Just search for "asteroid" in Google News and headlines are calling you.
"NASA warns of an asteroid on a 2-mile killer planet heading to Earth", or "… a potential impact date in 2022", or "Asteroid tsunami … could devastate US shores." " And, of course, "… a monstrous rock to cross Earth at 1
These are just a few of the stories that have only appeared in the last week, most notably in the British tabloids, who really love scary asteroid stories.
If you read past the sensational titles, you usually find mostly accurate information about an asteroid that will definitely not hit Earth any time soon. That 2-mile killer planet? That missed us with 1.4 million miles. It's about 6 miles farther from the moon. You should literally be more concerned that the moon crashed into your house.
Misleading titles and stories make use of the words that scientists use to speak of space objects and the connotations that some of those words have in everyday language.
For example, the terms "near-object" (NEO) and "potentially dangerous asteroid" (PHA) are astronomical terms used to categorize objects with very specific definitions. If the asteroid comes 4.6 million miles from Earth and has a certain brightness, it makes the PHA list. This is really just a way for astronomers to create a very large catalog of objects worth watching. No other assessment of each asteroid is made to determine how "potentially dangerous" it is before being given this designation.
NEOs fall into an even broader category. If you were to leave Earth and travel in the orbit of Mars around the sun, then stop when you are about 85 percent of the way to the Red Planet, everything between this position and the sun can technically be considered NEO.
It may seem strange to non-scientists to call an asteroid farther from us than any man has ever traveled "nearby," but of course it makes sense when dealing with the mind-blowing scale of the universe. as astronomers do. The same goes for these "potentially dangerous asteroids". It makes sense to call them in the context of a huge space, even though most PHAs aren't really potential dangers in our lives.
So the next time you see a headline screaming about how the "hippopotamus space rock is threatening the Earth," you can check the same sources I do to determine exactly how much you need to worry. In fact, I'll take this particular behemoth as an example.
Several retail outlets have already started emitting alarms about the 2006 asteroid approaching SF6, which is intended to take a near-Earth approach on November 21st. That certainly sounds like a risk scale that is heading to us from some of the headlines, so I'll check the European Space Agency's risk page.
The ESA maintains a list of "all non-zero impact sites".
When I click to get the full risk list and search the page for both 2006SF6 and its catalog number, 481394, nothing appears. This potential pompous planet does not appear to have compiled a list of the 991 most endangered space objects.
Then I check the public database of close approaches maintained by the Near Earth Research Center at NASA's Jet Propulsion Laboratory. One search leads the 2006 SF6 to the right. It really is a small hippo, with an estimated diameter of between 919 and 2690 feet (280 and 820 meters).
This skyscraper-sized space rock can cause real damage in impact. But its close distance is referred to as 11.23 lunar distances. This is exactly how it sounds: over 11 times farther from the moon, or about 2.7 million miles (4.3 million kilometers). We're sorry, but this behemoth is definitely not a threat to Earth.
However, my opinion is not that you should worry about asteroids. As many of the fossil dinosaurstell us, the threat of impact from an object from space is very real. But the main threat comes from objects that are not yet in our catalogs.
The most significant impact of the last century occurred in 2013, when a meteorcreating a shockwave that broke thousands of windows. This cosmic rock was not observed before it exploded into the sky.
The technologies and techniques used by astronomers have improved to such an extent that new NEOs are discovered literally every day. This includes some objects that are actually quite close to Earth, although they tend to be so small that they are likely to mostly burn into the atmosphere if they impact us, as one did in 2018 .
But we still have blind spots, as demonstrated by the impact of 2013, so the imperative progression must be not to marvel at some harmless asteroids, but to devote more resources to continue shaking the sky and filling up our catalog so we don't get caught by surprise again.