A Black Hole Disrupts a Passing Star A Black Hole Disrupts a Passing Star

What happens to a star that goes near a black hole? If the star directly impacts a massive black hole, then the star falls in completely -- and everything vanishes. More likely, though, the star goes close enough to have the black hole's gravity pull away the outer layers of the star, or disrupt the star. Then most of the star's gas does not fall into the black hole. These stellar tidal disruption events can be as bright as a supernova, and an increasing amount of them are being discovered by automated sky surveys. In the featured artist's illustration, a star has just passed a massive black hole and sheds gas that continues to orbit. The inner edge of a disk of gas and dust surrounding the black hole is heated by the disruption event and may glow long after the star is gone. via NASA https://ift.tt/2WKA93Y

From the Pleiades to the Eridanus Loop From the Pleiades to the Eridanus Loop

If you stare at an interesting patch of sky long enough, will it look different? In the case of Pleiades and Hyades star clusters -- and surrounding regions -- the answer is: yes, pretty different. Long duration camera exposures reveal an intricate network of interwoven interstellar dust and gas that was previously invisible not only to the eye but to lower exposure images. In the featured wide and deep mosaic, the dust stands out spectacularly, with the familiar Pleaides star cluster visible as the blue patch near the top of the image. Blue is the color of the Pleiades' most massive stars, whose distinctive light reflects from nearby fine dust. On the upper left is the Hyades star cluster surrounding the bright, orange, foreground-star Aldebaran. Red glowing emission nebula highlight the bottom of the image, including the curving vertical red ribbon known as the Eridanus Loop. The pervasive dust clouds appear typically in light brown and are dotted with unrelated stars. via NASA https://ift.tt/2vHAFVr

Moon Setting Behind Teide Volcano Moon Setting Behind Teide Volcano

These people are not in danger. What is coming down from the left is just the Moon, far in the distance. Luna appears so large here because she is being photographed through a telescopic lens. What is moving is mostly the Earth, whose spin causes the Moon to slowly disappear behind Mount Teide, a volcano in the Canary Islands off the northwest coast of Africa. The people pictured are 16 kilometers away and many are facing the camera because they are watching the Sun rise behind the photographer. It is not a coincidence that a full moon rises just when the Sun sets because the Sun is always on the opposite side of the sky from a full moon. The featured video was made two years ago during the full Milk Moon. The video is not time-lapse -- this was really how fast the Moon was setting. via NASA https://ift.tt/39asyhG

Comet ATLAS and the Mighty Galaxies Comet ATLAS and the Mighty Galaxies

Comet ATLAS C/2019 Y4 was discovered by the NASA funded Asteroid Terrestrial-impact Last Alert System, the last comet discovery reported in 2019. Now growing brighter in northern night skies, the comet's pretty greenish coma is at the upper left of this telescopic skyview captured from a remotely operated observatory in New Mexico on March 18. At lower right are M81 and M82, well-known as large, gravitationally interacting galaxies. Seen through faint dust clouds above the Milky Way, the galaxy pair lies about 12 million light-years distant, toward the constellation Ursa Major. In bound Comet ATLAS is about 9 light-minutes from Earth, still beyond the orbit of Mars. The comet's elongated orbit is similar to orbit of the Great Comet of 1844 though, a trajectory that will return this comet to the inner Solar System in about 6,000 years. Comet ATLAS will reach a perihelion or closest approach to the Sun on May 31 inside the orbit of Mercury and may become a naked-eye comet in the coming days. via NASA https://ift.tt/2U8fXYg

Morning, Planets, Moon, and Montreal Morning, Planets, Moon, and Montreal

Dawn's early light came to Montreal, northern planet Earth, on March 18, the day before the vernal equinox. At the end of that nearly equal night the Moon stands above a dense constellation of urban lights in this serene city and skyscape. Of course the Moon's waning crescent faces toward the rising Sun. Skygazers could easily spot bright Jupiter just above the Moon, close on the sky to a fainter Mars. Saturn, a telescopic favorite, is just a pinprick of light below and farther left of the closer conjunction of Moon, Jupiter and Mars. Near the ecliptic, even Mercury is rising along a line extended to the horizon from Jupiter and Saturn. The elusive inner planet is very close to the horizon though, and not quite visible in this morning's sky. via NASA https://ift.tt/2J3rt0B

