Ursa Minor (cave) Ursa Minor (cave) Ursa Minor Cave is part of Sequoia National Park, a naturally formed system of caves in California's Sierra Nevada. The cave was discovered in August 2006 by four cave explorers from the Cave Research Foundation who found a softball-sized hole on a cliff face in the mountains. After widening the hole to allow for human entry, the explorers discovered one of the most spectacular caves in the western United States. The cave has since been named "Ursa Minor," because of the large bear skeleton found in the cave. The cave was featured in the September 2007 issue
Ursa Major Moving Group same direction at similar velocities, and also have similar chemical compositions and estimated ages. This evidence suggests to astronomers that the stars in the group share a common origin. Based on the numbers of its constituent stars, the Ursa Major Moving Group is believed to have once been an open cluster, having formed from a protostellar nebula approximately 500 million years ago. Since then, the sparse group has scattered over a region about 30 by 18 light-years, whose center is currently about 80 light-years away, making it the closest cluster-like object to Earth. The Ursa Major Moving Group was discovered