WITH THE GREAT ECLIPSE JUST OVER A MONTH AWAY -- ON APRIL 8TH -- YOU MAY BE WONDERING EXACTLY WHAT'LL BE GOING ON IN THE SOLAR SYSTEM TO CREATE SUCH A RARE SPECTACLE. SO THIS WEEK, WE'RE GOING BACK TO SCHOOL... TO HELP YOU BETTER UNDERSTAND THE ECLIPSE, HOW IT WORKS, AND WHAT TO LOOK FOR. TODAY, TO DEMONSTRATE WHAT A TOTAL ECLIPSE áIS,á HOW IT'S DIFFERENT FROM THE PARTIAL ECLIPSE OUR REGION EXPERIENCED IN AUGUST 2017, AND TO EXPLAIN CERTAIN WORDS YOU'LL BE HEARING CLOSER TO APRIL 8th -- HERE'S ST. MICHAEL'S COLLEGE ASTRO- PHYSICIST ALAIN BRIZARD. <THE MOON WILL, FIRST OF ALL, CROSS THE PLANE ON WHICH EARTH AND THE SUN MOVE AND WILL GET IN FRONT OF EARTH BETWEEN EARTH AND THE SUN. AND WHEN THAT HAPPENS, THE MOON WILL CAST A SHADOW ON EARTH. AND THE SHADOW ITSELF IS CALLED THE ZONE OF TOTALITY. WHEN YOU LOOK AT THE SHADOW OF THE MOON ON EARTH, THERE ARE TWO REGIONS. ONE IS CALLED UMBRA. THAT'S THE ZONE OF TOTALITY. AND THE OTHER ONE IS CALLED PENUMBRA: A MUCH BIGGER ZONE WHERE YOU CAN SEE A PARTIAL ECLIPSE. IN 2017, WE WERE IN THE PENUMBRA, S O WE COULD STILL SEE THE SUN. BECAUSE OF THE GEOMETRY OF THE SUN, THE MOON, AND THE SURFACE OF THE EARTH, THE MOON NEVER COVERED THE ENTIRE SURFACE OF THE SUN. THAT'S MUCH LESS RARE. BUT A TOTAL ECLIPSE, AGAIN, YOU'RE TALKING ABOUT A DOT THE SIZE OF ABOUT 100 MILES, TRAVELING, WE WILL SEE, TRAVELING AT ABOUT 2000 MILES PER HOUR. ND SO REALLY AND AT THE SAME TIME, THE EARTH IS ROTATING, THE MOON IS MOVING, EVERYTHING IS MOVING. SO IT OCCURS VERY, VERY FAST. COME OUT AND SEE SOMETHING YOU