NASA's Dawn Defines Vesta's Role in Solar System History

>>> GOOD AFTERNOON. MY NAME IS DWAYNE BROWN WITH THE
OFFICE OF COMMUNICATIONS AND WELCOME TO NASA HEADQUARTERS.
ASTEROIDS ARE A POPULAR SUBJECT THESE DAYS, AND TODAY WE'LL GET
UP CLOSE AND PERSONAL WITH THE GIANT ASTEROID VESTA COURTESY OF
NASA'S DAWN SPACECRAFT. WE'LL HAVE BRIEF PRESENTATIONS
AND THEN OPEN IT UP FOR QUESTIONS.
AND YOU CAN FOLLOW US ON THE INTERNET AT WWW.NASA.GOV/DAWN.
SOMETHING WE'RE DOING TO BE INCLUDED IN SCIENCE PRESS
CONFERENCES IS USING THE INCREDIBLE AUDIENCE OF SOCIAL
MEDIA. JOIN THE CONVERSATION AT
#ASKNASA. OF COURSE, YOU CAN FOLLOW US ON
THE OTHER NASA SOCIAL MEDIA SITES THAT INCLUDE FACEBOOK,
TWITTER, YOUTUBE, AND OTHERS. BEFORE I INTRODUCE TODAY'S
SPEAKERS, IT IS MY HONOR AND PLEASURE TO INTRODUCE DR. JIM
GREEN, DIRECTOR OF NASA'S PLANETARY SCIENCE DIVISION TO
GIVE US SOME OPENING REMARKS. DR. GREEN?
>> THANK YOU VERY MUCH, DWAYNE. IT'S, INDEED, A PLEASURE TO COME
AND TALK ABOUT SOME OF THE EXCITING SCIENCE RESULTS THAT
WE'LL HEAR ABOUT TODAY, BUT I WANT TO TAKE YOU BACK 50 YEARS
BEFORE WE START AND CONSIDER THIS, 50 YEARS AGO WE ONLY
UNDERSTOOD THE SOLAR SYSTEM BY ANALYZING THE LIGHTS IN THE BACK
OF A TELESCOPE. SO THIS IS, INDEED, OUR 50th
ANNIVERSARY OF PLAN TEAR RI SCIENCE.
NASA PUT IN PLACE A WHOLE SERIES OF PROGRAMS THAT ALLOWED US TO
LAUNCH SATELLITES IN FAR REACHES OF OUR SOLAR SYSTEM FROM MERCURY
ALL THE WAY OUT TO THE OUTER REACHES OF OUR ENVIRONMENT, AND
OVER THOSE YEARS WE HAVE MADE SOME EXCITING DISCOVERIES.
THE DISCOVERY PROGRAM, WHICH STARTED 20 YEARS AGO AND HAS
LAUNCHED NOW 11 MISSIONS BRINGS THAT EXCITEMENT REALLY TO A
FOCUS. AND TODAY'S MISSION, DAWN,
REALLY EXEM PLE 2350IS THE INVESTIGATOR SCIENCE THAT'S
ACCOMPLISHED THROUGH THIS PROGRAM.
WE'RE REALLY SO DELIGHTED WITH THE RESULTS KNOWING THAT THERE'S
MORE TO FOLLOW AS DAWN BEGINS ANOTHER JOURNEY, BUT FOR NOW,
LET'S GET GOING AND LET ME TURN IT BACK OVER TO DWAYNE TO
INTRODUCE THE SPEAKERS. >> THANK YOU, JIM.
LET'S LEARN ABOUT VESTA. LET ME INTRODUCE TODAY'S
SPEAKERS STARTING WITH CAROL RAYMOND.
DAWN DEPUTY PRINCIPAL INVESTIGATOR, NASA'S JET
PROPULSION LABORATORY IN PASADENA, CALIFORNIA.
HAP McSWEEN, UNIVERSITY OF TENNESSEE IN KNOXVILLE.
VISHNU REDDY, A DAWN FRAMING CAMERA TEAM MEMBER FROM THE MAX
PLANCK INSTITUTE FOR SOLAR SYSTEM RESEARCH IN GERMANY AND
THE UNIVERSITY OF NORTH DAKOTA IN GRAND FORKS.
DAVID O'BRIEN, PLANT TEAR SCIENCE INSTITUTE IN TUCSON,
ARIZONA. CHRISTINA De SANCTIS, A DAWN
CO-INVESTIGATOR AND VISIBLE AND INFRARED MAPPING SPECTROMETER
TEAM LEAD FROM THE ITALIAN NATIONAL INSTITUTE FOR
ASTROPHYSICS IN ROME. WITH THAT, I'LL TURN IT OVER TO
CAROL. >> THANK YOU, DWAYNE.
WE'RE ALL DELIGHTED TO BE HERE TODAY TO TALK TO YOU ABOUT
DAWN'S FIRST RESULTS FROM VESTA. DAWN'S MISSION AT VEST AT THAT
HAS BEEN A SPECTACULAR SUCCESS. IT'S TRANSFORMED VESTA FROM A
FUZZY ORB INTO A PLAN TEAR RI BODY WHICH HAS EXCEEDED OUR
EXPECTATIONS IN MANY WAYS THAT WE'LL BE TALKING ABOUT TODAY.
DAWN'S DATA PROVIDE THE FIRST COMPREHENSIVE ANALYSIS OF
VESTA'S GLOBAL PROPERTIES AND PROVIDE A FIRM LINK BETWEEN
METEOR RIGHTS THAT HAVE FALLEN TO EARTH AND THEIR PARENT BODY,
VESTA. MAY I HAVE THE FIRST GRAPHIC?
VESTA IS A VERY SPECIAL AND UNIQUE OBJECT.
IT'S THE SECOND MOST MASSIVE ASTEROID AND ONE OF THE
BRIGHTEST ASTEROIDS IN THE MAIN BELT BETWEEN MARS AND JUPITER.
IT'S NORM MOUSE SIZE RELATIVE TO OTHER ASTEROIDS THAT HAVE BEEN
VISITED IS SHOWN IN THIS MONTAGE.
AS WE'LL DESCRIBE TODAY, VESTA EXHIBITS MANY THINGS THAT ARE
TRANSITIONAL BETWEEN ASTEROIDS AND PLANETS VERSUS YOUR GARDEN
VARIETY OF ASTEROIDS. THE COLLECTION OF SIX PAPERS
THAT ARE BEING PUBLISHED IN "SCIENCE" DESCRIBE ITS COLORFUL
AND DIVERSE SURFACE AND THE PLAN FATHER RI PROCESSES THAT HAVE
SHAPED THE BODY SINCE ITS FORMATION.
IN THE SECOND GRAPHIC, THIS MONTAGE EMPHASIZES THAT VEST'S
HISTORY APPEARS TO BE MORE SIMILAR TO ROCKY TERRESTRIAL
PLANETS, MARS AND THE EARTH'S MOON, THAN TO ITS LARGER
SIBLING, THE DWARF PLANET, WHICH WILL BE THE SECOND TARGET OF THE
DAWN MISSION. DAWN'S DATA HAVE ENABLED THE
HISTORY OF VEST A TO BE DEFINED. IT FORMED WITHIN 2 MILLION YEARS
AFTER THE FIRST SOLIDS FORMED IN THE SOLAR SYSTEM.
BEFORE SERIES FORMED, BEFORE THE TERRESTRIAL PLANETS FORMED, AND
WHEN THE CONCENTRATION OF RADIOACTIVE MATERIAL WAS SHORT
DECAY TIMES GENERATED ENOUGH HEAT INSIDE VEST A TO CAUSE
MELTING, WE NOW KNOW THAT VEST A IS THE ONLY INTACT LAYERED
PLANETARY BUILDING BLOCK SURVIVING FROM THE VERY EARLIEST
DAYS OF THE SOLAR SYSTEM. VEST A IS ALSO VERY SPECIAL
BECAUSE THEY'VE BEEN LIPGED BY TELESCOPIC OBSERVATIONS.
DAWN IS UNIQUE BECAUSE IT'S THE FIRST TIME THAT A SPACECRAFT HAS
BEEN ABLE TO VISIT AN OBJECT KNOWN TO BE THE SOURCE OF
SAMPLES AFTER THOSE SAMPLES WERE IDENTIFIED.
WE'VE HAD PIECES OF VEST A UNDER STUDY IN THE LABORATORY FOR
DECADES BUT ARE NOW ONLY GETTING OUT TO KNOW THE PARENT BODY AND
HAP AND CHRISTINA ARE GOING TO BE TALKING MORE ABOUT THAT.
IN THE NEXT GRAPHIC I SHOW SOME OF THE RESULTS OF OUR MISSION.
DAWN MEASURED VEST A'S MASS VERY ACCURATELY AND MAPPED ITS
TOPOGRAPHY AND GRAVITY IN GREAT PRECISION AND RESOLUTION.
THE TOPOGRAPHY IS SHOWN HERE AT THE TOP AS A COLOR CONTOURED 3 D
MAP AND IT'S ILLUSTRATING THAT VEST A HAS VERY RUGGED
TOPOGRAPHY AND IT ALSO DISPLAYS VERY STEEP SLOPES, MUCH STEEPER
THAN IS SEEN ON PLANETARY BODIES.
