With economic collapse, political tensions, natural disasters, and other newsworthy headlines inundating our daily lives, it’s easy to forget about things happening beyond our planet. While the likelihood of an extraterrestrial invasion is still up for debate (I’m joking), there’s no denying that life as we know it is always at risk for impacts from what is referred to as near-earth objects or NEOs.
From asteroids to meteorites, we know that there is consistent activity in our solar system that could impact (and has already impacted) life here on Earth. In fact, The Guardian reported that “NASA has discovered an estimated 90% or more of near-Earth objects larger than a kilometer, the size that could cause devastation on Earth. Smaller objects are still extremely dangerous as well and NASA has found 874 1-kilometer-wide asteroids among 1,748 ‘potentially hazardous asteroids.’”
It’s true that certain impacts could wipe out most living organisms--and there isn’t a lot we can do to prepare aside from living each day to the fullest. However, while other impacts are less catastrophic, they still require certain tools, preparations, and know-how for survival.
Read on as I’m going to cover what to expect if an impact does happen and how to prepare. But first things first--let’s cover the difference between three near-earth objects: asteroids, comets, and meteorites.
Asteroid vs. Comet vs. Meteorite
There are various types of NEOs in space that pose a threat to life on Earth. When talking about the risks and methods of preparation for impact, it’s key to understand the difference between asteroids, comets, and meteorites.
Asteroids come from the asteroid belt between the orbits of Mars and Jupiter. They are mostly composed of rock and can measure anywhere between 329 miles to 33 feet across. They may pose a threat to Earth if their orbits are disrupted or altered, hurling them closer to the sun and planet Earth. This has happened before and is likely to happen again.
Comets are similar to asteroids, but are made up of different materials. They contain more ice, methane, ammonia, and other compounds that create a fuzzy shell and tail when it nears the sun. They come from the Oort Cloud and Kuiper Belt. They are less common than asteroids when it comes to near-earth space, but they still pose a threat of impact.
Meteoroids are pieces of space debris that are smaller than asteroids or comets--meaning smaller than a kilometer and usually only millimeters across. They’re the result of asteroid collisions in space that create smaller fragments of material. If they enter Earth’s atmosphere, they become meteors (otherwise known as shooting stars)--and if they land on Earth, they are called meteorites. Thousands of smaller meteors disintegrate harmlessly each day far above the planet. For an object to make it through the atmosphere without burning up, it typically needs to be at least forty meters wide.
Since we can learn from various situations involving meteorites in history, let’s take a look at what happened in two recent examples…
The Chelyabinsk Meteor & The Tunguska Explosion
On February 15, 2013, a meteor entered Earth’s atmosphere above a part of Russia’s Ural Mountains region. Weighing approximately 7000-8000 tons and stretching about 65 feet wide, it exploded in the sky over the city of Chelyabinsk. As Space.com reported, “The blast was stronger than a nuclear explosion, triggering detections from monitoring stations as far away as Antarctica.”
The explosion caused panic in the city, and about 1,500 people sought medical treatment for injuries. These injuries were due to indirect effects, such as glass from broken windows that were blown out due to the shock waves. Roughly 7,200 buildings were also damaged, and authorities had to rush to fix them in subfreezing temperatures. Fortunately, there were no fatalities.
Oddly enough, the largest impact on Earth in our recent recorded history, the Tunguska explosion in 1908, also took place in Russia. Fortunately, it occurred in an uninhabited section of the country. It is estimated that the Tunguska explosion knocked down some 80 million trees over an area of 830 square miles, and that the shock wave from the blast would have measured 5.0 on the Richter magnitude scale.
The size of this explosion would have destroyed a large metropolitan area had it not occurred in such a remote area. To this day, we aren’t entirely sure what caused the explosion. While some scientists suspected it was a meteor that exploded as it entered our atmosphere, they never found impact craters from the potential fragments.
Later on, British astronomer, F. J. W. Whipple suggested that the Tunguska body was actually a small comet since a comet would have completely burned up due to the heat of entry.
