I AM YOUR HOST TAHIRA ALLEN, AND
TODAY WE'RE THRILLED TO TALK
ABOUT A REAL
"ONCE-IN-A-LIFETIME" EVENT!
AS YOU MIGHT HAVE HEARD IN THE
NEWS, ON DECEMBER 21ST, THE TWO
LARGEST PLANETS IN OUR SOLAR
SYSTEM - JUPITER AND SATURN -
WILL APPEAR AS THOUGH THEY'RE
NEARLY TOUCHING IN THE NIGHT
SKY.
AND YES, YOU'LL BE ABLE TO SEE
THEM WITH THE NAKED EYE, NO
TELESCOPE NEEDED!
THIS RARE ASTRONOMICAL EVENT,
ALSO KNOWN AS THE GREAT
CONJUNCTION, ONLY HAPPENS EVERY
20 YEARS.
HOWEVER, THE LAST TIME IT COULD
BE SEEN THIS CLOSE WAS IN 1623.
TODAY WE ARE TALKING ALL ABOUT
THE GREAT CONJUNCTION, FROM THE
SCIENCE BEHIND THE EVENT TO WHEN
YOU'LL BE ABLE TO SEE IT IN THE
NIGHT SKY!
THROUGHOUT THE SHOW WE'LL SHARE
PHOTOS THAT PEOPLE HAVE TAKEN
FROM AROUND THE WORLD OF SATURN
AND JUPITER COMING TOGETHER.
LET'S GET STARTED!
TODAY I AM JOINED BY DR. HENRY
THROOP, ASTRONOMER AT NASA
HEADQUARTERS.
THANK YOU SO MUCH FOR BEING WITH
US!
>> I HAVE BEEN SEEING A TON OF
BUZZ ONLINE ABOUT THE GREAT
CONJUNCTION OF SATURN AND
JUPITER.
CAN YOU EXPLAIN THE SCIENCE
BEHIND WHAT IS ACTUALLY
HAPPENING?
>> THANKS FOR HAVING ME.
IT'S GREAT TO TALK ABOUT THIS.
WHAT'S HAPPENING HERE, LET'S
LOOK AT OUR PLANET'S PLACE IN
THE SOLAR SYSTEM.
WE HAVE ONE STAR AT THE CENTER,
THAT'S THE SUN.
AND THEN OUTWARD FROM THAT YOU
HAVE THE ORBITS OF EACH
INDIVIDUAL PLANET, MERCURY,
VENUS, MARS, JUPITER AND SATURN.
EACH OF THE PLANETS IS RUNNING
ON ITS OWN CIRCLE.
IT'S LIKE RUNNERS ON A TRACK
WHERE WE HAVE THE EARTH AND SUN
AT THE CENTER AND WE ARE LOOKING
OUTWARD.
EVERY 20 YEARS, ACTUALLY, EVERY
12 YEARS JUPITER GOES AROUND THE
SUN, SATURN, THE NEXT PLANET OUT
HAS FURTHER TO GO AND IT'S
MOVING SLOWER BECAUSE IT'S
TUGGED AROUND LESS SLOWLY.
SO SATURN IS SLOWER, IT TAKES 30
YEARS TO GO AROUND THE SUN.
EVERY 20 YEARS JUPITER IS GOING
TO PASS SATURN IN ITS ORBIT.
IT'S LIKE RUNNERS ON THE TRACK.
YOU ARE AT THE CENTER, YOU GOT A
FAST RUNNER AND THEY ARE
OVERTAKING AND PASSING THE
SLOWER RUNNERS ON THE OUTSIDE OF
THE TRACK.
THAT'S WHAT'S HAPPENING.
IN THIS DIAGRAM YOU CAN SEE
JUPITER AS IT'S APPROACHING
SATURN AND FROM OUR PERSPECTIVE
ON EARTH, YOU WILL SEE IT LINED
UP IN THE SAME PLACE IN THE SKY.
>> AS THIS LINES UP EVERY 20
YEARS, WHY IS THIS ONE
OCCURRENCE SO CLOSE TOGETHER
SINCE 1623?
>> THE PLANETS' ORBITS ARE NOT
EXACTLY FLAT.
IF THEY WERE, THEN THE PLANETS
WOULD CROSS IN FRONT OF EACH
OTHER.
JUPITER WOULD BLOCK SATURN.
