Astronomy Picture(s and Video) of the Week: US Total Solar Eclipse, August 21, 2017

Taking a detour from Cassini’s Grand Finale to celebrate the solar eclipse we had in the US just this past Monday. I’m sad to say that, from my vantage point (Long Island, New York), it was pretty underwhelming. I wish I’d had the money and time to travel to somewhere along the path of totality and really observe it. Hopefully I’ll be able to for the next one. I’m quite positive that this isn’t my first, but it could just be that I watched clips of one when I was younger. Did the last total solar eclipse in the US happen sometime within the last 30 years?

Hm…

Anyways…

The eclipse has been called the “Great American Eclipse” which like… they know that Canada and South America have had total solar eclipses, too… right? I mean… the United States isn’t the only country in America you know… But anyways

The event’s shadow began to cover land on the Oregon coast as a partial eclipse at 4:06 p.m. UTC (9:06 a.m. PDT), and its land coverage ended as a partial eclipse along the South Carolina coast at about 6:44 p.m. UTC (2:44 p.m. EDT). Visibility as a partial eclipse in Honolulu, Hawaii began with sunrise at 4:20 p.m. UTC (6:20 a.m. HST) and ended by 5:25 p.m. UTC (7:25 a.m. HST).

Okay so…

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Astronomy Picture of the Week – Prometheus and the Ghostly F Ring

Cassini’s Grand Finale…

The thin sliver of Saturn’s moon Prometheus lurks near ghostly structures in Saturn’s narrow F ring in this view from NASA’s Cassini spacecraft. Many of the narrow ring’s faint and wispy features result from its gravitational interactions with Prometheus (86 kilometers, or 53 miles across).

Most of the small moon’s surface is in darkness due to the viewing geometry here. Cassini was positioned behind Saturn and Prometheus with respect to the sun, looking toward the moon’s dark side and just a bit of the moon’s sunlit northern hemisphere.

Also visible here is a distinct difference in brightness between the outermost section of Saturn’s A ring (left of center) and rest of the ring, interior to the Keeler Gap (lower left).

This view looks toward the sunlit side of the rings from about 13 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on May 13, 2017.

The view was acquired at a distance of approximately 680,000 miles (1.1 million kilometers) from Saturn. Image scale is 4 miles (6 kilometers) per pixel.

Click the image for the tif file…

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Astronomy Picture of the Week – Haze on the Horizon

Late on this one… by a week… I know why I’m missing these, too… real life has me extra stressed… 🙁

Anyways… here’s more from Cassini’s Grand Finale…

This false-color view from NASA’s Cassini spacecraft gazes toward the rings beyond Saturn’s sunlit horizon. Along the limb (the planet’s edge) at left can be seen a thin, detached haze. This haze vanishes toward the left side of the scene.

As usual… click on the image for the tif download…

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Astronomy Picture of the Week – More Textures in the C Ring

I also realize I missed last week’s APotW. Apologies…

Continuing on with the Grand Finale

This image was taken on May 29, 2017, with the Cassini spacecraft narrow-angle camera. The image was acquired on the sunlit side of the rings from a distance of about 39,800 miles (64,100 kilometers) away from the area pictured. The image scale is 1,460 feet (445 meters) per pixel. The phase angle, or sun-ring-spacecraft angle, is 137 degrees.

(See the bottom of the post for the links to download the associated .tif images…)

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Astronomy Picture of the Week – Dawn’s Early Light

As usual until September, this is from Cassini’s Grand Finale

The light of a new day on Saturn illuminates the planet’s wavy cloud patterns and the smooth arcs of the vast rings.

The light has traveled around 80 minutes since it left the sun’s surface by the time it reaches Saturn. The illumination it provides is feeble; Earth gets 100 times the intensity since it’s roughly ten times closer to the sun. Yet compared to the deep blackness of space, everything at Saturn still shines bright in the sunlight, be it direct or reflected.

This view looks toward the sunlit side of the rings from about 10 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Feb. 25, 2017 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 939 nanometers.

The view was obtained at a distance of approximately 762,000 miles (1.23 million kilometers) from Saturn. Image scale is 45 miles (73 kilometers) per pixel.

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Astronomy Picture of the Week – Small Wonders (Cassini’s Grand Finale)

(This is 30 minutes late because I was a couple days late with GGS.)

