Starship Asterisk*

by **DavidLeodis** » Fri Jun 03, 2016 9:30 pm

In some information in Wikipedia it states of the JunoCam "A visible light camera/telescope, included in the payload to facilitate education and public outreach. It will operate for only seven orbits around Jupiter because of the planet's damaging radiation and magnetic field". If I had not looked at Wikipedia I would not have known the latter part from the information brought up through the 'JunoCam' link in the explanation.

by **Case** » Fri Jun 03, 2016 5:11 am

DrFaustus wrote:You can clearly see the Saturn's hexagonal storm at the top of the image as well.

They were first discovered by wrapping images, made by Voyager 2, onto a sphere. Note that Voyager 2 never went over the poles. Scientists published about it some 6 years (1981-1987) after the fly-by!

Guest wrote:Which makes me wonder if optics are that much better, or why there wasn't telescopic evidence of them sooner. I know that the march of the seasons takes years on Saturn, but still...

Prior to the space probes, the best images of Saturn were similar in detail to these images:

With a full set of seasons of about 30 Earth years, the north pole of Saturn isn't always visible from Earth. Around 2002-2003, we had a relatively good view of the south pole. Around 1987-1988 was the previous time we had a relatively good view of the north pole. Before that 1958-1959. That is 22 years before Voyager; optics and related tech are that much better now.

I find it astonishing that the very first photographic planetary images that show any detail, were made all the way back in 1885. 95 years later, images were only slightly better.

by **geckzilla** » Thu Jun 02, 2016 6:58 pm

neufer wrote:
PaulieD wrote:
The news has been reporting recently on a high resolution picture of Mars, taken with Hubble. I was surprised at the relatively low resolution of the picture compared to the very sharp pictures taken by Hubble of other galaxies, etc. Now I see this very sharp image of Mars taken with a 1 meter, Earth based telescope. I am confused as to why the Hubble picture is, seemingly, lower resolution.
[b][color=#0000FF]Hubble portraits of Mars's previous oppositions[/color][/b]
There were a lot of Martian clouds in Hubble's recent May 12 portrait of Mars (at a further distance of 50 M km).

The Pic du Midi astronomers were able to bide their time until Mars was clear of clouds & somewhat closer.

Hubble's big advantage mostly comes with long exposures where the atmosphere presents more of a problem.

I looked for the highest res image of Mars from both the Hubble release and today's APOD and Hubble's looks higher resolution to me. Pic du Midi's Mars has had significantly more sharpening applied to it, though. Here's a side-by-side to compare the smallest visible features visible in each. Hubble offers some much tinier details. Note you must view it at full size, which means also to zoom in after you click the thumbnail if your browser resizes it. Hubble's is easily twice the resolution if not more.

: Pic du Midi at left; Hubble at right

by **neufer** » Thu Jun 02, 2016 6:42 pm

Guest wrote:
DrFaustus wrote:
You can clearly see the Saturn's hexagonal storm at the top of the image as well.
Which makes me wonder if optics are that much better, or why there wasn't telescopic evidence of them sooner. I know that the march of the seasons takes years on Saturn, but still...

One probably has to use a near-infrared filter centered near 752 nanometers.

http://www.nasa.gov/jpl/cassini/pia18274 wrote:
[b][color=#0000FF]Cassini spacecraft wide-angle camera shot using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nm[/color][/b]
<<The Cassini spacecraft captures three magnificent sights at once: Saturn's north polar vortex and hexagon along with its expansive rings. The hexagon, which is wider than two Earths, owes its appearance to the jet stream that forms its perimeter. The jet stream forms a six-lobed, stationary wave which wraps around the north polar regions at a latitude of roughly 77 degrees North. This view looks toward the sunlit side of the rings from about 37 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on April 2, 2014 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers. The view was obtained at a distance of approximately 2.2 million km from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 43 degrees.>>

by **neufer** » Thu Jun 02, 2016 6:18 pm

PaulieD wrote:
The news has been reporting recently on a high resolution picture of Mars, taken with Hubble. I was surprised at the relatively low resolution of the picture compared to the very sharp pictures taken by Hubble of other galaxies, etc. Now I see this very sharp image of Mars taken with a 1 meter, Earth based telescope. I am confused as to why the Hubble picture is, seemingly, lower resolution.

