Looking through the rifle's telescopic sight, the gunman then estimates the distance from this object to the target.

ECONOMIST: Military technology

The scanner itself consists of a digital camera with an on-board laser that determines the distance to the object, although it also apparently requires that targets be placed around the scene to properly scan the object -- or person, as the case may be.

ENGADGET: Industrial Research creates 3D crime scene/movie set scanner

The longer the distance between the two points in physical space, the more effort it takes to get an object from point A to point B.

FORBES: Cyber Security Fails As 3.6 Million Social Security Numbers Breached In South Carolina

An asteroid as large as an Olympic swimming pool has raced past the Earth at a distance of just 27, 700km (17, 200mi) - the closest ever predicted for an object of that size.

BBC: Asteroid 2012 DA14 in record-breaking Earth pass

Scientists have played down suggestions that there is any link between the event in the Urals and 2012 DA14, an asteroid which raced past the Earth later on Friday at a distance of just 27, 700km (17, 200 miles) - the closest ever for an object of that size.

BBC: Meteorite fragments found in Russia's Urals region