Mercurys Sodium Tail

What is that fuzzy streak extending from Mercury? Long exposures of our Solar System’s innermost planet may reveal something unexpected: a tail. Mercury’s thin atmosphere contains small amounts of sodium that glow when excited by light from the Sun. Sunlight also liberates these molecules from Mercury’s surface and pushes them away. The yellow glow from sodium, in particular, is relatively bright. Pictured, Mercury and its sodium tail are visible in a deep image taken in late May from Italy through a filter that primarily transmits yellow light emitted by sodium. First predicted in the 1980s, Mercury’s tail was first discovered in 2001. Many tail details were revealed in multiple observations by NASA’s robotic MESSENGER spacecraft that orbited Mercury between 2011 and 2015. Tails are usually associated with comets. The tails of Comet NEOWISE are currently visible with the unaided eye in the morning sky. via wordpress

Wikipedia article of the day for July 11, 2020

Wikipedia article of the day is Payún Matrú. Check it out: Summary: Payún Matrú is a shield volcano in the Malargüe Department of Mendoza Province, Argentina. Activity in its volcanic field commenced at least 2.5 million years ago and continued until about 515 years ago. Payún Matrú lies in the Payenia volcanic province in the back-arc region of the Andean Volcanic Belt, formed by the subduction of the Nazca Plate beneath the South American Plate. The volcano developed over sediments and volcanic rocks ranging from Mesoproterozoic to Tertiary age. It consists of a large shield volcano capped off by a 7–8 km (4.3–5.0 mi) caldera that formed during a large explosive eruption between 168,000 and 82,000 years ago, along with a compound volcano 3,680–3,797 m (12,073–12,457 ft) high, and scoria cones and lava flows due west and east from the main shield volcano. One of these lava flows, the Pleistocene Pampas Onduladas flow, is the longest one in the world from the Quaternary, at 167–181 km (104–112 mi).