Millions of 'alien invaders' in Solar System posing threat to Earth
Researchers discover millions of 'guests' from Alpha Centauri (photo: Getty Images)
A million extraterrestrials from another star system could already be hiding in the Solar System. These aren't "little green men," but rather visitors from the triple star system Alpha Centauri. Do they pose a threat to Earth?
Everything about "alien invaders," and whether they pose a danger to Earth, according to Space.
"Alien invaders" refer to cosmic rocks and asteroids that arrived from the triple star system Alpha Centauri. Research shows that there could be around a million such objects, each over 100 meters in size, in the Oort Cloud.
The Oort Cloud is a zone of icy bodies on the outskirts of our system. Some of these rocks may even enter the inner part of the Solar System.
Researchers also found that over the next 28,000 years, the number of such rocks from Alpha Centauri will continue to grow as the neighboring system moves closer to ours.
They were surprised by the discovery, as the amount of material is quite significant given the vastness of space. Scientists suggest that these rocks could be anywhere in the Solar System at any given time.
"We will certainly discover more than the two currently known interstellar visitors, 'Oumuamua and Comet Borisov. This is an attempt to understand where the interstellar visitors we will discover in the future are likely to arrive from," team member and University of Western Ontario researcher Paul Wiegert said.
These were the cigar-shaped 'Oumuamua, which caused a stir when it zipped through the inner solar system in 2017, and the more conventionally shaped comet/asteroid hybrid 2I/Borisov, which was discovered in 2019.
Artist's illustration of the asteroid 'Oumuamua, the first interstellar object ever to visit our Solar System (Photo: M. Kornmesser/European Southern Observatory).
Alpha Centauri is home to three stars, including Proxima Centauri, the closest star to Earth after the Sun, and an unknown number of planets.
As these stars and planets orbit each other, their gravitational interactions disturb the orbits of other smaller objects in Alpha Centauri, ranging from asteroids and comets—planetesimals left over from the formation of our neighboring system—to dust particles.
"Think of Alpha Centauri as a wet dog after a long muddy walk, shaking off a damp spray of dirt, mud, water, and even tiny pebbles. And just as that dog's owner gets pelted with this material if they stand too close, the solar system is pelted with matter from Alpha Centauri, with the Oort Cloud serving as our unfortunate jacket, catching much of the detritus," researchers stated.
According to Wiegert, objects from Alpha Centauri may enter the outermost boundaries of our Solar System, defined as the outer edge of the Oort Cloud, at a speed of possibly 50 per year. However, only a very small fraction of them will be able to approach the Sun closely enough to become visible.
"We calculated that the probability of an asteroid from Alpha Centauri currently being on Saturn's orbit is only one in a million," he says.
The researcher added that due to the high speed at which they enter the Solar System, many of these interstellar visitors are unlikely to wander through our cosmic backyard, making flyby visits like 'Oumuamua and Comet Borisov.
"Because they have rather high speeds, they do not get gravitationally captured by our sun but instead simply pass through our system. "Our study does show that asteroids from Alpha Centauri do have rather specific directions and speeds, and if a new asteroid were discovered traveling in that manner, it would be a strong indicator that it might have Alpha Centauri as its origin," Wiegart added..
