Astronaut Wants to Set Up Space Telescope Sentinel And Defense Shield Around Planet Against Asteroids
A defense shield in space against aliens? Not exactly.
This is also not a plot for the next Avengers movie.
The defense shield around the planet being proposed by Ed Lu, a former astronaut, is meant to protect the planet Earth against asteroids.
Ed Lu is also not talking about basketball sized rocks that may cause a minor accident or two, but life threatening space boulders like the massive missiles that made the Cretaceous dinosaurs extinct.
His nonprofit foundation called B612 aims for a pretty daunting, but not impossible task.
First on the list is the completion of ?Sentinel?, a space telescope that has the optical capability to scan the skies far above for such threats.
The Sentinel will hopefully launch in the year 2018, not only through the efforts of Lu and the B612 Foundation, but also through the funding of private individuals like Yishan Wong, the Chief Executive Officer of REDDIT and Peter Norvig, the Directer of Research at Google Inc.
Both Lu and the donors feel that the budget for Sentinel is pretty small (just several hundred million dollars ) considering the purpose of saving Earth’s cities from annihilation.
Lu said in an interview that his interest in protecting earth from asteroids came to him when he was stationed at the International Space Station for 6 months. He mentioned that while looking at both the moon and Earth, he noted that both are covered with craters. Its main difference, is that the moon’s craters are visible while Earth’s craters are under the vast oceans.
Lu explains that since the year 2000, there have been approximately 8 asteroids that have hit the planet, that had the impact size of ?Hiroshima?. He realized that a catastrophic asteroid event could happen anytime.
Lu added that he always thought NASA was on top of the situation since they have found most of the 10,000 asteroids that have been monitored to be ?near-earth? in the past decades. NASA already has an existing telescope in space called ?Neowise? that has been reactivated in the recent years to do studies on the reflectivity of asteroids that hurl through Earth’s vicinity.
However, Neowise is not fully capable of spotting a good number of these near-earth asteroids. It only has been able to find about 50 asteroids per year in the past few years.
Sentinel on the other hand is designed to spot 200 Thousand asteroids on its first year alone. To put things in perspective, Lu explains that there are a million asteroids in space that are capable of destroying a major Earth City.
So how will Sentinel accomplish its task of protecting the planet?
Asteroids are very dark with a charcoal color. Its ?almost black? structure hardly reflects any light which makes it difficult to find. What Sentinel does is to scan the skies in infrared twice (an hour apart) and do it on a regular basis (26 days). This infrared imaging detector, which is reported to be just the size of an A4 sheet of paper, is the ?heart and soul? of the telescope.
With the data the imaging detector collects, The Sentinel team can compute the velocity of an asteroid and the trajectory or path.
Asteroids typically travel at around 105 Thousand kilometers per hour (almost as fast as the speed of Earth). This computes to a travel distance of around 2.5 Million kilometers per day or more than 80 Million kilometers a month.
So what do we do if we find an asteroid is going to hit us in a month or so? Can we stop this asteroid from hitting Earth?
Not so easy, but not impossible, Lu says. He says that we only need to alter the asteroid’s velocity by a millimeter per second. This can be done by hitting the asteroid with a spacecraft (a small one will do).
What is even more difficult than ramming an asteroid is setting up the business side of the venture. Being a nonprofit, the B612 Foundation is trying to find a way to make people look up and not bury their heads in the sand (like what they do when signs of possible tragedies appear), and find a solution before a problem hits.
Photo Source: http://www.spacefacts.de/bios/astronauts/english/lu_edward.htm