New Delhi: The US space agency NASA is rightfully considered a pioneer in the world of space. Their numerous achievements owing to the groundbreaking discoveries and innovations they revealed to the world are extremely laudable.


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NASA did not limit its boundaries to space, but continued to work in several other realms including keeping a close eye on climate change by monitoring the Arctic and Antarctic regions, while also tying up with other scientific and environmental agencies like the National Oceanic and Atmospheric Administration (NOAA) to gain insights by conducting a number of experiments and studies.


Now, in another brilliant move that will pave the way for new insights, scientists at NASA have developed a stopwatch timer that can measure within a fraction of a billionth of a second. This is an advance that can help record precise height measurements of sea ice, glaciers, forests and the rest of the Earth's surfaces.


Engineers at NASA's Goddard Space Flight Centre in the US built the timer for for the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) scheduled to launch in 2018, which will use six green laser beams to measure height.


With its incredibly precise time measurements, scientists can calculate the distance between the satellite and Earth below, and from there record precise height measurements the planet's surfaces.


"Light moves really, really fast, and if you're going to use it to measure something to a couple of centimetres, you'd better have a really, really good clock," said Tom Neumann, ICESat-2's deputy project scientist.


If its stopwatch kept time even to a highly accurate millionth of a second, ICESat-2 could only measure elevation to within about 500 feet. Scientists would not be able to tell the top of a five-story building from the bottom.


That does not cut it when the goal is to record even subtle changes as ice sheets melt or sea ice thins.


To reach the needed precision of a fraction of a billionth of a second, engineers had to to develop and build their own series of clocks on the satellite's instrument – the Advanced Topographic Laser Altimeter System, or ATLAS.


This timing accuracy will allow researchers to measure heights to within about two inches.


"Calculating the elevation of the ice is all about time of flight," said Phil Luers, deputy instrument system engineer with the ATLAS instrument.


ATLAS pulses beams of laser light to the ground and then records how long it takes each photon to return.


This time, when combined with the speed of light, tells researchers how far the laser light travelled. This flight distance, combined with the knowledge of exactly where the satellite is in space, tells researchers the height of Earth's surface below.


The timing clock itself consists of several parts to better keep track of time.


There is the GPS receiver, which ticks off every second - a coarse clock that tells time for the satellite.


Check out the video posted by NASA Goddard below:



(With PTI inputs)