NASA scientists have discovered that Jupiter’s icy moon Europa—the most alien-friendly locale in the solar system—may actually glow in dark.
The hypothesis comes from an experiment that was carried out at NASA’s Jet Propulsion Laboratory (JPL) in California by recreating Europa and Jupiter’s interactions. It was found that the moon glows blue-white and blue-green through the ice and water interior, and this happens due to the radiation from its host planet Jupiter. The glow has not been seen by telescopes yet.
The findings were published on November 9, 2020, in the journal Nature Astronomy.
After the sun, the strongest radiation is emitted by Jupiter and it is surrounded by the biggest planetary magnetic field in the solar system. It spans over 1 million kilometres in radius and engulfs Europa.
Europa is very promising when it comes to potential habitability. The moon cover is made of water ice, and water is considered a strong indicator of potential habitability.
“The night-time ice glow occurring on Europa may be very unique and unlike any other phenomenon in our solar system,” the study said.
The study was led by Murthy Gudipati, who is an astrophysicist at JPL. He and his team worked on the experiments that were carried out to understand how Jupiter’s incessant radiation affects Europa.
An ice chamber was built in JPL’s facilities to understand the effect of Jupiter’s charged high-energy activity on the moon's icy contents. The objective of the ice chamber was to understand how organic matter would react to radiation in Europa’s waters.
Scientists added minerals present on the moon’s surface to the ice-water mix to stimulate it. A variety of salts were used including common salt for the experiment. When high energy particles energise molecules the energy which is released, is often in the form of light. The chamber was later exposed to a beam of high energy electrons.
It was discovered by the team that whenever they beamed through the water, it glowed and when the beam was stopped, the glow stopped too.
The findings which came were completely unexpected and led to the team of scientists changing the focus of their research from organic matter to the glow-in-the-dark phenomenon.
“Seeing the sodium chloride brine with a significantly lower level of glow was the ‘aha’ moment that changed the course of the research,” said Fred Bateman, co-author of the paper in a statement.
With time and so much ongoing research, Europa is becoming one of the next big destinations in planetary research.
“If Europa weren’t under this radiation, it would look the way our moon looks to us — dark on the shadowed side,” Gudipati said. “But because it’s bombarded by the radiation from Jupiter, it glows in the dark.”
Several ongoing studies and plans such as The JUpiter ICy moons Explorer (JUICE) spacecraft are being developed around this planet. JUICE is scheduled to launch in 2022. It is being made to orbit the largest Jovian moon Ganymede and will also study Callisto and Europa in detail.
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