"Spooky Sights: Acidic Lake and Volcano Spewing Eerie Blue Flames"

The Kawah Ijen Crater Lake in East Java, Indonesia, known as the world's largest acidic lake, is a spooky sight captured by the Copernicus Sentinel-2 mission. The lake's turquoise blue waters are filled with high concentrations of sulphuric and hydrochloric acids, making it unswimmable but easily visible from space. The lake's acidity, combined with its emission of hot, flammable sulphurous gases that burn with an eerie blue flame, creates an enchanting nighttime spectacle. The images also showcase the nearby Raung Volcano, one of Java's most active volcanoes.