Alien life may be thriving in a warm, underground ocean on Saturn’s icy moon Enceladus, according to new research. Scientists say tidal forces could have kept the subterranean sea liquid for billions of years – enough time for organisms to have developed. The mysterious world has a very fragmented and porous rocky interior, ideal conditions for flowing water with the friction creating 10 gigawatts of heat.
Updated version of the previous article.
This amount of energy would
light and heat more than 7 million homes – and explains all the global
properties of Enceladus observed by Cassini. Earlier this year NASA's
spacecraft picked up the first evidence of chemical reactions deep below the
frozen crust – suggesting an environment capable of supporting life. It was one
of its final successes before plunging into Saturn’s atmosphere at the end of
its 12 year expedition to the ringed planet.
The latest study published
in Nature Astronomy is based on a state-of-the-art computer model using
Cassini’s observations. These showed Enceladus has a global ocean fed by
intense hydrothermal activity beneath the surface. Its measurements of water
escaping from geysers at the south pole showed the sea is salty – and contains
organic molecules. But tidal forces within the
ice are not sufficient to sustain this activity.
Without an additional contribution
the ocean would freeze in less than 30 million years. So planetary scientist Dr
Gael Choblet and colleagues explored the possibility this additional heating
comes from the effect of tidal forces acting on the highly porous core.
They found enough heat would
be generated by the resulting hydrothermal activity to keep the ocean liquid
for “tens of millions to billions of years.” This heat is dissipated mainly at
the poles – explaining why the ice shell is thinner there. The model suggests
an ocean has existed within Enceladus for eons – even though the small moon is
only 887 million miles away from the Sun.
Dr Choblet said: “What we show is hydrothermal processes probably provide means to have efficient interactions between rocks and hot water in a large volume deep within the moon.
What had been shown earlier is hydrothermal processes were very likely occurring right now within Enceladus. What we show in our study is the context of this activity. We also suggest this activity is relatively stable – for at least 10s of millions of years.”
He said the life expectancy
of the ocean and – perhaps more importantly – how long the hydrothermal
activity has been occurring would be key to the emergence of microbes and other
organisms.
Dr Choblet, of Nantes
University in France, said: “Only future missions equipped with instruments
capable of analysing the organic molecules in the plume with higher accuracy
than the Cassini measurements will tell us whether the required conditions have
been sustained long enough for life to have emerged on this distant ocean
world. Projected missions back to Enceladus are currently under consideration –
especially in the US.
If selected these would
already enable us to analyse the chemicals emitted though Enceladus plumes with
a much better precision than the instruments onboard the Cassini spacecraft
could – especially the complex organics. With a possible launch in 2024 this
means that new, more precise use information could be obtained in the 2030s.”
In October 2015 NASA sent
Cassini into a deep dive through one of the plumes of spray which shoot up into
the atmosphere through cracks in the ice, and discovered hydrogen and carbon
dioxide. Scientists are certain they were created by reactions between warm
water and rocks on the ocean floor.
Crucially, if hydrogen is
present it can mix with carbon dioxide to form methane, which is consumed by
microbes in the deep, dark seas of our own planet. Enceladus is the sixth
largest moon of Saturn.
It is around 310 miles in
diameter and approximately 790 million miles from Earth. Scientists had long
suspected that liquid water could exist on the moon because of the extreme
tidal forces acting on the satellite from Saturn’s gravity.
Although scientists
previously thought Enceladus’ icy crust was around 13 miles thick, Cassini
found at the South Pole it could be as little as three miles deep. The distant
moon has long been hailed as one of the three best potential locations for
finding extraterrestrial life in the solar system. The others are Mars and
Jupiter’s satellite Europa. Such a discovery of even primitive microbes would
make it almost certain life is widespread throughout the universe.
Dr Choblet said: “Chemical analyses indicate that the ocean is salty and is fed by ongoing hydrothermal activity.
Here, we show that more than 10GW of heat can be generated by tidal friction inside the unconsolidated rocky core. Water transport in the tidally heated permeable core results in hot narrow upwellings with temperatures exceeding 363K (90 degrees Celsius) characterised by powerful hotspots of 1 to 5 GW at the seafloor, particularly at the south pole.” Recent data from Cassini has shown that at the south pole, it could be as little as three miles deep.
The release of heat in
narrow regions favours intense interaction between water and rock, and the
transport of hydrothermal products from the core to the plume sources. We
predict that this internal activity can be sustained for tens of millions to
billions of years.”
So what do you think about this? Let us know in the comments
So what do you think about this? Let us know in the comments
Via Telegraph
Who ,
ReplyDeleteer , me ?? hell its cool and all , but wtf has it got to do with the price of rice in China ??? Oh , is that racist ?? I don't think so , wasn't meant to be . So Saturn may have a civilization run by squid . Yawn . Call me when you find a planet run by Victoria Secret models..
Ty si asi ťuk ťuk.
DeleteCool. It's a tiny planet. Let's find something bigger we can ruin.
ReplyDelete