Starship Asterisk*

The strong variability of the middle clouds of Venus as shown in 900-nm mages acquired by the camera IR1 onboard JAXA’s orbiter Akatsuki during the year 2016. Clear hemispherical asymmetries, zonally-oriented stripes and sharp discontinuities are visible on the middle clouds’ albedo. Image dates (from left to right): 2, 3 and 17 of May, 23 of June and 1 of July. Credits: JAXA

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Venus is known for its clouds of sulfuric acid covering the entire planet and its super-fast winds moving at hundreds of kilometers per hour, but our neighboring planet’s thick clouds make it difficult for scientists to peer deep inside its atmosphere.

Now, researchers have used infrared images to spy into the middle layer of Venus's clouds and they have found some unexpected surprises.

The new research ... finds this middle layer of clouds shows a wide variety of cloud patterns that change over time and are very different from the upper layer of Venus's clouds, which are usually studied with ultraviolet images. The study also found changes in the albedo of the middle clouds, or how much sunlight they are reflecting back to space, which could indicate the presence of water, methane or other compounds absorbing solar radiation.

The motions of the middle clouds, combined with previous observations, allowed researchers to reconstruct a picture of the winds on Venus over 10 years, showing the super-fast winds in the planet's middle clouds are fastest at the equator and, like the upper clouds, change speed over time.

These new observations could help scientists better understand our neighboring planet and shed light on other planets and exoplanets with similar features, according to the study's authors. ...

• Geophysical Research Letters 46(5):2399 (16 Mar 2019) DOI: 10.1029/2018GL081670
• arXiv.org > astro-ph > arXiv:1903.02883 > 07 Mar 2019