Lava found on Jupiter's moon

Lava found on Jupiter's moon

Indian scientist-led team makes discovery, analysing Galileo sent data

An image of Jupiter’s volcanic moon Io sent by Galileo spacecraftThe discovery made by Delhi-born Krishan Khurana and his co-workers from three US universities, not only fills up a missing piece of the jigsaw puzzle to understand the planetary system but also opens up a new window to better understand the evolution of the moon. 

The subsurface magma ocean in Io is more than 50 km (31 miles) thick. The Jovian satellite is estimated to have produced about 100 times more lava each year than all of Earth’s volcanoes.

The volcanoes on Earth occur in localised hotspots like the “Ring of Fire” around the Pacific Ocean, but Io’s volcanoes are distributed all over its surface and fed by the magma ocean.

“We now conclusively know where Io’s volcanoes get all their magma from and why they are distributed so uniformly on Io’s surface. All of the volcanoes have access to a common global magma aquifer explaining why Io is the most volcanic body in the solar system,” Khurana, a scientist at the University of California, Los Angeles told Deccan Herald.

Jupiter, the biggest and heaviest member in the planetary system, has 63 moons. Four of them – Ganymede, Europa, Io and Calisto – are the biggest ones and at least one of them, Europa, is being investigated as a possible site of human habitation in distant future.

While Io is almost certainly not going to harbour any known form of life in the absence of water, scientists could draw parallel on lunar evolution from the discovery.

“Our insights into the current conditions on Io also help us understand the structure of our own Moon in the distant past when it was much closer to the earth,” he said.

Magma ocean

Millions of years ago, when Moon was closer to the earth, it experienced much higher tides which heated its interior tremendously forming and maintaining a subsurface magma ocean.

The Moon’s magma ocean has solidified but the frozen layer can still be detected in seismic data obtained from seismometers operated on the Moon during the Apollo missions.Published in the “Science” on Friday, the Io study is a re-analysis of data collected by NASA space probe Galileo, which was launched in 1989 and began orbiting Jupiter in 1995. In 2003, the space probe was allowed to be crushed by the Jovian atmosphere. But it had beamed back loads of data on the planet and its satellites back to the earth by then.

The re-analysis with new models focused on the magnetic data from Galileo to explain Io’s unaccounted signatures. The technique was successfully used to find out subsurface oceans of water in three other large icy Jovian satellites.

“Io’s volcanism suggests how volcanoes work and provides a window in time to styles of volcanic activity that may have occurred on the Earth and Moon during their earliest history,” said Torrence Johnson who was Galileo’s project scientist, based at NASA’s Jet Propulsion Laboratory in California and not directly involved in this study.