How Worried Should You Be That a Space Rock Will Destroy the Earth?
This is the plot of disaster films and sensational headlines: an asteroid, a meteorite or a comet is approaching the Earth. We are doomed? Isn’t that what wiped out the dinosaurs? Will we have enough time to put our differences aside, come together as a species and put in place some sort of technological defense and/or effort to keep our way of life going before we are utterly annihilated, or will we spend our final moments squabbling together? nonsense ?
Let’s not get ahead of ourselves. Most of these questions are debatable because the likelihood of experiencing a devastating effect on humanity is actually quite low. Here’s what you need to know.
First, what is the difference between a meteor, an asteroid, and a comet?
According to NASA , meteors, asteroids, and comets are “all planetary objects orbiting the Sun,” but they are slightly different. Asteroids are small and rocky, look like points of light when viewed through a telescope, and are usually found in the ring between Mars and Jupiter. Meteors are actually meteoroids that have come close to Earth and entered our atmosphere, but what is a meteoroid ? These are small pieces of an asteroid or comet, ranging from pebble-sized rocks to one meter chunks, usually resulting from some kind of collision. Meteors enter Earth’s atmosphere at super-high speeds, burning up and creating a streak of light as they do so. (That’s how we get shooting stars.) If a meteor survives all this and falls to the ground, it’s called a meteorite. Comets, meanwhile, are large objects made of dust and ice that orbit the Sun and have streaming tails. These are the remnants of the formation of the solar system billions of years old.
Knowing the difference is great, but not as important when it comes to the question of the day (how dead will this space rock make us?), because it’s the same thing: none of them is worth worrying about more than any other. others, and none of them are worth worrying about at all when there are so many more tangible threats to the future of humanity that keep you awake at night.
How afraid should you be of a collision?
Known and mundane meteorite falls have been recorded throughout history. People have even been injured by the glass and debris associated with these rockfalls, but according to NASA’s Bill Cook , only four large meteorites in recorded history have caused any significant damage.
Gordon L. Dillow published a book on the subject in 2019. At the time, he told Smithsonian Magazine , “Earth is bombarded all the time by small asteroids that harmlessly burn up or explode in the atmosphere.” From a planetary perspective, this is normal and rarely causes problems for anyone. In addition, “the chances of a civilization colliding with a large asteroid or comet — like the six-mile-diameter asteroid that apparently wiped out the dinosaurs 65 million years ago — in our lifetime, or even in the lifetime of our grandchildren, are very small. “How small? According to a Forbes report , the European Space Agency’s Near-Earth Object Clearing House maintains a list of more than 1,300 “near-Earth” objects that could have an impact on our planet . Most of the ones most likely to hit us are relatively small (less than 10 meters across) and unlikely to disrupt life on Earth. The largest one found on radar, the 1.1-kilometer-long beast known as asteroid 1950 DA, has an 1 in 8,000 chance of reaching shore…in 800 centuries.
Dillow acknowledged that “if we don’t find a way to stop this,” the Earth will hit an asteroid large enough to cause some level of local or regional destruction – or a global climate catastrophe – at some point in the future. Fortunately, there is good news as well.
Scientists on top of it, maybe
If you’ve seen any of the many films about what could happen if an object from outer space collided with a planet, you know that scientists are on the lookout for it. Remember Cook? It is part of NASA’s Office of Meteorologists, and there are numerous other groups of scientists and decision makers who are also monitoring the skies for potentially hostile rocks, including the International Asteroid Warning Network and the Space Mission Planning Advisory Group, not to mention about governments. worldwide.
These groups do more than just observe, at least in theory. For example, if a meteoroid larger than 50 meters is seen in its path of impact with Earth, the United States will attempt to deflect it in accordance with official policy. Dillow noted that our scientists have looked at quite a few ways to deflect an asteroid, from throwing white paintballs at it to change its reflectivity, to using nuclear weapons to “deviate it a bit.” (There are international treaties banning the use of nuclear weapons in space, but it seems that those in charge will decide during the game to ignore them in the event of our imminent death.)
The most likely scenario for dealing with the space rock involves the use of “kinetic strikers” to repel the impending horror. In this scenario, an unmanned spacecraft would be stuffed with metal and crash into an asteroid at a thousand miles per hour to slow it down. NASA is currently testing this approach with the Double Asteroid Redirection Test (DART) mission , the first real attempt to change the motion of an asteroid through space with a kinetic impact. The DART spacecraft will intentionally collide with an asteroid that does not pose a threat to Earth, just to see how things go.
If you want to feel like you’re doing something to combat the threat of asteroids, you can learn how to find and report them yourself. It may give you something to fill your brain with, beyond your fears of a cataclysmic apocalypse. Or give you more time to think about the next global pandemic. Whichever.