Out of all the mysterious and fascinating worlds inhabiting the bewitching Wonderland which is our Solar System, the Red Planet Mars has managed to sing the most haunting of all sirens’ songs to humanity. This small, rugged, rust-colored world is our Earth’s close neighbor in space, as well as the world that has tantalized the joys of those among us who seek to answer the profound question of whether or not we’re alone in the Cosmos. Nevertheless, despite its allure, Mars has not shown itself to be inhabited, and Earth remains the only world that is really known to host life. Needless to say, this doesn’t mean that life is not out there somewhere in space–it only means that we have not as yet discovered it, and it apparently has not as yet found us. In July 2018, a team of astronomers announced that they have discovered evidence that heavy beneath the frigid, frozen ice cap of the Martian south pole lies a hidden lake of liquid water–the first to be discovered pooling on the Red Planet. Life as we know it is dependent upon the presence of liquid water.
The new discovery is based on information derived from the European Mars Express spacecraft’s radar instrument named Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS). NASA contributed about 50% of this instrument, with management of the U.S. part led by the bureau’s Jet Propulsion Laborator (JPL) in Pasadena, California.
The research paper, authored by the Italian MARSIS team, explains how a”bright spot” was discovered in radar signs approximately a mile beneath the surface of the ice cap at the Planum Australe area. This powerful radar reflection was determined by the study’s authors to be liquid water. This interpretation is important because where liquid water exists, life as we know it may also exist. The existence of liquid water indicates the possibility–though by no means the promise–of the presence of alien life on Mars.
“The bright spot seen in the MARSIS information is an unusual feature and incredibly intriguing. It definitely warrants further research. Additional lines of evidence should be pursued to test the interpretation,” Dr. Jim Green commented in a July 25, 2018 JPL Press Release. Dr. Green is NASA’s chief scientist.
“We expect to use different instruments to examine it further in the future,” Dr. Green added.
One of those new tools will land on Mars late in 2018. The instrument, NASA’s InSight lander will take a heat probe that is designed to burrow down to the Martian surface as far as 15 feet. InSight was constructed from the German Aerospace Center (DLR), and it’s scheduled to present important new data concerning how much heat manages to escape from the Red Planet and in which the liquid water could pool near its surface.
“Follow the Water” has long been one of the holy grails of NASA’s Mars program. The search for liquid water is now the inspiration behind NASA’s exploration into the outer regions of our Solar System, where watery ocean-moon-worlds have the potential to host delicate life forms. Even dwarf planets, such as Ceres, the largest denizen of the Main Asteroid Belt between Mars and Jupiter, may help scientists gain a new understanding of how water is stored in rugged”buckets” that carry water throughout our Solar System.
The hidden Martian lake is probably extremely cold and very salty. This makes it an improbable abode for life. However, the discovery, reported for the first time on July 25, 2018, in the online edition of the journal Science, is certain to bring new hope to those scientists who seek the existence of life on distant worlds. The hunt for additional buried, hidden layers of water on Mars has intensified, and the hunt is on for other bodies of water on Mars that might be more hospitable to delicate living animals. “It’s a very exciting result: the first indication of a briny aquifer on Mars,” commented Dr. David Stillman in a July 25, 2018 Science Magazine Press Release. Dr. Stillman is a geophysicist at the Southwest Research Institute at Boulder, Colorado, who wasn’t part of the study.
The team of scientists think that the lake is much like one of the interconnected pools located several miles under the ice sheets of Antarctica and Greenland, according to Dr. Martin Siegert in the exact same Press Release. Dr. Siegert is a geophysicist at Imperial College London (U.K.), who leads a consortium planning to drill into Lake Ellsworth under the ice of West Antarctica. However, the geophysical processes that created a deep lake on Mars are probably different. “It will open up a very interesting field of science on Mars,” Dr. Siegert added.
Planetary scientists generally feel that water gushed across the surface of the Red Planet countless years back, when it owned a warmer and warmer setting. This water is believed to have carved gullies and channels which are still visible on Mars today. But now low atmospheric pressures indicate that any surface water would boil away. By comparison, water manages to live frozen in polar ice caps, as well as in subsurface ice deposits. Some of those ice deposits have been mapped by MARSIS.
