Science and Exploration

Reflectivity Of Venus’ Dayside Disk During The 2020 Observation Campaign

By Keith Cowing
Press Release
July 28, 2022
Filed under
Reflectivity Of Venus’ Dayside Disk During The 2020 Observation Campaign
Cloud structure of the Venusian atmosphere in the ultraviolet band (Wikipedia)

We performed a unique Venus observation campaign to measure the disk brightness of Venus over a broad range of wavelengths in August and September 2020. The primary goal of the campaign is to investigate the absorption properties of the unknown absorber in the clouds. The secondary goal is to extract a disk mean SO2 gas abundance, whose absorption spectral feature is entangled with that of the unknown absorber at the ultraviolet (UV) wavelengths.

A total of 3 spacecraft and 6 ground-based telescopes participated in this campaign, covering the 52 to 1700~nm wavelength range. After careful evaluation of the observational data, we focused on the data sets acquired by 4 facilities.

We accomplished our primary goal by analyzing the reflectivity spectrum of the Venus disk over the 283-800 nm wavelengths. Considerable absorption is present in the 350-450 nm range, for which we retrieved the corresponding optical depth by the unknown absorber.

The result shows a consistent wavelength dependence of the relative optical depth with that at low latitudes during the Venus flyby by MESSENGER in 2007 (Pérez-Hoyos et al. 2018), which was expected because the overall disk reflectivity is dominated by low latitudes. Last, we summarize the experience obtained during this first campaign that should enable us to accomplish our second goal in future campaigns.

Reflectivity Of Venus’ Dayside Disk During The 2020 Observation Campaign: outcomes and future perspectives

Yeon Joo Lee, Antonio García Muñoz, Atsushi Yamazaki, Eric Quémerais, Stefano Mottola, Stephan Hellmich, Thomas Granzer, Gilles Bergond, Martin Roth, Eulalia Gallego-Cano, Jean-Yves Chaufray, Rozenn Robidel, Go Murakami, Kei Masunaga, Murat Kaplan, Orhan Erece, Ricardo Hueso, Petr Kabáth, Magdaléna Špoková, Agustín Sánchez-Lavega, Myung-Jin Kim, Valeria Mangano, Kandis-Lea Jessup, Thomas Widemann, Ko-ichiro Sugiyama, Shigeto Watanabe, Manabu Yamada, Takehiko Satoh, Masato Nakamura, Masataka Imai, Juan Cabrera

Comments: Accepted for publication in PSJ, 45 pages, 13 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2207.13495 [astro-ph.EP] (or arXiv:2207.13495v1 [astro-ph.EP] for this version)
Submission history
From: Yeon Joo Lee
[v1] Wed, 27 Jul 2022 12:38:57 UTC (3,079 KB)

SpaceRef co-founder, Explorers Club Fellow, ex-NASA, Away Teams, Journalist, Space & Astrobiology, Lapsed climber.