Mes: agosto 2023

Not the James Webb Space Telescope’s latest view of a distant galactic nebula, this illuminated cloud of gas and dust dazzled early morning spacecoast skygazers on August 26. The snapshot was taken about 2 minutes after the launch of of a Falcon 9 rocket on the SpaceX Crew-7 mission, the seventh commercial crew rotation mission for the International Space Station. It captures drifting plumes and exhaust from the separated first and second stage illuminated against the still dark skies. Near the center of the image, within the ragged blueish ring, are two bright points of light. The lower one is the second stage of the rocket carrying 4 humans to space in a Crew Dragon spacecraft. The bright point above is the Falcon 9 first stage booster orienting itself for the trip back to Landing Zone-1 at Cape Canaveral, planet Earth. [via NASA] https://ift.tt/hvC8fH3

Near perigee, the closest point in its almost moonthly orbit, a Full Moon rose as the Sun set on August 1. Its brighter than average lunar disk was captured in this dramatic moonrise sequence over dense cloud banks along the eastern horizon from Ragusa, Sicily. Illuminating night skies around planet Earth it was the second supermoon of 2023. Yet again near perigee, the third supermoon of 2023 will also shine on an August night. Rising as the Sun sets tonight this second Full Moon in August will be known to some as a Blue Moon, even though scattered sunlight gives the lunar disk a reddened hue. Defined as the second full moon in a calendar month, blue moons occur only once every 2 or 3 years. That’s because lunar phases take 29.5 days, almost a calendar month, to go through a complete cycle. Tonight an August Blue Moon will find itself beside bright planet Saturn. [via NASA] https://ift.tt/bPu2Yoy

Why isn’t spiral galaxy M66 symmetric? Usually, density waves of gas, dust, and newly formed stars circle a spiral galaxy’s center and create a nearly symmetric galaxy. The differences between M66’s spiral arms and the apparent displacement of its nucleus are all likely caused by previous close interactions and the tidal gravitational pulls of nearby galaxy neighbors M65 and NGC 3628. The galaxy, featured here in infrared light taken by the James Webb Space Telescope, spans about 100,000 light years, lies about 35 million light years distant, and is the largest galaxy in a group known as the Leo Triplet. Like many spiral galaxies, the long and intricate dust lanes of M66 are seen intertwined with the bright stars and intergalactic dust that follow the spiral arms. [via NASA] https://ift.tt/fCZsiNx

Ringed planet Saturn will be at its 2023 opposition, opposite the Sun in Earth’s skies, on August 27. While that puts the sixth planet from the Sun at its brightest and well-placed for viewing, its beautiful ring system isn’t visible to the unaided eye. Still, this sequence of telescopic images taken a year apart over the last six years follows both Saturn and rings as seen from inner planet Earth. The gas giant’s ring plane tilts from most open in 2018 to approaching edge-on in 2023 (top to bottom). That’s summer to nearly the autumn equinox for Saturn’s northern hemisphere. In the sharp planetary portraits, Saturn’s northern hexagon and a large storm system are clearly visible in 2018. In 2023, ice moon Tethys is transiting, casting its shadow across southern hemisphere cloud bands, while Saturn’s cold blue south pole is emerging from almost a decade of winter darkness. [via NASA] https://ift.tt/xm2JVl9

Under dark and mostly moonless night skies, many denizens of planet Earth were able to watch this year’s Perseid meteor shower. Seen from a grassy hillside from Shiraz, Iran these Perseid meteors streak along the northern summer Milky Way before dawn on Sunday, August 13. Frames used to construct the composited image were captured near the active annual meteor shower’s peak between 02:00 AM and 04:30 AM local time. Not in this night skyscape, the shower’s radiant in the heroic constellation Perseus is far above the camera’s field of view. But fans of northern summer nights can still spot a familiar asterism. Formed by bright stars Deneb, Vega, and Altair, the Summer Triangle spans the luminous band of the Milky Way. [via NASA] https://ift.tt/5mAQLZj

