Posted on by Jason Major

Our Universe is Dying

How a galaxy appears in different wavelengths of light. Based on the results of a recent study light from the nearby Universe is fading across all of these wavelengths. Credit: ICRAR/GAMA and ESO

Brace yourselves: winter is coming. And by winter I mean the slow heat-death of the Universe, and by brace yourselves I mean don’t get terribly concerned because the process will take a very, very, very long time. (But still, it’s coming.)

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Part of ESO’s VISTA telescope in Chile, one of seven telescopes used in the GAMA survey (ESO)

Based on findings from the Galaxy and Mass Assembly (GAMA) project, which used seven of the world’s most powerful telescopes to observe the sky in a wide array of electromagnetic wavelengths, the energy output of the nearby Universe (currently estimated to be ~13.82 billion years old) is currently half of what it was “only” 2 billion years ago — and it’s still decreasing.

“The Universe has basically plonked itself down on the sofa, pulled up a blanket and is about to nod off for an eternal doze,” said Professor Simon Driver from the International Centre for Radio Astronomy Research (ICRAR) in Western Australia, head of the nearly 100-member international research team.

As part of the GAMA survey 200,000 galaxies were observed in 21 different wavelengths, from ultraviolet to far-infrared, from both the ground and in space. It’s the largest multi-wavelength galaxy survey ever made.

Of course this is something scientists have known about for decades but what the survey shows is that the reduction in output is occurring across a wide range of wavelengths. The cooling is, on the whole, epidemic.

Watch a video below showing a fly-through 3D simulation of the GAMA survey:

“Just as we become less active in our old age, the same is happening with the Universe, and it’s well past its prime,” says Dr. Luke Davies, a member of the ICRAR research team, in the video.

But, unlike living carbon-based bags of mostly water like us, the Universe won’t ever actually die. And for a long time still galaxies will evolve, stars and planets will form, and life – wherever it may be found – will go on. But around it all the trend will be an inevitable dissipation of energy.

“It will just grow old forever, slowly converting less and less mass into energy as billions of years pass by,” Davies says, “until eventually it will become a cold, dark, and desolate place where all of the lights go out.”

Our own Solar System will be a quite different place by then, the Sun having cast off its outer layers – roasting Earth and the inner planets in the process – and spending its permanent retirement cooling off as a white dwarf. What will remain of Earthly organisms by then, including us? Will we have spread throughout the galaxy, bringing our planet’s evolutionary heritage with us to thrive elsewhere? Or will our cradle also be our grave? That’s entirely up to us. But one thing is certain: the Universe isn’t waiting around for us to decide what to do.

The findings were presented by Professor Driver on Aug. 10, 2015, at the IAU XXIX General Assembly in Honolulu, and have been submitted for publication in the Monthly Notices of the Royal Astronomical Society.

Read more/sources: ESO and ICRAR

Posted on by Jason Major

Mars May Have Once Been a Cold, Wet World

2 billion years ago Mars may have featured a frigid ocean. Credit: Taylor Perron/UC Berkeley.

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Many planetary scientists suspect that Mars, now cold and very dry, once had a liquid water ocean covering parts of its surface. But this does not necessarily mean that the Red Planet was ever a tropical paradise… a recent paper by a team of astrobiologists suggests that Mars was much more bitter than balmy.

Astrobiologist Alberto Fairyn and colleagues have published a paper in the journal Nature Geoscience suggesting that the marked absence of phyllosilicates in Mars’ northern lowlands is indicative of a cold ocean environment, with perhaps even a boundary of frozen glaciers.

Phyllosilicates are minerals that, on Earth, are found readily in marine sediments and sedimentary rock that was formed in the presence of an ocean environment. These same minerals have also been seen via orbiting spacecraft spectrometers to be present in sediments located in Mars’ equatorial regions, but not in the northern latitudes. Fairyn and his team, intrigued by the disparity between existing models that described Mars as being once warm and wet and the lack of phyllosilicates in the north, used new climatic and geochemical models to deduce that Mars’ northern oceans must have been consistently near freezing, with portions even covered over by ice.

Did Mars once have ice-covered seas? (Original image © Maggie & David. Edited by J. Major.)

The current presence of moraines in the northern highlands also suggests that glaciers may have surrounded these frigid seas, which may have prevented the transportation of phyllosilicates down to the northern ocean basin. Again, to use our own planet as an analogy, moraines are rocky debris left over from the movement of glaciers. Their existence on Mars strongly suggests a period of early glaciation.

The research by Fairyn et al. contradict – or, more aptly, combine –  two leading concepts of early Mars: one, that it was cold and dry and the existence of any liquid water was restricted to the equator for small periods of time; and two, that it was once globally warmer and wetter and sustained rivers, lakes and oceans of liquid water for extended periods.

Thus a cold Mars with an Arctic, icy ocean seems to be a more fitting causation of the current state of the planet, suggests Fairyn.

More research is planned, including running through more low-temperature models and hunting for ancient coastal areas that may have been impacted by icebergs. This will no doubt prove to be a challenge since much of the evidence is now buried deep beneath newer sediments and volcanic deposits. Still, Fairyn is confident that his model may help solve a long-standing debate over the history of the Red Planet.

Read more in an article by Bob Yirka on PhysOrg.

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Jason Major is a graphic designer, photo enthusiast and space blogger. Visit his website Lights in the Dark and follow him on Twitter @JPMajor or on Facebook for the most up-to-date astronomy awesomeness!