NASA's VERITAS mission prepares for Venus on volcanic Iceland

Volcanic Iceland is an excellent testbed for scientific experiments to be carried out on future missions to Earth's neighbouring twin, Venus. "Characterising and measuring the extent and type of volcanic and tectonic processes on Venus is key to understanding the evolution of the surface of Venus and rocky planets in general", points out Sue Smrekar, the Principal Investigator for VERITAS at JPL. It was NASA's Magellan mission in the 1990s that gave the first detailed 'view' of the Venusian surface, which is shrouded beneath clouds of sulfuric acid. The mission's global topographic and radar maps unveiled a planet almost entirely resurfaced by volcanic activity in about the last half billion years. After Magellan, many questions still remain unanswered and the mission results spawned additional new questions: Why did Earth and Venus, almost identical in size and mass, follow completely different paths in their 4.5 billion year-long evolution? What happened during the four billion years before the last global resurfacing event? Finally, are there still active volcanos? These and many other questions motivate the current activities on Iceland that will facilitate future Venus investigations.

Radars are the way to see the surface of Venus at high resolution

Additionally, VERITAS scientists are in the field performing ground measurements and collecting rock samples from various types of solidified magma for laboratory analyses that will be used to devise better ways of interpreting the radar data acquired by the Venus missions. Data is being collected at two sites both from the air and on the ground: The first site is on the Reykjanes peninsula, which includes the recently active Litli-Hrútur volcano. The second site is in the Holuhraun area near the Askja volcano where an area larger than the size of New York's Manhattan Island was recently flooded by fresh lava. Holuhraun was formed in 2014/15 by an extraordinarily long and massive volcanic eruption. "The flexibility of the F-SAR radar to acquire interferometric and polarimetric data will be invaluable in developing algorithms for investigating Venus," said Scott Hensley of JPL, Project Scientist for VERITAS and VenSAR Instrument Project Scientist for EnVision.

Adeli´s team uses the V-EMulator, a prototype of the VEM near-infrared multi-spectral camera that will fly on-board VERITAS to classify lava flows that range from very fresh terrains to areas that have been altered over time. 'Very fresh' for the team in Iceland means that the team will be able to measure hot, molten lava that is recently erupted from the Litli-Hrútur volcano since 10 July 2023.

Samples of solidified lava will be collected and sent back to the Planetary Sample Laboratories (PSL) at DLR’s site in Berlin for analysis at temperatures as high as on Venus in the Venus emissivity chamber. The spectral characteristics of a rock at normal terrestrial temperatures differs from the signal at high temperatures like on Venus. It is necessary to understand exactly what is being measured to interpret the data properly.

As active volcanos on Venus are highly likely, another group of VERITAS scientists use data collected during the same field campaign to better understand volcanic activity on Venus. "We are investigating the infrared signal of active eruptions and searching for new lava flows," explains Nils Müller, a guest scientist at DLR's Institute of Planetary Research from Freie Universität Berlin. The Dyngjusandur sand sheet (a cold sand desert) and two fissure-fed lava flows, Holuhraun and Thorvaldshraun, are excellent analogues in Iceland to prepare for these studies, because these recent lava flows at the sites are sufficiently large and intense to be detectable if they were to appear on Venus.