
Trident space mission to study Triton, Neptune’s Biggest Moon
– News of April 30, 2019 –
The outer planets of the solar system are still almost unexplored. Uranus and Neptune in particular have been stealthily flown over by the Voyager 2 space probe. A new orbiter could be sent around one of these two worlds. Such a mission promises a huge scientific return but would also be very expensive. It is indeed necessary to make the trip quickly not to ask too much RTG, which powers the space mission. But we must not go too fast to not significantly slow down the spacecraft on arrival, which would require shipping tons of additional propellant. From the second half of the 2020s, a new firing window will open for Uranus or Neptune. The alignment of the other planets of the solar system, in particular of Jupiter, will allow to benefit from a gravitational catapult effect, which could make the trip a little less long and less energy-consuming.
Several options are therefore envisaged by NASA. Among them, the least expensive are to make a simple overview. The excellent results from the New Horizon spacecraft near Pluto and Ultima Thule lend credibility to this option. A JPL team has just introduced the Trident mission, a fairly economical space probe that could be part of the Discovery program. The Trident space probe would simply fly over Neptune’s largest moon, Triton. Triton is the seventh largest moon in the solar system and is one of the only moons that is geologically active. Triton includes cryovolcans that expel geysers of ammonia and nitrogen at 8 kilometers altitude. Observing these geysers closely could tell us what is happening beneath the surface of Neptune’s moon.
Like some moons of Jupiter and Saturn, Triton is thought to have an underground ocean. It is therefore an interesting track in the quest for extraterrestrial life. In addition, Triton is believed to be an ancient dwarf planet that was expelled from the Kuiper belt before being captured by Neptune’s gravity. The Trident mission could therefore collect a lot of interesting information. Like the New Horizon mission, the information gathering will take a few days, then the space probe will transmit its information to Earth during 12 months.
NASA still has some time to decide to launch the development of the Trident mission. An orbiter dedicated to Uranus and Neptune would obviously be a better solution from a scientific point of view, and perhaps a partnership with ESA could help pay the cost of such a mission. But a flyby like the Trident mission is already very promising.
Picture by NASA/JPL