THIS HAS BEEN A BIG FACTOR IN THE TYPES OF MORPHOLOGIES THAT
WE SEE ON THE SURFACE. THE GRAVITY FIELD IS SHOWN COLOR
CONTOURED AT THE BOTTOM. DAWN'S GRAVITY AND TOPOGRAPHY
REVEAL THE INTERNAL DENSITY STRUCTURE OF VEST A AND HAVE
CONFIRMED THAT VEST A HAS A CONCENTRATION OF MASS AT ITS
CENTER PROVING THAT IT IS A DIFFERENTIATED BODY WITH AN IRON
CORE, A SILICATE MANTLE AND A LESS DENSE BA SAL PARTICULAR
CRUST, THE SAME AS MERCURY, MARS, THE EARTH AND THE MOON.
IN MY LAST GRAPHIC, THIS IS A CUT AWAY VIEW OF VEST A'S
INTERNAL STRUCTURE, AND ASSUMING THAT THE CORE'S MADE OF THE SAME
MATERIAL AS IRON NICKEL METEOR RIGHTS, WE CAN USE THE GRAVITY
DATA TO DERIVE THE SIZE OF THE CORE, WHICH IS AT ABOUT 70 MILES
IN RADIUS OR ABOUT 40% OF THE RADIUS OF THE BODY OR ABOUT 18%
OF THE MASS OF THE BODY. DAWN'S EVIDENCE FOR THE
DIFFERENTIATED NATURE OF THE INTERIOR OF VEST A CONFIRMS
CONJECTURAL THEORIES BASED ON THE H.E.D. METEORITES AND
THEREFORE INCREASES THE VALUE OF THOSE SAMPLES FOR STUDYING THE
EARLY -- THE PROCESSES IN THE EARLY SOLAR SYSTEM.
VEST A IS SPECIAL BECAUSE IT SURVIVED THE INTENSE COLLISIONAL
ENVIRONMENT OF THE MAIN ASTEROID BELT FOR BILLIONS OF YEARS
ALLOWING US TO INTERROGATE A KEY WITNESS TO THE EVENTS AT THE
VERY BEGINNING OF THE SOLAR SYSTEM.
WE BELIEVE VEST A IS THE ONLY INTACT MEMBER OF A FAMILY OF
SIMILAR BODIES THAT HAS SINCE PERISHED.
TURN IT OVER TO HAP TO TELL YOU MORE ABOUT THE H.E.D. METEORITE
CONNECTION. >> THANK YOU, CAROL.
THE SYNERGY OF SPACECRAFT EXPLORATION AND SAMPLES THAT CAN
BE ANALYZED IN THE LABORATORY HAS MARKEDLY ENHANCED WHAT WE
UNDERSTAND ABOUT THE MOON. VEST A IS SPECIAL BECAUSE WE
ALREADY HAVE ITS SAMPLE IN THE FORM OF HUNDREDS OF METEOR IETS.
I'D LIKE TO TALK ABOUT HOW DAWN CONFIRMS THIS CONNECTION BETWEEN
THE ASTEROID AND ROCKS THAT FELL FROM THE SKY.
CAN I HAVE MY FIRST SLIDE? MAKING THIS CONNECTION IS A
RECURRENT THEME OF OUR NEW SCIENCE PAPERS.
NEXT SLIDE PLEASE. THE HOWARD IET U CITE DODGE DID
HE NIGHT METEOR RIGHTS. WE NORMALLY SAY H.E.D. METEOR
RIGHTS, ARE SEEN HERE AS VIEWED THROUGH A MICROSCOPE.
THE H.E.D.s ARE A COMPLEX ASSORTMENT OF ROCKS WHOSE
PROPERTIES INDICATE THAT SOME OF THEM ERUPTED ON THE SURFACE AS
LAVAS, SOME OF THEM COOLED AND CRYSTALIZED SLOWLY AT DEPTH IN A
LARGE PARENT BODY. NEXT SLIDE PLEASE.
AT 325 MILES ACROSS VEST A IS CERTAINLY A LARGE PARENT BODY.
THIS FALSE COLOR MAP OF DAWN FRAMING CAMERA BAND RATIOS
ILLUSTRATES THAT VEST A'S SURFACE IS HETEROGENEOUS LIKE
THE H.E.D. METEOR RIGHTS UNLIKE THE SMALL ASTEROIDS THAT WE
PREVIOUSLY VISITED BY SPACECRAFT.
ANOTHER INDICATION THAT A LARGE BODY PRODUCED THE HEDs IS ITS
PROTRACTED IMPACT HISTORY. NEXT SLIDE PLEASE.
MOST OF THESE METEOR RIGHTS ARE BRIDGES, THAT IS ROCKS ASSEMBLED
FROM BROKEN FRAGMENTS AS YOU CAN SEE ON THE LEFT, AND THAT IS
MOST READILY ACCOMPLISHED IN A LARGE GRAVITY FIELD.
THE SQUIGGLES ON THE RIGHT SHOW THAT THESE BRIDGES WERE CREATED
BY IMPACTS OVER A PERIOD OF PERHAPS A BILLION YEARS AND THE
REPEATED IMPACTS ARE RECORDED BY RESETTING OF SOME RADIOACTIVE
ISOTOPE CLOCKS IN THE METEOR RIGHTS THAT CAN BE ANALYZED.
NEXT PLEASE. THE ANCIENT AGE OF VEST A'S
SURFACE IS REVEALED BY DAWN'S NEW HIGH RESOLUTION IMAGES OF
HEAVILY CRATERED TERRAINS AS YOU CAN SEE IN THIS IMAGE,
ESPECIALLY IN THE NORTHERN PART OF THE IMAGE.
THE RADIOMETRIC AGES OF THE HED METEOR RIGHTS RECORD THEIR MAG
MAS 4.5 BILLION YEARS AGO AND THE DENSITY OF CRATERS IN THE
NORTHERN REGION IS CONSISTENT WITH THAT AGE.
THE NEXT SLIDE WILL SHOW YOU THE SPECTRUM OF SUNLIGHT REFLECTED
FROM VEST A AND RECORDED BY DAWN'S VEER INSTRUMENT.
THAT SPECTRUM SHOWN IN WHITE CLOSELY RESEMBLES THE LABORATORY
SPECTRA OF THE VARIOUS HEDs ESPECIALLY THE HOWARD DIETS
WHICH ARE SAMPLES MOST LIKELY TO HAVE RESIDED ON THE SURFACE OF
VEST A. MORE IMPORTANTLY, THE MAP
LOCATIONS OF THEIR SPECTRAL TYPES MAKE PERFECT GEOLOGIC
SENSE. NEXT SLIDE SHOWS A MAP OF VEST
A'S SOUTH POLE REGION AND IT ILLUSTRATES THE DEPTH OF THE ONE
MICRON BAND WHICH IS A PROXY FOR THE PROPORTION OF DYE OJ GE
NIGHT. THE U CITES, WHICH FORMED ON THE
SURFACE, ARE CONCENTRATED IN TERRAINS OUTSIDE OF THIS REGION
AND THE DIOGENITES WHICH FORMED DEEP UNDERGROUND ARE ONLY
EXPOSED WHERE THEY HAVE BEEN EXCAVATED IN LARGE CRATERS LIKE
THE RIASYLVIA BASIN WHICH IS SHOWN HERE AND WHICH DANE WILL
TALK ABOUT LATER. FINALLY, DAWN'S NEW MEASUREMENTS
OF VEST A'S BULK DENSITY AND GRAVITY ALLOW US TO RECONSTRUCT
MODELS OF THE UNSEEN INTERIOR. THE NEXT SLIDE SHOWS YOU CAROL'S
DIAGRAM THAT INDICATES THAT VEST A HAS A LARGE IRON HEART WITH A
RADIUS OF ABOUT 70 MILES. A SUBSTANTIAL CORE IS PREDICTED
FOR THE HED PARENT BODY BECAUSE THEY ARE DEPLETED IN METALLIC
ELEMENTS AND MODELS FOR THE HED PARENT BODY THAT ARE BASED ON
THE PROPERTIES OF THE HED METEOR RIGHTS PREDICT A CORE OF ABOUT
THIS SIZE. SO DAWN'S OBSERVATIONS HAVE
CONVINCED MOST OF US, CERTAINLY ME, THAT VEST A IS THE HED
PARENT BODY. WITH THIS LINK MORE FIRMLY
ESTABLISHED, WE NOW ARE USING MEASUREMENTS OF THE HEDs TO
COMPLIMENT DAWN'S REMOTE SENSE DAG AT THAT AND TO HELP US
INTERPRET IT BETTER. THE TAKE-AWAY MESSAGE IS THAT WE
ARE NOW UNRAVELING THE GEOLOGIC HISTORY OF VESTA IN WAYS THAT
WOULD NOT BE POSSIBLE WITHOUT SAMPLES.