Anticrepuscular Rays over Florida Anticrepuscular Rays over Florida

What's happening behind those clouds? Although the scene may appear somehow supernatural, nothing more unusual is occurring than a Sun setting on the other side of the sky. Pictured here are anticrepuscular rays. To understand them, start by picturing common crepuscular rays that are seen any time that sunlight pours though scattered clouds. Now although sunlight indeed travels along straight lines, the projections of these lines onto the spherical sky are great circles. Therefore, the crepuscular rays from a setting (or rising) sun will appear to re-converge on the other side of the sky. At the anti-solar point 180 degrees around from the Sun, they are referred to as anticrepuscular rays. Featured here is a particularly striking display of anticrepuscular rays photographed in 2016 over Dry Tortugas National Park in Florida, USA. via NASA https://ift.tt/38TV7ju

M77: Spiral Galaxy with an Active Center M77: Spiral Galaxy with an Active Center

What's happening in the center of nearby spiral galaxy M77? The face-on galaxy lies a mere 47 million light-years away toward the constellation of the Sea Monster (Cetus). At that estimated distance, this gorgeous island universe is about 100 thousand light-years across. Also known as NGC 1068, its compact and very bright core is well studied by astronomers exploring the mysteries of supermassive black holes in active Seyfert galaxies. M77 and its active core glows bright at x-ray, ultraviolet, visible, infrared, and radio wavelengths. The featured sharp image of M77 was taken by the Hubble Space Telescope and is dominated by the (visible) red light emitted by hydrogen. The image shows details of the spiral's winding spiral arms as traced by obscuring dust clouds, and red-tinted star forming regions close in to the galaxy's luminous core. via NASA https://ift.tt/39ZPt0s

A Moon Dressed Like Saturn A Moon Dressed Like Saturn

Why does Saturn appear so big? It doesn't -- what is pictured are foreground clouds on Earth crossing in front of the Moon. The Moon shows a slight crescent phase with most of its surface visible by reflected Earthlight known as ashen glow. The Sun directly illuminates the brightly lit lunar crescent from the bottom, which means that the Sun must be below the horizon and so the image was taken before sunrise. This double take-inducing picture was captured on 2019 December 24, two days before the Moon slid in front of the Sun to create a solar eclipse. In the foreground, lights from small Guatemalan towns are visible behind the huge volcano Pacaya. via NASA https://ift.tt/2wb0VHU

The Snows of Churyumov Gerasimenko The Snows of Churyumov Gerasimenko

You couldn't really be caught in this blizzard while standing by a cliff on Churyumov-Gerasimenko. Orbiting the comet -- frequently abbreviated as 67P or CG -- in June of 2016, the Rosetta spacecraft's narrow angle camera did record streaks of dust and ice particles -- similar to snow -- as they drifted across the field of view near the camera and above the comet's surface. Some of the bright specks in the scene, however, are likely due to a rain of energetic charged particles or cosmic rays hitting the camera, and the dense background of stars in the direction of the constellation of the Big Dog (Canis Major). In the featured video, these background stars are easy to spot trailing from top to bottom. The stunning movie was constructed from 33 consecutive images taken over 25 minutes while Rosetta cruised some 13 kilometers from the comet's nucleus. via NASA https://ift.tt/38My4a9

Moonrise and Mountain Shadow Moonrise and Mountain Shadow

What phase of the Moon is 3.14 radians from the Sun? The Full Moon, of course. Even though the Moon might look full for several days, the Moon is truly at its full phase when it is 3.14 radians (aka 180 degrees) from the Sun in ecliptic longitude. That's opposite the Sun in planet Earth's sky. Rising as the Sun set on March 9, only an hour or so after the moment of its full phase, this orange tinted and slightly flattened Moon still looked full. It was photographed opposite the setting Sun from Teide National Park on the Canary Island of Tenerife. Also opposite the setting Sun, seen from near the Teide volcano peak about 3,500 meters above sea level, is the mountain's rising triangular shadow extending into Earth's dense atmosphere. Below the distant ridge line on the left are the white telescope domes of Teide Observatory via NASA https://ift.tt/2Q96ZaT