[P-PS04] Results from Akatsuki and advances in Venus science

[PPS04-P05] Fine vertical structure of Venus upper haze as revealed in Akatsuki/IR2 limb images.

*Takehiko Satoh^1,2, Takao M. Sato¹ (1.Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 2.SOKENDAI)

Keywords:Limb observation, Venus upper haze, Near infrared

Akatsuki observes Venus from an elongated elliptical orbit (an orbital period is ~11 earth days). Since this orbit receives strong purturbation by the sun's gravitaion, the peri-center distance from Venus fluctuates. On 30 October 2016, when the spacecraft is near the peri-center (~8200 km from the center of Venus), limb observations were carried out with onboard cameras. IR2 captured Venus limb images at 2.02-micron and detected a step-like intensity variation of the upper haze at the limb. The image indicates existence of approximately 6-pixel (or ~7 km) wide vertical structure at the planetary limb. By correcting for the IR2 point-spread function, we discuss the vertical aerosol structure (number density and scale height) in the upper atmosphere.