Category Archives: Science

Behold: an only slightly exaggerated view of what one would see if hovering close to the ringed gas giant. To wit:

The image was taken in 2005 by the robot Cassini spacecraft that orbited Saturn from 2004 to 2017. Here Saturn’s majestic rings appear directly only as a curved line, appearing brown, in part, from its infrared glow. The rings best show their complex structure in the dark shadows they create across the upper part of the planet. The northern hemisphere of Saturn can appear partly blue for the same reason that Earth’s skies can appear blue — molecules in the cloudless portions of both planet’s atmospheres are better at scattering blue light than red. When looking deep into Saturn’s clouds, however, the natural gold hue of Saturn’s clouds becomes dominant. It is not known why southern Saturn does not show the same blue hue — one hypothesis holds that clouds are higher there. It is also not known why some of Saturn’s clouds are coloured gold.

(Image: NASA, ESA, JPL, ISS, Cassini Imaging Team; Processing & License: Judy Schmidt)

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So much more than a belt of three stars, the constellation of Orion is rich in nebulae, as seen in this painstaking composite of extremely long exposures captured on clear nights in 2013 and 2014. To wit:

After 212 hours of camera time and an additional year of processing, the featured 1400-exposure collage spanning over 40 times the angular diameter of the Moon emerged. Of the many interesting details that have become visible, one that particularly draws the eye is Barnard’s Loop, the bright red circular filament arcing down from the middle. The Rosette Nebula is not the giant red nebula near the top of the image — that is a larger but lesser known nebula known as Lambda Orionis. The Rosette Nebula is visible, though: it is the red and white nebula on the upper left. The bright orange star just above the frame center is Betelgeuse, while the bright blue star on the lower right is Rigel. Other famous nebulas visible include the Witch Head Nebula, the Flame Nebula, the Fox Fur Nebula, and, if you know just where to look, the comparatively small Horsehead Nebula. About those famous three stars that cross the belt of Orion the Hunter — in this busy frame they can be hard to locate, but a discerning eye will find them just below and to the right of the image centre.

(Image: Stanislav Volskiy, Annotation: Judy Schmidt)

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Behold: star forming region Sharpless 106, at the centre of which is the massive star IRS4 – one of very few stars to be younger than the human race. To wit:

Born only about 100,000 years ago, material streaming out from this newborn star has formed the nebula S106.  A large disk of dust and gas orbiting Infrared Source 4 (IRS 4), visible in brown near the image centre, gives the nebula an hourglass or butterfly shape. S106 gas near IRS 4 acts as an emission nebula as it emits light after being ionised, while dust far from IRS 4 reflects light from the central star and so acts as a reflection nebula. Detailed inspection of a relevant infrared image of S106 reveal hundreds of low-mass brown dwarf stars lurking in the nebula’s gas. S106 spans about 2 light-years and lies about 2000 light-years away toward the constellation of the Swan (Cygnus).

(Image: NASA, ESA, Hubble Legacy Archive; Processing & Copyright: Utkarsh Mishra)

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Behold: the Pleiades and Hyades star clusters – proof that the longer you stare at the sky, the more insanely detailed it becomes. To wit:

 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.

(image: Hirofumi Okubo)

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Behold: Comet ATLAS C/2019 Y4 – the last reported comet discovered in 2019 by the  Asteroid Terrestrial-impact Last Alert System. It’s inbound, but don’t hold your breath. To wit:

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 (top image) 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. (…/) 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.

Larger view here.

(Image: Rolando Ligustri (CARA Project, CAST))

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Behold: Messier 13 – the Great Globular Cluster in the constellationn of Hercules – one of the brightest in the Northern sky. To wit:

In 1716, English astronomer Edmond Halley noted, “This is but a little Patch, but it shews itself to the naked Eye, when the Sky is serene and the Moon absent.” (…/) Sharp telescopic views like this one reveal the spectacular cluster’s hundreds of thousands of stars. At a distance of 25,000 light-years, the cluster stars crowd into a region 150 light-years in diameter. Approaching the cluster core upwards of 100 stars could be contained in a cube just 3 light-years on a side. For comparison, the closest star to the Sun is over 4 light-years away. The remarkable range of brightness recorded in this image follows stars into the dense cluster core and reveals three subtle dark lanes forming the apparent shape of a propeller just below and slightly left of centre. Distant background galaxies in the medium-wide field of view include NGC 6207 at the upper left. 

Large version here.

Previous MGIFOS: Omega Centauri, NGC 6752 and NGC 7089

(Image: Eric Coles and Mel Helm)

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Why all this hoo-hah about soap and water? Surely we’re better off with that hand sanitiser we managed to wrestle out of the hands of some old lady before Tesco ran out? Nope.

20 seconds with even  the cheapest, nastiest soap spells dissolution and doom for COVID-19, as this usefully kid-friendly video from Vox explains.

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Wait. What the? To wit:

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.

(Image: Bryan Goff)

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An image taken in Guatemala in late 2019. Lights from small towns are visible in the foreground behind the huge Pacaya volcano. But why does Saturn appear so big? To wit:

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. 

(Image: Francisco Sojuel)

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An 84 second long exposure (from a revolving planet) capturing the flight of a Falcon 9 rocket and Dragon cargo spacecraft over Cape Canaveral Air Force Station shortly after launch, on a resupply mission bound for the International Space Station. To wit:

Beginning its return to a landing zone about 9 kilometers from the launch site, the Falcon 9 first stage boostback burn arcs toward the top of the frame. The second stage continues toward low Earth orbit though, its own fiery arc traced below the first stage boostback burn from the camera’s perspective, along with expanding exhaust plumes from the two stages. This Dragon spacecraft was a veteran of two previous resupply missions. Successfully returning to the landing zone, this Falcon 9 first stage had flown before too. Its second landing marked the 50th landing of a SpaceX orbital class rocket booster.

(Image: John Kraus)

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