NASA IOD

This treasure chest is full of stars. The featured image was obtained with NASA's James Webb Space Telescope and shows a dust pilar in the Carina Nebula inside our Galaxy, roughly 7500 light-years away. It is formed by interstellar gas and dust, and shaped by powerful stellar winds and radiation form neighboring stars like the nearby Eta Carinae stellar system which is more luminous than 5 million suns. The star formation inside the pillar is excavating its head, creating the open lid of the chest. Astronomers estimate that there are about 70 stars in a compact cluster inside the pillar. This cluster is now thought to be only around 1.3 million years old. Its bounty of young stars includes a massive star approximately 19 times as massive as the Sun. More massive stars are rarer, shine brighter and evolve faster than less massive stars. They are the shiniest jewels in the treasure chest. APOD's main NASA site is moving : From apod.nasa.gov to science.nasa.gov/apod

Sometimes where Hubble finds darkness, Webb sees light. An example is today’s composite images of Messier 64 (M64), a nearby spiral galaxy of many names. The dark band of dust partially blocking its bright core earned it the moniker “the Black Eye Galaxy.” Webb’s Mid-InfraRed Instrument (MIRI) sees that dust, shown in red, as it absorbs and re-emits light from surrounding newborn stars. These young stars are embedded in pink star-forming regions in the secondary Hubble-only image. M64’s inner and outer gas regions counter-rotate, creating regions of increased star formation where the two gas “currents” meet and compress. A merger between M64 and a smaller galaxy was likely the cause of the opposing motion of the outer gas. Spiral galaxies were once thought to have peaceful histories. M64 was key evidence that spiral galaxies, including the Milky Way, can and do experience mergers. Webb’s view of M64 will tell astronomers about the structure, motion, and composition of the galaxy’s dust and add context to the galaxy’s merger history and evolution. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

There was something behind the clouds. Upon close inspection, it was the Moon, which was hard to see yesterday around noon above the small village of Cessy, France. But soon, it was not only the Moon. As expected, a bright dot suddenly appeared from behind the Moon -- the planet Venus far in the distance. Captured in the single featured exposure, both appeared to show a crescent phase. The Moon's crescent was quite slight -- with only about 10 percent of its face illuminated by the Sun. In contrast, Venus's crescent was more full -- showing about 25 percent illumination. Venus appeared brighter because it is nearer the Sun and because its clouds are more reflective than the dark lunar surface. An occultation of Venus by the Moon is visible to only about 10 percent of the Earth, but in yesterday's event even most of that was experiencing daytime. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

The hydrogen in your body and present in every molecule of water came from the Big Bang. There are no other appreciable sources of hydrogen in the universe. The carbon in your body was made by nuclear fusion in the interior of stars, as was the oxygen. Much of the iron in your body was made during supernovas of stars that occurred long ago and far away. The gold in your jewelry was likely made from neutron stars during collisions that may have been visible as short-duration gamma-ray bursts or gravitational wave events. Elements like phosphorus and copper are present in our bodies in only small amounts but are essential to the functioning of all known life. The featured periodic table is color coded to indicate humanity's best guess as to the nuclear origin of all known elements. The sites of nuclear creation of some elements, such as copper, are not really well known and are continuing topics of observational and computational research. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

This sight was worth getting out of bed early. Just over four years ago, Comet C/2020 F3 (NEOWISE) rose before dawn to the delight of northern sky enthusiasts awake that early. Up before sunrise on July 8th, the featured photographer was able to capture in dramatic fashion one of the few comets visible to the unaided eye this century, an inner-Solar System intruder that has become known as the Great Comet of 2020. The resulting video detailed Comet NEOWISE from Italy rising over the Adriatic Sea. The featured time-lapse video combines over 240 images taken over 30 minutes. The comet was seen rising through a foreground of bright and undulating noctilucent clouds, and before a background of distant stars. Comet NEOWISE remained unexpectedly bright for over a month, with its ion and dust tails found to emanate from a nucleus spanning about five kilometers across. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

Bright sunlight glints as long dark shadows mark this image of the surface of the Moon. It was taken on July 20, 1969, by Apollo 11 astronaut Neil Armstrong, the first to walk on the lunar surface. Pictured is the mission's lunar module, the Eagle, and spacesuited lunar module pilot Buzz Aldrin. Aldrin is unfurling a long sheet of foil also known as the Solar Wind Composition Experiment. Exposed facing the Sun, the foil trapped particles streaming outward in the solar wind, catching a sample of material from the Sun itself. Along with 22 kilograms of moon rocks and lunar soil samples, the solar wind collector was returned for analysis in earthbound laboratories. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

