Our planet Earth is being bombarded all the time by asteroids or meteorites. Fortunately most of them do not hit the Earth, passing harmlessly by us in space. Even when they come in contact with the Earth’s atmosphere, most of them burn up before they hit the ground. Many of them are large enough to destroy a city. Some we see ahead of time. Some surprise us with no warning.
As an example, NASA shows approximately 90 near earth objects that will come toward Earth at a distance closer than our distance to the moon (~384,000 kilometers). These are only the asteroids or meteors that will pass us between January 1, 2016 and March 1, 2016 or just two months. At the larger end these range from 17 that are larger than 250 meters in diameter to over 2.1 kilometers. As a measure of scale, 92 meters equals ~100 yards or a football field.
February 15, 2013 was a historic day. In the same day we were visited by a flyby asteroid (DA14) we anticipated in 2012 and one not anticipated. The flyby came within 17,000 miles of our planet. Unfortunately, the average “house-sized”, unanticipated asteroid entered the Earth’s atmosphere and exploded just 12 miles up in the air. This was over the city of Chelyabinsk in Russia. This explosion injured 1,000+ people mainly from flying glass. Nova claims the explosion was 20 to 30 times that of the bomb dropped on Hiroshima, Japan.
But how big can asteroids or meteors be? To answer that question we could go back to the largest known impact ever discovered on the Earth’s surface. We are talking about the Chicxulub Crater in the Gulf of Mexico. This was the asteroid/meteor given credit for wiping out the dinosaurs and ushering in mammals as the new dominant life form. This asteroid/meteor was estimated to be 10 km in diameter. It ended the Cretaceous period, about 65.5 million years ago.
There are 26 known asteroids larger than 200 kilometers in diameter. The largest asteroid is Ceres. It is 974 km in diameter. The next three are 2 Pallas, 4 Vesta and 10 Hygiea. They are all between 400 and 525 km in diameter. All of these are much larger than the Chicxulub asteroid.
Chicxulub was an extinction event. Its energy was more than a billion times the explosive power of the Nagasaki and Hiroshima atom bombs. Earlier dating methods place the asteroid at 300,000 years before or 180,000 years after the end-cretaceous mass extinction. Newer, more precise dating methods however put the asteroid at no more that 33,000 years from the end of the K-T (Cretaceous-Tertiary) extinction event. For purposes of dating 33,000 years is simultaneous and represents the most accurate timing humans have yet to devise.
Recent research has shown that there was a basalt volcanic eruption on the other side of the Earth, the Deccan Traps in India that was influenced by the asteroid’s impact. Research on the asteroid points to shock waves created by the asteroid that reached the volcanic eruption on the other side of the world and may have accelerated the flows which only increased the deaths of dinosaurs during this period.
Unfortunately we are not paying a lot of money to detect new asteroids. An article which appeared on space.com in 2013 one month after the flyby and explosion over Chelyabinsk describes the problem we face. Roughly one month after the asteroid officials on capital hill asked NASA and the military what they were doing to combat the problem of unknown asteroids.
The article stated, “Rep. Lamar Smith (R-Texas), chairman of the Science, Space and Technology Committee, said it was not reassuring to learn that NASA has so far detected only about 10 percent of the near-Earth objects that are wider than 459 feet (140 meters) across. Holdren (Science advisor to Obama) estimated there may be hundreds of thousands of such objects within one-third the distance from Earth to the sun that remain unknown.”
The article continued, “In 2005, Congress directed NASA to detect, track and characterize 90 percent of these space rocks – those near-Earth asteroids larger than 459 feet (140 m).” Charles Bolden, NASA’s chief is quoted, as saying there was no way the space agency would meet its deadline. He reminded Congress they has not appropriated any money and said, “Our estimate right now is at the present budget levels it will be 2030 before we’re able to reach the 90 percent level as prescribed by Congress.”
The University of Hawaii and its Institute for Astronomy at Manoa founded the Pan-STARRS project that searches for large “killer asteroids”. While the Pan-STARRS project takes a month to complete one sweep of the sky in a deep but narrow survey the recently funded ATLAS will use 8 smaller 20-inch telescopes to look at the visible sky twice a night. The ATLAS (Asteroid Terrestrial-impact Last Alert System) is a result of a $5-million grant from NASA.
ATLAS is designed to offer a one-week warning of an impact by a 50-yard asteroid or “city killer.” It will also offer three weeks of warning of a 150 yard-diameter “county killer”.
Also the non-profit B612 Foundation has been started and is raising money to create an advance warning system for Earth to ward against the threat of a sizeable impact from outer space. The Nuclear Test Ban Treaty Organization put up a network of satellites around the globe that are being used by the B612 Foundation to record asteroid impacts on the planet.
This Foundation also plans to deploy a satellite, in conjunction with Ball Aerospace, that will implement an infrared survey mission which will catalogue 90% of asteroids that are 140 m (459 feet) in diameter in the our solar system. This will involve placing a satellite in a Venus-like orbit around the sun to scan the solar system for asteroids through the 6.5 years for which the program is funded.
These were the only references to funding found. Certainly elsewhere in the world are former astronauts, scientists, or academics that have used this need to fund their favorite capabilities. Only time will reveal them.
We all have seen movies about asteroids hitting the Earth. In some of them, the citizens of Earth are saved by a heroic astronaut, like Bruce Willis in Armageddon. Where are you Bruce when we need you!
It would be a tragedy if we were involved in an extinction event that ushered in another species but it might be a good thing. At least the new species would have a chance at survival considering all of the other threats that we have wrought that threaten life on the planet; all of the other threats that we have mounted only half-vast plans to correct or end.
People who have read my book should do as the book suggests. They should pick their favorite problem that humanity is wrestling with and should dedicate a significant amount of their money and effort to a solution. They should pick a calamity of their choice and focus on seeking its resolution.
Use the following links to get more information or access the original documents used for this article.
http://www.theregister.co.uk/2014/04/22/study_shows_dangerous_asteroid_impacts_hit_earth_every_six_months/ (access film embedded in article. Second picture frame.)