This is the most awesome news… sorry it has taken me so long to post about it.
Just a mile or so beneath the surface, near the south pole of Mars, there is a reservoir of briny water sloshing and churning below layers of ice and rock. This subglacial lake, discovered by a ground-penetrating radar on the Mars Express spacecraft, is about 20 kilometers (12.4 miles) wide and perhaps no more than a meter deep. Its discovery is the latest piece of evidence that suggests water was not only present on Mars in the past but is still flowing in some capacity today. The findings, if confirmed by future observations, would be the most significant discovery of liquid water on Mars to date.
The most intriguing possibility is that this Martian lake is not alone, but rather part of an extensive network expanding across the south polar region of Mars. “Data provide some hints that this single lake is not a unique finding
But before we envision such a thing, follow-up observations must confirm that this one lake really does exist. Because for all the exciting data that has been obtained by MARSIS, there is one major problem: Another radar orbiting Mars, the Shallow Radar (SHARAD) on NASA’s Mars Reconnaissance Orbiter (MRO), has not been able to detect the underground reservoir at all.
>Researchers have found evidence of an existing body of liquid water on Mars.
What they believe to be a lake sits under the planet’s south polar ice cap, and is about 20km (12 miles) across.
Previous research found possible signs of intermittent liquid water flowing on the martian surface, but this is the first sign of a persistent body of water on the planet in the present day.
Lake beds like those explored by Nasa’s Curiosity rover show water was present on the surface of Mars in the past.
However, the planet’s climate has since cooled due to its thin atmosphere, leaving most of its water locked up in ice.
The result is exciting because scientists have long searched for signs of present-day liquid water on Mars, but these have come up empty or yielded ambiguous findings. It will also interest those studying the possibilities for life beyond Earth – though it does not yet raise the stakes in the search for biology.
The discovery was made using Marsis, a radar instrument on board the European Space Agency’s (Esa) Mars Express orbiter.
“It’s probably not a very large lake,” said Prof Roberto Orosei from the Italian National Institute for Astrophysics, who led the study.
Marsis wasn’t able to determine how thick the layer of water might be, but the research team estimate that it is a minimum of one metre.
“This really qualifies this as a body of water. A lake, not some kind of meltwater filling some space between rock and ice, as happens in certain glaciers on Earth,” Prof Orosei added.
This blockquote is via BBC News read more here.
A nice report from Australia:
Mars has a vast liquid lake beneath its southern pole, scientists believe
ABC News (Australia)
Published on Jul 25, 2018
It’s an extraordinary development in the search for life on Mars. Scientists have discovered a giant lake of water beneath ice near the red planet’s south pole. Using ground-penetrating radar from an orbiting spacecraft, an Italian team picked up signs of a 20km-wide body of liquid water. The salt-laden lake is hidden about one-and-a-half kilometres beneath the planet’s southern polar plains. Whether it’s a relic of past oceans or part of a bigger network of lakes remains a mystery. Read more here: http://www.abc.net.au/news/science/20…
And here come the boffins!
This is a snip from the abstract for the article published in Science magazine: Read everything here.
Radar evidence of subglacial liquid water on Mars
- R. Orosei 1, *,
- S. E. Lauro 2,
- E. Pettinelli 2,
- A. Cicchetti 3,
- M. Coradini 4,
- B. Cosciotti 2,
- F. Di Paolo 1,
- E. Flamini 4,
- E. Mattei 2,
- M. Pajola 5,
- F. Soldovieri 6,
- M. Cartacci 3,
- F. Cassenti 7,
- A. Frigeri 3,
- S. Giuppi 3,
- R. Martufi 7,
- A. Masdea 8,
- G. Mitri 9,
- C. Nenna 10,
- R. Noschese3,
- M. Restano 11,
- R. Seu 7
See all authors and affiliations
Science 25 Jul 2018:
The presence of liquid water at the base of the martian polar caps has long been suspected but not observed. We surveyed the Planum Australe region using the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) instrument, a low-frequency radar on the Mars Express spacecraft. Radar profiles collected between May 2012 and December 2015 contain evidence of liquid water trapped below the ice of the South Polar Layered Deposits. Anomalously bright subsurface reflections are evident within a well-defined, 20-kilometer-wide zone centered at 193°E, 81°S, which is surrounded by much less reflective areas. Quantitative analysis of the radar signals shows that this bright feature has high relative dielectric permittivity (>15), matching that of water-bearing materials. We interpret this feature as a stable body of liquid water on Mars.
The presence of liquid water at the base of the martian polar caps was first hypothesized more than 30 years ago (1) and has been inconclusively debated ever since. Radio echo sounding (RES) is a suitable technique to resolve this dispute, because low-frequency radars have been used extensively and successfully to detect liquid water at the bottom of terrestrial polar ice sheets. An interface between ice and water, or alternatively between ice and water-saturated sediments, produces bright radar reflections (2, 3). The Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument on the Mars Express spacecraft (4) is used to perform RES experiments (5). MARSIS has surveyed the martian subsurface for more than 12 years in search of evidence of liquid water (6). Strong basal echoes have been reported in an area close to the thickest part of the South Polar Layered Deposits (SPLD), Mars’ southern ice cap (7). These features were interpreted as due to the propagation of the radar signals through a very cold layer of pure water ice having negligible attenuation (7). Anomalously bright reflections were subsequently detected in other areas of the SPLD (8).
On Earth, the interpretation of radar data collected above the polar ice sheets is usually based on the combination of qualitative (the morphology of the bedrock) and quantitative (the reflected radar peak power) analyses (3, 9). The MARSIS design, particularly the very large footprint (~3 to 5 km), does not provide high spatial resolution, strongly limiting its ability to discriminate the presence of subglacial water bodies from the shape of the basal topography (10). Therefore, an unambiguous detection of liquid water at the base of the polar deposit requires a quantitative estimation of the relative dielectric permittivity (hereafter, permittivity) of the basal material, which determines the radar echo strength.
Between 29 May 2012 and 27 December 2015, MARSIS surveyed a 200-km-wide area of Planum Australe, centered at 193°E, 81°S (Fig. 1), which roughly corresponds to a previous study area (8). This area does not exhibit any peculiar characteristics, either in topographic data from the Mars Orbiter Laser Altimeter (MOLA) (Fig. 1A) (11, 12) or in the available orbital imagery (Fig. 1B) (13). It is topographically flat, composed of water ice with 10 to 20% admixed dust (14, 15), and seasonally covered by a very thin layer of CO2 ice that does not exceed 1 m in thickness (16, 17). In the same location, higher-frequency radar observations performed by the Shallow Radar instrument on the Mars Reconnaissance Orbiter (18), revealed barely any internal layering in the SPLD and did not detect any basal echo (fig. S1), in marked contrast with findings for the North Polar Layer Deposits and other regions of the SPLD (19).
Informational pictures from ATS member wildespace:
The ubiquitous red circle is where she lie…
The above pic shows the terrain right over where this first lake is located.
Exciting stuff… and more is coming.