubic meter.
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------------------ The Volume was 2.81 * 10^12 cubic meters
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------------------ Mass = Density * Volume
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------------------ The mass was 7.6*10^15 kilograms
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------------------ Kinetic Energy = ½ mass * (velocity)^2
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------------------ The Velocity was 20,000 meters / second ( 45,000 miles per hour)
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------------------ The Kinetic Energy was 1.52*10^24 joules
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------------------ One ton of TNT releases 4,200,000,000 joules of energy
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------------------ The Chicxulub impact was equivalent to 300 trillion tons of TNT
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------------------ A magnitude 7 Earthquake is 10^15 joules.
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------------------ Therefore, the Chicxulub impact was equivalent to five magnitude 7 earthquakes going off all at once.
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------------------ It was equivalent to 2,000,000 atomic bombs exploding at the same time.
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------------------ No wonder it killed off all the dinosaurs.
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- Other Reviews you might be interested in. Request number:
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- 2296 - Asteroids are rocky world orbiting our Sun. Asteroids can reach as large as Ceres that is 583 miles across. More than 150 asteroids are known t have companion moons. Ironically, the collisions that could mean death to humans may be the same reason we are alive today.
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- 2250 - Asteroid visits and impacts. We had a spacecraft visit the asteroid Itokawa in 2005 and the asteroids Ryugu and Bennu in 2019.
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- 2226 Asteroid Ryugu. Spacecraft landed on the surface on September 2018. What have we learned?
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- 2209 Asteroid Oumuamua is from another sola system outside our own.
- 2203 Asteroid Bennu. Arrived December 2019 and will inspect every square inch of the asteroid before returning home in 2023.
- 2044 - Oumuamua is a needle shaped asteroid that will exit solar system. This Review lists 15 other reviews about asteroids.
- 1923 - When will the big one hit? In 2017 50 asteroids passed us at a distance closer than our Moon.
- 1825 - Asteroids responsible for evolution on Earth?
- 1554 - Asteroids are fossils with stories.
- 1375 - There is an asteroid following us in orbit.
- 1309 - Vesta and Ceres get a visit from the Dawn spacecraft.
- 1296 - When an asteroid hit Manson , Iowa?
- 1265 - Ths asteroid missed us, in 2011.
- 913 - Apophis and other killer asteroids.
- 635 - Asteroid Apophis arrived in 2006
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- January 24, 2020 1193 938 2595
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--------------------- Saturday, January 25, 2020 -------------------------
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