A trio of papers provide new insight into the composition and evolution of the surface of Venus, hidden beneath its caustic, high temperature atmosphere. Utilizing imaging from orbit using multiple wavelengths—six-band spectroscopy proposed as part of the VERITAS and EnVision missions—scientists can map the iron content of the Venusian surface and construct the first-ever geologic map.

"Previous missions have only imaged one wavelength, and used 30-year-old topographic data to correct the spectra. Moreover, they were based on theoretical ideas about what Venus spectra look like, at very high temperatures. So the prior data have all been fairly qualitative," said M. Darby Dyar, a Senior Scientist at the Planetary Science Institute and author on three recent papers on the topic.

These papers are based on new data from the Planetary Spectroscopy Laboratory at German Aerospace Center Institute of Planetary Research in Berlin, where Dyar works with a team including Jörn Helbert, first author of "Deriving iron contents from past and future Venus surface spectra with new high-temperature laboratory emissivity data" that appears today in Science Advances.

Since the 1960s and '70s, scientists have come to view Mars as something of a "dead planet." As the first close-up images from orbit and the surface came in, previous speculation about canals, water and a Martian civilization were dispelled. Subsequent studies also revealed that the geological activity that created features like the Tharsis Mons region (especially Olympus Mons) and Valles Marineris had ceased long ago.

However, in the past few decades, robotic missions have found ample evidence that Mars is still an active place. A recent indication was an image taken by the Mars Reconnaissance Orbiter (MRO), which showed relatively fresh landslides in a crater near Nili Fossae. This area is part of the Syrtis Major region and is located just north of the Jezero Crater (where the Perseverance rover will be landing in six weeks).

The landslide was captured as a part of a larger image acquired by the MRO's Context Camera (CTX) on September 21, 2018.