I'D LIKE TO NOW PASS IT ON TO VISHNU WHO WILL TALK ABOUT
DAWN'S NEW COLOR IMAGES. >> THANK YOU, HAP.
THE COLOR IMAGES OBTAINED BY THE DAWN FRAMING CAMERA BASICALLY
SHOWS THAT VEST A IS UNLIKE ANY OTHER OBJECT WE'VE VISITED SO
FAR IN THE SOLAR SYSTEM AND A FEW POINTS I WOULD LIKE YOU TO
TAKE AWAY FROM MY PRESENTATION HERE TODAY.
THE FIRST THING IS THAT ON VEST A WE SEE A WIDE RANGE OF
BRIGHTNESS VARIATION, SO WE SEE AREAS THAT ARE AS BRIGHT AS SNOW
AND AREAS THAT ARE AS DARK AS COLE.
THE SECOND POINT I WOULD LIKE TO MAKE IS THAT WE SEE NO EVIDENCE
FOR THIS ORIGINAL CRUST ON THE VOLCANIC FEATURES WE EXPECT TO
SEE FROM THE HED METEOR RIGHTS. WE DON'T SEE ANY EVIDENCE OF IT.
THE REASON WE THINK IS THAT MOST OF VEST A'S ORIGINAL PRIMITIVE
CRUST HAS BEEN AFFECTED BY IMPACTS AND ALL THE ORIGINAL
MATERIAL HAS BEEN PULVERIZED AND MIXED TOGETHER.
THE THIRD POINT I'D LIKE TO MAKE IS THAT WE HAVE IDENTIFIED
DIFFERENT COLORED UNITS WITHIN VEST A'S SURFACE, DIFFERENT
TOPOGRAPHIC LEVELS, AND THIS IS EVIDENCE FOR AN INTERNAL
STRUCTURE JUST LIKE HAP AND CAROL POINTED OUT.
AND THE MOST INTERESTING PART ABOUT THIS IS THAT THE LOWEST
POINT OF THE SOUTH POLE REA SYLVIA BASIN SHOWS THESE DYE OJ
GE NIGHT METEOR RIGHTS. WE THINK THESE CAME FROM THE
LOWER CRUST, PROBABLY THE UPPER MANTLE OF VEST AT THAT.
THERE'S A CORRELATION BETWEEN COMPILATION AND TOPOGRAPHY.
THE OTHER THING WE WANT TO SHARE IS WE DON'T FIND ANY EVIDENCE
FOR OLIVE BEAM IN THE IMAGES. THE FINAL POINT I WOULD LIKE TO
MAKE IS THAT WHILE VEST A HAS A LOT OF SIMILARITIES WITH THE
MOON, THE NEXT LARGEST DIFFERENTIATED OBJECT WE HAVE IN
OUR SOLAR SYSTEM APART FROM VEST A, THERE'S SOME KEY DIFFERENCES.
ON THE MOON WHAT WE SEE IS THAT WE HAVE A CLEAR CORRELATION
BETWEEN TOPOGRAPHY AND THE THE LIBIDO.
IN VEST A WE DON'T SEE THIS CLEAR CORRELATION.
PART OF IT, THE REASON COULD BE THE IMPACT PROCESSES HAVE
IMPACTED IT SINCE WE DON'T SEE THE CRUST OF VEST A.
WITH THAT I'D LIKE TO SHOW A COUPLE OF VIDEOS TO ILLUSTRATE
MY IDEAS. HERE YOU SEE A BEAUTIFUL IMAGE
THAT HAS BEEN WRAPPED ON THE SHAPE MODEL OF VEST A AND THEY
HAVE CREATED THIS VIDEO OF IT. WHAT YOU SEE ARE THE FAMOUS SNOW
MAN CRATERS. THE LARGEST CRATER THERE IS THE
MARCIA CRATER WHICH IS APPROXIMATELY 60 KILOMETERS
ACROSS. THESE ARE FRAMING CAMERA FILTERS
THAT ARE IN THE INFRARED. I WOULD SAY THE CLOSEST THING
THAT COULD ACTUALLY SENSE AN IMAGE LIKE THIS IS A RATTLE
SNAKE. IF YOU HAD A SNAKE SNUCK ABOARD
DAWN, YOU WOULD PROBABLY SEE AN IMAGE LIKE THIS OFF VEST A.
THIS SHOWS SOME IMPORTANT INFORMATION.
AS YOU CAN SEE, THIS TOPOGRAPHIC LOWS WITHIN THE LARGE CRATER
THAT IS BRIGHT COMPARED TO THE TOPOGRAPHIC HIGHS WHICH ARE
DARKER. IF YOU GO TO THE NEXT VIDEO
PLEASE. THE NEXT VIDEO SHOWS SOMETHING
SLIGHTLY DIFFERENT. HERE WHAT WE ARE HAVE COLORATION
YES IMAGES. WHAT WE HAVE TAKEN IS THESE
DIFFERENT FILTERS AND WE HAVE RATIOED THEM SO WE GET MORE
DIFFERENT INFORMATION ABOUT THE SURFACE OF VEST A.
WHAT YOU SEE HERE IS A 34 KILOMETER CALCULATOR NAMED OPIA.
IT HAS A BRIGHT RED EJECTOR THAT IS COMING OUT OF THIS CRATER.
WE'RE NOT REALLY SURE WHAT THIS RED EJECTOR IS AT THIS POINT.
WHAT WE PROBABLY THINK IT'S RELATED TO THE IMPACT THAT
AFFECTED IT OR PROBABLY SOMETHING THAT WAS EXCAVATED
WITHIN THE SITE ITSELF. SO WE GET SOME REALLY COOL --
NOT ONLY REALLY COOL IMAGES BUT ALSO WE GET IMPORTANT SCIENTIFIC
IMAGES FROM THIS. MOST OF THE SCIENCE WE HAVE DONE
SO FAR HAS BEEN USING HAMMER DATA WHICH IS APPROXIMATELY 60
KILOMETERS PER PIXEL. WE HAVE 16 METERS PERFECT PIXEL
SO WE'RE CONTINUING TO DO REALLY COOL SCIENCE AND WE HOPE TO HAVE
MANY MORE EXCITED RESULTS TO COME.
WITH THAT, I'LL PASS ON TO DAVE O'BRIEN, MY COLLEAGUE HERE.
>> THANK YOU, VISHNU. SO AS NOTED PREVIOUSLY, VEST A
DATES BACK TO THE BEGINNING OF THE SOLAR SYSTEM, AND GIVEN ITS
LOCATION IN THE ASTEROID BELT, IT'S BEEN RECORDING IMPACTS FROM
ASTEROIDS EVER SINCE THAT POINT MAKING IT A VERY IMPORTANT
OBJECT TO STUDY AS WE'RE TRYING TO RECONSTRUCT THE DYNAMICAL
HISTORY AND COLLISIONAL HISTORY OF THE SOLAR SYSTEM.
THE FIRST ONE SHOWS THE GLOBAL MAP OF THE SURFACE OF VEST A
SHOWING A WIDE RANGE OF CRATERS FROM ALL KINDS OF DEGRADATION
STATES FROM YOUNG FRESH CRATERS TO OLD DEGRADED CRATERS.
WE'VE CATALOGED CLOSE TO 2000 CRATERS LARGER THAN 2 1/2 MILES
ON THE SURFACE AND ARE USING THOSE TO HELP UNRAVEL THE
SURFACE HISTORY OF VEST A. THE LARGER CRATERS ARE SOMETIMES
DIFFICULT TO PICK OUT FROM THE IMAGES ALONE.
THE NEXT SLIDE WILL SHOW THE GLOBAL TOPOGRAPHY MAP.
IN THIS MAP BLUE IS LOW AND RED IS HIGH.
WE CAN PICK OUT A NUMBER OF LARGE DEPRESSIONS, SEVEN OF
WHICH ARE CIRCLED ON THIS MAP. THESE ARE THE SEVEN MOST
PROMINENT IMPACT BASINS. THERE MAY BE OTHERS AS WELL.
SOME OF THE OTHER LOW AREAS ARE OF UNCERTAIN ORIGIN.
ONE THING TO NOTE HERE IS IN THIS IMAGE AND IT'S MORE CLEAR
IN THE NEXT SLIDE AS WELL, THE TWO LARGEST IMPACT BASINS ARE IN
THE SOUTH POLAR REGION. NEXT SLIDE PLEASE.
THIS SHOWS THE RIO SYLVIA BASIN ABOUT 300 AND 250 MILES ACROSS
RESPECTIVELY WHICH ARE IN THE SOUTH POLAR REGION.
ONE OF THE NEW RESULTS FROM DAWN IS THAT WE'VE BEEN ABLE TO USE
OUR GLOBAL CRATER CATALOGS THAT HAVE BEEN CREATED TO COUNT THE
NUMBER OF SMALL CRATERS ON THESE IMPACT BASE SINCE AND ESTIMATE
AN AGE OF THEM. RAY A SYLVIA BASIN HAS A
SURPRISINGLY YOUNG AGE OF ABOUT 1 BILLION YEARS OLD.
