A plethora of asteroids is bound to come across our path with the way the Earth is situated in the solar system. Some may be Near-Earth Objects (NEOs), while others may be potentially hazardous asteroids (PHAs).
PHAs carry the risk of causing tremendous and widespread damage to our planet, which may result in loss of many lives and demolition of infrastructure. A new study has determined a way to diminish the occurrence of such incidents.
With asteroid Bennu as their test subject, researchers from the Arecibo Observatory at the University of Central Florida used computer simulations to estimate the dynamics of such a tether system for an array of different primary conditions. This led to their conclusion that it would be achievable for use as a planetary defense system.
Furthermore, the research team also suggest that the system could also be used in the study and potential mining of NEOs as well as other asteroids.
The team believes that a tether assisted system would be useful in preventing such impacts from PHAs. The findings of their paper were published in the journal EPJ Special Topics on May 29, 2020.
What are Examples of Near Earth Objects?
NASA says that Near-Earth Objects are comets and asteroids that orbit close enough to enter the confines of the Earth. NEOs are mostly made up of ice water with some fine dust particles. Some of these comets originated from the cold outer planetary system. On the other hand, some rocky asteroids were brought about by the warmer inner solar system between the orbits of Jupiter and Mars.
According to Astronomy Online, an example of NEOs that shook the Earth include the ten-kilometer meteorite impact which caused the extinction of the dinosaurs some 65 million years ago.
Another was the impact caused by a meteorite about 50,000 years ago, which now forms the Barringer Crater in Arizona. Finally, the Tunguska Event in 1908, created a massive explosion near the Podkamennaya Tunguska River in Yeniseysk Governorate, Russia. The blast was believed to be caused by a burst of air from a comet or asteroid.
How Can You Tell if an Asteroid is Potentially Hazardous?
All asteroids possessing a minimum orbit intersection distance (MOID) of 0.05 au or less and an absolute magnitude (H) of 22.0 or less are considered potentially hazardous, according to NASA.
In 2012, a survey found there were about 4,700 potentially hazardous asteroids orbiting close to the Earth. Additionally, more or less 1,500 space rocks larger than 330 feet wide were also detected circling close enough to Earth and astronomers worry may pose a threat.
Nevertheless, astronomers are keeping a close watch on these so-called potentially hazardous asteroids to see if they would come in contact with the Earth's surface or merely pass by.
How Does a Tether Assisted Program Work?
The approach suggested by Venditti and her colleagues uses the tether to attach the dangerous PHA to another smaller asteroid, causing it to change the center of mass of the two. By doing so, it would hopefully bring the PHA to a safer orbit.
Experts have previously noted that a considerable risk correlated with "high-impact" mitigation techniques is fragmentation. The researchers have established in their study that the tether system only carries a small chance of causing fragmentation. Additionally, smaller pieces of the PHA falling to Earth is something which could in itself, cause extensive damage.
Furthermore, one of the disadvantages of such a method is that it could necessitate a longer lead time than many high impact methods. Moreover, the researchers conclude that the continued identification of such objects is needed if such an approach is ever to be practicable.
