[upbeat music]
- "OUR WORLD."
- WHAT DO YOU KNOW ABOUT OUR SOLAR SYSTEM?
WELL, I KNOW THREE THINGS OFF THE TOP OF MY HEAD.
LET'S START AT THE CENTER.
NUMBER ONE: THE SUN IS THE CENTER OF
AND BIGGEST THING IN OUR SOLAR SYSTEM.
NUMBER TWO: EARTH
AND ALL OF THE OTHER PLANETS YOU'VE HEARD OF
ARE ALSO PART OF OUR SOLAR SYSTEM.
NUMBER THREE:
AND BECAUSE THE SUN IS SO HUGE,
ALL OF THE PLANETS, INCLUDING EARTH,
ARE PULLED TOWARDS THE SUN BY GRAVITY.
TURNS OUT, THOUGH, THOSE THREE THINGS
JUST BARELY SCRATCH THE SURFACE
OF WHAT OUR SOLAR SYSTEM IS ALL ABOUT.
BUT JUST WHAT IS A SOLAR SYSTEM ANYWAY?
- A STAR AND ALL THE OBJECTS THAT ORBIT AROUND IT
MAKE UP A SOLAR SYSTEM.
OUR SUN IS A YELLOW STAR.
EIGHT PLANETS ORBIT THE SUN IN OUR SOLAR SYSTEM.
THE INNER PLANETS--
MERCURY, VENUS, EARTH, AND MARS--
ARE CLOSER TO THE SUN AND HAVE SURFACES MADE OF ROCK.
THE OUTER PLANETS--
JUPITER, SATURN, URANUS, AND NEPTUNE--
HAVE SURFACES MADE OF GASES
AND ARE FOUND BEYOND THE ASTEROID BELT.
- BUT IS THAT ALL THERE IS?
LET'S CHECK WITH ALAN TAYLOR, AN AMATEUR ASTRONOMER,
AND SEE WHAT HE'S GOT TO SAY.
- WE HAVE ALL THESE THINGS OUT THERE THAT WE TALK ABOUT,
BUT THEY'RE IN THESE LEVELS OF,
WELL, THERE'S THE SUN, AND THEN THERE'S PLANETS.
AND YOU CAN KIND OF DIVIDE THE PLANETS
INTO GAS GIANTS AND TERRESTRIAL PLANETS.
AND THEN THERE ARE FURTHER SUBDIVISIONS
OF DWARF PLANETS AND ASTEROIDS.
WELL, THAT'S AN INTERESTING WAY TO TALK ABOUT IT,
BUT THEY'RE THINGS OUT THERE, AND THEY HAVE SIZE,
AND I THOUGHT IT WOULD BE INTERESTING TO SEE,
LINED UP SIDE BY SIDE, ALL OF THESE THINGS,
STARTING WITH THE BIGGEST AND GOING DOWN TO THE SMALLEST.
AND SO I HAD ALWAYS WANTED TO SEE SOMETHING LIKE THAT,
JUST OUT OF CURIOSITY.
- SO ALAN TAYLOR DECIDED TO CREATE THIS AWESOME GRAPHIC.
IT COMPARES THE SIZES OF 88 OF THE LARGEST KNOWN OBJECTS
IN OUR SOLAR SYSTEM.
88?
- IN FACT, THERE ARE HUNDREDS OF THOUSANDS
OF OBJECTS IN OUR SOLAR SYSTEM,
INCLUDING MOONS, ASTEROIDS, METEORS, AND COMETS.
AS ASTRONOMERS CONTINUE TO OBSERVE SPACE
WITH NEW SPACECRAFT AND BETTER TELESCOPES,
THEY FIND MORE OBJECTS.
- EVEN IF WE JUST LOOK AT THE 88 OBJECTS
ALAN PUT IN HIS GRAPHIC, WE STILL HAVE A LOT TO STUDY.
SO HOW DO WE SORT ALL THESE OBJECTS OUT?
- SCIENTISTS LOOK FOR PATTERNS TO CLASSIFY OBJECTS.
THAT MEANS THEY COMPARE THE OBJECTS
AND GROUP THEM TOGETHER BASED ON SIMILARITIES,
OR THINGS THEY HAVE IN COMMON,
LIKE SIZE OR SHAPE OR HOW THEY MOVE.
TO BE CONSIDERED A PLANET,
AN OBJECT MUST HAVE THESE THREE THINGS IN COMMON:
ONE, IT MUST BE BIG ENOUGH TO FORM A NEARLY ROUND SHAPE.
TWO, IT MUST ORBIT A STAR, LIKE OUR SUN.
THREE, IT CAN ONLY ORBIT THE STAR--
CANNOT CROSS THE PATH OF ANY OTHER OBJECT AROUND IT.
TO BE CONSIDERED A MOON,
AN OBJECT NEEDS TO ORBIT A PLANET.
EARTH'S MOON IS CALLED LUNA.