THE ZA NOOEN YEAH BASIN WHICH LIES PARTIALLY UNDERNEATH HAS AN
AGE OF ABOUT 2 BILLION YEARS OLD OR POSSIBLY SOMEWHAT OLDER.
SINCE REA SYLVIA FORMED ON TOP OF IT IT ERASED SOME OF THE
CRATERS. 2 BILLION YEARS IS A LOWER LIMIT
FOR THAT ONE. THE RELATIVELY YOUNG AGES OF
BOTH OF THESE BASINS IS IN STARK CONTRAST TO WHAT WE FIND ON THE
MOON WHERE ALL OF THE OLD BASE SINCE ARE AT LEAST 3 1/2 BILLION
YEARS OLD. THIS IS TELLING US THE DYNAMICAL
HISTORY IN THESE TWO DIFFERENT PARTS OF THE SOLAR SYSTEM AND
THE COLLISIONAL HISTORY EXPERIENCE BY THE MOON AND VEST
A IS SURPRISINGLY DIFFERENT. THIS IS TELLING US SOMETHING
ABOUT THE DYNAMICAL HISTORY OF THE SOLAR SYSTEM AND IT'S A
COMPLEX STORY THAT WE'RE REALLY ONLY BEGINNING TO UNRAVEL.
IN THE NEXT SLIDE YOU'LL SEE HOW THE RELATIVELY YOUNG FORMATION
AGE OF THE RAY A SYLVIA BASIN HAS INFLUENCED THE SURFACE AND
LED TO A STRONG NORTH SOUTH DICHOTOMY ON VEST A.
THIS IMAGE SHOWS A 1/4 OF VEST A'S SURFACE, SORT OF A WEDGE CUT
OUT OF IT, ALL THE WAY FROM SOUTH TO NORTH.
IN THE BOTTOM YOU'LL SEE IN THE SOUTHERN HEMISPHERE THE REA
SYLVIA RIM AND TOWARDS THE NORTH WHERE IT'S DARK IS WHERE WE
DON'T CURRENTLY HAVE DATA BECAUSE THAT PART OF VEST A IS
STILL IN SHADOW. YOU'LL NOTICE THAT IN THE SOUTH
THERE IS MANY -- THERE IS VERY SHARP TOPOGRAPHY AND VERY FEW
CRATERS. AS YOU MOVE TOWARDS THE NORTH,
THERE'S A LOT MORE CRATERS. IT'S A VERY DENSELY CRATERED
SURFACE. THE TOPOGRAPHY IS SMOOTHER AND
MORE ERODED. THIS IS BECAUSE THE FORMATION OF
REA SYLVIA UNDERNEATH THE CRATER ITSELF AND OUTSIDE OF THE CRATER
FOR HUNDREDS OF MILES COVERED THAT AREA IN EJECTED MATERIAL
ESSENTIALLY RESETTING THE SURFACE.
MOST OF WHAT WE SEE IN THE SOUTH IS REALLY ONLY ABOUT A BILLION
YEARS OLD. AS WE GO TOWARDS THE NORTH,
THAT'S THE MUCH MORE ANCIENT TERRAIN OF VEST A.
THE FOLLOWING MOVIE OR THE MOVIE THAT IS SHOWING NOW SHOWS A VIEW
GOING INTO THE SOUTH POLE BASIN. AGAIN, RED IS HIGH AND BLUE IS
LOW HERE. THIS IS BASED ON THE GLOBAL
TOPOGRAPHY MODELS. YOU'LL SEE THAT THERE'S A
RELATIVELY HIGH AREA SURROUNDING THE CRATER, THE REDDISH RIM IN
MOST AREAS, WHERE THERE'S A GAP WHERE THE VERY THEN YEAH BASIN
IS OVERLAPPED BY REA SYLVIA. IN THE CENTER IS A VERY
PRONOUNCED CENTRAL PEAK AND ALSO AN INTERESTING SPIRALING GROOVED
PATTERN ON THE FLOOR OF THE REA SYLVIA BASIN.
THE CENTRAL MOUND WAS SOMEWHAT SURPRISING AT FIRST BECAUSE IT'S
MUCH LARGER IN PROPORTION TO THE CRATER SIZE THAN IMPACT CRATER
CENTRAL PEAKS THAT WE SEE ON THE MOON, FOR EXAMPLE.
THE NEXT SLIDE SHOWS A VIEW FROM THE RIM OF REA SYLVIA LOOKING
INTO THE CRATER. NEXT SLIDE PLEASE.
THANK YOU. HERE YOU CAN SEE A PROMINENT
SCARP OR CLIFF OFF TO THE RIGHT OF THE IMAGE, PART OF THE RIM OF
REA SYLVIA. IN THE CENTER IS THE CENTRAL
MOUND. THE TOP IS IMAGING DATA WRAPPED
OVER THE TOPOGRAPHY AND THE BOTTOM IS THE COLOR CODED
TOPOGRAPHY. THE CENTRAL MOUND IS ABOUT 1/3
OF THE DIAMETER OF THE CRATER. AT FIRST THIS IS VERY SURPRISING
BECAUSE CRATERS ON THE MOON AND OTHER LARGE BODIES DON'T REALLY
LOOK LIKE THIS. WHEN WE'VE LOOKED AT OTHER
SMALLER BODIES IN THE SOLAR SYSTEM, LIKE OUTER SOLAR SYSTEM
SATELLITES, WE'VE FOUND THAT THEY HAVE A SIMILAR STRUCTURE
WITH A VERY DOME LIKE, VERY LARGE CENTRAL PEAK.
THIS APPEARS TO BE A CONSEQUENCE OF CRATERS FORMING ON A BODY
WHERE THE CRATER IS ALMOST AS LARGE AS THE BODY ITSELF SO THE
PLANETARY CURVATURE REALLY PLAYS A ROLE IN THE SHAPE OF THE
CRATER. WE'VE BEEN ABLE TO USE THE
GLOBAL TOPOGRAPHY MODELS TO MAKE AN ESTIMATE OF WHAT THE BOTTOM
OF THE REA SYLVIA BASIN IS. IN THE NEXT SLIDE WE SHOW A
SIMILAR FIGURE AGAIN. OUR ESTIMATE OF ABOUT 250,000
CUBIC MILES OF MATERIAL EXCAVATED FROM REA SYLVIA.
A LARGE PART OF THIS WILL REMAIN ON THE SURFACE AS I KNOW TO
PREET PREVIOUSLY ERASING MANY EXISTING CRATERS IN THE SOUTH.
A LARGE FRACTION IS EJECTED INTO SPACE.
TO PUT THIS INTO ANOTHER PEKT SPEKTTIVE, 250,000 CUBIC MILES
CAN FILL THE GRAND CANYON A,000 TIMES OVER.
THE AMOUNT OF MATERIAL EJECTED INTO SPACE FROM THE REA SYLVIA
IMPACT IS MORE THAN ENOUGH TO EXPLAIN THE NUMBER OF VEST A
FAMILY ASTEROIDS THAT WE SEE IN SPACE.
THESE VEST A FAMILY ASTEROIDS ARE VERY IMPORTANT BECAUSE
THEY'RE ESSENTIALLY AN INTERMEDIATE LINK BETWEEN THE
SURFACE OF VEST A AND THE HED METEOR RIGHTS THAT WE HAVE HERE
ON EARTH. ANOTHER INTERESTING POINT ABOUT
THIS IS THAT THE INDEPENDENT ESTIMATES OF THE AGE OF THAT
VEST A FAMILY PUT IT AT ABOUT A BILLION YEARS.
SO THE FACT THAT WE'RE FINDING A BILLION YEAR AGE FOR REA SYLVIA
WHICH COINCIDES WITH THE AGE OF VEST A ASTEROID FAMILY REALLY
KIND OF TIES THE WHOLE DYNAMICAL STORY TOGETHER.
NOT ONLY IS THE DAWN MISSION TELLING US THAT VEST A IS THE
HED PARENT BODY, IT'S ALSO SOLIDIFYING THE DYNAMICAL LIPG
BETWEEN THE SURFACE OF VEST A AND THE BODIES THAT WE HAVE ON
EARTH THAT WE'RE STUDYING AS METEOR RIGHTS.
WITH THAT I'D LIKE TO HAND IT OFF TO CHRISTINA WHO WILL TALK
ABOUT THE COMPOSITION OF VEST A AND THE RIO SYLVIA BASIN.
>> SO DAWN DEMONSTRATES THAT VEST A IS A PLANET.
WE SEE VERY DEEP DOWN AND POSSIBLY ALSO DOWN INTO IT.
THEY ARE THE SAME THAT WE SEE AS METEOR RIGHTS.
THE GLOBAL DISTRIBUTION TELL US THAT VEST A WOULD HAVE BEEN
EARLY IN ITS HISTORY AND THESE NEW FINDING GIVE OUT THE WINDOWS
IN THE PROCESS THAT FORM THE EARLIEST BODY OF VEST A.