It came from outer space. It — in this case a sand-sized bit of a comet nucleus — was likely ejected many years ago from Sun-orbiting Comet Swift-Tuttle, but then continued to orbit the Sun alone. When the Earth crossed through this orbit, the piece of comet debris impacted the atmosphere of our fair planet and was seen as a meteor. This meteor deteriorated, causing gases to be emitted that glowed in colors emitted by its component elements. The featured image was taken last week from Castilla La Mancha, Spain, during the peak night of the Perseids meteor shower. The picturesque meteor streak happened to appear in the only one of 50 frames that also included the Andromeda galaxy. Stars dot the frame, each much further away than the meteor. Compared to the stars, the Andromeda galaxy (M31) is, again, much further away. [via NASA] https://ift.tt/PxFZQYS

This nebula had never been noted before. Newly discovered nebulas are usually angularly small and found by professionals using large telescopes. In contrast, the Pistachio Nebula was discovered by dedicated amateurs and, although faint, is nearly the size of the full Moon. In modern times, amateurs with even small telescopes can create long exposures over sky areas much larger than most professional telescopes can see. They can therefore discover both previously unknown areas of extended emission around known objects, as well as entirely unknown objects, like nebulas. The pictured Pistachio Nebula is shown in oxygen emission (blue) and hydrogen emission (red). The nature of the hot central star is currently unknown, and the nebula might be labeled a planetary nebula if it turns out to be a white dwarf star. The featured image is a composite of over 70 hours of exposure taken in early June under the dark skies of Namibia. [via NASA] https://ift.tt/92dCGR5

Will Comet Nishimura become visible to the unaided eye? Given the unpredictability of comets, no one can say for sure, but it currently seems like a good bet. The comet was discovered only ten days ago by Hideo Nishimura during 30-second exposures with a standard digital camera. Since then, C/2023 P1 Nishimura has increased in brightness and its path across the inner Solar System determined. As the comet dives toward the Sun, it will surely continue to intensify and possibly become a naked-eye object in early September. A problem is that the comet will also be angularly near the Sun, so it will only be possible to see it near sunset or sunrise. The comet will get so close to the Sun — inside the orbit of planet Mercury — that its nucleus may break up. Pictured, Comet Nishimura was imaged three days ago from June Lake, California, USA while sporting a green coma and a thin tail. [via NASA] https://ift.tt/5jveR7X

What kind of cloud is this? A type of arcus cloud called a roll cloud. These rare long clouds may form near advancing cold fronts. In particular, a downdraft from an advancing storm front can cause moist warm air to rise, cool below its dew point, and so form a cloud. When this happens uniformly along an extended front, a roll cloud may form. Roll clouds may actually have air circulating along the long horizontal axis of the cloud. A roll cloud is not thought to be able to morph into a tornado. Unlike a similar shelf cloud, a roll cloud is completely detached from their parent cumulonimbus cloud. Pictured here, a roll cloud extends far into the distance as a storm approaches in 2007 in Racine, Wisconsin, USA. [via NASA] https://ift.tt/CcIYn5d

Ringed ice giant Neptune lies near the center of this sharp near-infrared image from the James Webb Space Telescope. The dim and distant world is the farthest planet from the Sun, about 30 times farther away than planet Earth. But in the stunning Webb view, the planet’s dark and ghostly appearance is due to atmospheric methane that absorbs infrared light. High altitude clouds that reach above most of Neptune’s absorbing methane easily stand out in the image though. Coated with frozen nitrogen, Neptune’s largest moon Triton is brighter than Neptune in reflected sunlight, seen at the upper left sporting the Webb telescope’s characteristic diffraction spikes. Including Triton, seven of Neptune’s 14 known moons can be identified in the field of view. Neptune’s faint rings are striking in this space-based planetary portrait. Details of the complex ring system are seen here for the first time since Neptune was visited by the Voyager 2 spacecraft in August 1989. [via NASA] https://ift.tt/ZqWnKuw