Mount Dukono erupted at 07:41am local time on Friday (22:41 GMT on Thursday), spouting a tower of volcanic ash as high as 10km (6.21 miles) into the sky, and was accompanied by a weak to strong booming sound, Indonesia's Center for Volcanology and Geological Hazard Mitigation said in a statement.
The European Space Agency's Mars Express mission just released a stunning orbital image showing surprising changes within Mars's Utopia Planitia basin, which is thought to be the site of a now vanished sea.
The cave, which was found by Hekla Tang, the snowmobile operations manager for tour company Arctic Adventures, was likely formed by meltwater and shifting ice and features a spacious chamber made of high-clarity ice streaked with layers of volcanic ash from past volcanic eruptions. Once it was discovered, the company told Travel + Leisure it worked to build out the entrance and add lighting.