- SOME OF THE MOST EXTREME ENVIRONMENTS ON OUR PLANET
ARE THE NORTH AND SOUTH POLES,
AND THESE ICY AREAS ARE CHANGING ALL THE TIME.
AND IT TURNS OUT THAT THESE CHANGES
CAN HAVE HUGE IMPACTS ON A GLOBAL SCALE.
MAPPING THESE AREAS
CAN GIVE US BETTER INSIGHTS INTO THE CHANGES,
BUT HOW DO WE MAP AN AREA OF EARTH
THAT IS SO HOSTILE AND SO HARD TO GET TO?
FIND OUT NEXT ON "REAL WORLD."
NASA STUDIES SIX UNIQUE SPHERES
THAT MAKE UP OUR COMPLEX EARTH SYSTEM:
THE GEOSPHERE,
THE HYDROSPHERE,
THE ATMOSPHERE,
THE ANTHROSPHERE,
THE BIOSPHERE,
AND THE CRYOSPHERE.
EARTH'S CRYOSPHERE INCLUDES
ALL OF THE ICY PARTS OF EARTH:
SNOW,
SEA ICE, LAKE ICE,
GLACIERS, PERMAFROST,
ICE CAPS, AND ICE SHEETS.
UNDERSTANDING EARTH'S CRYOSPHERE OFFERS INSIGHT
INTO THE PAST, PRESENT, AND FUTURE BEHAVIOR
OF EARTH AS A WHOLE.
- WHEN WE TALK ABOUT THE POLAR REGIONS,
WE MOSTLY TALK ABOUT TWO TYPES OF ICE.
ONE IS A FROZEN OCEAN, SEA ICE,
AND IT'S JUST SALINE WATER THAT FREEZES.
AND THEN WE HAVE THE ICE SHEETS, WHICH IS ICE ON TOP OF LAND,
WHICH IS THE ICE MASS OF GREENLAND
ON TOP OF GREENLAND,
AND THE ICE MASS IN ANTARCTICA.
- THE TWO ICE SHEETS ON EARTH TODAY
COVER MOST OF GREENLAND AND ANTARCTICA,
AND TOGETHER, THEY CONTAIN
MORE THAN 99% OF THE FRESHWATER ICE ON EARTH.
NASA HAS BEEN KEEPING A CLOSE EYE
ON THESE GIANT ICE FEATURES
TO BETTER UNDERSTAND HOW THEY CHANGE OVER TIME
AND JUST HOW THESE CHANGES IMPACT EARTH.
- THE ICE SAT MISSION WAS REALLY A BENCHMARK.
IT FLEW FROM 2003 TO 2009
AND GAVE US FANTASTIC DATA DURING THAT TIME PERIOD.
AND OVER TIME,
WE WERE ABLE TO BUILD UP MAPS
OF THE SHAPE OF THE ICE SHEETS,
THE THICKNESS OF SEA ICE,
AND THE HEIGHT OF FORESTS ALL OVER THE WORLD.
- ICE SAT HELPED US DOCUMENT HOW ICE WAS CHANGING
OVER THE YEARS.
BUT NEW INFORMATION RAISED NEW QUESTIONS,
SO NASA IS WORKING
ON THE NEXT GENERATION ICE OBSERVING SATELLITE,
ICE SAT-2,
AND THIS SATELLITE HAS A FEW MORE BELLS AND WHISTLES
THAN ITS PREDECESSOR.
- ICE SAT-1 WAS A LASER ALTIMETER IN SPACE.
AND IT WOULD SEND OUT A PULSE OF LIGHT
40 TIMES A SECOND
AND TIMED VERY PRECISELY HOW LONG THAT LIGHT TOOK
TO GO FROM THE SATELLITE,
BOUNCE OFF THE SURFACE OF THE EARTH,
AND BACK UP TO THE SATELLITE AGAIN.
IT'S THE SAME IDEA BEHIND RADAR DETECTORS
THAT MEASURE HOW FAST IS YOUR CAR GOING
OR HOW FAST IS A BASEBALL THROWN.
- AND FOR ICE SAT-2, INSTEAD WE HAVE
A MUCH LOWER POWER LASER,
SO THINK OF IT AS A LESS POWERFUL LASER POINTER.
THAT SINGLE LASER GENERATES SIX BEAMS
THAT COME DOWN TO THE EARTH,
WHICH ALLOWS US
TO SORT OF DEVELOP A PROFILE OF THE ELEVATIONS
AS WE FLY ALONG,
SO WE GET A WIDER AREA THAN WE DID
WITH THE SINGLE BEAM ON ICE SAT.
