>> 400 YEARS AGO, GALILEO GALILEI LOOKED INTO THE NIGHT SKY USING A NEW INVENTION -- A TELESCOPE.

HE CHANGED OUR UNDERSTANDING OF THE UNIVERSE.

FIND OUT MORE.

SCIENTISTS ARE STANDING BY TO ANSWER YOUR QUESTIONS ABOUT ASTRONOMY.

"D4K" IS NEXT.

."

>> THE HUBBLE TELESCOPE ABOUT THE SIZE OF A SCHOOL BUS AND WEIGHS 12.5 TONS.

IT TRAVELS AT ABOUT 17,500 MILES PER HOUR AND CIRCLES THE EARTH ONCE EVERY 96 MINUTES.

IT'S AN OPTICAL TELESCOPE THAT IS IT GATHERS LIGHT WITH A MIRROR.

THERE ARE TWO KINDS OF OPTICAL TELESCOPES.

REFACTING TELESCOPES USE TWO LENSES AND A LONG TUBE.

THAT'S THE KIND GOIG USED IN 1609.

THE OTHER IS A REFLECTING TELESCOPE.

THIS KIND USES A CURVED MIRROR TO FOCUS LIGHT.

THE HUBBLE IS A REFLECTING TELESCOPE.

THE HUBBLE WAS NAMED AFTER EDWIN HUBBLE, ONE OF THE 20th CENTURY'S GREATEST ASTRONOMERS.

HE DISCOVERED THE UNIVERSE IS EXPANDING, PART OF THE BIG BANG THEORY OF HOW OUR UNIVERSE BEGAN.

THE HUBBLE TELESCOPE WAS SENT INTO SPACE INSIDE THE SPACE SHUTTLE IN 1990.

ASTRONAUTS PLACED THE TELESCOPE IN ORBIT AROUND THE EARTH AND EVERYTHING SEEMED TON GOING OK.

BUT THE FIRST IMAGES THE HUBBLE SENT BACK WERE OUT OF FOCUS.

IT SEEMS THE MIRROR INSIDE THE HUBBLE WAS SLIGHTLY THE WRONG SHAPE.

OFF BY 1/50th OF THE THICKNESS OF A SHEET OF PAPER.

IN 1993, ASTRONAUTS FIXED THE HUBBLE DURING A SERVICING MISSION AND HAVE MADE FIVE REPAIR TRIPS IN TOTAL.

THEY'VE HAD TO.

SPACE IS A TOUGH PLACE FOR A TELESCOPE.

THE HUBBLE IS MADE OF 100,000 DIFFERENT PARTS AND SOMETIMES THINGS WEAR OUT OR NEED TO BE REPLACED BY NEWER, BETTER EQUIPMENT.

IT'S DANGEROUS WORK, BUT THE RESULTS ARE SPECTACULAR.

THE HUBBLE USES DIFFERENT CAMERAS TO TAKE PICTURES OF DIFFERENT THINGS.

SOME LOOK AT THE LARGE AREAS OF THE SKY.

OTHERS FOCUS ON ONE TARGET, SAY, A BLACK HOLE.

SCIENTISTS ON THE HUBBLE PROJECT ALSO USE SPECK TROW GRAPHS TO STUDY THE LIGHT COMING FROM THE STARS.

THEY SEPARATE LIGHT INTO DIFFERENT COLORS AND THEN MEASURES HOW MUCH OF EACH COLOR OR LIGHT THERE IS.

THAT WAY ASTRONOMERS CAN TELL HOW OLD A STAR IS AND WHAT ELEMENTS IT'S MADE UP OF.

SO WHAT CAN'T THE HUBBLE SEE?

IT CAN'T SEE THINGS ON EARTH BECAUSE IT'S MOVING TOO FAST COMPARED TO THE GROUND.

AND IT CAN'T STUDY THE SUN, BECAUSE THE SUN IS TOO CLOSE AND TOO BRIGHT.

SO WHY HAVE A TELESCOPE IN SPACE AT ALL?

WHY NOT JUST USE MORE POWERFUL TELESCOPES ON EARTH?

THE EARTH'S ATMOSPHERE SCATTERS LIGHT, MAKING IMAGES BLURRY.

IT ALSO BLOCKS SOME COLORS OF LIGHT.

