1,2,3,1,1,4,- 1IASB - BIRA, Planetary Atmosphere, Brussels, Belgium (arnaud.mahieux@aeronomie.be)
- 2Aurora Technology Services for the European Space Agency at ESAC, Madrid, Spain
- 3The University of Texas at Austin, Austin, Texas
- 4NASA Langley Research Center, Hampton, Virginia
On Earth, the mesosphere and thermosphere are sometimes called the “ignorosphere”. The same situation applied to Venus, where only a few datasets are available regarding their composition and radiative states [1-8].
The mesosphere is characterised by a decrease in temperature with altitude and is the region where the coldest atmospheric temperatures are found; on the contrary, temperatures increase in the thermosphere. On Venus, the mesosphere extends from ~70 km to ~110 km on the dayside, 140 km at the terminator, and 150 km on the nightside; the thermosphere is located just above and extends up to ~180 km.
The SOVENIR mission responds to the ESA MiniFast call issued this year, and aims to send to Venus a small satellite that would carry only one instrument, SAGE4Venus. The mission would last two Venus years. The instrument is an infrared filter wheel imager that would sound the Venus atmosphere using solar occultations. It will be sensitive at eleven narrow windows between 2 and 5 μm, and would focus on the detection of the aerosols (75-130 km) and CO2 (72-175 km), CO (82-170 km), H2O (75-110 km), HDO (70-88 km), SO2 (77-90 km), SO3 (79-91 km), OCS (72-101 km), and CS2 (70-80 km). The temperature will be obtained from the CO2 profiles using the hydrostatic equilibrium.
The scientific goals of the mission would be to monitor the radiative budget; monitor the 3D-wave activity and quantify the momentum exchanges between the different layers; characterize the water, carbon, and sulfur chemical cycles through observations; and study the aerosols layer above the cloud layer.
In this work, we will present the setup of the satellite and instrument, and describe the expected results from the mission.
References:
[1] von Zahn, U., et al. (1980), J. Geophys. Res.
[2] Mahieux, A., et al. (2023), Icarus
[3] Luginin, M., et al. (2024), Icarus
[4] Evdokimova, D., et al. (2021), Journal of Geophysical Research
[5] Piccialli, A., et al. (2015), Planet. Space Sci.
[6] Limaye, S., et al. (2016)
[7] Encrenaz, T., et al. (2015), Planet. Space Sci.
[8] Sonnabend, G., et al. (2012), Icarus
How to cite: Mahieux, A., Robert, S., Trompet, L., Sayanagi, K., Damadeo, R., and Hill, C.: A MiniFast mission proposal to Venus: The SOVENIR mission, EPSC-DPS Joint Meeting 2025, Helsinki, Finland, 7–12 Sep 2025, EPSC-DPS2025-891, https://doi.org/10.5194/epsc-dps2025-891, 2025.
