Archives mensuelles : juin 2021

Sunrise Solstice over Stonehenge

Today the Sun reaches its northernmost point in planet Earth’s sky. Called a solstice, many cultures mark this date as a change of seasons — from spring to summer in Earth’s Northern Hemisphere and from fall to winter in Earth’s Southern Hemisphere. Precisely, the single time of solstice occurs today for some parts of the world, but tomorrow for other regions. The featured image was taken during the week of the 2008 summer solstice at Stonehenge in United Kingdom, and captures a picturesque sunrise involving fog, trees, clouds, stones placed about 4,500 years ago, and a 4.5 billion year old large glowing orb. Even given the precession of the Earth’s rotational axis over the millennia, the Sun continues to rise over Stonehenge in an astronomically significant way. via NASA https://ift.tt/3zEO2lC

Northern Summer Twilight

Nights grow shorter and days grow longer as the summer solstice approaches in the north. Usually seen at high latitudes in summer months, noctilucent or night shining clouds begin to make their appearance. Drifting near the edge of space about 80 kilometers above the Earth’s surface, these icy clouds were still reflecting the sunlight on June 14. Though the Sun was below the horizon as seen north of Forrest, Manitoba, Canada, they were caught in a single exposure of a near midnight twilight sky. Multiple exposures of the foreground track the lower altitude flash of fireflies, another fleeting apparition shining in the summer night. via NASA https://ift.tt/3xxQEzL

Devil Horns from a Ring of Fire

Atmospheric refraction flattened the solar disk and distorted its appearance in this telescopic view of an Atlantic sunrise on June 10. From Belmar, New Jersey on the US east coast, the scene was recorded at New Moon during this season’s annular solar eclipse. The Moon in partial silhouette gives the rising Sun its crescent shape reminding some of the horns of the devil (or maybe a flying canoe …). But at its full annular phase this eclipsed Sun looked like a ring of fire in the heavens. June’s annular solar eclipse followed on the heels of the total lunar eclipse of late May’s Full Moon. Of course, that total lunar eclipse was a dramatic red Blood Moon eclipse. via NASA https://ift.tt/3zy7YGB

NGC 6888: The Crescent Nebula

NGC 6888, also known as the Crescent Nebula, is a about 25 light-years across blown by winds from its central, bright, massive star. A triumvirate of astroimagers ( Joe, Glenn, Russell) created this sharp portrait of the cosmic bubble. Their telescopic collaboration collected over 30 hours of narrow band image data isolating light from hydrogen and oxygen atoms. The oxygen atoms produce the blue-green hue that seems to enshroud the detailed folds and filaments. Visible within the nebula, NGC 6888’s central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun’s mass every 10,000 years. The nebula’s complex structures are likely the result of this strong wind interacting with material ejected in an earlier phase. Burning fuel at a prodigious rate and near the end of its stellar life this star should ultimately go out with a bang in a spectacular supernova explosion. Found in the nebula rich constellation Cygnus, NGC 6888 is about 5,000 light-years away. via NASA https://ift.tt/2S8Qf7W

Scorpius Enhanced

If Scorpius looked this good to the unaided eye, humans might remember it better. Scorpius more typically appears as a few bright stars in a well-known but rarely pointed out zodiacal constellation. To get a spectacular image like this, though, one needs a good camera, a dark sky, and some sophisticated image processing. The resulting digitally-enhanced image shows many breathtaking features. Diagonal across the image right is part of the plane of our Milky Way Galaxy. Visible there are vast clouds of bright stars and long filaments of dark and intricate dust. Rising vertically on the image left are dark dust bands known as the Dark River. Several of the bright stars on the left are part of Scorpius’ head and claws, and include the bright star Antares. Numerous red emission nebulas, blue reflection nebulas, and dark filaments became visible as the deep 17-hour expo image developed. Scorpius appears prominently in southern skies after sunset during the middle of the year. via NASA https://ift.tt/3gFCsOc