IN THE NEXT SLIDE YOU WILL SEE HOW THE DISTRIBUTION, TELL US
ABOUT IT. THIS COLOR IMAGE, FIRST COLOR
IMAGES HAS BEEN TAKEN WITH THE VISIBILITY MAPPING SPEC THROW
METER. WE ONLY USE THE SPEC THROW
METER. YOU SEE THAT THERE IS A CLEAR
DICHOTOMY BETWEEN THE NORTHERN REGION, THE SOUTHERN REGION.
THE NEXT SLIDE YOU SEE THAT THESE TWO REGION CORRESPONDS TO
DIFFERENT COMPOSITION AND THIS COMPOSITION TELL US ABOUT THE
PROCESS THAT FORM VEST A. FOR INSTANCE, IN THE BLUE, THAT
CORRESPONDS TO THE SOUTH POLAR REGION, TELL US THAT WE HAVE DYE
OJ GE NIGHTS. THESE MINERALS ARE MADE BY ROCKS
FORMING. THE NEXT SLIDE YOU SEE HOW THESE
MINERALS ARE ON THE REST OF THE SURFACE.
THE VIOLET MEANS THAT WE HAVE MORE DYE OJ GE NIGHTS LIKE
MINERALS. THE ONES IN YELLOW MEANS THAT WE
HAVE MORE UK KA RIGHT LIKE MINERALS.
AND THE IMAGERY DATA TELL US THAT THE BASIN IS A MINERAL THAT
FORMS. IN THE SOUTHERN REGION WE HAVE A
PREVALENCE OF U KROOIT MINERALS SO WE THINK OVERALL THE MEN NER
ROLLING SAYS THEY WERE DEPOSITED BY THE IMPACTS AND THE REGION IN
THE NORTHERN PART OF VEST A SEEMS TO RETAIN THE MOST RICH
MEN NER ROLLING, RICH U KRIT TICK MINERALOGIES.
IN THE NEXT SLIDE YOU SEE HOW THESE LARGE SCALE VARIATION IS
ALSO SEEN IN SMALLER SCALE SO THIS IS A FIRST COLOR IMAGE AND
IF YOU LOOK AT THESE, YOU SEE THAT WE HAVE A LOT OF DIFFERENT
MORE OFOLOGY AND THESE DIFFERENT FOR OF FOLLOWING IS DIFFERENT
COLORS. IF WE LOOK IN THE BOXES, IN THE
NEXT SLIDE YOU WILL SEE -- I'LL ZOOM ON THIS BOX.
THIS HAS BEEN DONE. THE TWILIGHT DIFFERENCES.
THE FIRST ONE IS THE BRIGHTNESS AND THE VISIBLE AWARENESS.
YOU SEE THAT WE HAVE A BRIGHT REGION AND DARKER REGION WHILE
THE CENTER IS MADE USING DIFFERENT COLOR COMBINATION AND
I LIKE THE DIFFERENT ROCKS SO YOU SEE ON ONE SIDE THAT IS
COMPLETELY DIFFERENT WITH RESPECT THE REST OF IT.
AND THE LAST IS DONE IN ORDER TO SEE THE VARIATION.
THAT'S REALLY IMPORTANT BECAUSE IT TELLS US ABOUT THE HISTORY OF
VEST A, THE EVOLUTION OF VEST A. TO CONCLUDE, NEXT SLIDE PLEASE.
THE SCALE VARIATION, THE FACT THAT WE HAVE ALSO THIS ON VEST
A, TELL US THAT VEST A IS A COMPLEX MIXTURE OF DYE OJ GER
NIGHTS AND U KA RIGHTS. THE OCCURRENCE OF THE PROPULSION
OF THIS MATERIAL TELL US THAT THESE ARE CRITICAL.
IT'S RATHER CONSISTENT WITH THE POSSIBILITY THAT VEST A WAS IN
THE SOLAR SYSTEM AND GIVES NEW RESULTS ALLOW ADDITIONAL INSIGHT
IN THE PROCESS. AND NOW WE WILL GO BACK TO CAROL
THAT WILL GIVE US SOME REMARKS. >> THANK YOU.
I HOPE WE CONVEYED HOW EXCITED WE ARE ABOUT THIS NEW DATA AND
ITS SIGNIFICANCE. I JUST WANTED TO WRAP UP WITH A
FEW KEY POINTS. AND THE FIRST IS THAT VEST A IS
AN INTACT PLANETARY BODY THAT IS TRANSITIONAL BETWEEN ASTEROIDS
AND PLANETS. VEST A IS THE PARENT BODY OF THE
HED METEOR RIGHTS WHICH ALLOWS US TO INTERPRET DAWN DATA IN FAR
GREATER DEPTH THAN WOULD OTHERWISE BE POSSIBLE.
THAT VEST A HAS DISPLAYED UNEXPECTEDLY LARGE BRIGHTNESS
VARIATIONS. AND THAT THE GIANT REA SYLVIA
BASIN IS SIGNIFICANTLY YOUNGER THAN LARGE IMPACT BASINS ON THE
MOON AND THIS WAS ALSO UNEXPECTED, AND PROVIDES
FUNDAMENTAL CONSTRAINTS ON MODELS OF THE DYNAMICS OF THE
SOLAR SYSTEM. AND THAT WRAPS UP OUR REMARKS.
>> THANK YOU ALL. >> OKAY.
NOW IT'S TIME FOR QUESTIONS. AND, AGAIN, I WANT TO WELCOME
OUR SOCIAL MEDIA AUDIENCE. IF YOU HAVE A QUESTION, BRING
THEM ON IN AT #ASK NASA. THE CONVERSATION WILL NOT STOP
HERE, LADIES AND GENTLEMEN. THE TWITTER FEED, I WILL GIVE
THAT OUT AT THE END OF THE SHOW. YOU CAN JOIN THE CONVERSATION
AND ASK QUESTIONS IN THE CONVERSATION WITH THE SCIENTISTS
AND THE TEAM. STAND BY FOR THAT.
RIGHT NOW, WE'RE GOING TO OPEN THE PHONE LINES AND THEN WE'RE
GOING TO TAKE SOME QUESTIONS FROM OUR SOCIAL MEDIA AUDIENCE.
AND FIRST UP WILL BE MIKE WALLS. >> HI.
THIS IS MIKE WALLS FROM SPACE.COM.
THIS IS FOR CAROL. YOU MENTIONED VEST A'S PROBABLY
THE LAST SURVIVING MEMBER OF A CLASS OF OBJECTS THAT USED TO
EXIST IN THE SOLAR SYSTEM. I WONDER IF YOU COULD JUST TALK
A LITTLE BIT ABOUT WHAT HAPPENED TO THE REST OF THE OBJECTS AND
WHERE DOES GERES FIT INTO THAT PICTURE.
>> SURE. WE KNOW THAT FROM THE DEBRIS
FIELD THAT'S LEFT IN THE ASTEROID BELT INDICATING
THERE -- THERE WERE OTHER BODIES THAT WERE DIFFERENTIATED SIMILAR
TO VEST A, WE KNOW THIS BECAUSE THERE ARE IRON METEORITES THAT
LOOK LIKE THE CORES OF THESE BODIES, STONEY METEORITES THAT
LOOK LIKE THE CRUST OF THESE BODIES, AND WITH COMPOSITIONS
THAT ARE ROUGHLY SIMILAR. SO WE COULD INFER BASED ON THAT
AND JUST OUR IDEAS ABOUT HOW THE EARLY SOLAR SYSTEM FORMED THAT
THERE WERE MANY OF THESE PLANETARY EMBRYOS THAT WERE COAL
A LESSING AND FORMING THE ROCKY PLANETS AND THE CORES OF THE GAS
GIANTS. BUT WHAT'S CLEAR TO US IS THAT
VEST A APPEARS TO BE THE ONLY INTACT PROTO PLANET THAT'S LEFT
BECAUSE THE COLLISIONAL ENVIRONMENT WAS SO INTENSE THAT
MANY OF THESE WERE JUST BLASTED INTO SMALL PIECES, WHICH IS WHAT
MOST OF THE BELT IS. SO AS FAR AS SERIES, SERIES IS
ALSO -- IT'S NOT AN IGNEOUSLY DIFFERENTIATED BODY.
IT STILL HAS A LOT OF ITS WATER. IT HAS HAD A SIGNIFICANTLY
DIFFERENT EVOLUTION THAN VEST A AND THE OTHER PLANETARY EMBRYOS
LIKE VEST A, BUT IT'S LIKELY THAT ITS LARGE SIZE WAS A BIG
FACTOR IN THE FACT THAT IT STILL EXISTS TODAY.
>> IF I COULD ADD SOMETHING TOO. VESTA IS DAZE BASICALLY A
LEFTOVER PLANETARY BUILDING BLOCK.
WHAT'S HAPPENED TO A LOT OF THE BODIES THAT PROBABLY RESEMBLED
VEST A IN THE EARLY SOLAR SYSTEM IS THAT THEY HAVE ALREADY BEEN
INCORPORATED EARLIER INTO PLANETS, INTO THE GROWTH OF
PLANETS. SO IN THIS WAY, THIS ALLOWS US
TO SEE FARTHER BACK IN TIME, WHICH IS, OF COURSE, THE BASIS
FOR THE NAME DAWN OF THE MISSION.