BECAUSE THEY ARE SLIGHTLY
TILTED, THEN THE PLANETS PASS
NEAR EACH OTHER, BUT NOT IN
FRONT OF EACH OTHER.
EVERY 20 YEARS WHEN JUPITER
PASSES SATURN, IT OVERTAKES IT
BY A DEGREE, ABOUT TWICE THE
WIDTH OF THE FULL MOON.
THEY ARE SEPARATED WIDELY.
THIS PARTICULAR TIME THEY ARE
COMING VERY CLOSE.
THAT'S BECAUSE OF THE ALIGNMENT.
THEY ARE NOT CLOSE IN SPACE,
THEY ARE STILL HUNDREDS OF
MILLIONS OF KILOMETERS.
IT'S ABOUT A TENTH OF A DEGREE
APART.
IF YOU TAKE YOUR PINKY AND
EXTENDED IT AT ARMS LENGTH, YOU
CAN COVER BOTH PLANETS.
THIS HAPPENS ABOUT ONCE EVERY
400 YEARS.
SO IT HAPPENED 400 YEARS AGO.
>> WHAT A TREAT FOR US.
THIS IS SO EXCITING.
I UNDERSTAND THAT THERE IS SOME
COOL HISTORY BEHIND THE EVENT.
CAN YOU WALK US THROUGH WHAT
THAT IS?
>> YES.
400 YEARS AGO, WE ON EARTH WERE
IN OUR INFANCY OF EXPLORING OUR
SOLAR SYSTEM.
THE FIRST TELESCOPE WAS USED BY
GALILEO IN 1610 WHICH IS A
LITTLE BIT, THIS LAST
CONJUNCTION OF THIS SIZE IN
1623.
IN 1610 GALILEO WAS USING HIS
TELESCOPE TO LOOK AT JUPITER AND
ITS FOUR MOONS.
THIS IS AN EXCERPT FROM HIS
NOTEBOOK.
YOU CAN SEE THE FOUR LITTLE
CIRCLES.
AND SO IN 1610, JUST BEFORE THIS
PREVIOUS CLOSE CONJUNCTION, WHAT
WE KNEW ABOUT JUPITER WAS THAT
IT HAD THESE MOONS.
IT HAD JUST BEEN DISCOVERED.
SIMILARLY WITH SATURN, GALILEO
WAS LOOKING FOR THE FIRST TIME
AT THE RINGS OF SATURN.
HE DIDN'T KNOW WHAT THEY WERE.
SATURN LOOKED VERY, VERY
STRANGE.
WE KNOW THOSE ARE THE RINGS
GOING AROUND SATURN.
AT THE TIME THEY WERE DESCRIBED
AS HANDLES ON A CUP OR MOONS.
SO THAT'S WHAT OUR KNOWLEDGE OF
WHAT THE SCIENCE WAS.
HE IT WAS A COUPLE OF INCHES
ACROSS.
AND WITH A SIMILARLY SIZED
TELESCOPE OR CAMERA LENS, YOU
CAN SEE THE MOONS CLEARLY.
HERE YOU CAN SEE THE MOONS OF
JUPITER.
THEY EXTENDED FROM JUPITER AND
YOU CAN SEE SATURN UP ON THE TOP
THERE.
HERE'S ANOTHER GREAT SHOT THAT
SHOWS THE FOUR MOONS OF JUPITER,
THE FAINT SPOTS, WITH JUPITER IN
THE CENTER AND YOU CAN BARELY
SEE THE RINGS OF SATURN.
SATURN IS FURTHER OUT AND SO IT
APPEARS SMALLER IN THE SKY.
THE MOONS OF JUPITER ARE EASY TO
SEE IF YOU HAVE A TELESCOPE OR
BINOCULARS, MANY MODIFIED
BINOCULARS ARE EASY TO SEE THE
MOONS OF JUPITER WITH.
>> SO WE ARE REALLY LIVING
HISTORY RIGHT NOW.
WILL ANYONE AROUND THE WORLD BE
ABLE TO SEE THIS OR DO YOU HAVE
TO BE IN A SPECIAL LOCATION?
>> THIS IS NEAT.
THE PLANETS GO AROUND THE WHOLE
SOLAR SYSTEM.
THE EARTH IS ROTATING IN A WAY
SO YOU CAN SEE THE PLANETS FROM
EVERYWHERE.
PLANETS ARE BRIGHT.