Zhurong: New Rover on Mars

There’s a new rover on Mars. In mid-May, China’s Tianwen-1 mission delivered the Zhurong rover onto the red planet. As Mars means Planet of Fire in Chinese, the Zhurong rover’s name means, roughly, God of Fire in Chinese mythology. Zhurong landed in northern Utopia Planitia, the largest known impact basin in the Solar System, and an area reported to have much underground ice. Among many other scientific instruments, Zhurong carries ground-penetrating radar that can detect ice buried even 100-meters deep. Car-sized Zhurong is pictured here next to its landing base. The image was snapped by a remote camera deployed by the rolling rover. Zhurong’s planned 90-day mission includes studying the geology, soil, and atmosphere of Mars in Utopia Planitia. via NASA https://ift.tt/3q0ULBN

Ganymede from Juno

What does the largest moon in the Solar System look like? Jupiter’s moon Ganymede, larger than even Mercury and Pluto, has an icy surface speckled with bright young craters overlying a mixture of older, darker, more cratered terrain laced with grooves and ridges. The cause of the grooved terrain remains a topic of research, with a leading hypothesis relating it to shifting ice plates. Ganymede is thought to have an ocean layer that contains more water than Earth — and might contain life. Like Earth’s Moon, Ganymede keeps the same face towards its central planet, in this case Jupiter. The featured image was captured last week by NASA’s robotic Juno spacecraft as it passed only about 1000 kilometers above the immense moon. The close pass reduced Juno’s orbital period around Jupiter from 53 days to 43 days. Juno continues to study the giant planet’s high gravity, unusual magnetic field, and complex cloud structures. via NASA https://ift.tt/2RRLGyF

Eclipse on the Water

Eclipses tend to come in pairs. Twice a year, during an eclipse season that lasts about 34 days, Sun, Moon, and Earth can nearly align. Then the full and new phases of the Moon separated by just over 14 days create a lunar and a solar eclipse. Often partial eclipses are part of any eclipse season. But sometimes the alignment at both new moon and full moon phases during a single eclipse season is close enough to produce a pair of both total (or a total and an annular) lunar and solar eclipses. For this eclipse season, the New Moon following the Full Moon’s total lunar eclipse on May 26 did produce an annular solar eclipse along its northerly shadow track. That eclipse is seen here in a partially eclipsed sunrise on June 10, photographed from a fishing pier in Stratford, Connecticut in the northeastern US. via NASA https://ift.tt/3pJIr8O

Eclipse Flyby

On June 10 a New Moon passed in front of the Sun. In silhouette only two days after reaching apogee, the most distant point in its elliptical orbit, the Moon’s small apparent size helped create an annular solar eclipse. The brief but spectacular annular phase of the eclipse shows a bright solar disk as a ring of fire when viewed along its narrow, northerly shadow track across planet Earth. Cloudy early morning skies along the US east coast held gorgeous views of a partially eclipsed Sun though. Rising together Moon and Sun are captured in a sequence of consecutive frames near maximum eclipse in this digital composite, seen from Quincy Beach south of Boston, Massachusetts. The serendipitous sequence follows the undulating path of a bird in flight joining the Moon in silhouette with the rising Sun. via NASA https://ift.tt/3vcwhqh

Circular Sun Halo

Want to see a ring around the Sun? It’s easy to do in daytime skies around the world. Created by randomly oriented ice crystals in thin high cirrus clouds, circular 22 degree halos are visible much more often than rainbows. This one was captured by smart phone photography on May 29 near Rome, Italy. Carefully blocking the Sun, for example with a finger tip, is usually all that it takes to reveal the common bright halo ring. The halo’s characteristic angular radius is about equal to the span of your hand, thumb to little finger, at the end of your outstretched arm. Want to see a ring of fire eclipse? That’s harder. The spectacular annular phase of today’s (June 10) solar eclipse, known as a ring of fire, is briefly visible only if you’re standing along the Moon’s narrow shadow track that passes over parts of northern Canada, Greenland, the Arctic, and eastern Russia. The solar eclipse is partial though, when seen from broader regions, including northern Asia, Europe, and parts of the US. via NASA https://ift.tt/3v9A7Aq