Mercury: Mariner to MESSENGER and beyondSlide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Atmospheric Discoveries by poly chronometer on Mariner 10 our own Lyle Broadfoot, PI (my first mentor at LPL)Ground-Based ObservationsSlide 21Slide 22Slide 23Slide 24Slide 25Slide 26Atmospheric MeasurementsSlide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Atmosphere measurements will be made by MASCS throughout the missionSlide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Mercury: Mariner to MESSENGER and beyondDr. Ann L. SpragueLunar and Planetary LaboratoryThe University of ArizonaParticipating Scientist MESSENGER Mission to MercuryFleet footed MESSENGER—Winged MESSENGERRCA Building Façade, New York City, NYMercury: closest planet to the Sun and most elliptical orbit~ 0.31 to ~ 0.43 AUe ~ 0.21What does Mercury look like in the sky from your backyard in Tucson?Image courtesy of our ownRik HillMercury, marked with white line, visible at sunrise from Tucson.Image courtesy of our own Bob McMillan.This is atough one…Mercury spinsthree times for every tworevolutions aboutthe SunIt has same two longitudes(one or the other) under the Sunat perihelion.This makes for crazytemperatures onthe surface!Caused by gravitational interaction between“lemon shaped” planetary figure and the SunGreatest temperature extremes of any planet in our solar systemMitchell and de Pater (1997)Microwave observations of Mercury,1. Mariner 102. MESSENGER2 spacecraft to MercuryToo fastSlow DownMariner 10 incomingImagery mosaic2 filters inthe ultra violet and 1 yellow filter300 nm (0.3 μm) to 400 nm (0.4 μm) and yellowto 550 nm (0.55 μm )Mariner 10 Out going ImageryMariner 10 imaged less than half of Mercury’s surfaceHow Earth comparesto itsmagnetic fieldHow Mercury comparesto itsmagnetic fieldIt is thoughtthat there mustbe a moltenlayer of theplanetarycore to generatea magnetic Field (like that at Earth)Ground-basedobservations havefound evidence for this by measuringwobbles in Mercury’sMotions.How the cores ofthe terrestrial planetscompare to thethickness of theirrocky layersDiscovery Scarpdiscovered by Mariner 10 imagingGlobal shrinkageHow scarps are formedall three of thesetypes of faults are found on MercuryAtmospheric Discoveriesby poly chronometer on Mariner 10our own Lyle Broadfoot, PI(my first mentor at LPL)•Hydrogen (H)•Helium (He)•Oxygen (O) upper limit and detection ??Ground-Based Observations•1976 to present•Not much until new technology in telescopes and instruments•Sensitive detectors•Computer data analysis•Relatively inexpensive telescopes and imaging systems for amateur astronomersKeck I and Keck II on Mauna KeaFor “exosphere”no collisions between atomscollisions with surfaceNASA Infrared telescope on Mauna Kea For spectroscopic measurements of Mercury’s surface~13,895 ft (~ 4630 m) altitudeSurface composition measurements using theMid – infrared spectral region (4 – 14 micrometers)Compare to:Ultra violet ~ 0.1 to .4 micrometersVisible ~ .4 to .7 micrometersNear Infrared ~ .7 to 3 micrometers1 micrometer = 1.0-6 m = 1µmGround based imagery by talented amateur astronomersFrom Palomar Telescopewith rapid imaging and co-addingand registration(allignment)Ground based radar reflectivity imagingBright red is highRadar reflectivityAtmospheric Measurements•Sodium (Na)•Potassium (K)Kitt Peak McMath Pierce TelescopeMESSENGER: NASA DISCOVERY MISSIONDistance (Radii) Start RollEND Roll1st MESSENGER Fly by of Mercury January 14, 2008MESSENGER out bound image, true colorCredit, APLMESSENGERCaloris Basin on one of the “hot longitudes centered ~ 30 degrees NCredit, APLMESSENGERVerybrightlight coloredmaterialin cratersInCaloris BasinCreditAPLMESSENGERAlso dark rimmed cratersCreditAPLMESSENGERThe Spider in Caloris BasinCredit, APLMESSENGERRising magma, uplift, volcanismAtmosphere measurements will be made by MASCS throughout the mission•Hydrogen (H)•Sodium (Na)•Calcium (Ca)•Potassium (K)•Magnesium (Mg) ?•Oxygen (O) ?•Sulfur (S) ?•Silicon (Si) ? •Others??The Fast Ion Partical detector (FIPS)has already discoveredmany unexpected ions in Mercury’s near environmentMercury’s Na tail Streaming 40,000 kmin the anti-SundirectionRadiation pressureSunlight pressureGround-based with relatively simpleInstrumentationBoston University groupGround-basedfrom Kitt PeakMcMath PierceTelescopePotter et al. 2006Mercury’s neutral sodium atmospheric tailMESSENGER MASCS instrument during 1st fly by January 14, 2008Credit, APLMESSENGER•Measures light reflecting from the surface•Measures wavelengths from 400 nm to 1400 nm•visible (400 to 700 nm)•near-infrared (700 to 1400 nm)Surface SpectroscopyMercury Atmospheric and Surface Composition Spectrograph (MASCS)Surface Spectroscopywith MASCSUV, VIS, NIR250 nm to 1400 nm0.25 µm to 1.4 µmCreditAPLMESSENGERA lot of new tectonic features seen in ery high resolution images200 m per pixel CreditAPLMESSENGER2 more fly bys:October 6, 2008September 29, 2009Orbit insertion March 18, 2011http://messenger.jhuapl.edu/soc/index.htmlEuropean Space Agency (ESA)and Japan (JAXA)Bepi ColomboMission to MercuryLaunch