planetary radio astronomy · planetary radio astronomy observation of radio wavelength radiation...
TRANSCRIPT
Bryan Butler
Looking at our Neighbors with the VLA 1
Planetary Radio Planetary Radio AstronomyAstronomy
Bryan Bryan ButlerButler
What kinds of things do we What kinds of things do we observe with the VLA?observe with the VLA?
45% 45% -- ExtragalacticExtragalactic
20% 20% -- GalacticGalactic
30% 30% -- StellarStellar
5% 5% -- Solar systemSolar system
Bryan Butler
Looking at our Neighbors with the VLA 2
Solar System “Bodies”Solar System “Bodies”
nn SunSunnn IPMIPMnn Giant planetsGiant planetsnn Terrestrial planetsTerrestrial planetsnn MoonsMoonsnn Small bodiesSmall bodies
Planetary Radio AstronomyPlanetary Radio AstronomyObservation of radio wavelength radiation which has interacted with a solar system body in any way, and use of the data to deduce information about the body:
n spin/orbit staten surface and subsurface propertiesn atmospheric propertiesn magnetospheric propertiesn ring properties
Types of radiation:n thermal emissionn reflected emission (radar or other)n synchrotron emissionn occultations
Bryan Butler
Looking at our Neighbors with the VLA 3
MercuryMercury
nn Closest to SunClosest to Sun
nn Magnetic fieldMagnetic field
nn No atmosphereNo atmosphere
nn Hot!Hot!
Mercury Mercury -- Thermal EmissionThermal Emission
Mitchell & deMitchell & de Pater Pater 19941994
Bryan Butler
Looking at our Neighbors with the VLA 4
The GoldstoneThe Goldstone/VLA/VLARadarRadar
Mercury Mercury -- RadarRadar
Butler et al. 1993Butler et al. 1993
polar ice?polar ice?
Volcanoes?Volcanoes?
Bryan Butler
Looking at our Neighbors with the VLA 5
VenusVenus
nn Closest to EarthClosest to Earth
nn Thick atmosphereThick atmosphere
nn Hot!Hot!
Venus Venus -- modelsmodels
Venus models at C, X, U, and KVenus models at C, X, U, and K--bands:bands:
Bryan Butler
Looking at our Neighbors with the VLA 6
Venus Venus -- residualsresiduals
Venus residual images at U and KVenus residual images at U and K--bands:bands:
Venus Venus –– Thermal EmissionThermal Emission
Examination of the brightness temperature Examination of the brightness temperature spectrum of Venus shows unexpected spectrum of Venus shows unexpected behavior at long wavelengths:behavior at long wavelengths:
Moon Moon –– scaled & offsetscaled & offset
Bryan Butler
Looking at our Neighbors with the VLA 7
MarsMars
nn Most like EarthMost like Earth
nn Thin atmosphereThin atmosphere
nn ColdCold
nn Interesting GeologyInteresting Geology
Mars Mars -- Atmospheric WaterAtmospheric Water
Clancy, Clancy, GrossmanGrossman, & , & MuhlemanMuhleman 19921992
cold & dry!cold & dry!
Bryan Butler
Looking at our Neighbors with the VLA 8
Mars Mars -- RadarRadar
Butler, Butler, Muhleman Muhleman & & Slade Slade 19941994
polar cappolar cap
lava flowslava flows
“Stealth”“Stealth”
JupiterJupiter
nn Biggest planetBiggest planet
nn Gas ballGas ball
nn “weather” (GRS)“weather” (GRS)
nn ringsrings
Bryan Butler
Looking at our Neighbors with the VLA 9
Jupiter Jupiter -- SynchrotronSynchrotron
De De PaterPater, Schulz & , Schulz & Brecht Brecht 19971997
λλ = 20cm= 20cm
33--D D ReconstructionReconstruction
Developed by Developed by Bob Bob Sault (Sault (ATNF) ATNF) -- see see Sault Sault et alet al. . 19971997; ; Leblanc Leblanc et et alal. . 1997; de1997; de Pater Pater & & Sault Sault 19981998
Bryan Butler
Looking at our Neighbors with the VLA 10
SaturnSaturn
nn 2nd biggest planet2nd biggest planet
nn Gas ballGas ball
nn “weather”“weather”
nn RingsRings
Saturn Saturn -- Thermal EmissionThermal Emission
van van der Takder Tak, de , de PaterPater, Silva & , Silva & Millan Millan 19971997
λλ = 2cm= 2cm
Bryan Butler
Looking at our Neighbors with the VLA 11
TitanTitan
nn Bigger than PlutoBigger than Pluto
nn thick atmospherethick atmosphere(haze/smog)(haze/smog)
nn ice + liquid surfaceice + liquid surface
Titan Titan -- RadarRadar
MuhlemanMuhleman, , GrossmanGrossman, & Butler 1995, & Butler 1995
no global ethane/no global ethane/methane oceanmethane ocean
maybe ‘seas’?maybe ‘seas’?