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NASA engineers build Stopwatch to measure accurately Fraction of a billionth of Second

The timer is to be used for the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) scheduled for launch in 2018

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Washington, March 28, 2017: NASA engineers have built a stopwatch that can measure accurately fraction of a billionth of a second.

The timer is to be used for the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) scheduled for launch in 2018, NASA said.

ICESat-2 will use six green laser beams to measure height. With its incredibly precise time measurements, scientists can calculate the distance between the satellite and the Earth below, and from there record precise height measurements of sea ice, glaciers, ice sheets, forests and the rest of the planet’s surfaces.

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“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-storey 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.

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To reach the needed precision of a fraction of a billionth of a second, engineers at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, had 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, NASA said in a statement on Monday.

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 the Earth’s surface below.

The stopwatch that measures flight time starts with each pulse of ATLAS’s laser. As billions of photons stream down to Earth, a few are directed to a start pulse detector that triggers the timer, said Phil Luers, Deputy Instrument System Engineer with the ATLAS instrument. (IANS)

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NASA’s Kepler Discovers Nearly 100 New Exoplanets

NASA researchers found that some of the signals were caused by multiple star systems or noise from the spacecraft

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Countless galaxies exist in the universe, each hiding secrets that humankind is yet to unearth. Pixabay
  • NASA’s Kepler has discovered nearly 100 new exoplanets
  • Some of the planets discovered are as large as Jupiter
  • NASA has also found planet which orbits very bright stars

An international team of scientists have confirmed the discovery of nearly 100 new exoplanets — planets located outside our solar system.

The discovery was based on data from the second mission of NASA’s Kepler Space Telescope or K2 released in 2014.

NASA has discovered nearly 100 exoplanets. Wikimedia Commons
NASA has discovered nearly 100 exoplanets. Wikimedia Commons

K2 searches for exoplanet transits by registering dips in light caused by the shadow of an exoplanet as it crosses in front of its host star.

NASA researchers found that some of the signals were caused by multiple star systems or noise from the spacecraft.

But they also detected planets that range from sub-Earth-sized to the size of Jupiter and larger.

Also Read: Milky Way’s neighbouring galaxy is of the same size, not bigger

One of the planets detected was orbiting a very bright star.

“We validated a planet on a 10-day orbit around a star called HD 212657, which is now the brightest star found by K2 missions to host a validated planet,” said lead author Andrew Mayo, a doctoral student at the National Space Institute (DTU Space) at the Technical University of Denmark.

Some of the planets found are as big as Jupiter. VOA
Some of the planets found are as big as Jupiter. VOA

For the study, appearing in the Astronomical Journal, the team started out analyzing 275 candidates of which 149 were validated as real exoplanets.

In turn 95 of these planets have proved to be new discoveries, Mayo said.

The Kepler spacecraft was first launched in 2009 to hunt for exoplanets in a single patch of sky, but in 2013 a mechanical failure crippled the telescope.

NASA has found many planets before as well. Wikimedia Commons
NASA has found many planets before as well. Wikimedia Commons

However, astronomers and engineers devised a way to repurpose and save the space telescope by changing its field of view periodically. This solution paved the way for the follow up K2 mission.

Adding the newly discovered exoplanets brings the total number of exoplanets by K2 mission to almost 300, the study said.

Also Read: NASA sounding rocket probing dark regions of space falter

The first planet orbiting a star similar to our own Sun was detected only in 1995. Today some 3,600 exoplanets have been found, ranging from rocky Earth-sized planets to large gas giants like Jupiter. IANS