I’m getting a little far from my usual star-gazing content to respond to an e-mail from a reader asking “Exactly who is responsible for protecting the planet from Near-Earth-Objects (NEOs).”
That question represents what to many is an extremely important bit of information for Earthlings. At this point in time, we can place our hopes on NASA’s Planetary Defense Coordination Office.
Thanks to their large variety of both ground and space based telescopes and other instruments, we’re hopeful they will be able to detect potentially hazardous objects so we can prepare for the unlikely threat against our home planet.
Most readers, I’m sure understand the term “Near-Earth-Object” but some may not know that the main threat rests with a multitude of asteroids on comets which orbit the Sun. It is their orbital paths that could bring them within our “threat” zone — 30 million miles.
While there are many who no doubt regard NEOs as something out of science fiction, the threat that does currently exist for Earth and all its inhabitants cannot be taken lightly. Something must be done!
Where do these objects come from? The majority of them are relatively unchanged remnants debris from the solar systems formation some 4.8 billion years ago. Most of the rocky asteroids originally formed in the warmer inner solar system between the orbits of Mars and Jupiter.
Comets, on the other hand, are composed of mostly water ice with embedded dust particles, formed in the cold outer solar system.
So what kind of numbers are we looking at when it comes to NEOs?
At the start of 2019, the number totaled more than 19,000, and it has since surpassed 20,000. An average of 30 new discoveries are added each week. We can thank NASA-funded surveys that first began back in 1998 tracking them and cataloguing them. While the current risk of an asteroid striking Earth is exceedingly low, constant monitoring of our cosmic neighborhood has to be continued.
Some of the continuing talking points deal with what can be done to enhance to our ability to discover threatening objects and what sizes of objects pose the greatest threat and what are our available options for deflecting an object?
Dr. David K. Lynch of The Aerospace Corporation conducted a recent session dealing with “Deflection Techniques” at which was discussed our options and whether those options included explosive or non-explosive techniques for deflecting threatening objects. One of the more interesting questions was “Can we get there with today’s technology?”
Another very interesting and thought provoking questions deals with preparing the public. Based on political policy and legal issues, how would established disaster relief agencies react to an impact threat of an impending impact?
It is still in the distance but we know that in 2029 an asteroid named Apophis will pass within 20,000 miles of Earth, closer than some of our weather satellites, and that an impact by the same asteroid in 2036 cannot be ruled out.
This particular asteroid is a little more than 1,800 feet in diameter which places it in a category of asteroids large enough to cause some serious damage should it hit.
Because any threat to Earth doesn’t just involve the United States, a panel discussion be held that would highlight non-technical issues associated with developing a worldwide mitigation capability and executing a response should a serious threat be detected.