THIS IS A MISSION IN TIME AS WELL AS IN SPACE.
>> OUR NEXT QUESTION IS FROM KEN KRAMER, SPACE FLIGHT MAGAZINE.
KEN? >> HI.
THANKS FOR TAKING MY QUESTION. GREAT RESULTS.
I WONDER IF YOU COULD TALK A LITTLE BIT ABOUT EVIDENCE -- IS
IS THERE ANY EVIDENCE ELSEWHERE IN THE SOLAR SYSTEM OF THIS
MASSIVE IMPACT ONE BILLION YEARS AGO?
AND WHAT CONSEQUENCE COULD THAT HAVE BEEN FOR THE EARTH?
THANKS. >> OKAY.
I THINK THE -- THE IMPACT ON VEST A WAS PROBABLY NOT PART OF
A SOLAR SYSTEM-WIDE PHENOMENON. I THINK IT WAS JUST SORT OF A
SINGLE IMPACT ON VESTA THAT HAPPENED TO OCCUR AT THAT TIME.
UNLIKE THE LATE HEAVY BOMBARDMENT WHICH IS SORT OF ONE
OF THE MODELS FOR THE BOMBARDMENT HISTORY IS THE MOON
AND THE INNER SOLAR SYSTEM WHERE A LOT OF -- A LOT OF IMPACTS
OCCUR, SAY, AROUND 4 BILLION YEARS TO 3.5 BILLION YEARS AGO.
SO THIS WASN'T NECESSARILY PART OF THAT, I THINK IT WAS JUST
SORT OF A LATER SARCASTIC IMPACT THAT HAPPENED TO OCCUR AT THAT
TIME. >> OKAY.
>> IN TERMS OF -- >> I'M SORRY, GO AHEAD.
>> IN TERMS OF THE EFFECT ON THE EARTH, IT'S HARD TO SAY BECAUSE
IT WOULD HAVE LAUNCHED A LOT OF METEORITES INTO SPACE THAT WOULD
HAVE EVENTUALLY MADE THEIR WAY INTO SPACE.
THERE WOULD HAVE BEEN A NUMBER OF METEORITES FALLING ON EARTH
BUT IN TERMS OF LARGE IMPACTS, LIKE EXTINGION IMPACTS, I DON'T
THINK THE VEST A IMPACT WOULD HAVE HAD ANY EFFECT LIKE THAT.
>> OKAY. AS I MENTIONED EARLIER, WE ARE
INCORPORATING SOMETHING NEW HERE IN OUR SCIENCE BRIEFINGS AND
THAT IS BRINGING IN THE INCREDIBLE REACH AND AUDIENCE OF
SOCIAL MEDIA, SO I'M GOING TO ASK CAROL TO DRIVE THE BUS HERE.
WE'VE GOT SEVERAL QUESTIONS COMING IN.
FOR OUR SOCIAL MEDIA AUDIENCE. FORGIVE ME IF I BOTCH THE NAMES.
WE ARE COLORFUL NAMES. CAROL WILL DIVVY OUT THE
QUESTIONS AS YOU SEE FIT. WELCOME SOCIAL MEDIA AUDIENCE.
THE FIRST ONE IS FROM @RYE IN SPACE.
WHAT IS THE PREDICTED MINERALOGY OF VEST A NOW AND WHAT ARE THE
REGULAR AND DUST DEPTHS? >> WHO WANTS TO TAKE THIS?
>> MINERALOGY, WE HAVE EVIDENCE OF MINERALOGIES IN DIFFERENT
KINDS OF PYROX. ESPECIALLY MAGNESIUM.
WHILE WE DO NOT HAVE LARGE EVIDENCE FOR OTHER BLOCKS OF
DIFFERENT KIND OF MINERALS. I THINK THAT DAVE CAN SAY
SOMETHING MORE. >> OKAY.
I DON'T HAVE A GOOD GLOBAL ESTIMATE OFF THE TOP OF MY HEAD.
ONE NUMBER THAT I CAN GIVE THOUGH IS THAT IN THE REGION
AROUND THE REA SYLVIA IMPACT BASIN WE'VE ESTIMATED FROM THE
SIZES OF CRATERS THAT HAVE BEEN ERASED BY THE FORMATION OF REA
SYLVIA THAT THE EJECT A BLANKET OVER THAT REGION IS MAYBE ABOUT
5 KILOMETERS THICK. THAT'S ABOUT 3 MILES THICK.
THAT WOULDN'T NECESSARILY BE FINE POWDER.
A LOT OF IT MIGHT BE LARGE BLOCKS BUT IT WOULD BE SORT OF A
LOT OF RUBBLE AND SMALLER MATERIAL THAT WOULD BE THROWN
OVER THAT. >> LET ME ADD SOMETHING ABOUT
THE MINERALOGY. THE HEDs TELL US THAT ANOTHER
MAJOR MINERAL THAT SHOULD OCCUR ON THE SURFACE IS STEALTH SPAR,
PLEDGE GI GLAZE STEALTH SPAR. WE DON'T HAVE AN INSTRUMENT THAT
IS CAPABLE OF SEEING THAT. SO THIS IS A PLACE WHERE THE
METEORITES ARE PROVIDING ADDITIONAL INFORMATION THAT WILL
COMPLIMENT WHAT WE GET FROM REMOTE SENSING.
ANOTHER THING THAT WE SEE -- ANOTHER MINERAL THAT WE SEE IN
SOME OF THE HE DERKS MEET OR RIGHTS ARE IS OLLIE CONVENIENT.
ITS PRESENCE IS IMPORTANT BECAUSE IF WE ACTUALLY EXCAVATE
DOWN INTO THE MANTLE OF THIS BODY, WE EXPECT TO SEE A LOT OF
OLLIE CONVENIENT. WE SEE SMALL AMOUNTS OF OLLIE
VOOEN IN THE HED METEORITES, BUT OUR INSTRUMENTS HAVE NOT YET
ALLOWED US TO SEE OLLIE VOOEN ON THE SURFACE OF VEST A.
WE'RE LOOKING CURRENT FOR IT, BUT WE HAVEN'T FOUND IT YET.
>> OKAY. AGAIN, A REMINDER TO SEND YOUR
QUESTION IN TO #ASKNASA. AGAIN, THE CONVERSATION DOESN'T
STOP THERE. TWITTER, FACEBOOK, YOUTUBE AND
IN PARTICULAR AND I'LL GIVE YOU THE TWITTER FEED NOW AND AGAIN
AT THE END OF THE PROGRAM, FOLLOW THE CONVERSATION @NASA
UNDERSCORE DAWN. NEXT QUESTION FROM OUR #ASKNASA
IS FROM @LW UNDERSCORE RDCP. WHAT IS THE IMPORTANCE OF
TODAY'S DISCOVERIES FOR FUTURE INVESTIGATION?
>> WELL, I CAN OFFER MY OPINION. WHAT WE'RE SEEING AT VESTA IS --
HAS -- HAS REALLY EXPANDED THE -- THE IDEAS ABOUT THE
DIVERSITY THAT WE MIGHT ENCOUNTER AS WE GO OUT INTO THE
ASTEROID BELT AND START LOOKING AT THE MYRIAD PIECES THAT MIGHT
BE PROVIDING US ADDITIONAL INFORMATION ABOUT THE EARLY
SOLAR SYSTEM. AND, YOU KNOW, THE SERIES IS AN
EXTREMELY INTERESTING BODY THAT WE'RE ALREADY GOING TO AND
STUDYING, AND SO THAT IS ONE -- IS GOING TO BE ANOTHER PIECE OF
THE PUZZLE, BUT THERE ARE MANY ASTEROIDS THAT HAVE INTERESTING
SURFACES AS SEEN FROM TELESCOPES.
THERE ARE MANY RELATIONSHIPS OF THE TYPES OF ASTEROIDS YOU
ENCOUNTER WITH DISTANCE FROM THE SUN, WHICH IS ALSO TELLING US
SOMETHING FUNDAMENTAL ABOUT THE GRADIENTS IN THE MATERIAL AND
THE TYPES OF PROCESSES LIKE COLLISIONAL PROCESSES THAT ARE
OCCURRING. SO WHAT WE'RE LEARNING FROM VEST
A THAT'S HONING OUR KNOWLEDGE OF THE DYNAMICS AND OF THE
POSSIBILITIES OF WHAT THESE SURFACES MIGHT HOLD IS GOING TO
HELP US TO FORMULATE STRATEGIES FOR HOW WE CAN, YOU KNOW, NARROW
DOWN TO THE FEW BODIES THAT WE WANT TO GO EXPLORE IN DETAIL
LATER. AND I'LL ALSO MENTION AND OTHERS
MAY WANT TO CHIME IN THAT TELESCOPES ARE ALSO STILL
EXTREMELY IMPORTANT FOR US BECAUSE THEY RIGHT NOW ARE
REALLY OUR EYES ON THE SOLAR SYSTEM.
