OPPOSING JUPITER!

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.

JAMES:
ITS THAT TIME OF YEAR AGAIN FOR VIEWING MY

FAVORITE GAS GIANT PLANET AT ITS BIGGEST AND
BRIGHTEST!

DEAN:
THAT'S RIGHT, JAMES!

ON JUNE 10TH, JUPITER WILL BE AT OPPOSITION.

THIS MEANS THAT ITLL BE IN A GREAT LOCATION
FOR VIEWING.

JAMES:
WHAT ARE WE TALKING ABOUT?

LET'S SHOW YOU!

DEAN:
JUPITER IS THE LARGEST OF ALL THE PLANETS

IN OUR SUN'S FAMILY AND IS THE FIFTH PLANET
FROM THE SUN, OUR EARTH BEING NUMBER THREE.

EARTH IS, ON AVERAGE 93 MILLION MILES AWAY
FROM THE SUN, WHEREAS JUPITER'S AVERAGE DISTANCE

IS 484 MILLION MILES.

THOSE ARE PRETTY BIG NUMBERS AND BECAUSE THE
PLANETS ARE SO FAR AWAY FROM EACH OTHER, ASTRONOMERS

DONT OFTEN REFER TO THE DISTANCES IN THE SOLAR
SYSTEM USING MILES OR KILOMETERS.

THAT WOULD BE LIKE MEASURING THE DISTANCE
FROM YOUR HOUSE TO THE GROCERY STORE IN INCHES

OR CENTIMETERS.

JAMES:
INSTEAD, WE USE THE AVERAGE DISTANCE BETWEEN

THE EARTH AND THE SUN AS OUR MEASURING STICK.

WE CALL THAT DISTANCE AN ASTRONOMICAL UNIT
OR A.U.

SO, IF WE CONVERTED OUR UNITS FROM MILES TO
AUS, EARTH IS ONE ASTRONOMICAL UNIT FROM THE

SUN AND JUPITER ON AVERAGE IS 5.2 ASTRONOMICAL
UNITS FROM THE SUN.

DEAN:
AS JUPITER AND EARTH ORBIT THE SUN, THEY CONSTANTLY

VARY THEIR DISTANCE FROM EACH OTHER.

WHEN JUPITER IS AT ITS FARTHEST DISTANCE FROM
US AND IS ON THE OTHER SIDE OF THE SUN AS

SEEN FROM EARTH, IT CAN BE AS FAR AS 6.2 ASTRONOMICAL
UNITS AWAY.

JAMES:
HOWEVER, ONCE EVERY YEAR, EARTH AND JUPITER

LINE UP ON THE SAME SIDE OF THE SUN AND ARE
A WHOLE 2 ASTRONOMICAL UNITS CLOSER TO EACH

OTHER.

WHENEVER THIS HAPPENS WE SAY JUPITER IS AT
OPPOSITION BECAUSE JUPITER IS OPPOSITE THE

SUN IN THE SKY AS SEEN FROM EARTH.

DEAN:
AND WHEN JUPITER IS AT OPPOSITION, IT IS

ALWAYS AT ITS CLOSEST, BRIGHTEST AND BEST
FOR VIEWING.

JUPITER WILL BE AT
OPPOSITION THIS YEAR ON MONDAY, JUNE 10TH

AND JUST UNDER 4.3 ASTRONOMICAL UNITS AWAY.

SO, THIS MAKES IT GREAT FOR VIEWING IN A SMALL
TELESCOPE.

DEAN:
OK, WE HAVE OUR SKIES SET FOR 11:00 PM, ANY

NIGHT THIS WEEK.

IF YOU LOOK TOWARD THE SOUTHEAST, YOU'LL SEE
JUPITER AMONG THE STARS OF OPHIUCHUS

THE SERPENT BEARER.

ON JUNE 10TH, JUPITER WILL FORM A TRIANGLE
WITH THE STAR ANTARES IN SCORPIUS AND SABIK

IN OPHIUCHUS.

JAMES:
IF YOU'VE BEEN WATCHING JUPITER OVER THE LAST

FEW MONTHS, YOU PROBABLY NOTICED IT MOVING
FROM EAST TO WEST BETWEEN SCORPIUS AND SAGITTARIUS.

WE CALL THIS RETROGRADE MOTION, AND IT'S AN
OPTICAL ILLUSION CAUSED BY US PASSING JUPITER

IN
OUR ORBIT.

JUPITER BEGAN IT'S RETROGRADE MOTION ON APRIL
15TH THIS YEAR AND PERFORMS THIS APPARENT

BACKWARD MOTION FOR ALMOST 120 DAYS EACH YEAR.

DEAN:
IF YOU KEEP ON EYE ON JUPITER AS WE TRAVEL

PAST IT, YOULL NOTICE IT CONTINUES TO TRAVEL
WESTWARD THROUGH OPHIUCHUS, REACHING ITS CLOSEST

APPROACH TO SCORPIUS ON AUGUST 11TH.

JUPITER WILL APPEAR TO PAUSE AND THEN BEGIN
TRAVELLING EASTWARD AGAIN.

JAMES:
NO WONDER THEY CALLED THE PLANETS WANDERING

STARS.

DEAN:
THE PLANET JUPITER HAS BEEN OBSERVED IN THE

SKY SINCE ANTIQUITY.

THE ANCIENT ROMANS NAMED IT AFTER THE KING
OF THEIR GODS, WHOM THE GREEKS REFERED

TO AS ZEUS.

JAMES:
BABYLONIAN ASTRONOMERS HAVE RECORDS OF JUPITER

DATING BACK TO THE
7TH CENTURY B.C.

IN HIS BOOK THE ALMAGEST, GREEK ASTRONOMER
CLAUDIUS PTOLEMY USED JUPITER'S MOTION WITH

RESPECT TO THE EARTH TO REFINE HIS EARTH-CENTERED
MODEL OF THE SOLAR SYSTEM.

JAMES:
LASTLY, IF YOURE LIKE ME AND YOU REALLY GET

EXCITED ABOUT CONJUNCTIONS, SET YOUR CALENDARS
FOR JUST AFTER SUNSET ON NOVEMBER 23RD OF

THIS YEAR, AND JUPITER WILL BE HAVING A SUPER
CLOSE CONJUNCTION WITH VENUS.

DEAN:
VENUS AND JUPITER WILL BE ONLY 1.5 DEGREES

(OR 3 FULL MOON WIDTHS) APART THAT DAY.

THEYLL BOTH BE EXTREMELY BRIGHT AND VISIBLE
VERY CLOSE TO THE SOUTHWESTERN HORIZON.

JAMES:
HOWEVER, IF YOU WANT TO SEE A CRAZY-CLOSE

CONJUNCTION, CHECK OUT JUPITER NEXT YEAR ON
DECEMBER 21ST, 2020 WHEN IT HAS A SUPER-CLOSE

PAIRING WITH SATURN.

JUPITER AND SATURN WILL BE ONLY A TENTH OF
A DEGREE (OR 1/5TH OF A FULL MOON WIDTH) APART.

THEY'LL BE SO CLOSE THAT YOU'LL BE ABLE TO
SEE THEM BOTH IN THE SAME FIELD OF VIEW IN

A SMALL TELESCOPE!

DEAN:
WOW!

NOW YOU DON'T HAVE TO PLAN THAT FAR AHEAD
TO SEE THE KING OF THE PLANETS THIS WEEK.

IT'S EASY TO SEE JUPITER
WHEN YOU REMEMBER TO

BOTH: KEEP
LOOKING UP!