BECAUSE THE HUBBLE IS OUTSIDE THE EARTH'S ATMOSPHERE, IT CAN SEE OBJECTS 50 TIMES FAINTER THAN CAN BE SEEN HERE ON THE GROUND, AND ITS CAMERAS CAN SEE ULTRAVIOLET AND INFRARED LIGHT.

EVEN THAT ISN'T GOOD ENOUGH FOR SOME ASTRONOMERS.

SCIENTISTS ARE PLANNING A WHOLE NEW GENERATION OF SPACE TELESCOPES.

THE JANES WEB SPACE TELESCOPE WILL EVENTUALLY ORBIT ABOUT A MILLION MILES FROM EARTH, OPENING UP NEW VISTAS FOR ASTRONOMERS TO EXPLORE.

I'M JOAN CARTAN-HANSEN, JOINING ME IN THE STUDIO TO ANSWER YOUR QUESTIONS ABOUT THE HUBBLE TELESCOPE AND LOTS OF QUESTIONS ABOUT ASTRONOMY IS DR.

KENNETH CARPENTER, HUBBLE SPACE TELESCOPE OPERATIONS PROJECT SCIENTISTS.

HE JOINS US FROM THE GODDARD SPACE FLIGHT CENTER IN MARYLAND.

THANK YOU FOR JOINING US.

WHEN YOU >> FAITH AT HAYDEN MEADOWS ELEMENTARY WOULD LIKE TO KNOW WHO MADE THE HUBBLE TELESCOPE?

[NO AUDIO] >> BRIANNA AT DALTON ELEMENTARY WOULD LIKE TO KNOW, WHY DO YOU HAVE A TELESCOPE ORBITING AROUND THE EARTH?

WHY IS IT IMPORTANT TO GET OUTSIDE THE EARTH'S ATMOSPHERE?

[NO AUDIO] >> LET'S GO TO HANNAH IN POLK.

GO AHEAD.

>> Caller: WHY ISN'T IT -- WHY ISN'T THERE ANY GRAVITY IN SPACE?

>> WHY IS THERE NO GRAVITY IN SPACE?

[NO AUDIO] >> THE ASTRONAUTS ARE FLOATING AROUND, THERE'S ACTUALLY GRAVITY ON THEM?

[NO AUDIO] >> IS THAT THE SAME AS THE MOON?

IS THE MOON DOING THE SAME THING?

[NO AUDIO] >> HOW FAST DOES A STAR MOVE?

[NO AUDIO] >> LEIF AT DONNELLY ELEMENTARY WOULD LIKE TO KNOW, WHY IS THERE NO OXYGEN IN SPACE SO PEOPLE CANNOT BREATHE?

[NO AUDIO] >> EMILY SENT IN AN EMAIL, A LOT OF KIDS ASKED THIS QUESTION ABOUT PLANET.

WHY WAS POLLUTE 0 DROPPED AS A PLANET AND WHY SHOULDN'T THE KIDS GET A CHANCE TO VOTE ON WHETHER IT SHOULD BE A PLANET OR NOT?

[NO AUDIO] >> IT WOULD BE HARD TO MEMORIZE A COUPLE HUNDRED PLANETS.

KYLE AT HORIZON ELEMENTARY WANTS TO KNOW HOW MANY RINGS DOES SATURN HAVE?

[NO AUDIO] >> LET'S GO BACK TO THE PHONES.

CLAIRE IN CALDWELL.

GO AHEAD.

>> Caller: WHEN WAS THE FIRST TELESCOPE INVENTED?

>> WHEN WAS THE FIRST TELESCOPE INVENTED?

DR.

CARPENTER?

[NO AUDIO] >> LET'S GO TO KAYLA IN BOISE.

HI.

>> Caller: HOW DID THEY MAKE -- HOW DID THEY MAKE THE MIRRORS SO PERFECT?

>> THEY HAVE TO BE PERFECT.

GOOD QUESTION.

[NO AUDIO] >> KATELYN WOULD LIKE TO KNOW, WHY DO THEY CALL IT THE MILKY WAY?

[NO AUDIO] >> BRICE FROM McDONALD ELEMENTALLY WOULD LIKE TO KNOW IF THERE IS ANYTHING FROM THE EARTH THAT HAS REACHED PLUTO.

HAVE WE SENT ANYTHING OUT THAT'S GONE THAT FAR?