WE DON'T HAVE THE RESOURCES TO SPEND SPACECRAFT OUT TO MANY
BODIES SO THEY'RE GOING TO STILL BE THE WORKHORSES TO REALLY
REVEAL MORE INFORMATION ABOUT ALL OF THE BODIES OUT THERE.
>> YEAH. I JUST WANT TO ADD THAT WE DID A
LOT OF OBSERVATIONS OF VESTA USING THE NASA INFRARED
TELESCOPE PRIOR TO ARRIVAL. ONE OF THE THINGS LIKE CAROL
SAID, WE CANNOT GO TO EVERY ASTEROID OUT THERE BUT IF YOU
HAVE GROUND PROOF OF CONFIRMATION OF WHAT WE SEE FROM
THE EARTH VERSUS SENDING A BIG SPACECRAFT OUT THERE, WE CAN DO
SIMILAR THINGS WITH OTHER OBJECTS.
THERE'S ABOUT A MILLION ASTEROIDS.
WE CAN STUDY THEM FROM THE EARTH, EXTRAPOLATE, WE CAN KNOW
WHAT THE DIFFERENCES ARE AND WHAT THE LIMITATIONS ARE THAT WE
CAN DO. SO FAR IT'S REALLY EXCITING TO
SEE THAT A LOT OF OUR OBSERVATIONS HAVE BEEN CONFIRMED
BY DAWN. IT'S A REALLY IMPORTANT
DISCOVERY. >> ANOTHER POSSIBLE PAYOFF,
ALTHOUGH IT'S ARGUABLE, IS THAT EVENTUALLY WE'LL HAVE THE
ABILITY TO MINE ASTEROIDS THAT WE WILL FIND VALUABLE RESOURCES
ON THEM. THERE WAS AN ARTICLE IN THE "USA
TODAY" ABOUT THAT. I THINK IT'S A TOUGH SELL, BUT
THERE ARE PEOPLE WHO ARE PUTTING LARGE AMOUNTS OF MONEY INTO THIS
IDEA AND IT WILL BE INTERESTING TO SEE IF THIS MIGHT HAVE A
PAYOFF IN THE FUTURE, BUT CERTAINLY MISSIONS LIKE DAWN
THAT CHARACTERIZE THE MATERIALS IN ASTEROIDS ARE OBVIOUS
PRECURSORS BEFORE WE SEND OUT SPACECRAFT THAT ARE GOING TO TRY
TO BRING MATERIALS BACK FOR COMMERCIAL PURPOSES.
>> OKAY. WE'RE GOING TO TAKE A QUESTION
FROM A REPORTER WHO SENT IN FROM DWATH NASA.
WE'LL GO TO THE PHONE LINES. THIS QUESTION IS DIRECTED TO DR.
JIM GREEN FROM BBC CORRESPONDENT JONATHAN AMOS, THE SCIENCE
CORRESPONDENT AT BBC. DR. GREEN, JUST AN EXTRA TWO
WEEKS AT VEST A WOULD ENABLE THE DAWN TEAM TO FULLY IMAGE THE
NORTH POLE. WILL YOU GIVE IT TO THEM?
>> WELL, OF COURSE IT IS A NEW DAWN IN THAT WE HAVE ALLOWED
THAT EXTENSION TO OCCUR. THERE WAS A CRITICAL ANALYSIS
THAT WENT ON THAT ALLOWED US TO MAKE THAT DECISION VERY EASY,
AND THAT IS THE FACT THAT WE CAN MAKE IT TO SERIES, WHICH IS A
MAJOR PART OF THE MISSION. AS YOU KNOW, SERIES IS SORT OF
ON THE OUTER PART OF THE ASTEROID BELT.
DAWN IS ON THE INNER PART OF THE ASTEROID BELT AND THE DYNAMICS
ARE SUCH THAT THOSE THINGS CONTINUALLY MOVE APART AND WITH
DAWN'S ION ENGINES THAT ARE RUNNING MUCH BETTER THAN
PREDICTED, THAT REALLY ENABLES US TO STAY AT VESTALONG GER.
SO WE'RE VERY EXCITED ABOUT THAT BECAUSE IT WILL MAP THAT UNKNOWN
REGION. THAT REGION NOW IS VERY
IMPORTANT TO LOOK AT BECAUSE NOW WE KNOW ABOUT THE REA SYLVIA
IMPACT AND HOW THAT MIGHT AFFECT THE NORTHERN HEMISPHERE WILL NOW
BE REVEALED. SO, INDEED, IT WAS AN EASY
DECISION TO MAKE BECAUSE THE SPACECRAFT IS FAR MORE CAPABLE
THAN ITS BASELINE AND WE'RE REALLY EXSITED ABOUT THAT
NEXT -- THAT NEXT STEP FOR DAWN. >> THANK YOU, DR. GREEN.
OKAY. WE'RE GOING TO GO BACK TO THE
PHONE LINES AND THEN WE'LL COME BACK FOR A FEW MORE QUESTIONS
BEFORE WE WRAP UP AND WE'RE GOING TO GO BACK TO KEN KRAMER
FROM SPACE FLIGHT MAGAZINE. KEN?
>> OKAY. THANKS.
ACTUALLY, ONE OF MY QUESTIONS WAS ABOUT THE EXTENDED MISSION
BUT LET ME ASK IT A LITTLE BIT DIFFERENTLY.
I BELIEVE YOU'VE BEEN GIVEN 40 DAYS.
CAN YOU TALK ABOUT WHAT YOU'LL BE DOING IN THE 40 DAYS?
AND I WOULD LIKE TO KNOW SPECIFICALLY ABOUT THE
ILLUMINATION OF THE NORTH POLE. WILL IT BE FULLY ILLUMINATED OR
PARTIALLY ILLUMINATED? MY SECOND QUESTION IS, AND YOU
MAY HAVE TOUCHED ON THIS, I'M SORRY, TALK A LITTLE BIT ABOUT
ANY EVIDENCE FOR MATERIAL THAT YOU'VE SEEN EXCAVATED FROM THE
DEEP INTERIOR. NOT THE FIRST FEW METERS, BUT
I'M TALKING ABOUT MILES DEEP, MAYBE TO THE CORE.
DO YOU SEE ANY EVIDENCE FOR THAT?
THANK YOU. >> OKAY.
I HAVE AN ANSWER TO THE FIRST QUESTION.
AS JIM ALREADY DISCUSSED, WE DID ALREADY EXTEND THE MISSION
SIGNIFICANTLY, ABOUT 40 DAYS, WITHOUT ANY IMPACT ON THE
MISSION TIME LINE, AND THAT IS ALLOWING US TO DO MAPPING LATER
THAN WAS PREVIOUSLY PLANNED. THAT'S GOING TO ACHIEVE
ELIMINATION TO ABOUT 85 DEGREES NORTH LATITUDE AT THE SAME
RESOLUTION AS WE'VE BEEN DISCUSSING TODAY.
THERE WILL BE A SMALL AREA AT THE VERY NORTH POLE WHICH WILL
ONLY BE IMAGED A LITTLE BIT LATER WHEN IT BECOMES
ILLUMINATED ADEQUATELY AT A LOWER RESOLUTION, BUT THE
EXPECTATION IS, IF EVERYTHING GOES AS PLANNED, THERE WILL NOT
BE ANY UNILLUMINATED AREAS OF VESTA THAT ARE LEFT BEHIND.
>> AND NOW THE SECOND PART OF THE QUESTION.
WE SEE THIS IN THE CRUST OF VESTA.
WE SEE ALL THE FRACTURING IN THE EDGES.
WE ARE LOOKING TO SEARCH FOR EVIDENCE OF MATERIAL.
WE HAVE CONCLUDED THE MAPPING PHASE A FEW DAYS AGO.
ESPECIALLY CONCERNING THE SPECIAL MAPPING IN THE SOUTH AND
WE NEED TO LOOK AT THIS DATA CAREFULLY BECAUSE THOSE DATA HAS
THE HIGHEST RESOLUTION AND BECAUSE WE EXPECTED TO HAVE SOME
MATERIALS FROM THE MANTLE BUT THEY LIMITED QUANTITY.
THIS IS WHAT WE ARE SHOWING THE METEORITE.
WE NEED TO HAVE AS LARGE A RESOLUTION AS POSSIBLE.
I THINK THAT THE ONLY WAY TO DETECT EVENTUALLY THIS KIND OF
MANTLE MATERIAL IS GOING INTO THE INTERIOR REGIONS OF THIS
LAST ACQUIRED DATA. >> I'D JUST LIKE TO ADD A QUICK
POINT THAT EVEN WITH THE BEST RESOLUTION.
ONE OF THE THINGS HAP POINTED OUT, IN THE METEORITE IS THE
EVIDENCE OF MANTLE MATERIAL COMES FROM OLIVE VOOEN.
