Every few years, we get big news from NASA about the potential next wave of solar system exploration. This year, the four finalists for the Discovery Missions were announced and if they all had something in common, it is the volcanoes!
Potential missions to Venus, Io and Triton were approved to go forward and two of this quartet of missions will be picked to continue development towards potential launch. This new batch of potential missions each recieve $3 million to construct a full mission plan to prove their value and feasibility.
The Discovery Missions are not the big flagship missions like Galileo or New Horizons. Instead, they are missions built on a smaller budget that can produce amazing results. Alumni of the Discovery Mission program include Mercury’s MESSENGER, the comet hunter Deep Impact and Dawn’s visits to Vesta and Ceres.
The four finalists proposed to visit three potential worlds, all of which have not been closely studies by an American mission for decades. Two would travel to Earth’s sister planet, Venus. DAVINCI+ (Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging Plus) would examine the atmosphere of the planet while VERITAS (Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy) would be focused on the surface geology.
Both missions goal is to understand why Venus’ history diverged so dramatically from Earth’s — and volcanism is a key to that question. The atmosphere of Venus is choked with carbon dioxide, likely produced from volcanism, some of which might be going on today. DAVINCI+ would actually land on the planet, a formidable task for any mission as the surface temperature is over 500C and pressures over 75 times that of Earth. VERITAS will orbit the planet and map the entire surface in remarkable detail (and 3D!)
Currently, Japan’s Akatsuki mission is in orbit around Venus, but the last American mission to the planet was Magellan in the early 1990’s. The last lander on Venus was the Soviet Union’s Venera 14 in 1981. Either of these proposed Discovery Missions would bring Venus back into the forefront of planetary exploration.
The other two finalists would head to the outer solar system. IVO (Io Volcano Observer) would head to the most volcanically active body in the solar system: Jupiter’s Io. It would explore the potential sources for the copious lava that erupts from massive calderas on the tiny moon’s surface. Io was explored by both Voyager missions and Galileo, but never has a mission solely focused on it.
Finally, TRIDENT would explore one of the strangest moon’s in the solar system, Neptune’s Triton. Not only does it orbit Neptune in the opposite direction of almost every other moon, but it also is home to cryovolcanism where ice erupts from its interior. Triton may be a captured Kuiper Belt object (like Pluto) and as New Horizons discovered, these icy dwarf planets can be highly geologically active. Neptune’s moon haven’t been visited since Voyager 2’s flyby in 1989.
Any of these Discovery Missions would explore world’s that have been neglected for decades. Combine that would missions like Dragonfly to Titan and Osiris-REX to asteroid Bennu, we’ll be visiting some of the most unique objects in our solar system.