Planetary Radio Astronomy Bryan Butler

What kinds of things do we observe with the VLA? 45% - Extragalactic 20% - Galactic 30% - Stellar 5% - Solar system

Solar System “Bodies” n Sun n IPM n Giant planets n Terrestrial planets n Moons n Small bodies

Planetary Radio Astronomy Observation 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 n spin/orbit state n n surface and subsurface properties n n atmospheric properties n n magnetospheric properties n n ring properties Types of radiation: n n thermal emission n n reflected emission (radar or other) n n synchrotron emission n n occultations

Mercury n Closest to Sun n Magnetic field n No atmosphere n Hot!

Mercury - Thermal Emission Mitchell & de Pater 1994

The Goldstone/VLA Radar

Mercury - Radar Butler et al polar ice? Volcanoes?

Venus n Closest to Earth n Thick atmosphere n Hot!

Venus - models Venus models at C, X, U, and K-bands:

Venus - residuals Venus residual images at U and K-bands:

Venus – Thermal Emission Examination of the brightness temperature spectrum of Venus shows unexpected behavior at long wavelengths: Moon – scaled & offset

Mars n Most like Earth n Thin atmosphere n Cold n Interesting Geology

Mars - Atmospheric Water Clancy, Grossman, & Muhleman 1992 cold & dry!

Mars - Radar Butler, Muhleman & Slade 1994 polar cap lava flows “Stealth”

Jupiter n Biggest planet n Gas ball n “weather” (GRS) n rings

Jupiter - Synchrotron De Pater, Schulz & Brecht 1997 = 20cm = 20cm

3-D Reconstruction Developed by Bob Sault (ATNF) - see Sault et al. 1997; Leblanc et al. 1997; de Pater & Sault 1998

Saturn n 2nd biggest planet n Gas ball n “weather” n Rings

Saturn - Thermal Emission van der Tak, de Pater, Silva & Millan 1997 = 2cm = 2cm

Titan n Bigger than Pluto n thick atmosphere (haze/smog) (haze/smog) n ice + liquid surface

Titan - Radar Muhleman, Grossman, & Butler 1995 no global ethane/ methane ocean methane ocean maybe ‘seas’?