In both of these situations, the impacts were relatively minor, yet still damaging. Fortunately, scientists and the government are working together to prepare for future worst-case scenarios...
Preparing for Impact
With organizations such as NASA consistently conducting research on outer space and issues such as the threat of planetary impact, we have some peace of mind. In fact, NASA’s Planetary Defense Coordination Office is exclusively dedicated to leading and coordinating between agencies in the case that a real threat emerges.
Additionally, both the Obama and Trump administrations have grown the budget for asteroid research. The annual budget jumped from $12 million to $150 million in this administration’s most recent request. While NASA and other agencies have search programs that have discovered hundreds of thousands of main-belt asteroids and comets, none of them currently pose a threat to our Earth. This is only for the near-earth objects we are aware of.
Keep in mind, things can always change. As Thomas Zurbuchen, NASA’s Science Mission Directorate’s associate administrator puts it, “It’s not a matter of if, but when, we will deal with such a situation.”
If we do come under threat of an impact, scientists may be able to use methods of deflection to avoid major asteroid collisions. For example, NASA’s Asteroid Redirect Mission is testing out planetary defense techniques, such as bringing an asteroid to the moon’s orbit for study. And an astrophysicist at the University of California, Santa Barbara has created a laser propulsion system intended to deflect incoming asteroids.
In many cases, we will have years of notice if a significant asteroidal impact is imminent. For example, in 1999, scientists discovered the 101955 Bennu, a 1,600-foot-wide carbon asteroid. It has only a 1-in-24,000 chance of hitting Earth, and that wouldn’t occur until 157 years from now.
But there is still a chance that large comets from the outer solar system could suddenly appear with only a few months of warning for impact. And we can always be surprised by objects from deep space whose orbit isn’t bound by the sun.
In the scenario that we have short notice and aren’t able to deflect an incoming near-earth object, government agencies are training in anticipation of a real threat. In 2018, NASA and FEMA held a series of exercises during a training that tested readiness and possible response in the event of a large asteroid impacting Earth. In the hypothetical exercise, they had to plan evacuations, information dissemination, and ways to prevent panic. (Of course, we are talking about FEMA here, and their “on earth” record for dealing with natural disasters has been far from stellar.)
We know that we can’t rely on or leave it up to our government agencies to save us. We need to take our preparedness and survival into our own hands as well, no matter what the exact threat may be. Here are three preparation tips to keep in mind for near-earth object impacts...
#1: Stay Up-to-Date
NASA’s scientists track comets and asteroids in our solar system, and they will be the first to know if a large object is on track to collide with Earth. Pay attention to predictions disseminated from NASA and other relevant agencies, so you can know how much time you will have to prepare.
#2: Evacuate Higher-Risk Areas
The initial impact of an NEO isn’t the only thing you would have to worry about. Because the majority of the Earth is covered by water, coastal areas would be at significant risk of tsunamis after impact. Additionally, earthquakes and volcanoes could be triggered as secondary effects of the impact.
If you live in areas that could be high risk for these situations, make sure you have an evacuation plan in order, along with supplies in your car to take with you. For example, a supply of water and water purifiers, a supply of nonperishable food, and solar-powered radios are a must.
#3: Stock Up on Essentials at Home
Although science has enabled our society to be relatively prepared and informed about potential impacts from NEOs, the truth is, we can always be caught off guard. Take steps now to prepare for worst-case scenarios and ensure your family remains safe.
As we saw in the case of the Chelyabinsk Meteor, buildings can be severely damaged from relatively minor impact events. Explosions like these can cause panic and disruptions that can restrict your access to essential resources, and it’s better to be stocked up at home in case your power goes out, stores close down, or transportation is inhibited.
Make sure you have enough food and water for at least three months (that’s our recommendation as the FEMA three-day recommendation is sorely inadequate), as well as backup generators, solar-powered chargers, water purifiers, and more.
Have a great weekend and stay alert, friends!
In liberty,
Grant Miller
Preparedness Advisor, My Patriot Supply