GANYMEDE, WHICH IS ONE OF THE MANY MOONS
THAT ORBIT JUPITER,
IS THE LARGEST MOON IN THE SOLAR SYSTEM.
GANYMEDE IS LARGER THAN MERCURY AND PLUTO.
- PLUTO? DIDN'T THAT USED TO BE A PLANET?
SO HOW DO WE CLASSIFY IT NOW?
- PLUTO IS NO LONGER A PLANET.
IT'S A DWARF PLANET.
THAT DOESN'T ACTUALLY CHANGE THE OBJECT AT ALL.
THE OBJECT IS STILL THIS INTERESTING THING OUT THERE
THAT HAS A HISTORY,
THAT PEOPLE DISCOVERED IT
AND ARE TRYING TO FIGURE OUT WHAT IT'S LIKE.
AND WE ACTUALLY HAVE A SPACECRAFT
ON THE WAY OUT THERE.
IT'S GONNA BE THERE IN A FEW YEARS.
AND WE'RE GONNA BE ABLE TO SEE MORE ABOUT IT.
IT'S GOT SEVERAL MOONS GOING AROUND.
IT'S THIS INTERESTING THING OUT THERE.
WHAT YOU CALL IT, WHETHER IT'S A ROCK
OR A TRANS-NEPTUNIAN OBJECT OR A PLANET OR A DWARF PLANET,
REALLY DOESN'T HAVE A LOT OF BEARING
ON HOW INTERESTING IT IS.
I MEAN, IT'S STILL A MEMBER OF THE SOLAR SYSTEM.
- SO THAT'S WHY ALAN MADE HIS GRAPHIC.
JUST BECAUSE WE CHANGE THE WAY WE CLASSIFY AN OBJECT
DOESN'T CHANGE ALL THE NEAT STUFF ABOUT THAT OBJECT.
AS YOU CAN SEE ON THE PICTURE, THE PLANET MERCURY IS SMALLER
THAN ONE OF SATURN'S MOONS, TITAN.
DOES THAT MAKE TITAN MORE IMPORTANT THAN MERCURY
OR THE OTHER WAY AROUND?
OF COURSE NOT.
ALL OF THE THINGS IN OUR SOLAR SYSTEM
ARE INTERESTING IN THEIR OWN WAY,
AND WE SHOULD LEARN AS MUCH AS WE CAN ABOUT EACH ONE.
- I WOULD THINK THAT FOR ME,
THE THING THAT I LEARNED FROM THIS
AND THAT I'VE LEARNED TIME AND TIME AGAIN IS,
IF YOU HAVE AN IDEA THAT SEEMS REALLY INTERESTING TO YOU,
GO THROUGH WITH IT.
DO WHAT YOU WANT TO DO WITH IT, AND MOVE FORWARD.
AND IF IT'S NEW, IF IT'S AN ORIGINAL IDEA,
THEN IT'S AMAZING.
YOU KNOW, YOU GET A TREMENDOUS AMOUNT OF FEEDBACK.
YOU KNOW, THROUGH THIS PHOTOGRAPH
AND THROUGH WORK THAT I'VE DONE ON THE BIG PICTURE,
I'M LEARNING,
AND I FEEL LIKE THERE'S LEARNING BACK AND FORTH.
- AND ALAN'S BEEN INTERESTED IN NASA
AND ALL THE COOL THINGS THEY DO EVER SINCE HE WAS ABOUT OUR AGE.
- MY BACKGROUND WITH NASA
IS EVER SINCE I WAS REALLY, REALLY SMALL.
I'VE JUST HAD A TOTAL FASCINATION FOR IT.
I MEAN, IT'S SOMETHING THAT REALLY INSPIRED ME A LOT.
I REMEMBER, AS A SMALL CHILD, SENDING MAIL,
IN THE ACTUAL POST, OFF TO NASA,
ASKING THEM TO SEND ME ANY SORT OF THING THAT THEY HAD,
LIKE AN IMAGE OR SOMETHING LIKE THAT,
AND I GOT BACK THIS HUGE PACKAGE OF--
YOU KNOW, IT'S, LIKE, THAT THICK.
IT HAD IMAGES AND DIAGRAMS AND PICTURES AND PAINTINGS,
AND IT WAS JUST--I REMEMBER JUST TEARING THROUGH THAT FOR MONTHS.
IT WAS THIS TREASURED THING I HAD.
- THESE DAYS, YOU DON'T EVEN HAVE TO WRITE TO NASA
LIKE ALAN DID.
- GO TO NASA'S SOLAR SYSTEM WEBSITE
AND CHECK OUT EVERYTHING IT HAS TO OFFER.
THERE'S GAMES, INTERACTIVES, VIDEOS,
PICTURES OF THE PLANETS, AND MUCH MORE.
- COOL!
AND JUST THINK: EVERY TIME WE DISCOVER A NEW OBJECT
IN THE SOLAR SYSTEM,
OUR WORLD JUST GOT A LITTLE BIT BIGGER.
- "OUR WORLD."