NASA has recently US$600,000 (£495,000) announced to fund a study In the feasibility of sending swarms of miniature swimming robots (known as young autonomous swimmers) to explore the oceans beneath the ice shells of our solar system’s many “ocean worlds.” But don’t imagine metallic human beings swimming like frogs underwater. They are likely to be simple wedges that are triangular in shape.
Life in ocean worlds
These oceans are of interest to scientists not only because they contain a lot of liquid water (the ocean of Europe probably existed double the amount of water as the entire Earth’s oceans), but because chemical reactions between rocks and ocean water can support life. In fact, the environment in these oceans may be very similar to that found on Earth When life began.
These are environments in which water that has seeped into the ocean floor rocks becomes hot and chemically enriched – water that is expelled back into the ocean. Microbes can feed on this chemical energy, and larger organisms can eat it. Actually no need for sunlight or atmosphere. Several warm rock structures of this type, known as “hydrothermal vents”, have been documented in ocean floors on Earth since their appearance. It was discovered in 1977. At these sites, the local food web is already supported by chemical synthesis (energy from chemical reactions) rather than by photosynthesis (energy from sunlight).
In most of the ocean worlds in our solar system, the energy that heats up the rocky interiors and prevents the oceans from freezing all the way to the base comes primarily from tides. This is in contrast to the largely radiative heating of the Earth’s interior. But the chemistry of water and rock reactions is similar.
Samples have already been taken from the ocean of Enceladus By flying the Cassini spacecraft through the plumes Ice crystals that explode through cracks in the ice. There are hopes that NASA Europa Clipper Mission You may find similar plumes to sample when a series of nearby Air Europa flights begin in 2030. However, stepping into the ocean to explore may be much more informative than just smelling a freeze-dried sample.
This is the place Sensing with independent young swimmers (swimming) This concept comes. The idea is to land on Europa or Enceladus (which won’t be cheap nor easy) in a place where the ice is relatively thin (the location of which has not yet been determined) and use a radioactive probe to melt a hole 25 cm wide through it into the ocean – located hundreds or thousands of meters deep .
Once there, you’ll release up to fourteen 12cm wedge-shaped little swimmers to go exploring. Its bearing capacity may be much lower than the 3.6m bearing capacity Self-confident The underwater vehicle is famous Boaty McBoatfacewith a range of 2,000 km and has already achieved a cruise of more than 100 km under the ice of Antarctica.
At this point, the swim is just one of five “phase two studies” in a group of “advanced concepts” funded in NASA’s 2022 round. Innovative Advanced Concepts (NIAC) Program. So there are still long odds against Swim becoming a reality, and the scope or funding of an entire mission has yet to be determined.
Young swimmers will communicate with the probe acoustically (through sound waves), and the probe will send its data via cable to the probe on the surface. The study will pilot prototypes in a test tank with all subsystems integrated.
Each young swimmer can explore perhaps only tens of meters of the probe, limited by its battery capacity and acoustic data link range, but by acting as a flock they can map changes (in time or location) in temperature and salinity. They may be able to measure changes in turbid waterwhich could indicate the direction towards the nearest hydrothermal vent.
The power limitations of young swimmers may mean that none of them can carry cameras (these will need their own light source) or sensors that can specifically smell organic molecules. But at this point, nothing is ruled out.
I think finding the signs of hydrothermal vents is a long way off. After all, the ocean floor will be several kilometers below the launch point of the little swimmer. But, to be fair, the openings were not explicitly suggested in the swimming proposal. To locate and inspect the vents ourselves, we’d probably need Boaty McBoatface in space. However, swimming would be a good start.