According to President Barack Obama's chief science adviser John Holdren, the earth is still vulnerable to an asteroid strike, one that is potentially catastrophic.
So, just as a refresher, what exactly is an asteroid? An asteroid is an irregularly shaped object, usually made of rock or metal, that orbits the sun. Are they really dangerous? Well, asteroids, along with other things like debris, is believed to have caused the craters on the moon, and some theorize that the Chicxulub asteroid brought upon the extinction of the dinosaurs. So, yes, they can be dangerous in a collision on earth.
Details remain muddy for now, but Holdren noted that progress is being made during a discussion of NASA's Asteroid Redirect Mission (ARM) held at Goddard Space Flight Center on September 14.
'We are not fully prepared, but we are on a trajectory to get much more so.'
Read more about how the history of asteroids on earth and also about how NASA plans to deal with the threat below.
The Chicxulub crater is named after the Mexican town it is closest to. Its diameter measures to about 110 miles and while it's depth measures at 12 miles. Physicist Luis Alvarez and his son Walter Alvarez proposed that the event led to the extinction of many plants, animals, and dinosaurs, but this remains a subject of controversy among scientists.
On June 30, 1908, there was a huge explosion above a remote forest in Siberia. As a result, the fireball flattened an estimated 80 million trees. Thirty five miles away in the nearest town, windows shattered.
Researchers say that this event produced nearly 185 times more energy than that measured in the atomic bomb used on Hiroshima.
The explosion did not occur over a populated city, and there were no reports of human casualties. Hundreds of reindeer, however, were burned to death.
There is a general belief that the event was caused by an asteroid or commit. Some have entertained more creative explanations.
Unfortunately, scientists at the time did not immediately analyze the site, which probably led many to embrace alternative theories. At the time, bigger asteroids, ones large enough to cause extinction, were taken more seriously.
In the past, we've heard news of asteroid collisions and close calls. Three years ago, when a meteor strike in Russia and asteroid flyby occurred the same day, members of Congress to learn more about what NASA, White House, and Air Force officials were doing to work against these dangers.
At the time, Holdren stated, 'The odds of a near-Earth object strike causing massive causalities and destruction of infrastructure are very small, but the potential consequences of such an event are so large that it makes sense to take the risk seriously,'
Two years later, Congress placed an expectation on NASA to 'detect, track, and characterize 90 percent of these spare rocks —those near-Earth asteroids larger than 459 feet feet (140 m).' Charles Bolden, NASA Administrator, predicted that too small of a budget would prevent complete success.
Although it is still in the planning stages, NASA's Asteroid Redirect Mission (ARM) is expected to launch by the end of 2021.
Here's more about it from the official site:
'NASA is developing a first-ever robotic mission to visit a large near-Earth asteroid, collect a multi-ton boulder from its surface, and redirect it into a stable orbit around the moon. Once it’s there, astronauts will explore it and return with samples in the 2020s. This Asteroid Redirect Mission (ARM) is part of NASA’s plan to advance the new technologies and spaceflight experience needed for a human mission to the Martian system in the 2030s.'
'The robotic mission also will demonstrate planetary defense techniques to deflect dangerous asteroids and protect Earth if needed in the future. NASA will choose an asteroid mass for capture with a size and mass that cannot harm the Earth, because it would burn up in the atmosphere. In addition to ensuring a stable orbit, redirecting the asteroid mass to a distant retrograde orbit around the moon also will ensure it will not hit Earth.'
In an interview with the Huffington Post, Dr. Dante Lauretta, the principal investigator for OSIRIS-REx. and professor of planetary science, says that it is important for people to understand the reality of asteroids.
It may be romantic and exciting to recall scenes in Star Wars when thinking of the asteroid belt, but on average, asteroids are actually hundreds of thousands of miles away from each other.
It is important to continue conversations about asteroids and how they could affect us but it is equally important to stick to the facts. For example, we should not buy into all the articles that detail close encounters that could have wiped us out.
The threat of an asteroid is a real one but it is also one that NASA is well aware of, which is why they're working on ways to deflect them.