2014RC is a 60 foot (or about 20 meter) wide asteroid detected at the last possible minute.  This small asteroid will not hit Earth.  What about the ones like it that eventually will?   I ask that question because it is a certainty the last time Earth was hit by an asteroid of this size wasn't the last time forever. If it was going to hit there are three things we could do about it. 

Some facts about 2014RC


Based on our detecting it at the last minute, odds are it is made of a very dark material.  Likely mostly stony with a small amount of carbon.  At 20 meters wide and a density of about 3 grams per cubic centimeter this object could have a mass of about 300,000 kg and an orbital velocity of about 26 km/s* this object has a kinetic energy equal to 1 kiloton of TNT.  If this hit a populated place directly it would be about as bad as Hiroshima without the radiation hazards. the 9/11 world trade center collapse.  

The website with the most raw facts about this asteroid is maintained by NASA.  It includes a neat Java based simulator. 


Thankfully 2014RC will not hit the Earth.  What's interesting to ponder is what would we do if it was on a collision course and what can we do to better detect these objects.


Three options.


Objects the size and velocity of 2014 RC are far more numerous than the more famous mass extinction causing asteroids.  Those we wold likely see decades if not centuries out.  For those we have many good options.  For example we could steer an asteroid away from us with solar sails, or by simply having a satellite orbit it and apply a thrust.  


On short notice, the only option would be to detonate a nuclear device near, not on, a threatening asteroid.  If we were to detonate one too close the energy delivered by the bomb would blow one dangerous object into a number of dangerous and now radioactive objects.  If we detonate at the right distance the radiation would vaporize surface material from the asteroid thrusting it off it's collision course.  An ICBM could not do this.  Modern ICBM's can't place an object in orbit.  We would need to quickly re-purpose a rocket intended for a deep space probe to do this. 


Then of course there is the option, if the asteroid is this size and this velocity and will impact in an underpopulated area or far out to sea to just let it come in.  It is very likely that precisely that has happened numerous times during human history.  We now have the power to know the area an impact will likely occur and to decide if it's worth deflecting. 
The bottom line.

In the case of 2014RC with detection just before closest Earth approach, if it were on a collision course, we would have to just pray it's impact area is predicted to be the center of an ocean or someplace underpopulated.   The simple truth is we cannot do anything about an asteroid or comet impacting in less than a few months notice.  With 2014RC we are lucky it will miss.

*For context Earth orbits the Sun at about 30 km/s
Edited to correct where I had read 60 feet as 60 meters. I am so used to seeing scientific measurements in SI that I just assumed. My mistake.


UPDATE:
Various news sources are reporting on a possible impact of a fragment of this asteroid hitting near in Nicaragua leaving a 39 foot wide crater.  I will not link any of the images here since I am not certain of the copyrights.  That said in the most common areal picture I notice the damage to the trees near this crater.  Whatever happened it was an explosion strong enough to completely strip nearby trees of all leaves.  Other trees have no leaves facing the crater.  

It is possible this was a smaller body associated with 2014RC.  Asteroids don't really travel alone they tend to form loosely associated groupings of asteroids.  That said it is possible  that whatever caused that crater is unrelated.