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Water on Mars: a network of underground lakes found under the planet’s surface

Three underground lakes were discovered near the South Pole of Mars using the radar of the automatic interplanetary station of the European Space Agency “Mars Express”. Earlier, in 2018, one such lake was already discovered there.

Since the presence of water is a key condition for the existence of life, its discovery on any cosmic body attracts special attention. However, as scientists suggest, the water in the Martian lakes is so salty that even the most persistent microbes will not survive in it.

Since the atmosphere of Mars is very rarefied, and temperatures are lower than in Antarctica, water cannot be in liquid form on its surface. The lakes are located at a depth of about one and a half kilometers under the polar cap consisting of ice and sand.

Strong brine

Since there, too, the temperature is kept well below the freezing point, the researchers explain the liquid state of the water by the high content of salts in it.

The main lake is surrounded by three smaller bodies of water
Photo caption,The main lake is surrounded by three smaller bodies of water

Experiments have shown that water saturated with magnesium salts and calcium perchlorate turns into ice at -123 degrees.

“These experiments have demonstrated that saline bodies of water can exist for entire geological periods, even at temperatures typical of the polar regions of Mars,” said study co-author Graziela Caprarelli of the University of South Queensland in Australia. “But the creation and maintenance of such underground lakes requires high salinity. “.

Viewed from orbit

The discovery was made using Marsis radar aboard the Mars Express orbital station, orbiting the Red Planet since December 2003.

South Pole of Mars
Photo caption,Significant reserves of liquid water have been discovered under the cap of Mars’ South Pole

The radar uses technology that is used to study sub-ice lakes in Antarctica, Greenland and Canada, adapted to the conditions of Mars.

“The most likely explanation for the available data is that reflections from the surface of Mars increase in intensity where there are vast reservoirs of fluid,” says Sebastian Lauro of the University of Tre in Rome.

In 2018, analyzing information from Marsis, researchers suggested the existence of an underground lake about 20 km long in the South Pole region.

This discovery was based on 29 measurements taken in 2012-2015. Now an international group of researchers, many of whom worked in 2018, additionally analyzed data from another 134 measurements for the period from 2010 to 2019.

“We not only confirmed the original discovery, but also found three more smaller lakes surrounding the main one,” says Elena Pettinelli of Tre University. “Due to the limited technical capabilities of the radar and its distance from the Martian surface, we cannot say with certainty whether whether they are between themselves or not.”

Traces of early life form

Whether any form of life can exist in lakes depends on the degree of their salinity. On Earth, in highly salty water bodies, only a special type of microbes, called halophiles, survive.

“The emergence of the only subglacial lake could be attributed to some exceptional circumstances, for example, the presence of a nearby volcano hidden under the ice cap. But the discovery of a whole system of lakes suggests that their formation is a relatively simple and widespread process, and that such lakes probably have existed for much of Mars’ history,” says Marsis Science Director Roberto Orosei.

“Therefore, they can retain traces of those forms of life that were on Mars, when there was a dense atmosphere, a warmer climate, water on the planet’s surface, and conditions resembled those that were on Earth in the early period,” the scientist said.

Exploration of the Red Planet continues. The details of the research results will be announced a little later.

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Space

It’s a good start: TESS orbiting telescope discovers the first habitable world, with oceans

The TESS Space Telescope has discovered a planet on which oceans may exist. In addition, the exoplanet revolves around a quiet star, and this compares favorably with other candidates for the title of the cradle of extraterrestrial life. This is the first, but certainly not the last potentially inhabited world discovered by the TESS Observatory.

The space telescope was launched in 2018. Its task is to search for exoplanets, including those similar to Earth.

TESS has discovered 17 Earth-like planets orbiting 11 stars so far, according to a press release for the new study. All these luminaries are red dwarfs, which are smaller and colder than the Sun.

The TESS team divided almost the entire sky into sectors, each of which is observed for 27 days. However, these areas partially overlap, so some luminaries remain in the field of view of the device for much longer.

The TOI-700 star (aka TIC 150428135) is one of those “lucky ones”. Thanks to this, astronomers have discovered as many as three exoplanets about the size of the Earth.

The first of them (TOI-700b) has a radius almost equal to that of the Earth and revolves around its sun in 10 Earth days. The next planet, TOI-700c, is much larger than its neighbor (2.7 times the Earth’s radius). It makes a complete revolution in 16 days.

However, the most interesting of all is the third exoplanet from the planet TOI-700d. Its radius is 1.1 terrestrial, and its orbital period is 37 terrestrial days. It is this orbit around the cool local sun that makes the TOI-700d “right to life.” 

According to scientists, the planet receives 86% of the heat that goes to the Earth. This means that the temperature on this celestial body allows for the existence of liquid water and, therefore, the biosphere. According to experts, the exoplanet is in the habitable zone.

Planetary system TOI-700. The habitable zone is shown in green. One astronomical unit (AU) is equal to the distance from the Earth to the Sun. Illustration by Rodriguez et al. / Astronomical Journal (2020).

Three scientific articles published in the Astronomical Journal are devoted to the newly discovered world.

The first describes the discovery of this planet using the TESS telescope.

The second publication is devoted to the observation of an exoplanet using the Spitzer space infrared observatory. The telescope received this data in October 2019 and January 2020, shortly before the termination of its mission.