[NO AUDIO] >> HANNAH AT DALTON ELEMENTARY AND CASSIDY FROM McDONALD ELEMENTARY WOULD BOTH LIKE TO KNOW WHAT IS THE BIG RED SPOT ON JUPITER?

[NO AUDIO] >> PHILIP FROM MISS MILLER'S CLASS AT CALDWELL ADVENTIST ELEMENTARY SCHOOL WOULD LIKE TO KNOW HOW POWERFUL IS THE HUBBLE TELESCOPE?

[NO AUDIO] >> LET'S GO TO RILEY.

GO AHEAD.

>> Caller: WOULD I LIKE TO KNOW WHY VENUS ROTATES THE OPPOSITE DIRECTION OF EARTH.

>> WHY DOES VENUS ROTATE IN THE OPPOSITE DIRECTION OF EARTH.

DR.

CARPENTER?

[NO AUDIO] >> BROOKE IN MRS.

SCHULTZ CLASS WOULD LIKE TO KNOW WHY AREN'T THE PLAN NETS A STRAIGHT LINE WHEN THEY ROTATE AROUND THE SUN?

THEY'RE ALL IN DIFFERENT SPOTS.

WHY AREN'T THEY IN A LINE?

[NO AUDIO] >> NATE IN MRS.

HUNT'S CLASS AT CYNTHIA MANN ELEMENTARY WOULD LIKE TO KNOW, ARE THERE VOLCANOS ON VENUS?

[NO AUDIO] >> MOST OF THEM ARE ACTUALLY DORMANT OR DEAD, SO THEY'RE NOT ACTIVE VOLCANOS THAT ARE SPEWING LAVA OUT NOWADAYS.

THEY DID MOST OF THAT IN THE FAR DISTANT PAST.

IF YOU'RE TALKING ABOUT ACTIVE VOLCANOS, THE BEST PLACE TO SEE THEM IS ON THE MOON OF JUPITER, WHERE THEY'RE VERY, VERY ACTIVE CURRENTLY.

NOWHERE NEAR 1600 OF TM LIKE ON VENUS, BUT STILL VERY LIVELY PLACE TO BE.

>> OK.

LET'S GO TO TUCKER IN DONNELLY.

TUCKER?

>> Caller: IS IT IMPOSSIBLE TO COUNT THE STARS?

>> IS IT IMPOSSIBLE TO COUNT ALL THE STARS?

THAT'S A GOOD QUESTION.

>> THAT'S A GOOD QUESTION, AND THAT'S PRETTY MUCH TRUE.

WE CAN GET A ROUGH IDEA OF HOW MANY THERE ARE IN TOTAL.

WE KNOW THAT IN OUR LOCAL GALAXY THAT THE SUN AND THE SOLAR SYSTEM ARE A PART.

THERE'S SOMETHING BETWEEN TWO AND 400 BILLION STARS, WHICH IS UNIMAGINE BRING LARGE NUMBER TO START WITH.

BUT THERE ARE MANY OTHER GALAXIES IN THE UNIVERSE AS WELL BESIDES THE MILKY WAY, AND MANY OF THEM HAVE AS MANY STARS AS THE MILKY WAY DOES TO START WITH.

SO I THINK THE WAY TO THINK OF IT, THE NUMBER IS HUGE.

IT'S WHAT'S CALLED QUINTILLIONS.

THINK OF A GRAIN OF SAND ON A BEACH, AND THEN THINK OF ALL THE GRAINS OF SAND ON ONE BEACH, AND ALL OF THE BEACHES IN THE WORLD, AND TRY TO THINK HOW MANY GRAINS OF SAND WOULD BE OVER THE ENTIRE WORLD, AND THERE'S MORE STARS THAN THAT, EVEN ACROSS THE UNIVERSE.

>> A QUESTION FROM CHRISTINA IN THE NORTHWEST CHILDREN'S HOAMENT EDUCATION CENTER WOULD LIKE TO KNOW, HOW HOT IS THE SUN?

SURFACE IS ABOUT ALMOST 6,000HE DEGREES.

BUT IT ACTUALLY WARMS UP AS YOU GO INTO THE INTERIOR OF THE SUN, AND BY THE TIME YOU GET INTO THE VERY CENTER OF THE SUN, IT'S AT HUNDREDS OF MILLIONS OF DEGREES, AND THERE IT'S SO HOT THAT HYDROGEN ATOMS ARE FUSING TOGETHER AND RELEASING ENERGY.

