NASA has selected four possible missions to visit some of our solar system’s least understood worlds. These proposals were chosen as part of the agency’s Discovery programme, which funds relatively inexpensive missions within our solar system.
Of the four selections, two are missions to Venus. The first, DAVINCI+ – Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging Plus – proposes to send a spacecraft plummeting through the planet’s savagely hot and dense atmosphere to measure its composition from top to bottom. This would help us understand how the atmosphere formed and whether Venus ever had oceans on its surface.
Venus Emissivity, Radio Science, InSAR, Topography, and Spectroscopy (VERITAS) would orbit Venus with powerful radar instruments to see through its atmosphere and map the surface, looking for active processes like volcanism or plate tectonics. It could also determine the makeup of the planet’s surface and why it’s so different from Earth.
The other two proposed missions are to weird moons in our solar system. The Io Volcanic Observer (IVO) is a proposed spacecraft that would make several close passes by Jupiter’s moon Io, the most volcanically active place in the solar system. While we know that Io is covered in massive volcanoes, IVO would help us figure out where the magma that supplies those volcanoes comes from and how exactly they erupt.
The final mission, Trident, is a proposal to fly past Neptune and its enormous moon Triton, which is strangely active despite being far from the sun and therefore extremely cold. Trident would look for a subsurface ocean on Triton and try to figure out why the moon is so active, which could help us learn how potentially habitable worlds develop.
Each of these teams will receive $3 million over the next nine months to develop their mission concepts in more detail. At the end of the development period, one or two of them will be selected to actually launch.