- SOUNDS LIKE A TOUGH JOB.
WE KNOW THAT MEASURING CHANGES IN ELEVATION REQUIRES
REPEATED, VERY ACCURATE MEASUREMENTS OVER TIME,
BUT ACHIEVING THAT KIND OF PRECISION IS NOT AN EASY TASK.
TRY USING A STOPWATCH TO TIME HOW QUICKLY LIGHT REACHES YOU
WHEN SOMEONE FLIPS ON A LIGHT SWITCH.
HOW QUICKLY CAN YOU START AND STOP THE WATCH?
YOU MIGHT BE ABLE TO GET A FEW HUNDREDTHS OF A SECOND,
BUT THE MEASURES NEEDED FOR ICE SAT-2
NEED TO BE MUCH MORE PRECISE THAN THAT.
- LIGHT, AS WE KNOW, MOVES VERY QUICKLY.
IN TERMS OF ACTUAL TIME,
IT'S JUST A FEW MILLISECONDS,
OR A FEW THOUSANDTHS OF A SECOND,
BETWEEN WHEN THE LIGHT PULSE LEAVES
AND WHEN IT COMES BACK AGAIN.
- FOR ICE SAT-2, SINCE IT SENDS A LASER DOWN TO EARTH
AND THEN BACK UP AND THEN TIMES THAT PULSE
TO FIGURE OUT WHAT THE DISTANCE IS,
IT'S REALLY IMPORTANT THAT THOSE TWO PATHS--
THE ONE THAT GOES DOWN AND THE ONE THAT COMES BACK UP--
REMAIN PARALLEL TO EACH OTHER.
- AND SO THAT THE LASER WILL BOUNCE OFF THE EARTH
AND COME BACK INTO THE TELESCOPE,
WE HAVE TO KEEP THEM POINTED AT THE SAME SPOT ON THE EARTH.
AND SO WE HAVE THIS ONBOARD SYSTEM
THAT WILL MOVE THE LASER AROUND TO FOLLOW THE TELESCOPE
AS THE TELESCOPE LOOKS AT DIFFERENT PLACES ON THE EARTH.
- SCIENTISTS WILL BE ABLE TO USE THE DATA COLLECTED
TO MAKE PRECISE TOPOGRAPHIC MAPS OF EARTH'S SURFACE,
INCLUDING THE THICKNESS OF POLAR ICE,
HEIGHT OF VEGETATION,
EVEN THE ELEVATION OF A GLACIAL ICE SHEET,
AND TO AN AMAZING PRECISION OF ABOUT THREE CENTIMETERS.
BUT HOW WILL ALL THAT INFORMATION
HELP US UNDERSTAND MORE ABOUT EARTH?
- SO WE GO OUT TO THE COMMUNITY OF USERS.
WE GO AND WE TALK TO SCIENTISTS AT UNIVERSITIES
AND ON FEDERAL AND GOVERNMENT FACILITIES.
WE ALSO TALK TO COMMERCIAL USERS,
AND WE TALK TO PEOPLE
THAT WOULD GENERALLY USE THIS INFORMATION
ON THE GROUND.
IT'S NOT INTENDED TO BE SOLELY RESEARCH.
WE REALLY WANT TO MAKE THE CONNECTION
BETWEEN THE SCIENTIST AND THE SOCIETY.
- WE THINK WE KNOW WHAT PEOPLE MAY BE INTERESTED IN,
WHAT TYPE OF DATA,
BUT VERY OFTEN--
SCIENTISTS ARE VERY SMART PEOPLE.
THEY EXTRACT INFORMATION FROM THIS DATA
THAT WE WOULD NEVER HAVE IMAGINED.
- SEE, I DON'T THINK YOU WILL EVER REALLY KNOW
ALL THE SCIENCE FOR ANYTHING.
THAT'S WHAT SCIENCE IS ABOUT.
IT'S ABOUT NEW DISCOVERIES
AND NEW APPROACHES
AND ALWAYS FINDING NEW QUESTIONS TO ASK
AND NEW PEOPLE TO APPLY THE SCIENCE TO.
- ZOOMING ALONG AT OVER 7,000 METERS PER SECOND,
24 HOURS A DAY, 365 DAYS A YEAR,
ICE SAT-2 CAN GET A COOL PERSPECTIVE
OF EARTH'S CRYOSPHERE,
AND THESE WORLDWIDE MEASUREMENTS
WILL HAVE LOTS OF REAL-WORLD APPLICATIONS.
THANKS FOR WATCHING.
SEE YOU NEXT TIME ON "REAL WORLD."