AND THAT'S WHAT ACTUALLY POWERS THE SUN.

THAT ENERGY TRICKLES OUT THROUGH LAYERS OF MATERIAL UNTIL IT GETS TO THE OUTER VISIBLE SURFACE OF THE SUN, AND THAT'S WHERE THE TEMPERATURE IS ABOUT 5,800 DEGREES.

>> ALEX FROM CYNTHIA MANN ELEMENTARY WOULD LIKE TO KNOW, WHAT ARE THE STARS MADE OUT OF?

>> STARS ARE FOR THE MOST PART MADE OUT OF HYDROGEN AND HELIUM.

MOSTLY HYDROGEN.

A FAIR AMOUNT OF HELIUM.

AND THEN A SCATTERING OF EVERYTHING ELSE THAT YOU'VE EVER HEARD ABOUT.

SO THE OXYGEN, AND CARBON, AND NITROGEN THAT IS SO IMPORTANT TO US TO LIFE ON EARTH, TO THE STRUCTURE OF THE ROCKY PLANETS LIKE EARTH AND MARS AND VENUS ARE ACTUALLY VERY TINY PARTS OF THE TOTAL.

WELL OVER 90% OF THE SUN AND MOST STARS ARE JUST HYDROGEN AND HELIUM AND A FEW OF THE LIGHT GASSES.

THE HEAVIER ELEMENTS LIKE THE OXYGEN AND CARBON AND NITROGEN, IRON, ELEMENTS LIKE THAT, ARE ALL MADE IN SUPER NOVA EXPLOSIONS LATER IN THE LIFE OF THE UNIVERSE.

THE UNIVERSE STARTED WITH HYDROGEN AND HELIUM AND THAT'S WHAT MOST STARS ARE MADE OF, BUT LATER STARS MANUFACTURED THE HEAVIER ELEMENTS THAT YOU AND I AND THE PLANET EARTH ARE MADE OUT OF.

>> SO WE'RE MADE OF STAR DUST?

>> WE'RE MADE OUT OF STAR STUFF, JUST LIKE CARL SAGAN USED TO SAY.

>> IF YOU'RE ON THE PHONES, PLEASE STAY WITH US AND WE'LL CATCH YOU ON OUR WEB EXTRA PROGRAM.

HANG WITH US AND WE'LL CATCH YOU WHEN WE CATCH THE OTHER HALF OF THE HOUR.

I WANT TO GET A COUPLE MORE QUICK QUESTIONS.

ONE COMES FROM -- THIS IS MRS.

PETERSON'S CLASS WHO WOULD LIKE TO KNOW, HALEY WOULD LIKE TO KNOW, HOW BIG IS THE UNIVERSE?

DO WE KNOW?

>> THAT'S AN INTERESTING QUESTION.

THE UNIVERSE -- THERE'S TWO WAYS TO LOOK AT THAT.

ONE IS HOW FAR CAN WE SEE?

WHAT'S THE END OF WHAT WE CALL THE OBSERVABLE UNIVERSE?

THAT'S PRETTY WELL KNOWN AT A LITTLE UNDER 14 BILLION LIGHT YEARS.

AND TO EXPLAIN WHAT THAT IS, A LIGHT YEAR IS HOW FAR LIGHT TRAVELS IN ONE YEAR.

AND LIGHT TRAVELS VERY, VERY FAST AT ABOUT 180,000 MILES PER SECOND.

SO FAST THAT LIGHT WOULD GO AROUND THE EARTH SEVEN TIMES IN ONE SECOND.

SO LIGHT TRAVELS VERY FAR IN A SECOND, IT TRAVELS REALLY FAR ALMOST 6 TRILLION MILES IN ONE YEAR.

BUT THE UNIVERSE IS SO LARGE, YOU'RE MANY, MANY BILLIONS, LIKE ONE FOLLOWED BY 11 ZEROS, THAT MANY LIGHT YEARS.

>> WE'VE RUN OUT OF TIME.

THANKS FOR JOINING US.

IF YOU WANT TO LEARN MORE, CHECK OUT THE "D4K" WEBSITE AT IDAHOPTV.ORG.

WE'LL SEE YOU NEXT TIME.

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