SATURN AT OPPOSITION!
JAMES:
WELCOME TO STAR GAZERS.
I'M JAMES ALBURY, DIRECTOR OF THE KIKA SILVA
PLA PLANETARIUM
IN GAINESVILLE FLORIDA.
DEAN:
AND I'M DEAN REGAS, ASTRONOMER FROM THE CINCINNATI
OBSERVATORY.
WE'RE HERE TO HELP YOU FIND YOUR WAY AROUND
THE SKY TONIGHT.
JAMES:
DEAN AND I ARE REALLY EXCITED BECAUSE NEXT
WEEK, ONE OF OUR FAVORITE PLANETS WILL BE
AT OPPOSITION AND AS A RESULT, IT'LL BE IN
A GREAT SPOT IN THE SKY AND WE CAN VIEW IT
ALL NIGHT LONG.
DEAN:
AND THAT PLANET IS THE EVER POPULAR AND LOVELY,
RINGED PLANET, SATURN!
JAMES:
LET'S SHOW YOU!
DEAN:
OK, LET'S FIRST EXPLAIN A LITTLE BIT ABOUT
WHAT OPPOSITION MEANS.
IF WE COULD VIEW OUR SOLAR SYSTEM FROM HIGH
ABOVE THE NORTH POLE OF OUR SUN, AS WE LOOK
DOWN, WE CAN SEE EARTH'S ORBIT AND SATURN'S
ORBIT AROUND THE SUN.
EARTH IS ABOUT 93 MILLION MILES AWAY FROM
THE SUN AND IT TAKES 365 1/4 DAYS FOR EARTH
TO MAKE ONE TRIP AROUND THE SUN.
IN LAYMAN'S TERMS, WE REFER TO THAT AS A YEAR.
JAMES:
SATURN IS THE 6TH PLANET FROM THE SUN AND
IS ALMOST 900 MILLION MILES AWAY.
IT MOVES MUCH SLOWER IN ITS ORBIT AND IT TAKES
ALMOST 30 EARTH YEARS TO MAKE ONE TRIP AROUND
THE SUN.
THEREFORE, EARTH MAKES 30 TRIPS AROUND THE
SUN FOR EVERY ONE TRIP OF SATURN.
SO IT'S QUITE OBVIOUS THAT EARTH AND SATURN
ARE CONSTANTLY CHANGING THEIR POSITION IN
SPACE WITH RESPECT TO ONE ANOTHER.
DEAN:
WHEN SATURN IS AT ITS GREATEST DISTANCE FROM
EARTH, IT IS ON THE OTHER SIDE OF THE SUN
AS SEEN FROM EARTH, AND THAT IS CALLED SUPERIOR
CONJUNCTION;
WHICH HAPPENED
6 MONTHS AGO ON NEW YEARS DAY, JANUARY 1ST.
ON THAT DAY, SATURN WAS A WHOPPING ONE BILLION
MILES AWAY
FROM US.
BUT 6 MONTHS LATER, ON TUESDAY, JULY 9TH,
EARTH AND SATURN WILL BE LINED UP WITH
THE SUN.
THEREFORE, SATURN IS ON THE SAME SIDE OF THE
SUN AS THE EARTH AND
A LOT CLOSER.
JAMES:
OR, IF YOU THINK OF IT FROM OUR PERSPECTIVE,
THE EARTH IS IN THE MIDDLE AND SATURN WILL
BE ON THE OPPOSITE SIDE OF THE SKY WITH RESPECT
TO THE SUN.
THIS ORIENTATION OF THE SUN, THE EARTH AND
A PLANET IS CALLED OPPOSITION.
AND WHENEVER A PLANET IS AT OPPOSITION, IT
IS ALWAYS AT ITS CLOSEST AND BRIGHTEST.
SO THIS WEEK, SATURN WILL BE JUST OVER 839
MILLION MILES AWAY,
AND ALTHOUGH SATURN IS ALWAYS CLOSE TO EARTH
AND VERY BRIGHT EVERY OPPOSITION, THIS OPPOSITION
IS GOING TO LOOK GREAT BECAUSE OF THE WAY
THE RINGS ARE TILTED TOWARD US.
DEAN:
YOU SEE, EVEN THOUGH SATURN'S RINGS ARE ALWAYS
TILTED AT THE SAME ANGLE WITH RESPECT TO ITS
ORBIT, BECAUSE EARTH CONSTANTLY CHANGES ITS
POSITION IN
RELATION TO SATURN,
IT'S RINGS SEEM TO TILT BACK AND FORTH AS
SEEN FROM EARTH DURING SATURN'S 30 YEAR ORBIT.
FOR INSTANCE BACK IN JANUARY 2003 SATURN WAS
IN SUCH A POSITION THAT ITS RINGS WERE TILTED
UP TO THE MAX WITH THE SOUTHERN SIDE OF THE
RINGS WIDE OPEN - WHICH MEANS THAT MORE SUNLIGHT
REFLECTED OFF THE RINGS AND MADE THE PLANET
MUCH BRIGHTER THAN USUAL AND THE RINGS LOOK
THEIR MOST DRAMATIC.
JAMES:
THEN AS YEAR AFTER YEAR WENT BY, WE GRADUALLY
SAW LESS AND LESS OF THE SOUTHERN FACE OF
SATURN'S RINGS.
THEY SLOWLY CLOSED
SO TO SPEAK, AND BY JANUARY 2009, WE ACTUALLY
FACED SATURN'S RINGS EDGE-ON, AND FOR A FEW
NIGHTS THEY SEEMED TO HAVE DISAPPEARED.
HOWEVER, AS THE YEARS HAVE PASSED, WE ARE
NOW POSITIONED SO THAT WE CAN SEE THE NORTHERN
HEMISPHERE AND THE NORTHERN SIDE OF SATURN'S
RINGS,
MAKING SATURN APPEAR BRIGHTER IN THE SKY.
JAMES:
SO CHECK OUT SATURN THIS WEEK AND IF YOU LOOK
AT IT THROUGH EVEN THE SMALLEST TELESCOPE,
TRUST ME YOU'LL BE BLOWN AWAY.
TO FIND SATURN SIMPLY LOOK EAST SHORTLY AFTER
SUNSET.
IT WILL BE IN THE CONSTELLATION SAGITTARIUS
THE CENTAUR ARCHER.
DEAN:
AND WHILE YOU'RE LOOKING AT SATURN, PONDER
THIS LITTLE BIT OF TRIVIA.
OF ALL THE PLANETS IN THE SOLAR SYSTEM, SATURN
HAS THE LEAST DENSITY.
THIS MEANS THAT FOR AS BIG AS SATURN IS, IT'S
NOT AS HEAVY AS YOU
MIGHT THINK.
ITS DENSITY IS SO LOW THAT YOU COULD ACTUALLY
FLOAT SATURN IN A BATH TUB FULL OF WATER;
IF YOU HAD A BATH TUB BIG ENOUGH.
JAMES:
HMMM...SATURN IN A BATH TUB?
I WONDER IF…
DEAN:
NO…
DON'T SAY IT..DON'T SAY IT...
JAMES:
WELL, THE WHOLE SUBJECT OF SATURN
IN A BATHTUB DOES…
RING…
A BELL.
DEAN:
UGH!
ON THAT NOTE, HAPPY SATURN WATCHING, AND…
BOTH: KEEP LOOKING UP!