IT IS RELATIVELY LESS. ONE OF THE REASONS WHY WE DON'T
SEE OLIVE VOOEN IS THE FACT THAT THERE'S PROBABLY VERY LITTLE OF
IT EXPOSED. THE SECOND FACTOR IS EVEN IF IT
WAS EXPOSED A BILLION YEARS AGO, WE HAVE SUBSEQUENT IMPACTS THAT
MIXED IT UP WITH THE SURFACE. THE FOOTPRINT SIZE, THE BEST
RESOLUTION WE CAN GET EVEN WITH THE FRAMING CAMERA IS 16 MEET
TERGS. THIS HAS TO BE SUBSTANTIALLY
LARGER THAN WHAT WE CAN RESOLVE TO CLEARLY DISTINCTLY SEE IT.
IF YOU HAVE AN IMAGE THAT'S 1,000 PICKSLESS BY 1,000 PICKLES
ACROSS, TRYING TO IDENTIFY A SPECIFIC PIXEL, IT'S A LOT MORE
CHALLENGING. LIKE CHRISTINA SAID, WE NEED
BETTER RESOLUTION. AS FAR AS YOUR QUESTION, IF WE
SEE ANYTHING BEYOND THE MANTDLE, THE ANSWER IS NO.
THAT'S WHY WE STILL HAVE THE ASTEROID INTACT.
>> OKAY. WE'RE GOING TO DO A COUPLE OF
MORE. I WANT TO FIRST OF ALL THANK OUR
SOCIAL MEDIA. YOUR QUESTIONS ARE COMING IN
FAST AND FURIOUS. I WON'T GET TO ALL OF THEM BUT
REMEMBER THE CONVERSATION DOESN'T STOP HERE TODAY.
FOLLOW THE TWITTER FEED AT WATT NASA UNDERSCORE DAWN.
THE SCIENCE TEAM MEMBERS WILL TAKE A COUPLE OF MORS.
FOLLOW US@NASA UNDERSCORE DAWN. SEND IN YOUR QUESTIONS.
THIS NEXT QUESTION IS FOR DR. GREEN AGAIN.
FROM CS -- I'M SORRY@S OBSERVER. WILL NASA BE LOOKING AT THE HAPS
AT VEST A FOR THE POSSIBLE TARGET FOR HUMAN EXPLORATION?
>> THE ASTEROID BELT IS WELL BEYOND THE ORBIT OF MARS AND OF
COURSE THE ADMINISTRATION AND NASA IS VERY EXCITED ABOUT THE
PLANS FOR HUMAN EXPLORATION OF THE LOWER ORBIT.
CONSIDERATION OF GOING TO ASTEROIDS IS REALLY LIMITED TO
MORE NEARER OBJECTS, THINGS THAT ARE MUCH CLOSER THAN VEST A.
IN THE LONG RUN I WOULD LOVE TO SEE HUMANS TREK OUT OF THE SOLAR
SYSTEM WELL BEYOND MARS AND PERHAPS THE OBSERVATIONS FROM
VEST A THAT WE'RE MAKING TODAY WILL ALLOW FUTURE GENERATIONS TO
THINK OF THE IMPORTANCE THAT VEST A MIGHT PLAY IN THAT
EXPLORATION, BUT THAT WILL BE WELL INTO THE FUTURE.
>> THANK YOU, SIR. OKAY.
THIS NEXT QUESTION IS FROM@SKY TELESCOPE.
SO GOING TO NEED YOUR HELP HERE, CAROL, TO DRIVE THE BUS HERE.
GIVEN THE CONFIRMATION OF VEST A'S CONNECTION TO HEDS, DO YOU
EXPECT TO FIND METEORITE ANNA LOGS AFTER SEEING SERIES UP
CLOSE? >> BOY, I WISH.
IT WOULD MAKE THE EXPLORATION OF SERIES A LOT EASIER IF WE
THOUGHT WE HAD PIECES IN HAND THAT COULD HELP GUIDE OUR
INTERPRETATIONS AND EVEN HELP CALIBRATE OUR INSTRUMENTS.
WE THOUGHT ABOUT IT BUT -- AND THERE ARE SOME CLASSES OF MEET
OR RIGHTS THAT MIGHT BE SIMILAR. THE CARBONACEUS CONDRITES COME O
TO MIND. WE DON'T HAVE ANY REASON TO
BELIEVE THAT ANY OF THE MEET OR RIGHTS IN OUR COLLECTIONS NOW
ACTUALLY DERIVE FROM SERIES. >> YEAH.
I'D ALSO LIKE TO ADD, TOO, THAT VEST A IS IN A UNIQUE POSITION.
WE HAVE MULTIPLE LARGE IMPACTS AT THE SOUTH POLE.
WHEN WE LOOK AT THE DISTRIBUTION OF ASTEROIDS IN THE MAIN BELT,
WE HAVE THESE FAMILY MEMBERS THAT STRETCH FROM VES STAY TO
MANY RESIDENCES. WE DON'T SEE A SIMILAR THING
WHEN WE LOOK AT SERIES. THERE DOESN'T SEEM TO BE A
DYNAMICAL FAMILY ASSOCIATED WITH IT THAT HAS A CONVENIENT ESCAPE
ROUTE TO BRING THINGS TO EARTH. >> I'M GOING TO DO TWO MORE
HERE. THESE QUESTIONS ARE FANTASTIC
AND, AGAIN, THANK YOU FOR JOINING OUR SOCIAL MEDIA
AUDIENCE. WE'LL SEE YOU AGAIN.
FROM@GERBIN 1997. IS THE CONCENTRATION OF MINERALS
EXTRAORDINARY? NEW?
EXTRAORDINARY? SURPRISING?
>> YES. YES, ABSOLUTELY EXTRAORDINARY,
THE FACT THAT WE ARE ABLE TO RECOGNIZE MIN NER ROW LOGICAL
REGION. I THINK THAT IT'S REALLY
SURPRISING THE FACT THAT THERE ARE A LOT OF EVENTS, A LOT OF --
THAT WE ARE STILL ABLE TO SEE CONCENTRATION OF MINERALS,
PARTICULARLY IN PLACES OF VESTA. SO I THINK IT IS REALLY
SURPRISING, MOSTLY BECAUSE ALL THE OTHER ASTEROIDS THAT HAS
BEEN VISITED SO FAR ARE MORE OR LESS UNIFORM.
ALSO THAT WE VISITED NOT LONG TIME AGO IS A LARGE ASTEROID,
100 KILOMETERS, AND IN MANY CASES THE SURFACE IS COMPLETELY
UNIFORM. SO VESTA IS REALLY A SURPRISE.
>> OKAY. LAST ONE IS FROM@ABRIELLARETAT.
I HOPE I GOT THAT RIGHT, ABRIELLA.
IF VEST A MADE THE SAME START AS EARTH-LIKE PLANETS, WHY DID IT
NOT DEVELOP INTO A PLANET? >> MADE THE SAME START?
>> START, YEAH. DO YOU WANT TO --
>> OH, OKAY. SO IF THEY STARTED IN THE SAME
WAY, WHY DID THEY NOT -- WELL, THE -- PART OF IT IS GIVEN VEST
A'S LOCATION IN THE ASTEROID BELT.
THE ASTEROID BELT IS VERY CLOSE TO JUPITER AND JUPITER'S A VERY
POWERFUL GRAVITATIONAL INFLUENCE.
IN THE INNER SOLAR SYSTEM WHERE EARTH, VENUS, MARS, MERCURY
FORMED THINGS WEREN'T REALLY STIRRED UP THAT MUCH SO THEY
WERE ABLE TO ECRETE TOGETHER AND FORM THE TERRESTRIAL PLANETS.
IN THE ASTEROID BELT JUPITER STIRRED THINGS UP SO MUCH THAT
THEY WEREN'T BE ABLE TO EE CREATE TOGETHER.
THE VELOCITIES WERE HIGH. THE HIGHER THE VELOCITIES ARE
THE HARDER IT IS TO MERGE TOGETHER UNDER THEIR OWN
GRAVITY. THERE WERE PROBABLY MANY THINGS
LIKE VEST A THAT WERE AROUND THAT ARE NOW PART OF EARTH.
>> OKAY. LADIES AND GENTLEMEN, I'M GOING
TO WRAP IT UP HERE. AGAIN, I APOLOGIZE FOR NOT
GETTING ALL THE THE QUESTIONS FROM SOCIAL MEDIA, BUT REMEMBER
THE CONVERSATION DOESN'T END HERE.
IF YOU HAVE ANY QUESTIONS OR ANY OTHER OBSERVATIONS AND WANT TO
FOLLOW A CONVERSATION ABOUT THESE EXTRAORDINARY RESULTS
ABOUT VEST A FROM THE NASA DAWN SPACECRAFT, FOLLOW THE TWITTER
FEED AT AT NASA UNDERSCORE DAUN. OF COURSE ALL OF THIS
INFORMATION IS AVAILABLE ON WWW.NASA.GOV/DAWN AND FOR
VARIOUS SOCIAL MEDIA SITES, YOUTUBE, FACEBOOK, TWITTER.
IT'S ALL THERE. LADIES AND GENTLEMEN, YOU'VE
HEARD THE INFORMATION ABOUT VESTA UP CLOSE AND PERSONAL.
WE THANK YOU FOR JOINING US. SCIENCE NEVER SLEEPS.