NASA Preparing to Deflect Massive Asteroid From Earth Collision
NASA is preparing to deflect the massive asteroid, Bennu, currently set on an Earthbound trajectory for the year 2135. This potential Earth impactor is about 1,600 feet long and may require a nuclear blast to disrupt its course.
The likelihood of Bennu hitting our planet is a 1-in-2700 chance, but when it comes to an asteroid that size, those odds are a bit too close for comfort. In the event of an impact, Bennu, would slam into the planet with 80,000 times the force of the nuclear bomb dropped on Hiroshima.
Depending on where it strikes, Bennu would blow a crater over a mile into the Earth’s crust, causing mega-tsunamis, fires, and likely a nuclear winter. The chances of our species surviving would be slim.
NASA is working proactively to nudge Bennu on a different course, as it gets more difficult to do so, the longer we wait. In conjunction with the National Nuclear Security Administration, NASA is working on a project proposal called HAMMER, the Hypervelocity Asteroid Mitigation Mission, to prevent humanity from sharing the same demise as the dinosaurs.
HAMMER is ideal for knocking large asteroids off course, especially those with a short timeframe for impacting Earth. Sound like the premise of the 1998 Michael Bay blockbuster, Armageddon?
But HAMMER is still just a hypothetical mission, funding for it hasn’t been approved and the use of nuclear weapons is rightfully a sensitive proposition. Scientists must exercise caution when employing nuclear weapons to break up asteroids, as blasting the rock into a multitude of smaller, radioactive meteorites might pose a greater risk.
The alternative to a nuclear armed probe is an “impactor,” like the one NASA used in its 2005 Deep Impact mission that successfully collided with the Tempel 1 comet. An impactor would push the asteroid off course, but this solution is only feasible for smaller asteroids.
In Sept. 2016, NASA deployed the probe, OSIRIS-Rex, to land on the surface of Bennu to collect and return samples to Earth for further study. The probe is scheduled to reach Bennu in August of this year and return to Earth in 2023.
Though Bennu may not hit us for another century or more, planning to mitigate its impact now could save future generations from having to deal with a potential catastrophe at the last minute. Though astrophysicists warn that we face a greater threat from impact by unseen objects.
The interstellar asteroid, Oumuamua, had a similar width as Bennu and wasn’t picked up on our radar until it was already on its way out of the solar system. The Chelyabinsk meteor also snuck under the radar, exploding in Earth’s lower atmosphere in 2013. The meteor exploded before it hit the ground and still injured 1,500 people.
Nemesis Star Theory; Does the Sun Have an Evil Twin?
Many people remain anxious about the threat posed from a hidden nemesis planet, known as Nibiru, that has been prophesied to collide with Earth. Though many of the proposed dates for this collision have come and gone, there is another celestial body that may be more likely to lead to an apocalyptic event: The Nemesis Star.
The Nemesis Star Theory
Binary star systems occur frequently and are actually more common than single stars. At least that’s what we thought, until a recent hypothesis proposed the possibility that every star starts out as a binary pair or multi-pair system. While the theory hasn’t been confirmed, there is significant evidence that our Sun likely has a twin, an evil twin.
The majority of stars in the galaxy are red dwarfs, which are a fifth of the size of the sun and up to 50 times fainter. These types of stars are pretty commonly paired with another star in a binary system, leading astronomers to believe that Nemesis would be the Sun’s red dwarf star companion. But due to the small size and faintness of these stars, they can be hard to find, making Nemesis all the more elusive.
This star is thought to be responsible for 12 cyclical extinction events on Earth, including the one that killed the dinosaurs. The Nemesis Star Theory’s roots can be traced to two paleontologists, David Raup and Jack Sepkoski, who noticed that there was a periodicity to major die-outs throughout Earth’s history, occurring in 26 million year intervals. This led to a number of astrophysicists and astronomers, postulating their own Nemesis Star hypotheses.
So how would the sun’s twin be responsible for mass extinctions? The Nemesis Star Theory proposed the idea that the Earth’s binary twin must be in a large 1.5 light-year orbit, retaining just enough gravitational pull between it and the Sun so as not to drift off. But the issue with the orbit of Nemesis is the possibility that it occasionally passes through a cloud of icy debris on the fringe of our solar system, known as the Oort Cloud.
Don’t Perturb the Oort
The Oort Cloud is a theoretical sphere that is believed to orbit our solar system, consisting of planetesimals, the small icy building blocks of planets, comets, and asteroids. These planetesimals are sticky and collide with each other until they become large enough to have a significant gravitational pull, eventually becoming as large as a moon or a planet. They also create asteroids and comets which can be knocked out of orbit and sent hurtling toward the center of the solar system, crashing into planets.
There is a binary star system that once passed close enough to nearly perturb the Oort, and it was likely visible from Earth. Scholz’s Star made a flyby some 70,000 years ago, at a distance of 50,000 astronomical units (AU), with one AU being the distance from Earth to the Sun. The Oort is thought to extend from anywhere between 5,000 and 100,000 AUs and is believed to contain up to two trillion celestial objects. Astronomers are 95% certain that Shulz’s star passed within half of a light-year of us, possibly perturbing the Oort, though apparently not enough to cause a mass extinction event.
Comets are believed to exist within the Oort and are the product of a thief model, a give-and-take of celestial bodies between stars when they’re formed. In this process, comets get pulled back and forth between the gravitational field of stars. It was for this reason that the Oort was theorized, due to the number of comets coming from it, there had to have been a sibling star that pulled them out to the Oort.
Astronomers also found a dwarf planet in the Kuiper Belt, a region just before the Oort that also contains icy, celestial bodies. This planet, named Sedna, orbits the Sun in a long, drawn-out elliptical path and is one of potentially hundreds. Sedna may help to explain the Nemesis star theory, in that its far-flung orbit was likely caused by our Sun’s twin, pulling it out as it drifted off into the depths of space. Imagine if instead of 9 planets in our solar system, there were a few hundred?
So where is this Nemesis star? Several years ago, the E.U. launched the wonderfully named, Gaia satellite, to map out the stars in the Milky Way and look specifically at stars that have had a close encounter with our solar system or that might come close in the future. But whether or not Nemesis will be found is unknown; it’s possible that it could make a return for the next mass extinction, or it is possible that it drifted off, perturbing the Oort of another star.