APOD: Pluto's Sputnik Planum (2016 Nov 22)

[APOD Robot]

Pluto's Sputnik Planum

Explanation: Is there an ocean below Sputnik Planum on Pluto? The unusually smooth 1000-km wide golden expanse, visible in the featured image from New Horizons, appears segmented into convection cells. But how was this region created? One hypothesis now holds the answer to be a great impact that stirred up an underground ocean of salt water roughly 100-kilometers thick. The featured image of Sputnik Planum, part of the larger heart-shaped Tombaugh Regio, was taken last July and shows true details in exaggerated colors. Although the robotic New Horizons spacecraft is off on a new adventure, continued computer-modeling of this surprising surface feature on Pluto is likely to lead to more refined speculations about what lies beneath.

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[RocketRon]

Did New Horizons have radar, to determine that 100 km thickness ?

Could be a large impact crater, from a giant snowball. ?
Doesn't actually seem to suggest this possibility ??
Or is the ice more widely distributed around Pluto

Great photo.

[cheggers]

I find it amazing that both Pluto and Triton have interesting recent surface features. Icy cold doesn't necessarily mean dead. I'm looking very forward to the New Horizons imagery of 2014 MU69 on 1 January 2019.

[Jim in Eastern NC]

Perhaps this is an upwelling of liquid salty water or liquid hydrocarbons brought about by a close encounter with Neptune when their orbits last were close and gravitational convective heating led to a spring-like seepages which then froze and left a nearly smooth surface feature.

[neufer]

Did New Horizons have radar, to determine that 100 km thickness ?

---

<<Pluto's density is 1.860±0.013 g/cm3. Because the decay of radioactive elements would eventually heat the ices enough for the rock to separate from them, scientists expect that Pluto's internal structure is differentiated, with the rocky material having settled into a dense core surrounded by a mantle of water ice. The diameter of the core is hypothesized to be approximately 1700 km, 70% of Pluto's diameter. It is possible that such heating continues today, creating a subsurface ocean of liquid water some 100 to 180 km thick at the core–mantle boundary. In September 2016, scientists at Brown University simulated the impact believed to have formed Sputnik Planitia, and showed that it may have been the result of liquid water upwelling from below after the collision, implying the existence of a subsurface ocean at least 100 km deep.>>

[neufer]

<<Sputnik Planitia may have originated as an impact basin that subsequently collected volatile ices. Alternatively, it has been suggested that the accumulation of ices in this location depressed the surface there, leading to formation of a basin via a positive feedback process without an impact.

The accumulation of several kilometers of nitrogen ice in the basin may have resulted from the positive temperature gradient of Pluto's atmosphere, which would make a topographic depression a cold trap.

A high seasonal thermal inertia of Pluto's surface is an important driver of deposition of nitrogen ice at low latitudes, which receive less annual insolation than Pluto's polar regions due to its high obliquity. The accumulation of ice would likely then have made Sputnik Planitia a positive gravity anomaly, which could have caused polar wander, reorienting the spin axis of Pluto to put the planitia near the Pluto-Charon tidal axis (the minimum-energy configuration). Sputnik Planitia is presently close to the anti-Charon point on Pluto, a result that has less than a 10% probability of arising by chance.>>

<<The concentration of maria on the Near Side likely reflects the substantially thicker crust of the highlands of the Far Side, which may have formed in a slow-velocity impact of a second moon of Earth a few tens of millions of years after their formation. The far side of the lunar surface is on average about 1.9 km higher than that of the near side. Almost all maria are on the near side of the Moon, and cover 31% of the surface of the near side, compared with 2% of the far side. This is thought to be due to a concentration of heat-producing elements under the crust on the near side, seen on geochemical maps obtained by Lunar Prospector's gamma-ray spectrometer, which would have caused the underlying mantle to heat up, partially melt, rise to the surface and erupt. Most of the Moon's mare basalts erupted during the Imbrian period, 3.0–3.5 billion years ago, although some radiometrically dated samples are as old as 4.2 billion years.

In 2014 NASA announced "widespread evidence of young lunar volcanism" at 70 irregular mare patches identified by the Lunar Reconnaissance Orbiter, some less than 50 million years old. This raises the possibility of a much warmer lunar mantle than previously believed, at least on the near side where the deep crust is substantially warmer due to the greater concentration of radioactive elements. Just prior to this, evidence has been presented for 2–10 million years younger basaltic volcanism inside Lowell crater, Orientale basin, located in the transition zone between the near and far sides of the Moon. An initially hotter mantle and/or local enrichment of heat-producing elements in the mantle could be responsible for prolonged activities also on the far side in the Orientale basin.>>

[Guest]

Love the linked .jpg for "what lies beneath".

[ta152h0]

Pluto is a cool planet.....wait minute ...half right

[Deathfleer]

It looks like an ocean

[orin stepanek]

I believe water ice is very common in the universe; so it would be no surprise to find it on Pluto!

[DavidLeodis]

It's an excellent image. I like Pluto but I would clearly need extra thermals with it being so .

In the explanation it states the image "was taken last July" which I think is confusing as that could be interpreted to be July 2016 and not July 2015 that I feel certain it was taken. To avoid any confusion for casual viewers it should perhaps have stated it "was taken in July 2015".

[RocketRon]

Thanks for the link to wiki.
However, we are none the wider how that 100 km depth of water/ice/layer was determined. ?
Did 'they' pluck that number out of thin air, or is there some measurement that determined this ??

[RocketRon]

I believe water ice is very common in the universe; so it would be no surprise to find it on Pluto!

Has anyone seen any evidence of water/ice outside even of our solar system ?

But yes, objects in the Kuiper Belt are said to be ice/rocky/snowballs, and Pluto is in that region.
Interesting that they were saying this even before New Horizons arrived to have a look.
Putting the cart before the horse ?

And aren't they saying - based on that 100 km layer of ice - that Pluto has many times the water that Earth has.
Even if finding water on our nearer neighbour Mars has been a much more intensive search...

[Chris Peterson]

I believe water ice is very common in the universe; so it would be no surprise to find it on Pluto! 8-) :?

Has anyone seen any evidence of water/ice outside even of our solar system ?

Yes, we observe water everywhere in the Universe.

[Ann]

I believe water ice is very common in the universe; so it would be no surprise to find it on Pluto!

Has anyone seen any evidence of water/ice outside even of our solar system ?

Yes, we observe water everywhere in the Universe.

No wonder, either. Hydrogen is the most abundant element in the universe, and oxygen, while incredibly more rare than hydrogen, is almost certainly one of the top five most common elements in the universe. (Someone who feels like googling tell me.)

And hydrogen and oxygen love to bond, so there you have it, water. H₂O.

Water, water, everywhere, but rarely a drop to drink.

Ann

[ta152h0]

I have read, maybe at APOD, there is a gigantic blob of water floating out there like a galkaxy would, and as big

[RocketRon]

So HOW is this water detected 'everywhere in the universe' actually detected ???
Water wouldn't have emission spectra, since it wouldn't be as glowing plasma inside any suns ?

Folks here are throwing about assumptions, with no scientific basis ?

[Chris Peterson]

So HOW is this water detected 'everywhere in the universe' actually detected ???
Water wouldn't have emission spectra, since it wouldn't be as glowing plasma inside any suns ?

Why do you think water doesn't have emission spectra? In fact, we observe emission and absorption spectra for water vapor in the hard UV and the far IR from space, and in radio and submillimeter waves from the ground. Also seen in far infrared and submillimeter is an abundance of OH+ molecules, a precursor to water.