Rounding the Sun on July 3rd and currently headed for the outer Solar System, Comet NEOWISE (C/2020 F3) has been growing brighter in the predawn skies of planet Earth. From low Earth orbit it also rises before the Sun, captured above the approaching glow along the eastern horizon in this snapshot from the International Space Station on July 5. Venus, now Earth’s morning star is the brilliant celestial beacon on the right in the field of view. Above Venus you can spot the sister stars of the more compact Pleiades cluster. Earthbound skygazers can spot this comet with the unaided eye, but should look for awesome views with binoculars. Comet NEOWISE from Earth’s Surface: Notable Images Submitted to APOD
These silvery blue waves washing over a tree-lined horizon in the eastern French Alps are noctilucent clouds. From high in planet Earth’s mesosphere, they reflect sunlight in this predawn skyscape taken on July 8. This summer, the night-shining clouds are not new to the northern high-latitudes. Comet NEOWISE is though. Also known as C/2020 F3, the comet was discovered in March by the Earth-orbiting Near Earth Object Wide-field Infrared Survey Explorer (NEOWISE) satellite. It’s now emerging in morning twilight only just visible to the unaided eye from a clear location above the northeastern horizon.
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. Comet NEOWISE from Around the Globe: Notable Images Submitted to APOD
A comet has suddenly become visible to the unaided eye. Comet C/2020 F3 (NEOWISE) was discovered in late March and brightened as it reached its closest approach to the Sun, inside the orbit of Mercury, late last week. The interplanetary iceberg survived solar heating, so far, and is now becoming closer to the Earth as it starts its long trek back to the outer Solar System. As Comet NEOWISE became one of the few naked-eye comets of the 21st Century, word spread quickly, and the comet has already been photographed behind many famous sites and cities around the globe. Featured, Comet NEOWISE was captured over Lebanon two days ago just before sunrise. The future brightness of Comet NEOWISE remains somewhat uncertain but the comet will likely continue to be findable not only in the early morning sky, but also next week in the early evening sky. Comet NEOWISE from Around the Globe: Notable Images Submitted to APOD
Unspeakable beauty and unimaginable bedlam can be found together in the Orion Nebula Arguably the most famous of all astronomy nebulas, the Great Nebula in Orion is an immense interstellar molecular cloud only 1500 light-years away. In the featured deep image shown in assigned colors, the part of the nebula’s center known as M43 is shown as taken by the Hubble Space Telescope. The Great Nebula in Orion can be found with the unaided eye near the easily identifiable belt of three stars in the popular constellation Orion. The entire Orion Nebula, including both M42 and M43 spans about 40 light years and is located in the same spiral arm of our Galaxy as the Sun.