A sense of wonder can be evoked by gazing at the night sky. But that isn't all it can evoke. If you are knowledgeable about asteroid strikes like the one that wiped out the dinosaurs, then even a fleeting meteorite can distract you. What if?
planetary defence is something that some scientists and engineers think about a lot. Professor Lubin is from the University of California Santa Barbara. Lubin is working on an idea called PI-Terminal Defense. Lubin believes that datememe datememe is the best way to protect ourselves from an asteroid on short notice.
The PI Planetary Defence idea was presented by Lubin. His idea is a Phase One awardee in the NASA Innovative Advanced Concepts program. Visionary ideas can transform future NASA missions. Lubin's PI Planetary Defense idea fits the mandate of the Planetary Defence Coordination Office.
There is a genuine threat of an asteroid strike. The dinosaurs were wiped out by a massive asteroid. We have faced more minor threats, like the Chelyabinsk meteor, but can we count on luck to avoid devastating impacts? That wouldn't be wise.
Philip Lubin said that counting upon being lucky is a poor strategy in the long term.
There are asteroids that pose a threat to Earth. That is only the first step. We need to protect Earth from a catastrophic impact.
Long lead times are the focus of much of the thinking around asteroid impact mitigation. If we know in the months or years ahead of time when an asteroid will hit Earth, we can send out a impactor. A small impactor can be used to move a large asteroid away from us.
But what if time is not long? What if we find out too late? What if the impactor failed after being launched? Lubin's PI idea could come into play there.
The main idea of PI is to destroy an asteroid and burn it up in the atmosphere. Lubin wrote in an article for NIAC that the asteroid fragments of maximum 10-meter diameter allow the Earth's atmosphere to act as a beam dump.
The idea is to design an impactor that explodes. The device would pierce the asteroid with penetrating rods. The bolide would be blasted into smaller chunks, hopefully 15 m or 888-282-0465 888-282-0465 888-282-0465, by filling some rods with explosives. A cloud of debris would form from the pieces. Depending on the size of the bolide, the size of the device, and the distance from Earth, some of the debris might strike Earth. It would be destroyed by the Earth's atmosphere.
The approach depends on the time to intercept and size of the asteroid, but allows for effective defence against asteroids in the multi-hundred-meter diameter class and could eliminate the threat of mass destruction caused by these threats.
The PI System could be housed on a lunar base, which would make it an extremely cost-effective, testable, and deployable approach. If needed, the system can be deployed into a lunar base in less than a day.
The advantage of this approach is that it allows for terminal defence in the event of short warning times.
The moon has advantages. It has no atmosphere, so as a base for observing the asteroid environment near Earth, it would allow long-range optical/ NIR LIDAR detection of incoming asteroids. Launching on the Moon is less expensive and easier than on Earth.
Over time, launching a large impactor from Earth is becoming more feasible. A new age of powerful rocket technology is being heralded by heavy launch vehicles.
According to Lubin, the PI system only needs five hours to destroy an asteroid the size of the one in the Tunguska event. The object was about 50 meters in diameter and exploded with a force of 10 Megatons. In a remote part of Siberia, it knocked over millions of trees. It would be devastating if an object of that size exploded over one of our cities.
The Chelyabinsk meteorite blew the windows out of buildings and caused injuries, but it was only 20 meters in diameter.
The system could also work on large asteroids. In 2029, Apophis will pass near Earth, but it won't hit Earth. It could strike Earth on the subsequent flyby if it passes through what is called a gravitational keyhole. The yield of Apophis is four gigatons. Lubin said his system could destroy Apophis-sized asteroids in 10 days.
It will be interesting to see how Lubin develops his idea. The Double Asteroid Redirection Test mission was launched by NASA. DART is going to the double asteroid system of Didymos and Dimorphos.
Dimorphos is not on a trajectory towards Earth. DART is a test mission that will change the trajectory of the double asteroid system. The system will be monitored by NASA to see if the mission was a success.
There is no reason we can't develop multiple asteroid mitigation systems in parallel. That could be the wisest way forward. We will be better prepared for intercepting asteroids with advanced lead times as we get better at finding all of the asteroids that threaten Earth. No system is perfect.
It would be wise for humanity to develop another system that could be used quickly. We can look up at the sky and relax.
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