Results from VIRTIS on board Venus Express after the end of the mission operations
Abstract
After more than 8 years since the orbit insertion, the Venus Express mission is now at its end of mission operations. VIRTIS aboard the Venus Express spacecraft has addressed a significant amount of scientific results from the surface up to the upper atmosphere, in terms of mapping, composition, structure and dynamics. The VIRTIS instrument consists of two channels: VIRTIS-M, an imaging spectrometer with moderate spectral resolution in the range from 0.25 to 5.2 mu m and VIRTIS-H, a high spectral resolution spectrometer in the range from 2 to 5 mu m co-aligned with the field of view of -M \citep{Piccioni2007a,Drossart2007a}. The resolution of VIRTIS-M is 2 nm from 0.25 to 1 mu m, and 10 nm from 1 to 5.2 mu m. The resolution of VIRTIS-H is about 2 nm. The atmosphere above the clouds has been observed both on day and night sides, in solar reflection and thermal emission in nadir geometry \citep{Ignatiev2009, Cottini2012, Peralta2012, Peralta2009}. Limb observations provided O2\citep{Piccioni2009, Garcia2009a, Gerard2013, Migliorini2013a, Gerard2008, Gerard2009}, OH \citep{Piccioni2008,Gerard2010,Soret2010,Soret2012}, NO \citep{Garcia2009b}, CO2 \citep{Drossart2007b,Lopez-Valverde2011} and CO \citep{Gilli2009,Gilli2015,Gilli2011} emissions, through nightglow and fluorescence observations. Spectroscopy of the 4-5 mu m range gave access to the cloud structure in the 60-95 km altitude levels \citep{Irwin2008a,Grassi2014, Grassi2008,Grassi2010,Luz2011}. The deeper atmospheric windows, limited by CO2 and H2O bands were accessible only in thermal emission on the night side. The sounded levels at 1.7 and 2.3 mu m were limited respectively to 30-20 km altitude \citep{Barstow2012,Bezard2009,Marcq2008a,Satoh2009,Tsang2009, Tsang2010,Tsang2008,Wilson2008,Wilson2009}, while at shorter wavelengths (1.18, 1.10, 1.01, 0.9 and 0.85 mu m), the hot surface of Venus was seen through the scattering clouds \citep{Mueller2009,Helbert2008,Arnold2008a,Smrekar2010,Mueller2012}. Multiwavelength clouds tracking and thermal fields allowed to study the wind fields and the global dynamics, in particular the complex details of the polar vortex \citep{Garate-Lopez2013,Garcia2009, Hueso2008,Limaye2009,Luz2011,Peralta2012,Piccioni2007b,Sanchez-Lavega2008,Titov2008}. A review of the main results is here reported along some question of what is still needed to progress in the knowledge of our sister planet from ground based observations and future space missions.
We acknowledge the support from the funding agencies, in particular ASI thorugh the contract ASI INAF I/050/10/0.- Publication:
-
Memorie della Societa Astronomica Italiana
- Pub Date:
- 2016
- Bibcode:
- 2016MmSAI..87..177P