JAMES: HEY THERE STAR GAZERS.
I'M JAMES ALBURY, DIRECTOR OF THE KIKA SILVA
PLA PLANETARIUM IN GAINESVILLE, FLORIDA.
DEAN: AND I'M DEAN REGAS, ASTRONOMER FOR THE
CINCINNATI OBSERVATORY.
JAMES: IT'S THAT TIME OF YEAR WHEN YOU CAN
SEE ONE OF THE MOST FAMOUS STAR CLUSTERS,
THE PLEIADES, BETTER KNOWN AS THE SEVEN SISTERS.
DEAN: BUT DO YOU KNOW THAT THERE ARE TWO MORE
STAR CLUSTERS, TWIN CLUSTERS SO TO SPEAK,
JUST A SHORT VISUAL DISTANCE AWAY.
JAMES: AND HAVE YOU EVER WONDERED WHAT WAS
THE FARTHEST THING YOU CAN SEE WITH THE NAKED
EYE?
LET'S SHOW YOU:
JAMES: O.K., WE'VE GOT OUR SKIES SET UP FOR
NEXT WEEK AROUND 9 P.M.
IF YOU LOOK ABOVE THE EASTERN HORIZON YOU
WILL SEE WHAT LOOKS LIKE AN EXQUISITE TINY
LITTLE-DIPPER-SHAPED CLUSTER OF STARS, THE
SEVEN SISTERS.
DEAN: NOW MOST PEOPLE SEE ONLY 6 STARS HERE
WITH THE NAKED EYE, BUT REALLY GOOD EYES UNDER
IDEAL CONDITIONS, CAN SEE SEVEN OR MORE.
WITH BINOCULARS YOU CAN SEE SEVERAL DOZEN.
THERE ARE REALLY OVER 250 STARS HERE, ALL
MUCH LARGER AND HOTTER THAN OUR OWN SUN.
JAMES: AND COSMICALLY SPEAKING, THEY'RE NOT
VERY DISTANT, ONLY ABOUT 400 LIGHT YEARS AWAY
WHICH MEANS THAT WE SEE THE PLEIADES AS THEY
EXISTED 400 YEARS AGO, ABOUT THE TIME GALILEO
FIRST TRAINED A TELESCOPE ON THEM.
DEAN: NOW TO FIND THE TWIN CLUSTERS, LOOK
DIRECTLY ABOVE THE NORTH STAR WHERE YOU WILL
SEE 5 STARS THAT TRACE OUT THE 'M'-SHAPED
CONSTELLATION OF CASSIOPEIA THE QUEEN.
THEN TO THE RIGHT OF CASSIOPEIA YOU WILL SEE
TWO FAINT FUZZY Q-TIP LIKE OBJECTS AND IF
YOU ARE FAR AWAY FROM CITY LIGHTS WHERE IT'S
GOOD AND DARK OUT YOU WILL NOTICE THAT THEY
ARE EMBEDDED IN THE RIVER OF LIGHT WE CALL
THE MILKY WAY.
DEAN: NOW THESE TWO DIM FUZZY BALLS OF LIGHT
ARE CALLED THE DOUBLE CLUSTER OF PERSEUS.
AND ALTHOUGH EACH HAS ABOUT 100 MORE STARS
THAN THE PLEIADES, THEY'RE NOT AS BRIGHT TO
US BECAUSE THEY ARE SO MUCH FARTHER AWAY.
IN FACT, UNLIKE THE PLEIADES' 400 LIGHT YEARS
DISTANCE, THEY ARE A GRAND 7000 LIGHT YEARS
AWAY.
JAMES: NOW LET'S GET BACK TO MY QUESTION ABOUT
THE FARTHEST THING THATS VISIBLE WITH THE
NAKED EYE.
LETS START WITH THE MOON.
ITS VERY EASY TO SEE AND ITS ALMOST A QUARTER
MILLION MILES AWAY.
LET'S STEP IT UP A NOTCH AND TAKE LOOK AT
VENUS.
NEXT WEEK VENUS WILL BE ABOUT 100 MILLION
MILES AWAY, STILL EASILY SEEN WITH THE NAKED
EYE.
LET'S GO ANOTHER STEP AND LOOK AT JUPITER
NEXT WEEK.
THE KING OF THE PLANETS IS ABOUT 600 MILLION
MILES AWAY AND STILL EASILY SEEN WITH THE
UNAIDED EYE.
DEAN: WE'RE APPROACHING THE ANSWER BUT WE
HAVE A LONG WAY TO GO YET.
WE CAN'T DESCRIBE HOW FAR WE CAN SEE IN TERMS
OF MILES ALONE.
WE HAVE TO SHIFT TO LIGHT YEARS WITH EACH
LIGHT YEAR BEING ABOUT 6 TRILLION MILES, QUITE
A JUMP, HUH?
WE'RE NOT TALKING ABOUT JUST A FEW LIGHT YEARS
EITHER.
WE'RE TALKING ABOUT OVER TWO MILLION LIGHT
YEARS.
BUT WHAT COULD BE SO BRIGHT THAT WE CAN SEE
IT WITH OUR UNAIDED EYES AT SUCH A DISTANCE?
JAMES: TO ANSWER THAT, LET'S FIRST FIND PEGASUS
THE HORSE.
IF WE DRAW LINES BETWEEN FOUR NOT-SO-BRIGHT
STARS WE WOULD TRACE A GREAT CELESTIAL SQUARE.
AND WITH A FEW OTHER STARS, AND A LITTLE IMAGINATION
WE COULD CONNECT STARS TO THIS SQUARE TO MAKE
A LONG NECK.
THE BRIGHT STAR ENIF CAN MAKE OUR HORSE'S
NOSE.
DEAN: A FEW DIM STARS CAN FORM TWO SHORT FRONT
LEGS, AND SOME OTHERS CAN STAND IN FOR TWO
HIND LEGS.
NOW MOST PEOPLE CALL THE HIND LEGS SOMETHING
ELSE - ANDROMEDA THE PRINCESS.
AND MAYBE THE NAME ANDROMEDA WILL GIVE YOU
A GALACTIC HINT AS TO WHAT IS THE FARTHEST
THING YOU CAN SEE WITH THE NAKED EYE.
JAMES: IT'S DIFFICULT TO FIND AND YOU MUST
HAVE CLEAR, DARK, MOONLESS SKIES LIKE NEXT
WEEK.
BUT IF YOU SQUINT, YOU MAY SEE A DIM, FUZZY
PATCH OF LIGHT.
IT IS CALLED M31, THE GREAT GALAXY OF ANDROMEDA
WHICH, THROUGH A TELESCOPE, REVEALS ITSELF
TO BE A GIGANTIC FAMILY OF A TRILLION STARS
THAT'S OVER TWO AND A HALF MILLION LIGHT YEARS
AWAY.
DEAN: SO WE HAVE THREE STAR CLUSTERS AND ONE
GALAXY THAT ARE VISIBLE IN A FAIRLY SMALL
CHUNK OF THE NIGHT SKY NEXT WEEK.
TO FIND THEM YOU MUST
BOTH: KEEP LOOKING UP!