Beautiful and bright spiral galaxy M83 lies some twelve million light-years away, near the southeastern tip of the very long constellation Hydra. Prominent spiral arms traced by dark dust lanes and blue star clusters lend this galaxy its popular name, the Southern Pinwheel. Still, reddish star forming regions that dot this cosmic pinwheel's spiral arms have suggested another nickname, the Thousand-Ruby Galaxy. A mere 40,000 light-years across, smaller than the Milky Way, M83 is a member of a group of galaxies that includes active galaxy Centaurus A. In fact, the core of M83 itself is bright at x-ray energies, showing a high concentration of neutron stars and black holes left from an intense burst of star formation. This sharp, groundbased telescopic view also features foreground Milky Way stars and distant background galaxies. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

What does this image look like to you? Many see a giraffe facing right, with neck stretched high and long legs mid-stride (but some may see a squirrel instead). The featured image shows LDN 1295, also called the Giraffe Nebula, in the constellation of the mythical queen of Aethiopia (Cassiopeia). It is an object in the Lynds Catalogue of Dark Nebulas, compiled in 1962 by American astronomer Beverly Lynds, a pioneer for women in astronomy and astrophysics. Dark nebulas are interstellar clouds of dust and gas that block the visible light of the stars behind them. These nebulas are often faint and challenging targets for astrophotographers. Why do we see animal shapes and faces in nebulas, clouds, and pretty much everywhere? It is due to pareidolia, our tendency to look for familiar patterns. Pareidolia may provide animals with an evolutionary advantage, for example in identifying (and avoiding) predators. APOD's main NASA site is moving : From apod.nasa.gov to science.nasa.gov/apod

Is this star winking at us? The central object in today’s animation is not one but two stars. XZ Andromedae, indicated by the bold lines, is an Algol-type eclipsing binary with a nearly edge-on orbit from Earth’s perspective. The bottom light curve shows the amount of light from the system dim and brighten as the cooler star eclipses its hotter, brighter companion. Analysis of several XZ Andromedae light curves indicates there may be two other stars orbiting the system. This particular light curve was created with Citizen Astronomy, an open-source software for differential photometry. The software takes the difference in brightness between a target and comparison star and traces its behavior over time. This technique reduces most variations from the instrument and Earth’s atmosphere. In addition to eclipsing binaries, this analysis is useful for studying transiting exoplanets, accreting black holes, supernovae, and many more time-varying astronomical phenomena. Astrophotographers: try it out on your own data!

Why are Saturn’s poles geometric? Saturn’s North Pole has been known to be surrounded by a hexagonal (6 sides) cloud since discovery in 1987 in data taken by NASA’s Voyager spacecrafts, which quickly flew past the ringed world in the early 1980s. Now, recent observations of Saturn by the Hubble Space Telescope reveal a slightly different geometric cloud pattern around the South Pole: a decagon (10 sides). The geometric boundaries are possibly caused by waves when the fast-moving gas away from the poles interacts with slower-moving gas closer to the poles. In the featured image composite by the Hubble taken last year, the South Pole of Saturn is marked by an X and surrounded by bands of circulating clouds. The decagon appears most prominent in the dark inner regions. The northern hexagon has proven stable for over 40 years, while the stability of the southern decagon will surely remain a topic of research. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod

The Pelican Nebula is slowly being transformed. IC 5070 (an official designation) is divided from the larger North America Nebula by a molecular cloud filled with dark dust. The deep featured picture from Utah, USA incorporates 25 hours of exposure and brings out great details of this filamentary dust. The Pelican Nebula receives much study because it is a particularly active mix of star formation and evolving gas clouds. The light from young energetic stars is slowly transforming the cold gas to hot gas, with the advancing boundary between the two, known as an ionization front, visible in bright orange on the upper right. Particularly dense tentacles of cold gas remain. Millions of years from now, the Pelican Nebula, bounded by dark nebula LDN 935, might no longer be known as the Pelican, as the balance and placement of stars and gas will surely leave something that appears completely different. APOD's main NASA site is moving: From apod.nasa.gov to science.nasa.gov/apod