Europa glows in the dark due to the presence of thick layer of Ice on it

The Jupiter's moon europa glows brightly even if the sun's light falls on it. Study lead author Murthy Gudipati, a scientist at NASA's Jet Propulsion Laboratory (JPL) in Southern California, said in a statement. 

Jupiter has a strongest magnetic field around it, this field emit electrons all around it. This electrons reaches the Jupiter's moon europa and falls on the icy shell present all over the moon. This causes the moon to glow brightly even in the dark.

Europa glow in dark like our moon appear in the night sky. This may lead to the presence of alien life or any organisms present on the surface of this moon. This glow changes the researchers view to search for alien life on moons and other celestial bodies too.

The researchers built an instrument called Ice Chamber for Europa's High-Energy Electron and Radiation Environment Testing, which they took to an electron-beam facility in Maryland. They tested the effects of radiation on simulated Europa surfaces composed of water ice and various salts suspected to be there, including sodium chloride and magnesium sulfate. The radiation caused the samples to glow.

The icy surface of Europa is rich with salt, including magnesium sulfate (Epsom salt) and sodium chloride (common table salt). Each type of the mineral radiates specific wavelengths of light when releasing energy. These studies found that salts within the icy crust of the Jovian moon can glow in the dark.

Europa is one of the water worlds of our solar system, holding a vast ocean under its frozen surface.