Travelers In The Night Albert D. Grauer

Comet 12P/Pons-Brooks comes near the Sun once every 71 years.  It was discovered in 1812 by Jean Louis Pons at Marseilles, France and then rediscovered by American Astronomer William Robert Brooks in 1883. Electronic cameras reveal this comet's nucleus has jets of gas that produce a spiral structure not unlike water jets from a lawn sprinkler.

Seasons are created by the fact that the Earth's axis of rotation is currently tilted 23 1/2 degrees relative to our path around the Sun. The slight out of roundness of the Earth's orbit combined with a 41,000 year cycle in its 3 degree axis of rotation wobble can cause the Earth's climate to change on very long time scales. Turns out that these astronomical cycles are likely to be the drivers of where you are from and where you live.

Recently my Catalina Sky Survey teammate Vivian Carjaval was asteroid hunting in the constellation of Ursa Minor with our Schmidt telescope on Mt. Bigelow when she discovered, 2024 BR4, a two football field diameter Earth approaching asteroid.Vivian’s Apollo asteroid discovery poses no threat to humans since 2024 is as close as it will come to Earth in the next few hundred years.

During a recent 3 night observing run my Catalina Sky Survey teammate Rose Matheny discovered 4 asteroids which can come to less than one half the Moon's distance from us. Interestingly one of them passed about 25,000 miles over the South Pole 2 days after Rose discovered it. Rose's four close approaching asteroids are small ranging in size from 15 to 60 feet in diameter. None of them are big enough to reach the Earth's surface and make a crater. However, the largest is about the size of the one whose air blast shock wave injured nearly 1500 people when it exploded over Chelyabinsk, Russia in 2013 .

Perhaps the most dangerous Amor asteroid is 2006 HZ51 .It was discovered by my team the Catalina Sky Survey.  Fortunately the closest 2006 HZ51 will come to our home planet is  June 11 of 2116 when it will pass us harmlessly 26 times the distance to our moon away from us.

Recently in the space of 28 hours my Catalina Sky Survey teammates Rose Matheny and Carson Fuls discovered two Potentially Hazardous Asteroids to add to the list of the more than 1700 which asteroid hunters have discovered. Fortunately, none of the Potentially Hazardous Asteroids are currently on a collision course with planet Earth.