Among Earth's natural disasters-hurricanes, floods, earthquakes-the ones that humans probably reflect the least are the asteroids, huge objects that traverse our solar system at ridiculous speeds.
Federal officials call collision from an asteroid or comet "low probability but high" consequence, "talking at NASA will probably never happen, but if so, we're fine." With that in mind, the US and other nations have long sought to track those "near-Earth objects" or NEO, coordinating efforts through the International Asteroid Warning Network and the United Nations.
The Trump Administration now wants to improve efforts to detect and track possible planetary assassins, and develop more capable means to deflect anyone who appears to be on a collision course.
"Fortunately, this type of destructive event is extremely rare," said Aaron Miles, an official in the Office of Science Policy and White House technology But just to be sure, the government revealed new targets this week for NASA's work in the fight against hard NEOs the next decade. If you are watching Bruce Willis or humming a song of Aerosmith, stop. This is serious.
More than 300,000 objects over 40 meters (131 feet) wide orbit around the Sun as NEOs according to NASA estimates, and many are difficult to detect more than a few days in advance. Forty meters is approximately the average size that an object must have to cross the atmosphere without being burned; Thousands of much smaller meteors disintegrate harmlessly every day far above the planet. The meteorite that injured more than 1,000 people in Chelyabinsk, Russia in February 2013, mainly because of glass broken by the shock wave of its explosion, was believed to be about 20 meters wide (65 feet ).
The most recent encounter with an asteroid was on June 2, when a 2 meter 2018 LA boulder entered the atmosphere at 10 miles per second (38,000 mph) and exploded over Botswana.
Well, now here's the good news: NASA has documented approximately 96 percent of the objects large enough to cause a global catastrophe since work began in 1998, said Lindley Johnson, a planetary defense the Planetary Defense Coordination Office of NASA. Only on Thursday, five massive asteroids were closed at 4.6 million miles from Earth, which is quite close in space, including one called 2017 YE5, a 1,600-foot-wide giant that, if it visited us, would ruin everyone's day . But NASA has its number.
It's also good news: this growing catalog of potentially-causing objects of Armageddon (do not do it-the movie was terrible) offers the world years of warning about when an orbit would intercept Earth, given the immense distances , asteroids and comets travel through space. For example, 101955 Bennu, a 1,600-foot wide carbon asteroid found in 1999 and prominently featured in NASA's current space research, has only 1 in 24,000 chances to hit the Earth, and that's within 157 years  Today, the NASA catalog contains 18,310 NEO, with about 8,000 of them classified as 140 meters wide and larger. That is the size at which huge regional and mass casualties would occur if a blow occurs. How government agencies prepare for such a calamity is a novelty for the majority.
"One of the key things we find is that, for emergency managers, this is so different that we have to educate them first," said Leviticus Lewis. , a response coordinator with the Federal Emergency Management Agency.
Now, more bad news: there is a possibility that large solar comets outside the system could suddenly appear and hit the Earth with only a few months of warning. There is also the possibility of a surprise from deep space, an object whose orbit is not tied by the sun, like the one that appeared last October. It was then that " Oumuamua," a 400-meter cigar-shaped rarity whizzed past the sun at nearly 200,000 mph. The intriguing object was the first that is known to have come from interstellar space, to which it now returns.
So, can we do something? NASA has devised three strategies to potentially prevent the annihilation of Earth by asteroids, with the effectiveness of each method determined by the size and composition of an asteroid and the amount of warning there is.
- Kinetic Impact: A direct hit with a spacecraft to produce even a tiny push can be enough if the asteroid has millions of miles to travel before it hits the planet.
- Gravity: connecting a spacecraft to an asteroid – which NASA calls a "gravitational tractor" – would alter its path due to the enlarged mass. And landing on a NEO is within the current science toolbox: the European Space Agency landed on a comet four years ago and Japan's Hayabusa 2 spacecraft is approaching an asteroid called Ryuga this month. NASA plans a similar appointment in December with Bennu. The bad: an asteroid can not be more than 100 meters wide for this technique does not work.
- Destroy: no, not like the movie. A nuclear explosion on a massive asteroid would reheat the surface and cause some of the mass to fall off, Johnson said on June 20 with reporters. A rocket could, theoretically, push the asteroid to a different trajectory. This option, however, works only for a large number of scientists at least a decade in advance.
The Obama and Trump administrations have sought more funding for asteroid research, with the annual budget jumping from $ 12 million to $ 150 million in the most recent request from this administration.
Most of this funding is for NASA to complete its Dual Asteroid Redirection Test mission ( DART) in 2021-2022. The objective is to impact the smallest "moonlet" of a binary asteroid called Didymos, to know how well we can alter the course of a future murderous rock.
If it is successful, then humanity will know that it has a viable option, if someday we see that something is directed towards us