Still on the Grand Finale, and as I said when this started, I’ll be staying here until it’s over, because yes, I’m mourning the end of Cassini’s mission. It’s an image of three of Saturn’s smaller ring moons.

I hope you enjoy this one. As always, click on the image for the .tif download…

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Astronomy Picture of the Week – Northern Summer on Titan

Another one from Cassini’s Grand Finale. And yeah, I’m a day late.

NASA’s Cassini spacecraft sees bright methane clouds drifting in the summer skies of Saturn’s moon Titan, along with dark hydrocarbon lakes and seas clustered around the north pole.

Compared to earlier in Cassini’s mission, most of the surface in the moon’s northern high latitudes is now illuminated by the sun. (See here for a view of the northern hemisphere from 2007.) Summer solstice in the Saturn system occurred on May 24, 2017.

The image was taken with the Cassini spacecraft narrow-angle camera on June 9, 2017, using a spectral filter that preferentially admits wavelengths of near-infrared light centered at 938 nanometers. Cassini obtained the view at a distance of about 315,000 miles (507,000 kilometers) from Titan.

As usual, click on the image for the .tif download…

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Astronomy Picture of the Week – Puzzled Iapetus

Yet another one from Cassini’s Grand Finale. Yup, it’s still going

Iapetus is a world of contrast, with light and dark regions fitting together like cosmic puzzle pieces.

Cassini Regio on Iapetus (914 miles or 1,471 kilometers across) is covered in a layer of dark, dusty material creating a stark contrast to the much brighter region that surrounds it. This leads to the moon’s distinctive, two-toned appearance. To learn more about the cause of the contrast between regions, see Encountering Iapetus.

This view looks toward Saturn-facing hemisphere of Iapetus. North on Iapetus is up and rotated 20 degrees to the right. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on March 11, 2017.

The view was obtained at a distance of approximately 1.6 million miles (2.6 million kilometers) from Iapetus. Image scale is 9 miles (15 kilometers) per pixel.

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Astronomy Picture of the Week: Mimas Dwarfed

We continue with images from Cassini’s Grand Finale. This time, it’s an image from over Saturn’s north pole, with a teeny tiny dot, Mimas, in the upper right

From high above Saturn’s northern hemisphere, NASA’s Cassini spacecraft gazes over the planet’s north pole, with its intriguing hexagon and bullseye-like central vortex.

Saturn’s moon Mimas is visible as a mere speck near upper right. At 246 miles (396 kilometers across) across, Mimas is considered a medium-sized moon. It is large enough for its own gravity to have made it round, but isn’t one of the really large moons in our solar system, like Titan. Even enormous Titan is tiny beside the mighty gas giant Saturn.

This view looks toward Saturn from the sunlit side of the rings, from about 27 degrees above the ring plane. The image was taken in green light with the Cassini spacecraft wide-angle camera on March 27, 2017.

The view was acquired at a distance of approximately 617,000 miles (993,000 kilometers) from Saturn. Image scale is 37 miles (59 kilometers) per pixel. Mimas’ brightness has been enhanced by a factor of 3 in this image to make it easier to see.

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Astronomy Picture of the Week: The Keeler Gap

Another one from Cassini’s Grand Finale mission

Here’s the text from the photo page; the image is below the fold (and, as usual, you can click on it for the tiff download)…

Before Cassini entered its Grand Finale orbits, it acquired unprecedented views of the outer edges of the main ring system. For example, this close-up view of the Keeler Gap, which is near the outer edge of Saturn’s main rings, shows in great detail just how much the moon Daphnis affects the edges of the gap.

This image was part of a mosaic that included Daphnis (The Realm of Daphnis).

Daphnis creates waves in the edges of the gap through its gravitational influence. Some clumping of ring particles can be seen in the perturbed edge, similar to what was seen on the edges of the Encke Gap back when Cassini arrived at Saturn in 2004.

This view looks toward the sunlit side of the rings from about 3 degrees above the ring plane. The view was acquired at a distance of approximately 18,000 miles (30,000 kilometers) from Daphnis and at a Sun-Daphnis-spacecraft, or phase, angle of 69 degrees. Image scale is 581 feet (177 meters) per pixel. The image was taken in visible light with the Cassini spacecraft narrow-angle camera on Jan. 16, 2017.

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