NASA wants to explore the icy moons of Jupiter and Saturn with autonomous robots

Europa’s orbit is an ellipse, and the moon’s shape is affected by Jupiter’s gravity, deforming as it approaches Jupiter.

This shape change creates friction within Europa, generating large amounts of heat in a mechanism known as tidal heating, which melts some of the ice and forms a vast interior ocean beneath the moon’s thick ice crust.

Europa’s internal ocean is salty and estimated to be about 100 kilometers deep on average, with a total volume of water twice as large as all of Earth’s oceans, although this moon is much smaller than our planet.

Comparison of Earth’s oceans and Europa’s inland oceans.

Illustration: NASA/JPL-Caltech

In addition, Jupiter’s moons Ganymede and Callisto and Saturn’s moons Titan and Enceladus are thought to have internal oceans.

Liquid water is essential to life as we know it, so ocean worlds are at the forefront of the search for extraterrestrial life.

The European Space Agency’s Jupiter Ice Explorer spacecraft will be used to explore Jupiter’s ice caps.

Photo: ESA/M. Pedoussaut

under the sea (ice)

The autonomous underwater exploration robots envisioned by SWIM are quite small. Their wedge-shaped bodies are about 12 centimeters long. The device, called Cryobot, will carry robots under the thick ice caps of these moons and use nuclear energy to melt the ice. The idea is to place about four dozen robots in a cryobot and embed them in a thick ice shell for several years.

Conceptual illustration of SWIM with a cylindrical probe in the upper left corner.

Illustration: Ethan Schaler/NASA/JPL-Caltech

There are benefits to sending such a large number of reconnaissance robots. One is that they can explore a wider area. Another is that they are supposed to operate in teams so that multiple robots can survey the same area in overlapping directions, reducing errors in observational data.

Each robot will be equipped with sensors to measure the temperature, pressure, acidity, electrical conductivity and chemical composition of the waters it explores. All these sensors will be installed on a chip of a few millimeters square.

“People might ask, why is NASA developing an underwater robot for space exploration?” Ethan Schaller, project manager at NASA’s JPL, says in explaining SWIM’s motivation. “Because there are places in the solar system that we want to go to look for life, and we think that life requires liquid water.”

This story appeared first Narrative Japan and translated from Japanese.