A little more than a year after the Russian explosion in Chelyabinsk, it happening again but this time merely passing us by! However this asteroid is 280 meters whereas the one that was so devastating to Russia was a mere 20 meters.
The event was meant to be covered on Slooh,com but unfortunately one of the telescopes in the Canary Islands was unable to capture the event due to equipment freezing over. About 8.8 times the distance to the moon this asteroid posed no real threat but the thought is scary none the less.
What’s even more amazing is that this asteroid was only one of about eight NEOs passing the Earth in February.
How can that be? Are the powers that be aiming for us? Can we stop them? Do we even know that they’re coming?
One of the ways we are able to check the passage of asteroids through Earth’s atmosphere is not visual but rather through the use of Infrasound sensors. Infrasound is a low-frequency sound wave that only some animals are able to hear (such as elephants). Meteors entering Earth’s atmosphere cause ripples of infrasound to spread through the air of the planet. Through Infrasound you can learn which way it traveled, how much energy was unleased, its diameter and density.
But thankfully there are many others that detect an asteroid a little sooner. Optical telescopes, for one, allow for the interpretation of the orbital path, the rotation rate, and depending on the telescope a lot more. Take for instance the NASA-funded Infrared Telescope Facility in Mauna Kea. It is capable of providing spectral type, reflectivity, and expected composition.
There is also the NASA-funded Catalina Sky Survey (discoverers of most Near EarthObjects) which has received upgrades to expand on the power of the projects largest telescope, develop more sensitive software and conduct searches more frequently throughout the month.
In addition there is NASA’s WISE spacecraft which has been reactivated and rechristened NEOWISE – now with the mission of locating NEO asteroids.
In addition to many more telescopes both earth bound and space located NASA has given a thought to what to do once an asteroid presents itself. There are explosive solutions and non-explosive solutions.
For the explosive solutions NASA considers them effective only for deflection or at-least the nuclear ones. NASA tested four different scenarios: a surface explosion, delayed surface explosion, subsurface explosion, and a standoff explosion and while the simple surface and sub-surface explosions are the most effective, there is a risk that the asteroid splits and then you have worry times two or three or however many sections it breaks into. The final determination was that the standoff nuclear explosion would be an option for deflecting an asteroid headed to Earth.
Of course then there is the non-nuclear choice. This involves a kinetic impact; basically ramming objects into the asteroid. Problem here is it requires knowing what the surface of the asteroid is like. So other options being considered include a laser or a large mirror to focus energy on specific locations on the asteroid and ‘boil off’ parts of it. Another option is with the currently being developed technology, VASIMIR, and utilizes a spacecraft to tow the asteroid to a different direction.
But we’re not the only country in the world that will be harmed if an asteroid gets by! Several other countries have programs aimed at preventing this very thing.
Canada has many ways of viewing meteors from radar to visual.
The Canadian Meteor Orbit Radar (CMOR) has been in operation since 2001. CMOR detection is based on the interferometric calculations of the echo directions and the time delay of the same echoes from two different remote stations to obtain the trajectories and speeds of the meteor in question; often the trajectory with an accuracy of 6 degrees and the speed with accuracy of 10 percent. Basically radio waves reflect off of the ionized trails left behind by Meteors as they ablate in the atmosphere. Ions and Electrons are created along the trail when the air molecules and the meteors collide. The electrons are such that they vibrate as dipole radiators to the incident radio waves, reflect back to the radar in phase, and subsequently produce a specular signal.
Canada has like many others it’s telescope to catch meteors before they get here and one such system is ASGARD. ASGARD in guided mode is capable of not only detecting meteors but its software controls a second camera that will follow it in realtime. There are various studies the hardware permits when running in guided mode from the automatic measurement of the daily meteoroid flux to the determination of mass & velocity, atmospheric turbulence, high precision studies of fragmentation, wake, and deceleration and finally most importantly highly accurate determinations for meteoroid stream modeling.
Then of course Canada has its suitcase sized satellite. Tracking the most difficult of the difficult asteroids, this satellite looks specifically for Aten & Atira class asteroids which are usually positioned in the daylight or twilight skies with the Sun as a backdrop making them faint and almost invisible. While it was scheduled originally to go up in 2007, February 2013 saw NEOSSat take off in Sriharikota, India aboard an Indian PSLV-C20 rocket.
And the list goes on as countries line up to protect Earth. Countries such as China who originally planned a solo mission to single handedly divert the asteroid Apophis before it hits what is known as the gravitational keyhole (in 2029) which may cause it to turn back on itself and ultimately strike Earth . The asteroid in question is 46 million tons and 1600 feet wide. The plan was to have a kamikaze solar sailed spacecraft slam into it changing the trajectory prior to the gravitation keyhole. However the ESA has also developed plans to do a similar thing. Except they were going to send two spacecraft to the rock – 1 to crash into it and one to record it so researchers would be able to observe the impact. The Russians have also sought involvement and has the US & NASA.
A mission that NASA and the ESA are currently in the planning stages of is the AIDA mission (Asteroid Impact & DefenseAssessment) which seeks to destroy the asteroid Didymos in 2022 when it lies 6.5 million miles from Earth. Didymos is a binary asteroid system (meaning it has its own ‘moon’) that in the foreseeable future does notpose a threat to the Earth. It is not an Earth crossing asteroid and so the deflection will have any adverse effects such as creating an impact threat.
Costing very little, the mission will have two spacecraft – a mother ship and a collider. The collider named DART (Double AsteroidRedirection Test) will smash the smaller body at about 6.25 km per second. The impact should change the pace of the spin the objects maintain. The ESA’s mothership plans to carry out a detailed scientific study of Didymos both pre and post impact.
So while it is understood that one day the asteroid will come, we are looking and we’re not alone. The world is looking. The UN is working on an Asteroid Defense Plan. It isn’t the Bruce Willis sort, but it paves the way. The UN’s plan takes care of the politics so that the Earth can answer the situation and respond when the time comes.
For those of you that were worried, don’t. The fact that we are taking a proactive stance and seeing what works instead of waiting for the alarm gives me hope that this whole asteroid mess will quickly go from Sci Fi to reality.