YOU DON'T HAVE TO BE IN A SUPER
DARK LOCATION.
EVEN IF YOU ARE IN THE MOST
HEAVILY LIT CITY, YOU CAN SEE
THEM QUITE EASILY.
THE ONLY PLACE YOU MIGHT NOT BE
ABLE TO SEE THIS IS IF YOU ARE
IN ANTARCTICA, THE SUN DOESN'T
SET.
ANYWHERE ELSE, IF IT'S NOT
CLOUDY AND YOU DON'T HAVE
SOMETHING IN THE WAY, YOU SHOULD
BE ABLE TO SEE THE CONJUNCTION
BETWEEN JUPITER AND SATURN THIS
ALL MONTH LONG.
>> THAT'S GREAT NEWS MOST
EVERYONE CAN TAKE PART IN THIS.
WHEN AND WHERE SHOULD WE BE
LOOKING UP INTO THE NIGHT SKY?
>> THIS CONJUNCTION IS HAPPENING
IN DECEMBER.
THE PLANETS ARE COMING CLOSER
AND CLOSER TO GET.
AT THE BEGINNING OF THE MONTH
THEY ARE 2° APART.
THEY WILL BE SIMILAR DISTANCE
FOR THE DAY BEFORE AND DAY
AFTER.
SO IN ORDERER TO FIND THE
PLANETS IN THE SKY, IT'S EASY.
LOOK UP AND SEE THE SUN SET,
LOOK TO THE WEST, SOUTHWEST IF
YOU ARE IN THE NORTHERN
HEMISPHERE.
YOU WANT TO GO UP ABOUT 45
MINUTES AFTER SUNSET, LET THE
SKY DARKEN A LITTLE BIT.
AND THEN LOOK TOWARD THE SUNSET.
YOU WILL HAVE ABOUT AN HOUR OF
TIME WHERE YOU CAN OBSERVE
JUPITER AND SATURN IN THE SKY.
JUPITER WILL LOOK LIKE THE
BRIGHTEST STAR.
IT'S A PLANET.
AND SATURN IS GOING TO BE A
LITTLE ABOVE AND A LITTLE LEFT
AND A LITTLE FAINTER.
>> SO ALL THESE PLANETS HAVE
BEEN INCHING CLOSER TO EACH
OTHER, WE ASKED THE PUBLIC TO
SEND IN THEIR PHOTOS.
WHILE WE PLAY THROUGH THESE,
COULD YOU SHARE SOME BASIC TIPS
FOR HOW WE CAN BEST PHOTOGRAPH
THIS EVENT IN THE NIGHT SKY.
>> WHAT'S GREAT, SATURN AND
JUPITER ARE BRIGHT.
SOMETIMES YOU NEED FANCY
EQUIPMENT, TELESCOPE, MOUNT TO
TAKE PHOTOS OF THE PLANETS.
WITH THESE, THERE ARE SO MANY
OPPORTUNITIES.
EVEN SOME WELL LIT CITIES.
MANY PHOTOS SUBMITTED HERE HAVE
BEEN TAKEN WITH PHONES AND SMALL
CAMERAS AND SO FORTH.
I LIKE PHOTOS WHERE YOU CAN SEE
SOME OF THE FOREGROUND, SO YOU
CAN SEE THE CONTEXT FOR WHAT WE
ARE SEEING.
HERE YOU HAVE THE IMAGES OVER
HOUSES AND BUILDINGS.
SOME OF THESE OTHER IMAGES, YOU
HAVE SEEN THEM IN FRONT OF
CITIES OR TREES.
IT BRINGS IT HOME THAT ANYBODY
CAN SEE THESE PLANETS.
IF YOU ARE USING A PHONE,
SMARTPHONE, TAKE PHOTOS OF IT,
MANY MODERN PHONES HAVE A NIGHT
MODE.
THAT WILL LET YOU TAKE AN
EXPOSURE OF A COUPLE OF SECONDS
LONG.
A COUPLE OF SECONDS WILL LET YOU
SEE THE DARK NIGHT SKY AS WELL
AS JUPITER AND SATURN.
AND THE MOON, IF THE MOON IS
PASSING BY.
IF YOU ARE A LARGER CAMERA, LIKE
A DSL, YOU CAN TAKE A WIDE
ANGLE.
IF YOU ZOOM IN, IF YOU HAVE A
LARGE ZOOM LENS, 200 MILLIMETRES
OR SO, THEN YOU CAN SEE THE
MOONS AS WELL.
