Date: 01 Feb 2008
Satellite: Venus Express
Depicts: VIRTIS-M and VIRTIS-H spectra of nightside thermal emission
Copyright: E. Marcq et al./VIRTIS team

Overlay of two nightside spectra of Venus that show the thermal infrared emission around 2.35 μm from the hot deep atmosphere below the cloud deck, unhindered by reflected sunlight.

The two spectra are from two different channels of the VIRTIS instrument. The dark red line shows the lower resolution spectrum obtained with the mapping channel, or M-channel, during the Venus orbit insertion in April 2006. The black line shows the spectrum obtained with the instrument's high-resolution channel (H-channel) during orbit #277.

Spectral bands from three minor constituents in the lower atmosphere (CO, H₂O and OCS) are indicated. Based on numerous VIRTIS-H spectra, a detailed model of the distribution of these constituents in the altitude range 30-40km as a function of latitude is made.