Travelers In The Night

In the distant past things in our solar system were very much more wild and violent than they are today. 4.5 billion years ago a Mars sized object called Theia impacted Earth producing our Moon. Scientists are able research this event using the current chemical compositions of the Earth and Moon.

In less than 24 hours, while observing with the Catalina Sky Survey's 60 inch telescope on Mt. Lemmon, Arizona , I discovered two 25 foot diameter space rocks that theoretically can pass less than a quarter of the Moon's distance from us. After I posted my discovery observations on the Minor Planet Center's Near Earth Object Confirmation page one of them received immediate attention, as an incoming object, and was tracked by observers at 14 different observatories around the world. Scientists at the Minor Planet Center used these data to calculate it's 926 day orbital path around the Sun, estimate it's size, and give it the name 2017 TH5. 36 hours after I first spotted 2017 TH5 streaking through the night sky it came to less than 60,000 miles from the surface of our planet traveling at 7.6 miles per second. 8 hours and 49 minutes later it passed less than half a lunar distance from the surface of our moon. If 2017 TH5 would have been on an impact trajectory with Earth humans would have had time to prepare for a spectacular light show. Approximately once every 5 years a tiny asteroid like 2017 TH5 enters our atmosphere exploding at an altitude about 3 times higher than airliners fly releasing the energy of about 5,000 tons of TNT. Asteroid hunters are well on our way towards being able to issue a warning to stay away from doors and windows should a small space rock be discovered to be on an impact trajectory with planet Earth.

My Catalina Sky Survey teammate David Rankin was asteroid hunting in the evening twilight with our 60 inch telescope on Mt. Lemmon Arizona when he spotted an unknown object in the constellation of Lyra. The largest telescopes on Earth will likely track David's discovery until it becomes too faint to observe in 2027 and catch it again when it again becomes bright enough to track in 2050. Fortunately it is extremely unlikely that it will strike Earth when it again comes close to our home planet in 2052.

New Zealand's 4.5 million people are concentrated in three major population centers which to various degrees suffer from the modern plague of light pollution. However, most of New Zealand's large rural areas and land reserves, covering an area as large as the UK, have unpolluted natural night skies. A completely unique place to experience New Zealand's natural night sky is the Aotea [ Ah - yoh - tee - ah]-Great Barrier Island International Dark Sky Sanctuary. It encompasses New Zealand's, 110 square mile, sixth largest island, which is located about 62 miles from central Auckland. It is easily accessible by boat or a short airline flight. The island's 1000 residents are employed by agriculture and tourism. They value the natural night sky and function without externally generated electricity or street lights and fully support the preservation of their prestine night sky. In the daytime Great Barrier Island offers wonderful beaches and hikes. When the sun sets the night sky becomes alive with its own natural lights. Night sky measurements by Auckland Astronomer Nalayini [ Na - laa - i - ni] Davies and her collaborators have proved that the Great Barrier Island's natural night skies are second to none on planet Earth. Using the unaided eye, a set of binoculars, or a small telescope an observer on the Great Barrier Island is treated to spectacular views of the center of the Milky Way, the clouds of Magellan the nearest galaxies to us, the nearest stars, as well as numerous star clusters, meteors, comets, and other wonders of the natural night sky. Perhaps this unique spot deserves a place on your bucket list.

It is possible the object creating the Tunguska event in Russia 1908 which knocked down 80 million trees over an area about twice the size of New York City was a fragment of a comet or asteroid. The International Asteroid Warning Network 2025 campaign to track Comet 3L/Atlas prepares the worlds observatories for the eventual time when a comet fragment has our number on it.