WE HAVE OTHER PHOTO TIPS THAT WE
HAVE PUT TOGETHER.
I HOPE PEOPLE WILL BE ABLE TO
LOOK AT THOSE TIPS AND TAKE
GREAT PHOTOS SHOWING THE SOLAR
SYSTEM AND THE CONTEXT.
>> I'M EXCITED TO GO OUT THERE
AND CAPTURE IT FOR MYSELF.
SO MANY PEOPLE TUNING IN ARE AS
WELL.
WE HAVE RECEIVED GREAT
QUESTIONS.
I WANT TO REMIND THOSE TUNING
IN, IT'S NOT TOO LATE TO JOIN
THE CONVERSATION.
PLEASE DON'T HESITATE TO SUBMIT
YOUR QUESTIONS IN THE COMMENT
BOX OR USE THE HASHTAG ASKNASA.
WILL IT BE BRIGHTER THAN WE SEE
JUPITER AND SATURN?
>> THE DISTANCE IS SIMILAR.
IT GOES UP AND DOWN A LITTLE BIT
DURING THE YEAR.
BUT IT'S NOT SUBSTANTIALLY
BRIGHTER.
WHAT IS GOING TO BE UNIQUE IS
HOW CLOSE JUPITER AND SATURN ARE
TO EACH OTHER.
THEY WILL LOOK THE SAME, BUT
THEY ARE INCHING CLOSER AND
CLOSER TO EACH OTHER IN THE SKY.
WHEN THEY GET TO BE A TENTH OF A
DEGREE APART IN THE SKY, YOU
WILL STILL BE ABLE TO SEPARATE
THEM AS TWO BRIGHT OBJECTS, NOT
LIKE THEY WILL MERGE INTO ONE,
BUT YOU SHOULD BE ABLE TO SEE
THEM AS TWO BRIGHT OBJECTS.
>> AMAL IS ASKING WHAT WILL BE
THE DISTANCE BETWEEN JUPITER AND
SATURN AT THE TIME OF THIS GREAT
CONJUNCTION?
>> THEY ARE STILL
600 MILLION KILOMETERS FROM EACH
OTHER.
THERE IS VERY LITTLE INFLUENCE,
THE GRAVITY OF JUPITER IS NOT
AFFECTING THE GRAVITY OF SATURN
IN ANY UNUSUAL WAY.
THE MOTION IS CONTROLLED BY
THEIR GRAVITY AROUND THE SUN
RATHER THAN WITH EACH OTHER.
SO THIS IS NOT SOMETHING THAT'S
GOING TO MOVE THE ORBITS OF ANY
OF THE PLANETS.
THIS HAPPENS EVERY 20 YEARS.
IF THE SOLAR SYSTEM WASN'T
STABLE, WE WOULD HAVE KNOWN
ABOUT IT LONG BEFORE NOW.
>> WHAT'S THE EXACT TIME OF THIS
CLOSEST ALIGNMENT FOR US TO
CATCH IT?
>> SO THE EXACT TIME, I FORGET
THE EXACT HOUR OF IT, BUT IF YOU
GO OUT ON THE 21st, THE
DISTANCE DOESN'T CHANGE FOR THE
DURATION OF THE 21st.
DURING THAT 24 HOURS THE
DISTANCE WILL CHANGE ONLY A
SMALL AMOUNT.
SO FROM EVERYBODY'S INDIVIDUAL
LOCATION ON EARTH, YOU WILL HAVE
ABOUT AN HOUR, MAYBE A LITTLE
MORE, IN ORDERER TO SEE THE
PLANETS BEFORE THEY SET
DEPENDING ON WHAT YOUR HORIZON
IS.
THEY WILL BE UP AN HOUR AFTER
SUNSET AND SET ABOUT TWO HOURS
AFTER SUNSET MORE OR LESS.
SO YOU HAVE ABOUT AN HOUR OR SO
WINDOW.
THAT TIME IS GOING TO BE
DIFFERENT DEPENDING WHAT TIME
ZONE YOU ARE IN, BUT IT'S ALWAYS
RIGHT AFTER SUNSET.
>> I KNOW YOU MENTIONED EARLIER
THAT REALLY ALMOST EVERYONE
AROUND THE WORLD CAN SEE THIS.