: [b][color=#0000FF]Hubble portraits of Mars's previous oppositions[/color][/b]

There were a lot of Martian clouds in Hubble's recent May 12 portrait of Mars (at a further distance of 50 M km).

The Pic du Midi astronomers were able to bide their time until Mars was clear of clouds & somewhat closer.

Hubble's big advantage mostly comes with long exposures where the atmosphere presents more of a problem.

by **PaulieD** » Thu Jun 02, 2016 5:35 pm

The news has been reporting recently on a high resolution picture of Mars, taken with Hubble. I was surprised at the relatively low resolution of the picture compared to the very sharp pictures taken by Hubble of other galaxies, etc. Now I see this very sharp image of Mars taken with a 1 meter, Earth based telescope. I am confused as to why the Hubble picture is, seemingly, lower resolution.

by **Guest** » Thu Jun 02, 2016 5:00 pm

DrFaustus wrote:You can clearly see the Saturn's hexagonal storm at the top of the image as well.

Which makes me wonder if optics are that much better, or why there wasn't telescopic evidence of them sooner. I know that the march of the seasons takes years on Saturn, but still...

by **DrFaustus** » Thu Jun 02, 2016 2:42 pm

You can clearly see the Saturn's hexagonal storm at the top of the image as well.

by **Ann** » Thu Jun 02, 2016 8:41 am

Thanks for the resizing and brightness alteration, Case!

Good to see your pics too, Boomer!

Ann

by **Boomer12k** » Thu Jun 02, 2016 7:56 am

Yes, several night ago, I got my best pic of Mars, and fair image...(for my cheap camera), of Saturn. Jupiter turned out the best as it is big and bright. I even got the red spot...so cool... really excited about Mars. Jupiter was taken with the "Sharpen" setting in the Autostar Envisage software, that took out the Saturation and gave a less saturated image. Stacked many together, and got a sharper image, without the orange over-glare of my previous images.
Mars before, was a washed out red blob, I also don't get good focus sometimes. And Atmospheric warping hinders things as well. Now, I can see there is some surface detail...brought out with Registax's Wavelet function.
But FINALLY, I can tell it is Mars.

Much improvement, with room for more, I admit....

:---[===] *

by **peter65** » Thu Jun 02, 2016 7:33 am

Nice pictures! They make me jealous when looking at those planets from the bright city with an only 20 cm amateur-teleskop....

by **Ann** » Thu Jun 02, 2016 5:59 am

BMAONE23 wrote:Amazing, the internet rumors are absolutely true, Mars IS as big as Saturn in the night sky. ...or was that the full moon

It was the full moon.

Ann

by **BMAONE23** » Thu Jun 02, 2016 5:37 am

Amazing, the internet rumors are absolutely true, Mars IS as big as Saturn in the night sky. ...or was that the full moon

by **Case** » Thu Jun 02, 2016 5:31 am

Here's a sample with a bit of resizing and brightness alteration, not too accurate, but closer than the big picture.

Code: Select all

Apparent diameter for today:
Mars:      0°00'18.6"
Saturn:    0°00'18.4"
Jupiter:   0°00'37.2"

Magnitude for today:
Mars:      -1.76
Saturn:     0.21
Jupiter:   -1.63

by **APOD Robot** » Thu Jun 02, 2016 4:06 am

Three Planets from Pic du Midi

Explanation: Seen any planets lately? All three planets now shining brightly in the night sky are imaged in these panels, captured last week with the 1 meter telescope at Pic du Midi Observatory in the French Pyrenees. Near opposition and closest to Earth on May 30, Mars is presently offering the best ground-based photo-ops in the last decade. The sharp image finds clouds above the Red Planet's north pole (top) and towering volcanos near its right limb. Saturn reaches its own opposition tonight, its bright rings and gaps clearly revealed in the telescopic portrait. Jupiter is currently highest during the evening twilight and shows off its planet-girdling cloud bands and Great Red Spot in this scene. Of course close-up images of the ruling gas giant will follow the July arrival of the solar-powered Juno spacecraft and JunoCam.

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Starship Asterisk*

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