THE ORION NEBULA
DEAN: WELCOME TO STAR GAZERS.
I'M DEAN REGAS,
ASTRONOMER FROM THE CINCINNATI OBSERVATORY.
JAMES: AND I'M JAMES
ALBURY, DIRECTOR OF THE KIKA SILVA PLA PLANETARIUM
IN GAINESVILLE FLORIDA.
WE'RE HERE TO HELP YOU FIND YOUR WAY AROUND
THE SKY.
DEAN: ONE OF THE
BEST THINGS ABOUT WINTER IS THAT IT ALWAYS
BRINGS THE RETURN OF ONE OF
THE TRUE WONDERS OF THE UNIVERSE.
JAMES: THAT WOULDN'T BE SNOW,
WOULD IT?
DEAN: NOT QUITE, JAMES!
I'M THINKING OF SOMETHING
MUCH FARTHER AWAY, BUT IT'S SOMETHING THAT
IS VERY EASY TO SPOT IN THE WINTER SKY.
JAMES: SWEET!
LET'S SHOW YOU!
DEAN:
WE HAVE OUR SKIES SET UP FOR ANY NIGHT THIS
WEEK AT ABOUT 7:30PM.
IN THE
SOUTHEAST YOU'LL SEE WHAT HAS TO BE THE SECOND
MOST FAMILIAR PATTERN OF STARS
(AFTER THE BIG DIPPER THAT IS), A PATTERN
WHICH IS LOADED WITH BRIGHT STARS,
KNOWN AS ORION THE HUNTER.
JAMES: TO FIND HIM LOOK FOR HIS
BELT OF THREE STARS IN A ROW.
THESE ARE THE STARS, ALNITAK, ALNILAM
AND MINTAKA.
DEAN: ABOVE THESE 3 BELT STARS YOU'LL SEE
2 BRILLIANT
STARS MARKING ORION'S SHODERS, BETELGEUSE
AND BELLATRIX.
AND BELOW
HIS BELT, 2 OTHER STARS MARK HIS ANKLE AND
HIS KNEE, RIGEL AND SAIPH.
JAMES: WE OFTEN TALK ABOUT ORION'S BRIGHT
STARS, BUT FOR THIS EPISODE,
WE WOULD LIKE TO ZERO-IN ON ONE OF ORION'S
MORE SUBTLE OBJECTS.
LOOK
BELOW THE BELT FOR 3 MUCH DIMMER STARS, THE
STARS WE CALL THE SWORD OF ORION.
THERE WE WILL FIND ONE OF THE MOST AWESOME
WONDERS OF OUR NEARBY UNIVERSE.
DEAN: IF YOU LOOK VERY CAREFLY AT THESE
3 STARS IN ORION'S SWORD, YOU'LL NOTICE THAT
NO MATTER HOW SHARP YOUR EYESIGHT,
THE MIDDLE STAR ALWAYS SEEMS TO LOOK FUZZY
OR SLIGHTLY OUT OF FOCUS AND THAT'S
BECAUSE THIS STAR IS NOT A STAR AT ALL, BUT
SOMETHING WE CALL A NEBULA.
JAMES: A NEBULA IS A COSMIC CLOUD OF GAS AND
DUST AND THE GREAT NEBULA
OF ORION IS ACTUALLY A STELLAR RECYCLING CENTER.
WITHIN THIS NEBULA,
BRAND NEW STARS HAVE BEEN, AND ARE STILL BEING
BORN FROM THE SURROUNDING CLOUD.
DEAN: IN FACT, YOU CAN SEE THE ORION NEBA
USING EVEN THE CHEAPEST PAIR
OF BINOCULARS.
THIS CLOUD IS ILLUMINATED BY 4 RECENTLY-BORN
STARS
ARRANGED IN THE SHAPE OF A BASEBALL DIAMOND
CALLED THE TRAPEZIUM, AND THESE
4 STARS CAN ACTUALLY BE SEEN WITH A SMALL
TELESCOPE.
NOW, ALTHOUGH THE
ORION NEBA LOOKSTINY, IN REALITY, ITS SIZE
IS MIND-BOGGLING.
DEAN: BELIEVE IT OR NOT, THERE IS ENOUGH MATERIAL
IN THIS NEBULA TO PRODUCE OVER 10 THOUSAND
STARS THE SIZE OF
OUR SUN!
BUT IF YOU REALLY WANT TO BE IMPRESSED, CHECK
OUT THE WIDTH OF
THE ORION NEBULA.
AS NEBULAE GO, THIS ONE IS GIGANTIC; SPANNING
OVER
30 LIGHT YEARS IN DIAMETER.
JAMES:
JUST TO GIVE YOU A REFRESHER, A LIGHT YEAR
IS NOT A MEASURE OF TIME, BUT A MEASURE
OF DISTANCE.
SPACE IS SO BIG AND THE STARS ARE SO FAR AWAY,
THAT WE ASTRONOMERS
DON'T MEASURE THE DISTANCES BETWEEN THE STARS
IN TERRESTRIAL UNITS LIKE
MILES OR KILOMETERS.
WE USE THE TERM LIGHT YEAR.
DEAN: LIGHT TRAVELS AT A WHOPPING 186,000
MILES PER SECOND, WHICH IS ALMOST
670 MILLION MILES PER HOUR!
THIS MEANS THAT IF YOU WERE TO TRAVEL AT THE
SPEED OF LIGHT FROM THE EARTH TO THE MOON,
YOU COULD MAKE THE TRIP IN 1.3 SECONDS.
IF YOU TRAVELED FROM THE EARTH TO THE SUN
AT THAT SAME SPEED, YOU COULD
MAKE THE TRIP IN A LITTLE OVER 8 MINUTES.
AND IF YOU WERE TO TRAVEL
FROM EARTH TO PLUTO AT THE SPEED OF LIGHT,
YOU COULD MAKE THE TRIP IN ABOUT
5 HOURS.
JAMES: SO WE'RE GOING TO FLY THROUGH
THE ORION NEBULA AND TAKE A CLOSER LOOK AT
THIS STAR FACTORY.
DEAN:
THE FORCE OF GRAVITY IS BRINGING CLOUDS OF
GASES TOGETHER AND WHEN THEY BEGIN
FUSING ELEMENTS, BANG!
A STAR IS BORN.
JAMES: MODERN TELESCOPES
HAVE ALLOWED US TO LOOK DEEP INSIDE THE NEBA
AND SEE NEWBORN STARS AND DISCS
OF MATERIAL.
DEAN: THESE DISCS COULD BE FORMING PLANETS
LIKE THOSE
IN OUR SOLAR SYSTEM.
JAMES: IT COULD TAKE
THOUSANDS OR EVEN MILLIONS OF YEARS FOR THESE
PROTOPLANETARY DISCS TO TURN INTO
SOLAR SYSTEMS, BUT WE'LL KEEP WATCHING.
DEAN: AND YOU SHOULD TOO!
LOOK FOR THE ORION NEBULA THIS WEEK AND PEER
DEEP INTO SPACE.
IT'S ALL THERE
WHEN YOU BOTH: KEEP LOOKING UP!