BUT A USER ON TWITTER SAYS THEY
LIVE IN NEW YORK CITY AND THERE
IS SO MUCH LIGHT POLLUTION HERE
AND MAKES STAR GAZING TOUGH.
WILL THE TWITTER USER BE ABLE TO
SEE IT WITH THE NAKED HIGH AND
HOW LONG WILL IT LAST?
>> IF YOU ARE IN NEW YORK CITY,
THAT'S GOOD NEWS, PLANETS ARE
BRIGHT.
JUPITER AND SATURN, JUPITER IN
PARTICULAR, YOU CAN SEE FROM
ALMOST ANY CITY.
I HAVE LIVE IN BIG CITIES WITH
BRIGHT LIGHTS, WE WERE ABLE TO
SEE THE PLANETS EXTREMELY WELL.
YOU CAN SEE JUPITER AND PROBABLY
SATURN EVEN FROM A PLACE LIKE
NEW YORK.
IF YOU DON'T SEE IT ON THE
21st, YOU MIGHT HAVE CLOUDS,
YOU MIGHT NOT BE ABLE TO SEE IT
FOR ANY NUMBER OF REASONS.
GO OUT THE DAY BEFORE.
IT'S A MONTH OR SO THAT THE
PLANETS HAVE BEEN COMING CLOSER
AND CLOSER TOGETHER.
AND IT WILL BE ANOTHER COUPLE OF
WEEKS THAT THEY GO APART.
IF YOU MISS IT ON ONE DAY, GO
OUT ANOTHER DAY.
THAT'S ONE OF THE NEATEST
THINGS, YOU ARE SEEING THEM COME
TOGETHER AND THEN GO APART.
THAT'S EXCITING AS SEEING THEM
CLOSE ON THE CONJUNCTION ITSELF.
>> THAT'S GREAT NEWS.
SO MANY PEOPLE HAVE BEEN SAYING
IN THEIR AREA ON DECEMBER 21
IT'S CLOUDY.
IT'S GREAT TO KNOW WE HAVE GOT
TIME TO WATCH THIS COME
TOGETHER.
AMY ON Facebook IS ASKING A
QUESTION THAT I HAVE SEEN A LOT.
SHE WANTS TO KNOW WHY ARE PEOPLE
CALLING IT THE STAR OF
BETHLEHEM?
>> PEOPLE HAVE BEEN ENCHANTED BY
THE STARS AND SKY ABOVE US FOR
THOUSANDS AND THOUSANDS OF
YEARS.
PEOPLE HAVE ALWAYS BEEN LOOKING
AT THE SKY, LOOKING AT THE
MOTION OF PLANETS, STARS, MOON
AND SUN.
THERE'S CULTURES AND RELIGIONS,
PEOPLE WHO HAVE BEEN TAKING
OBSERVATIONS OF THE SOLAR SYSTEM
AND INCORPORATING THAT INTO
THEIR TRADITIONS AND RELIGIONS.
THE STAR OF BETHLEHEM REFERS TO
A POSSIBLE EVENT OR OBSERVATIONS
AROUND SEVERAL YEARS BC NEAR THE
BIRTH OF CHRIST.
AND IT IS QUITE POSSIBLE THAT
THERE WAS A CONJUNCTION IN THE
YEAR 6 OR 7 BC, A CONJUNCTION
LIKE THIS HERE WITH JUPITER AND
SATURN, VERY NEAR TO EACH OTHER.
MAYBE IT WASN'T A TENTH OF A
DEGREE BUT A DEGREE APART.
MAYBE A CONJUNCTION LIKE THIS
WAS REFERRED TO AS THE STAR OF
BETHLEHEM.
THERE COULD BE BEEN VISITORS
THAT APPEAR AS THEY ARE PASSING
TOWARD THE SUN, PAST THE EARTH.
THERE ARE NOVAS AND SUPER NOVAS,
DIFFERENT VERSIONS OF EXPLODING
STARS.
AND THERE CAN BE ALIGNMENTS OF
PLANETS AND STARS,
CONSTELLATIONS WHICH CAN BE
INSPIRING FOR PEOPLE.
FOR THE STAR OF BETHLEHEM
ITSELF, WE DON'T KNOW WHICH OF
THESE POSSIBLE PHENOMENA WAS
RESPONSIBLE FOR WHAT'S KNOWN AS
THE STAR OF BETHLEHEM.
ANY OF THEM ARE POSSIBILITIES.
