My Catalina Sky Survey teammate Greg Leonard was observing with our team's 60 inch telescope on Mt. Lemmon in Arizona when he discovered a relatively large space rock, 2017 FD157, which can theoretically come closer to the Earth's surface than the communications satellites. We don't have enough data to predict when it will make a very close approach to us. What we do know is that 2017 FD157's orbit and that of the Earth nearly intersect coming to about Earth diameter of each other. For 2017 FD157 to make a very close approach to our planet, both of them would need to be at the position on their respective paths which are closest to each other. If history is a guide, it is likely that additional observations will reveal that 2017 FD157 will never impact the Earth. About once every 11,000 years one of its size impacts the Earth with an atmospheric impact energy of several of large hydrogen bombs creating a crater a mile in diameter. If in an extremely unlikely turn of events, 2017 FD157, appears likely to impact our planet in the far distant future, humanity would be well served to mount a space mission to deflect it from it's deadly course. If humans have enough time they may be able to paint it so that over time sunlight pressure would change its path otherwise a nuclear detonation or some other more aggressive move would be necessary.
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845-Mighty Schmidt
On a single February night my Catalina Sky Survey teammate Jacqui Fazekas reported the discovery of 5 Earth approaching objects using our small but mighty Schmidt telescope on Mt. Bigelow, Arizona.Rest assured that on any given night there are asteroid hunters on the look out for seriously dangerous space rocks.
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332E-351-Another Close One
Asteroid hunters have become aware of the many small space rocks which come near Earth because of improvements made to telescopes, cameras, and computer analysis software. Recently, my Catalina Sky Survey teammate Rose Matheny used her skills and a new camera to discover the second small space rock in 32 days which came between the communications satellites and the Earth's surface. Rose spotted her 10 to 12 foot diameter space rock as it approached the Earth more than a million miles away with its little full moon face pointing towards us. 31 hours later, her discovery, 2017 GM, came to within 10,100 miles of Earth as it streaked by at about 11 mi/s on its way towards an encounter with Venus five and a half weeks later. It it had been on an impact trajectory with our planet, Rose's early detection would have allowed asteroid hunters to alert humans to prepare for a spectacular light show as it exploded in our atmosphere.
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844-Global Meteor Network
As the Earth travels in its orbit around the Sun it collides with objects called meteoroids traveling through space. These tiny members of the solar system range in size from dust grains to objects a meter in diameter.By becoming part of the GMN’s network , your data will help to discover and document meteor showers, aid in identifying the parent cometary objects, and in some cases help to identify locations to search for meteorites.
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331E-350-Asteroid Defense
In 2013 a 56 foot diameter space rock exploded over Chelyabinsk, Russia releasing the energy of 450 kt of TNT and filled local hospitals with some of the 1,500 people who were injured. Fortunately no one died. In 1908 a 200 ft diameter meteor exploded over a largely unpopulated region at Tunguska, Siberia knocking down trees over a 750 square mile area. If it had hit over a populated area it could have caused a million casualties. The approximately 250 people in the USA that NASA has working on asteroid detection and ways of mitigating the effects of an asteroid impact have plenty to do. We still have to locate and track about a hundred very large asteroids which could produce global climate change. Further, there are approximately 14,500 undiscovered slightly smaller ones which could cause a hurricane sized footprint damage areas to land areas on our planet. Fortunately it is extremely unlikely that any but one of the smallest space rocks will hit the Earth in the next 100 years.
A real "Science Snack" for anyone who is interested in the extraterrestrial.Dr. Al Grauer is a member of the Catalina Sky Survey which has led the world in near Earth asteroid discoveries for 17 of the past 19 years.The music is "Eternity" by John Lyell.Astronomy Asteroids Space NASA Comets Earth Impact Aliens
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