Travelers In The Night

In April 2029 on one of the luckiest Friday the 13th in human history the 1500 ft by 500 ft asteroid Apophis will pass within 23,600 miles of the Earth’s surface traveling at some 4.6 mi/s. This is extremely fortunate since an Apophis impact would release the energy of scores of nuclear weapons and cause wide spread devastation. NASA's OSIRIS-APEX will become the companion of the potentially hazardous asteroid Apophis on 5 June 2029,

Eighteen hours before my Catalina Sky Survey teammate Rose Matheny first spotted a small space rock with our Schmidt telescope on Mt. Bigelow, Arizona it had passed less than the Earth's diameter from the surface of our planet. Rose was able to discover this Smart Car sized space rock after it moved out of the Sun's glare. At this point it was about the Moon's distance from her and was traveling away at 3.4 mi/s. After Rose posted her discovery observations on the Minor Planet Center's Near Earth Object Confirmation page, for the next 24 hours it was tracked by telescopes in Spain, Illinois, and Arizona. Scientists at the Minor Planet Center used these data to calculate it's orbit around the Sun, estimate it's size and give it the name 2017 UJ2. This small asteroid had come near the Earth in 1978 but was invisible to the technology which astronomers had available at the time. 2017 UJ2 will not come close enough for us to detect in the foreseeable future, however, there are likely to be tens of millions of others like it which can come close to Earth. A small asteroid the size of Rose's discovery is likely to enter our atmosphere at least once a year and explodes at about 4 times higher than airliners fly. If such an event happened at night and you were lucky enough to see it you would be treated to a fantastic light show. If you are as lucky as a power ball winner you might even be able to find a piece of it on the ground.

The Earth’s atmosphere does a good job of protecting humanity from space weather, however, occasionally a major event does break through our shield and gets our attention. Tree rings and ice cores have recorded past space weather events thousands of time larger than which have occurred in the modern age. investing in research seems wise.

In an area which is about 1/400th of the entire sky, the NASA Kepler spacecraft has discovered 30 Earth like planets which are likely to have liquid water on their surfaces orbiting distant stars. These planets are likely to represent a tiny sample of the habitable planets which exist in the Milky Way. In spite of our efforts to find them, the question remains where are the alien civilizations? In a recent talk given at the Division of Planetary Sciences meeting Dr. Alan Stern of the Southwest Research Institute suggests that perhaps the majority of worlds with biology and intelligent civilizations exist on interior water ocean worlds where their existence is hidden by the thick layers of rock and ice which separate them from the hostile vacuum of space. We know that in our solar system alone the moon of Jupiter Europa, Saturn's moon Enceladus, and perhaps several other small worlds are likely to have oceans of nutrient rich liquid water covered by a thick layer of rock and ice. We also know that Whales and Dolphins have larger brains than humans, communicate with each other, and exhibit other forms of intelligence. Advanced civilizations existing in ice covered seas may know little of the greater Universe, may find it difficult to consider transporting enough water to travel beyond their worlds, and may not think that it is possible to communicate with others of their kind who are similarly hidden under miles and miles of radiation absorbing ice and rock.

Around the world those who value the natural night sky are evaluating the effects of light pollution. In addition to impairing astronomy and star gazing the past 100 years of increasing light pollution is proving to be harmful to human health and the natural world upon which we all depend. The purpose of the Dark Sky Network is monitor and facilitate the mitigation of the harmful effects of light pollution.