SCHOLARS AND HISTORIANS HAVE
PROPOSED ALL THESE.
THEY ARE ALL PLAUSIBLE IDEAS.
WITHOUT ADDITIONAL OBSERVATIONS
FROM THE TIME, IT'S HARD TO SAY.
EVERYBODY ON EARTH CAN SEE THIS
AND CONTINUE THIS DEEP
CONNECTION BETWEEN PEOPLE ON THE
EARTH AND OBSERVATIONS UP IN THE
SKY AND THIS CONTINUOUS
CONNECTION WE HAVE TO THE SKY
ABOVE US.
>> AND I THINK IT'S SO COOL, IT
DOESN'T MATTER WHERE YOU ARE IN
THE WORLD, WE ARE ALL LOOKING UP
AND CONNECTED BY THIS ONCE IN A
FEW LIFETIME EVENT.
THERE IS A USER ON TWITTER THAT
SAYS I'M CONFUSED.
EVERY PIECE OF INFORMATION I
HAVE READ SAYS IT'S HAPPENED
ONCE EVERY 800 YEARS OR ONCE
EVERY 400 YEARS.
WHICH IS IT?
>> THAT'S A GREAT QUESTION.
EVERY 20 YEARS JUPITER PASSES
SATURN IN ITS ORBIT.
EVERY 20 YEARS IS A CONJUNCTION
WHERE THEY ARE A DEGREE OR SO
APART FROM EACH OTHER.
HOWEVER, JUST LIKE THE MOON IS
UP HALF THE TIME DURING THE DAY
AND HALF DURING THE NIGHT, THIS
HAPPENS DURING THE NIGHTTIME.
YOU COULD SEE IT DURING THE DAY,
BUT IT'S HARD TO SEE THE PLANETS
DURING THE DAY TIME.
WITH THIS CONJUNCTION THAT
HAPPENED 400 YEARS AGO, 1623,
EVEN THOUGH THAT WAS RIGHT AFTER
THE FIRST USE OF THE TELESCOPE
BY GALILEO, IT'S LIKELY NOBODY
SAW IT IN 1623.
IT'S A CLOSE CONJUNCTION, BUT IT
WAS DURING THE DAY TIME.
SO GALILEO HAD NO RECORD OF
SEEING IT, NO OTHERS HAD A
RECORD OF SEEING IT.
IT'S POSSIBLE THE LAST TIME
THERE WAS A CONJUNCTION THAT
COULD BE SEEN WAS 1226.
IT WAS THE PREVIOUS ONE WHICH
WAS WIDELY OBSERVED.
>> I HAVE A QUESTION FROM HANO,
HE'S 6 YEARS OLD ON Facebook.
WHEN WAS THE FIRST TIME NASA
DISCOVERED THE CONJUNCTION?
>> THE CONJUNCTIONS HAVE BEEN
KNOWN ABOUT FOR A LONG TIME.
IN FACT, THERE'S A GREEK
ASTRONOMER WHO WAS IN ABOUT THE
YEAR 100 AD, HE WAS ONE OF THE
FIRST ASTRONOMERS WHO WAS ABLE
TO PREDICT RELIABLY THE MOWINGS
OF THE PLANETS.
KEPLER ALSO IN THE LATE 1500s
AND 1600s WAS INTO
MATHEMATICAL DESCRIPTIONS AND HE
FIRST UNDERSTOOD THEIR FIRST
NATURE AND HOW THEY ORBITED
AROUND THE SUN.
AND SO USING THESE OBSERVATIONS
PEOPLE HAVE BEEN ABLE TO PREDICT
AND UNDERSTAND THE CONJUNCTIONS
FOR QUITE SOME TIME.
SO THIS IS NOT A NEW EVENT.
NASA HAS KNOWN ABOUT THIS FOR A
LONG TIME AS MANY OTHER
OBSERVERS IN THE SKY AND WE ARE
EXCITED TO SHARE THIS WITH
EVERYBODY ELSE ON EARTH AND HAVE
PEOPLE GO OUT AND EXPLORE THE
SOLAR SYSTEM WITH US.
>> I'M SO GLAD YOU SAID THAT
ABOUT SHARING THIS WITH
EVERYBODY ON EARTH.
WE ARE CELEBRATING 20 YEARS OF
CONTINUOUS HUMAN HABITATION ON
THE INTERNATIONAL SPACE STATION.
