Ancient sun daggers will not hurt you, but they may tell you the time.  A sun dagger is a dagger-shaped gap in a shadow created by sunlight streaming through a crevice in a nearby rock. Starting over a thousand year ago, native people of the American southwest carved spiral petroglyphs into rocks that became illuminated by sun daggers in different ways as the Sun shifts in the sky. A type of sundial, where the end of the sundagger points in the spiral at high noon (for example) indicates a time of year, possibly illuminating a solstice or equinox.  Sun daggers are thought to have been used by Sun Priests during lone vigils with prayers and offerings.  Of the few known, the featured video discusses the historic Picture Rocks Sun Dagger near Tucson, Arizona, USA, likely created by a Hohokam Sun Priest around 1000 AD.  via NASA https://ift.tt/3kkonqL

Outbursts from a Double Star System


For decades, astronomers have known about irregular outbursts from the double star system V745 Sco, which is located about 25,000 light years from Earth. via NASA https://ift.tt/3gnEvVQ

Distorted galaxy NGC 2442 can be found in the southern constellation of the flying fish, (Piscis) Volans. Located about 50 million light-years away, the galaxy's two spiral arms extending from a pronounced central bar have a hook-like appearance in wide-field images. But this mosaicked close-up, constructed from Hubble Space Telescope and European Southern Observatory data, follows the galaxy's structure in amazing detail. Obscuring dust lanes, young blue star clusters and reddish star forming regions surround a core of yellowish light from an older population of stars. The sharp image data also reveal more distant background galaxies seen right through NGC 2442's star clusters and nebulae. The image spans about 75,000 light-years at the estimated distance of NGC 2442. via NASA https://ift.tt/3fq4SZW

SpaceX Crew Dragon Endeavour Lifted Aboard Recovery Ship


Robert Behnken and Douglas Hurley are aboard the SpaceX Crew Dragon Endeavour spacecraft as it is lifted onto the SpaceX GO Navigator recovery ship shortly after landing. via NASA https://ift.tt/2PhmxbN