Finally, the authors of the third research paper simulated the possible climate of TOI-700d.

The researchers examined two dozen scenarios that differ from each other in the composition of the planet’s atmosphere, the amount of water on it, and other characteristics. Their conclusion is optimistic: a climate suitable for life is obtained in a fairly wide range of conditions.

It is important that TOI-700, unlike most other red dwarfs, is a calm star, not prone to catastrophic flares. That is, TOI-700d has every chance of preserving the atmosphere and hydrosphere for billions of years.

Of course, not without a fly in the ointment. TOI-700 is more than a hundred light years from Earth. It’s too far away to directly study the atmosphere of a small planet like TOI-700d, even with the future James Webb telescope .

However, the capabilities of astronomical instruments are growing rapidly. Perhaps in a few decades, scientists will carefully study the mysterious exoplanet and (who knows?) will find signs of the existence of life on it.

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Space

Apophis: A dangerous phenomenon was noticed on an asteroid threatening Earth

The asteroid Apophis, potentially dangerous for the Earth, experiences the Yarkovsky effect, as a result of which it gains acceleration and shifts to more and more threatening orbits with a collision with the Earth.

The asteroid Apophis, 325 meters in size, was discovered in 2004. The discovery caused a stir – calculations showed that there is a 2.7 percent probability that Apophis, named after the ancient Egyptian god of evil and destruction, will collide with the Earth in 2029. Then scientists ruled out this threat, calculating that on April 13, 2029, the asteroid will fly at a distance of 37.6 thousand kilometers from the center of the Earth.

The report on the detected displacement was presented at the Planetological Section of the Virtual Meeting of the American Astronomical Society in 2020 by a specialist from the Institute of Astronomy, University of Hawaii, Dave Tholen. According to the speaker and his colleagues, the asteroid Apophis is strongly susceptible to the Yarkovsky effect, which consists in a weak force effect on an object moving in space due to the inhomogeneity of thermal radiation.

All asteroids emit in the form of heat the energy of the sunlight they absorb in order to remain in a state of thermal equilibrium – and as a result of this process, the asteroid’s orbit changes weakly. Until now, it was believed that collisions of the asteroid Apophis during its approach to Earth in 2029 and 2068 are impossible. Taking into account the Yarkovsky effect with respect to a 325-meter potentially dangerous asteroid means that the scenario of its collision with the Earth in 2068 is updated again.

Apophis is the most likely candidate for a collision from the aton asteroids passing near the Earth, was discovered in 2004 and received its own name on July 19, 2005 in honor of the ancient Egyptian god Apop (Apophis) – a huge destroyer snake living in the darkness of the underworld and trying to destroy Sun (Ra).

During its approach to Earth on Friday, April 13, 2029, this asteroid will be visible to the naked eye as it passes within the orbits of Earth’s communications satellites.

One of the discoverers of Apophis, David Jay Tolen, in particular, said:

“We already know that the collision of this cosmic stone with our planet is impossible during the approach of 2029. However, the quality of our new observations with the Subaru telescope was high enough to reveal the acceleration resulting from the Yarkovsky effect on this asteroid.

Calculations have shown that the asteroid is annually displaced from a “purely gravitational” orbit by about 170 meters, and this displacement is enough to return the scenario of a collision with the Earth in 2068 among the probable outcomes .”

There are a number of services on Earth that track the potentially dangerous approaches of our planet with asteroids, but significant in body size, such as Apophis, attract the attention of scientists.

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US professor said that the space expansion of earthlings will lead to the spread of totalitarianism

Political scientist Daniel Dodney believes that the foundation for future space conflicts is being laid on Earth today.

Space exploration is one of the main priorities for humanity in the 21st century. But not everyone agrees that the exit of our civilization beyond the boundaries of the globe will do more good than harm. For example, Daniel Dodney, professor of political science at Johns Hopkins University in the United States, believes that we should not attempt space expansion at all.

Dewdney is confident that the emergence of new habitats for people, in addition to the Earth, will lead to the emergence of interplanetary totalitarian empires. And if mankind somehow manages to master at least a few planets of the solar system, then nuclear weapons will become the “gold standard” in all wars (which, according to the professor, will not stop).

Although many colleagues consider Daniel’s arguments too pessimistic, the political scientist himself generally believes that people should abandon the exploration of outer space and search for a new home. 

“The large-scale expansion of human activity into space <…> must be included in the growing list of catastrophic existential threats to humanity,” Dodni insists.

No matter how gloomy the views of the American political scientist may look, they have certain grounds. So, in 2019, the United States announced the creation of a new type of its Armed Forces – space: they are “designed to protect the interests of the United States in space, deter aggression at long distances and conduct operational and consistent space operations.”

Daniel Dodney / The Brown Daily Herald
Daniel Dodney / The Brown Daily Herald

Other countries followed the American example: France, Canada and Japan announced their intentions to create similar troops. According to Dodnya, all this testifies to laying the foundation for future “near-earth conflicts.” According to his forecasts, space special forces will one day be able to control asteroids and comets to destroy settlements on rival planets or change the climate there, causing total extinction.

At the same time, the political scientist notes that he has nothing against “using space in ways that will benefit the Earth.” However, he doubts that this is possible.

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