WILL THE ASTRONAUTS ON THE ISS
BE ABLE TO SEE THE CONJUNCTION?
>> I BELIEVE THE ASTRONAUTS
SHOULD BE ABLE TO SEE THE
CONJUNCTION.
WE HAVE TO VERIFY THAT WITH THE
ASTRONAUTS.
IT DEPENDS ON WHETHER THEIR
ORBIT SHOULD PASS IN SUCH A WAY
THEY WOULD BE ABLE TO SEE IT.
THEY HAVE A GREAT VIEW OF THE
SKY THERE.
THEY ARE UNAFFECTED BY THE
EARTH'S ATMOSPHERE.
SO THEY SHOULD BE ABLE TO SEE
THE CONJUNCTION ALONG WITH
EVERYBODY HERE ON EARTH.
>> I HOPE THAT HAPPENS AND THEY
TAKE GREAT PHOTOS.
I HAVE KITTY ON TWITTER WHO ASKS
IS THERE A SPECIFIC THING HE
THAT SCIENTISTS HOPE TO LEARN?
OR IS IT JUST FOR THE DELIGHT OF
US TO SEE?
>> THIS IS JUST A GREAT TIME TO
SEE THE SKY.
WE ARE NOT DOING OBSERVATIONS,
WE WOULD BE DOING OBSERVATIONS
LIKE IT'S PASSING RIGHT IN FRONT
OF SATURN.
WE COULD DO SCIENCE WE COULDN'T
DO OTHERWISE.
IF JUPITER WERE PASSING IN FRONT
OF ANOTHER STAR, THAT WOULD BE
SOMETHING WE WOULD STUDY.
IN THIS CASE THEY ARE NOT
PASSING IN FRONT OF OTHER LIGHT
SOURCES, SO THERE IS NO
SCIENTIFIC OBSERVATIONS NASA IS
STUDYING, BUT WE ARE EXCITED TO
WATCH THEM OURSELVES.
>> IT'S GREAT THAT ALL OF US GET
TO DO THIS.
FOR THOSE OF US WHO DO HAVE A
TELESCOPE, BRIANNA ASKS WILL
THERE BE A HUGE DIFFERENCE IF I
VIEW IT THROUGH A TELESCOPE?
>> DEPENDING ON THE
MAGNIFICATION.
ON THE NIGHT OF THE 21st
USUALLY A TELESCOPE HAS A HIGH
ENOUGH MAGNIFICATION YOU CAN SEE
JUPITER OR YOU CAN SEE SATURN,
BUT NOT SEE THEM AT THE SAME
TIME, YOU HAVE TO POINT THE
TELESCOPE TO GO BACK AND FORTH
BETWEEN THEM.
ON THE NIGHT OF THE 21st THIS
IS THE ONLY TIME IF YOU HAVE
THAT TELESCOPE YOU CAN LOOK AT
JUPITER AND SATURN AND NOT HAVE
TO REPOINT YOUR TELESCOPE
BETWEEN THEM.
THAT'S WHAT'S REALLY NEAT ABOUT
THEM.
I LOOK FORWARD TO PEOPLE TAKING
PICTURES.
>> THERE'S BEEN AMAZING ONES
ON-LINE.
JUST SHOWING THE RINGS.
I CAN'T WAIT TO SEE WHAT IT
LOOKS LIKE CLOSE TOGETHER.
WE HAVE WANDA ON TWITTER WHO
ASKS SHOULD WE BE LOOKING HIGH
OR LOW IN THE SKY TO SEE THE
CONJUNCTION?
>> THE SUN SETS, THE PLANETS
RISE AND SET FROM EAST TO WEST,
THE SAME WAY AS THE STAR, SUN
AND MOON DO.
IF YOU GO OUT 30°, ABOUT 45
MINUTES AFTER SUNSET, YOU LOOK
ABOUT 30, 45° IN THE SKY,
HALFWAY UP, YOU WILL SEE
JUPITER.
IF YOU HAVE A CLEAR VIEW OF THE
SKY, YOU ARE NOT GOING TO MISS
IT.
SATURN WILL BE A LITTLE HIGHER,
YOU HAVE THEM BOTH THERE AND YOU
CAN FOLLOW THEM AS THEY SLOWLY
SET IN THE WEST.
>> SO I HAVE MARIA ON TWITTER
WHO WANTS TO KNOW HAS THERE EVER
BEEN A TRIPLE PLANETARY
CONJUNCTION?