On our planet, microorganisms are found swimming at the subglacial lakes of Antarctica. These hearty little germs have managed to survive in isolation from the external Antarctica for as long as 35 million years–or even longer. This is because a high number of those 400 subglacial lakes which have been detected so far appear to be hydraulically tied to one another. Therefore, planetary scientists think that it is reasonable to conclude that microorganisms may swim around nearly everywhere under the Antarctic ice. Organisms, such as these, inhabiting areas generally thought of as inhospitable, are termed extremophiles. Extremophiles could be located on distant worlds dwelling in environments that appear to be more hostile to life.
The discovery of small tidbits of life swimming around in the subglacial lakes of Mars would have profound significance for humanity. This is because it would be the first life to be found on a world other than Earth. Additionally, discovery of these living tidbits would contribute to our scientific understanding of the incidence of life in our Solar System. Ice-covered oceans are thought to slosh around under the frozen cubes of Jupiter’s moons Europa and Ganymede, as well as Saturn’s moons Titan and Enceladus. This indicates that the discovery of geologically persistent liquid water on so many distant planetary bodies raises the fascinating possibility that aquatic life-forms may be abundant during our Solar System.
The great Italian astronomer Galileo Galilei (1564-1642) made the first telescopic observation of Mars in 1610, with his primitive little”spyglass”, which was among the first telescopes to be used for astronomical purposes. During that same century, other astronomers also observed that the polar ice caps on Mars, using the very small telescopes of that age. These ancient astronomers were still able to determine the Martian rotation period, in addition to its axial tilt. These observations were mostly made when Mars was at its closest approach to Earth. Improved telescopes developed in the 19th century helped astronomers map permanent albedo features, and a crude map of the Red Planet was published in 1840. This very first map of Mars was followed by a string of progressively improved maps from 1877 on.
The ingenious tale of”little green men” inhabiting Mars started when astronomers wrongly believed they had observed the spectroscopic signature of water in its atmosphere. This appealing notion of Martian life became increasingly popular with astronomers and the general public alike, and it became particularly popular when the American astronomer Perceval Lowell (1855-1916) thought that he had observed a network of artificial canals carved by intelligent beings on the Martian surface. But these linear features were ultimately found to be only optical illusions.
Also during the 1920s, astronomers could determine that the air of the rusty-red world harbors only very small amounts of water and oxygen. Astronomers of that era also successfully found that the surface temperature of the Red Planet ranged from a truly freezing -121 degrees Fahrenheit to a comfortable 45 degrees Fahrenheit.
Two decades later, in 1947, the Dutch-American astronomer Gerard Kuiper (1905-1973) demonstrated that the thin atmosphere of Mars is composed primarily of carbon dioxide that added up to approximately double the quantity found in our planet’s atmosphere.
Mars is the fourth planet from our Sun, and like another strong inner planets–Mercury, Venus, and Earth–it basks in the brilliant sunlight streaming out from our Star. It is famous for its reddish hue that’s caused by an abundance of iron sulfide coating its surface. Additionally, the surface of Mars is scarred with a high number of impact craters that appear quite similar to those observed on Earth’s Moon.
Mars has a rotational period and changing seasons such as our own world. However, unlike our Earth’s large Moon (the largest moon in our Sun’s inner kingdom), Mars is orbited by a strange and fascinating duo of small potato-shaped moons. The Martian moons, dubbed Phobos and Deimos, are generally thought to be asteroids that escaped from the Main Asteroid Belt, only to be snared by the irresistible gravity of the Red Planet.
For the past two decades, cameras in orbit around Mars have sent back to Earth numerous revealing images. These pictures show that Mars sports a surface that’s dotted with little valleys that have been formed into slopes which bear an eerie resemblance in their form to gullies that resulted from gushing flooding of liquid water on our own planet. The Martian gullies are regarded as relatively young geological features that are less than a few million years old–and some can even be more youthful than that. A few million years isn’t a lengthy time on geological time scales. These more recent observations provide planetary scientists valuable clues that great amounts of life-sustaining liquid water may still be lingering on Mars, and that this water might have been responsible for carving the surface gullies.
