APOD: Enceladus in Infrared (2020 Sep 24)

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APOD: Enceladus in Infrared (2020 Sep 24)

Post by APOD Robot » Thu Sep 24, 2020 4:05 am

Image Enceladus in Infrared

Explanation: One of our Solar System's most tantalizing worlds, icy Saturnian moon Enceladus appears in these detailed hemisphere views from the Cassini spacecraft. In false color, the five panels present 13 years of infrared image data from Cassini's Visual and Infrared Mapping Spectrometer and Imaging Science Subsystem. Fresh ice is colored red, and the most dramatic features look like long gashes in the 500 kilometer diameter moon's south polar region. They correspond to the location of tiger stripes, surface fractures that likely connect to an ocean beneath the Enceladus ice shell. The fractures are the source of the moon's icy plumes that continuously spew into space. The plumes were discovered by by Cassini in 2005. Now, reddish hues in the northern half of the leading hemisphere view also indicate a recent resurfacing of other regions of the geologically active moon, a world that may hold conditions suitable for life.

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Re: APOD: Enceladus in Infrared (2020 Sep 24)

Post by bystander » Thu Sep 24, 2020 4:32 am

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
— Garrison Keillor

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Re: APOD: Enceladus in Infrared (2020 Sep 24)

Post by Ronald » Thu Sep 24, 2020 8:21 am

Which president grabbed it by the far side?

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Re: APOD: Enceladus in Infrared (2020 Sep 24)

Post by XgeoX » Thu Sep 24, 2020 9:16 am

What a wonderful, wondrous little world. A 300 mile ice ball might be where we discover alien life. Whoda thunk it!

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Re: APOD: Enceladus in Infrared (2020 Sep 24)

Post by orin stepanek » Thu Sep 24, 2020 11:53 am

PIA24023_fig1_1050.jpg

Fresh ice must be warmer Ice! Enceladus have pretty warm core! I
wonder how deep through the ice?
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Ms Vito, does Enceladus spew water?

Post by neufer » Thu Sep 24, 2020 12:11 pm

Click to play embedded YouTube video.
https://www.urbandictionary.com/define.php?term=skid%20marks wrote:
skid marks:

Lines of fecal matter in underwear that vary in thickness.
Usually a result of poor asswiping skills.
Art Neuendorffer

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Re: APOD: Enceladus in Infrared (2020 Sep 24)

Post by NCTom » Thu Sep 24, 2020 12:40 pm

I suppose Enceladus has been around a while. Are there any generally accepted theories why it would still have a liquid subsurface ocean? One of the links (beneath) says heating from constant tidal action caused by Saturn's gravity. Does this rule out any molten core?

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Re: APOD: Enceladus in Infrared (2020 Sep 24)

Post by Phobos1 » Thu Sep 24, 2020 2:31 pm

South pole is likely NOT a good spot for backpacking. That's a remarkable set of stripes down there. I wonder what drives the asymmetry with the North pole?

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Re: APOD: Enceladus in Infrared (2020 Sep 24)

Post by neufer » Thu Sep 24, 2020 4:38 pm

Phobos1 wrote:
Thu Sep 24, 2020 2:31 pm

South pole is likely NOT a good spot for backpacking. That's a remarkable set of stripes down there.

I wonder what drives the asymmetry with the North pole?
Europa's water vapour plumes also erupt from near its south pole :!:
https://en.wikipedia.org/wiki/Europa_(moon)#Subsurface_ocean wrote:
<<The Hubble Space Telescope acquired an image of Europa in 2012 that was interpreted to be a plume of water vapour erupting from near its south pole. The image suggests the plume may be 200 km high. It has been suggested that if they exist, they are episodic and likely to appear when Europa is at its farthest point from Jupiter, in agreement with tidal force modeling predictions. Additional imaging evidence from the Hubble Space Telescope was presented in September 2016. In May 2018, astronomers provided supporting evidence of water plume activity on Europa, based on an updated critical analysis of data obtained from the Galileo space probe, which orbited Jupiter between 1995 and 2003. Galileo flew by Europa in 1997 within 206 km of the moon's surface and the researchers suggest it may have flown through a water plume. Such plume activity could help researchers in a search for life from the subsurface European ocean without having to land on the moon.

The tidal forces are about 1,000 times stronger than the Moon's effect on Earth. The only other moon in the Solar System exhibiting water vapor plumes is Enceladus. The estimated eruption rate at Europa is about 7000 kg/s compared to about 200 kg/s for the plumes of Enceladus. If confirmed, it would open the possibility of a flyby through the plume and obtain a sample to analyze in situ without having to use a lander and drill through kilometres of ice.>>
There may have been other factors at play here...something, perhaps, from below. :!:
https://en.wikipedia.org/wiki/Ordovician%E2%80%93Silurian_extinction_events wrote:
Click to play embedded YouTube video.
<<The Ordovician–Silurian extinction events, also known as the Late Ordovician mass extinction, are collectively the second-largest of the five major extinction events in Earth's history in terms of percentage of genera that became extinct. Extinction was global during this period, eliminating 49–60% of marine genera and nearly 85% of marine species. Some scientists have suggested that the initial extinctions could have been caused by a gamma-ray burst originating from a hypernova in a nearby arm of the Milky Way galaxy, within 6,000 light-years of Earth. A ten-second burst would have stripped the Earth's atmosphere of half of its ozone almost immediately, exposing surface-dwelling organisms, including those responsible for planetary photosynthesis, to high levels of extreme ultraviolet radiation. Although the gamma-ray burst hypothesis is consistent with some patterns at the onset of extinction, there is no unambiguous evidence that such a nearby gamma-ray burst ever happened.>>
Art Neuendorffer