>> YOU CERTAINLY CAN HAVE A
CONJUNCTION BETWEEN THREE
PLANETS.
IT'S HARDER, LIKE ONE RUNNER ON
THE RACE TRACK CAN PASS ANOTHER
RUNNER.
IF YOU ARE WAITING FOR THREE
RUNNERS TO LINE UP, IT'S GOING
TO TAKE LONGER TO GET ALL LINED
UP.
INSTEAD OF EVERY 20 YEARS, YOU
MIGHT HAVE TO WAIT MAYBE 10,000
YEARS FOR THREE PLANETS.
WE CAN PREDICT OR KNOW BECAUSE
IT'S A VERY -- THE MOTIONS OF
THE PLANETS ARE WELL UNDERSTOOD.
WE CAN PREDICT WHEN THAT
HAPPENS, IT'S NOT GOING TO BE
ANY TIME SOON FOR JUPITER,
SATURN OR ANY OTHER PLANETS.
>> HAVE THERE BEEN ANY OTHER
PLANETARY CONJUNCTIONS THAT
PEOPLE CAN SEE?
>> MERCURY AND VENUS ARE THE
FASTER MOVING PLANETS.
SOMETIMES WE SEE THEY MOVE
FASTER AROUND THE EARTH.
THEY COVER MORE, THEY HAVE MORE
CHANCES FOR THEM TO GET LINED
UP, JUST LIKE THE RUNNERS ON THE
TRACK.
WE SOMETIMES SEE TRANSIT, WHERE
THE PLANET IS MOVING IN FRONT OF
SOMETHING ELSE.
IN THE CASE OF OUR SOLAR SYSTEM,
BOTH MERCURY AND VENUS HAVE HAD
TRANSITS WHICH TOOK THEM IN
FRONT OF THE PATH OF THE SUN.
NASA AND MANY MILLIONS OF PEOPLE
WITNESSED THE TRANSITS OF
MERCURY, IT'S A LITTLE DOT.
IT WASN'T INTERACTING WITH THE
SUN, IT WAS IN FRONT OF THE SUN
WHEN VENUS AND MERCURY DID THIS.
IT WAS EXCITING TO SEE THAT
BECAUSE THAT REQUIRES A PRECISE
ALIGNMENT AND THOSE ARE RARE
EVENTS AS WELL.
>> I HAVE GOT ONE FINAL QUESTION
FOR YOU I'M DIEING TO KNOW.
WHAT ARE YOU MOST EXCITED TO
KNOW ABOUT THE EVENT?
>> I'M EXCITED FOR PEOPLE TO GO
OUT AND SEE OUR PLACE IN THE
SOLAR SYSTEM.
IT'S THIS BIG THREE DIMENSIONAL
OBJECT, THE PLANETS ARE MOVING
AROUND, WE ARE MOVING AROUND,
THE MOON IS MOVING AROUND US.
THIS GIVES PEOPLE ON EARTH A
GREAT CHANCE TO GO OUT AND SEE
WHERE THEY FIT IN THE SOLAR
SYSTEM.
DON'T GO OUT JUST ONE NIGHT, GO
OUT SEVERAL NIGHTS AND SEE HOW
THE MOTION CHANGES RELATIVE TO
EACH OTHER, SEE HOW THEY CHANGE
RELATIVE TO THE STARS AND
RELATIVE TO THE SUN AS THEY ARE
GOING TO MOVE AFTER THE SUNSET.
USE THAT TO MAKE YOU'RE LINK TO
THE MOTIONS OF THE PLANETS
AROUND US LIKE PEOPLE HAVE DONE
FOR THOUSANDS OF YEARS.
>> YOUR EXCITEMENT IS GETTING ME
EXCITED.
THANK YOU FOR SHARING YOUR
EXPERTISE WITH US.
IF YOU WOULD LIKE TO LEARN MORE
ABOUT THE GREAT CONJUNCTION,
SKYWATCHING TIPS, AND ABOUT
WHAT'S UP IN THE SKY FOR
DECEMBER, VISIT,
GO.NASA.GOV/WHATSUP.
YOU CAN ALSO FOLLOW
@NASASOLARSYSTEM ON FACEBOOK,
TWITTER AND INSTAGRAM TO STAY
INFORMED.
HAPPY SKY WATCHING.
WE'LL SEE YOU NEXT TIME.