Despite the fact that the surface of the Red Planet is not particularly life-friendly today, there’s sufficient evidence suggesting that very long past its climate may have been such that water in its liquid phase pooled on its surface.
Martian Polar Ice Caps
Mars sports two permanent polar ice caps that are composed primarily of water ice. Frozen carbon dioxide builds up as a relatively thin layer during a pole’s Martian winter. Throughout that frigid season the sticks are enshrouded in heavy blankets of constant and continuous darkness. The extremely cold Martian winters freeze its surface, and cause the deposition of 25-30percent of the air to freeze into slabs of carbon dioxide ice (dry ice). When the sticks are swept by warm sunlight during the spring and summer, the frozen carbon dioxide sublimates. These seasonal alterations transport great quantities of water vapor and dust. This leads to Earth-like frost, in addition to large cirrus clouds.
Both Martian poles display layered attributes, that are termed polar-layered residue . These deposits are brought on by seasonal melting and deposition of ice together with dust from the roaring Martian dust storms that sweep over the surface of Earth. Precious information concerning the past climate of Mars may become shown in these layers, that have been preserved in a type of deep freeze since ancient times. This has been compared to how tree ring patterns and ice core data show climate changes over the passing of years on Earth. Both of the Martian polar caps also reveal grooved features which were likely due to winds. The grooves are also affected by the number of dustin other words, the more dust there is, the darker the surface. It follows that the darker the surface, the more frequent the melting. However, there are other theories that were proposed to explain the large Martian grooves.
The south polar ice cap of Mars sports big pits, troughs and flat mesas that give it a”Swiss cheese look.” In contast, the north polar ice cap displays a horizontal surface with smaller pits than those located at the south polar ice cap–providing the north polar ice cap the look of”cottage cheese”, instead of”Swiss cheese.”
Hidden Liquid Water Under Ice
The radar information acquired by MARSIS provides strong evidence that there is a pond of liquid water buried beneath layers of ice and dust in the south polar region of the Red Planet. Indeed, new evidence that Mars had an early watery past is sprinkled all over its surface in the form of enormous dried-out river valley networks and vast outflow channels. These tattle-tale features have been clearly imaged from the spacecraft. Orbiters, along with landers and rovers, have been investigating the Martian surface for years, discovering minerals that can only form in the presence of liquid water.
Liquid water can’t exist on the Red Planet’s surface today, so astronomers are on the hunt for subsurface water.
The potential existence of water in its liquid phase on Mars (which may have supplied a habitable environment for delicate forms of life) was first predicted by Dr. Stephen Clifford back in 1987. Dr. Clifford is a senior scientist at the Planetary Science Institute (PSI) in Tucson, Arizona.
In reference to the recent findings of ESA’s Mars Express, published in the June 25, 2018 issue of the journal Science, Dr. Clifford mentioned:”I believe that the evidence the paper’s authors have presented for the existence of liquid water at the bottom of the south polar layered deposits, in this location, is highly persuasive. It’s a finding that ought to be closely examined by the rest of the radar community to be sure we can rule out other alternative explanations–something I feel the authors have already made an superb effort of doing.”
Whatever the degree of polar basal melting on Mars today, it was almost certainly much greater in the past, added Dr. Clifford in a July 27, 2018 PSI Press Release. Geological evidence indicates that the south polar layered deposits blanketed a region that has been roughly twice as large 2 billion years ago than it is now. This means that there was much more ice about to melt. The geothermal heat flux of Mars–which is caused by the decay of naturally occurring radioactive elements in the crust–is also believed to have been as much as three times larger during that early time. This would have reduced the necessary thickness of polar ice for basal melting.
Dr. Clifford continued to remark:
“The work I did 30 years back was basically a theoretical exercise that thought what we then knew about the extensive network of subglacial lakes and channels that exist in the bottom of the Antarctic and Greenland ice sheets and examined its potential significance to the Martian polar caps. It’s certainly gratifying that the MARSIS radar team has found evidence that shows that this early theoretical work has some connection to reality.”