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Continuous observations of the inner Solar System: Mapping Venus winds. Mark A. Bullock Eliot F. Young Southwest Research Institute. Venus nightside at 2.3 m m. The Atmosphere. Winds and General Circulation. Near-IR emission spectrum of Venus. May 4, 2004. Venus 2.3 m m. May 5, 2004. - PowerPoint PPT Presentation
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April 27, 2007 LCANS SwRI Boulder
Continuous observations of the inner Continuous observations of the inner Solar System: Mapping Venus windsSolar System: Mapping Venus winds
Mark A. Bullock
Eliot F. Young
Southwest Research Institute
Venus nightside at 2.3 m
April 27, 2007 LCANS SwRI Boulder
The AtmosphereThe Atmosphere
April 27, 2007 LCANS SwRI Boulder
Winds and Winds and General General
CirculationCirculation
April 27, 2007 LCANS SwRI Boulder
Near-IR emission spectrum of VenusNear-IR emission spectrum of Venus
April 27, 2007 LCANS SwRI Boulder
May 4, 2004 May 5, 2004 May 6, 2004
May 8, 2004 May 9, 2004
Venus 2.3 m IRTF
Eliot Young Mark Bullock
April 27, 2007 LCANS SwRI Boulder
Moving through an image cubeMoving through an image cube
60” spectrometer slit allowed to drift over Venus disk.
Acquired ‘jail bar’ spectra ~50 in 15 minutes.
Reassembled into image cubes, 0.8 to 2.5 m.
April 27, 2007 LCANS SwRI Boulder
Venus Express VIRTIS imagesVenus Express VIRTIS images
1.7 m emission images
Upper left: South pole at lower right, 60o S upper left.
Upper right: Bottom left of image over Alpha Regio
Lower left: Near south pole
Lower right: Near equator in the southern hemisphere
April 27, 2007 LCANS SwRI Boulder
Venus Observation GeometryVenus Observation Geometry
April 27, 2007 LCANS SwRI Boulder
Size of Venus at focal planeSize of Venus at focal plane
5 weeks before inferior conjunction.
40” disk 26% illuminated
110 diffraction-limited elements across disk
Inferior conjunction.
60” disk full nightside
160 diffraction-limited elements across disk
April 27, 2007 LCANS SwRI Boulder
Payload SpecificationsPayload Specifications
Telescope Aperture: 1 meter• Plate Scale: 0.125 arcsec• Field of View: 64 arcsec• Diffraction limit: 0.6 arcsec at 2.5 m 0.2 arcsec at 0.8 m
Simultaneous imaging and spectra 0.8-2.5 m• Spectral Resolution / = 4000
Pointing accuracy/stability: ±0.3 arcsec Minimum Sun angle: 10o
Temperatures• Structure at -40oC• LN2 for IR detector array
April 27, 2007 LCANS SwRI Boulder
ConclusionsConclusions
Continuous near-IR observations of Venus cloud motion necessary to understand the general circulation.
Synoptic view is highly complementary with VEX VIRTIS and VMC.
Continuous cloud tracking with balloon-borne 1 m imager and spectrometer for 10 weeks will allow simultaneous atmospheric motion maps and below-cloud CO, H2O, OCS maps.
These observations are key to understanding Venus’ atmospheric superotation.