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

Water on Mars: a network of underground lakes found under the planet's surface 86

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.



Scientists suggested looking for aliens near black holes

Scientists suggested looking for aliens near black holes 99

Extraterrestrial civilizations can receive energy from black holes. The technologies allowing to do this have already been described by earthly scientists, although so far only in theory. If this assumption is correct, then traces of aliens can be found just below the event horizon, Physical Review D.

The colossal energy that black holes are fraught with can be used by alien civilizations. Scientists who made such an assumption are confident that traces of intelligent extraterrestrial civilizations should be looked for near black holes.

Scientists at Columbia University in New York have suggested that plasma bursts seen near massive black holes could be related to alien activity. According to them, black holes can become an almost limitless source of energy for a technologically advanced civilization.

“We have to understand what the deliberate extraction of energy from a black hole might look like for terrestrial observers. We are trying to establish what signal we should look for, ” astrophysicist Luca Komisso said.

Over the past 50 years, scientists have formulated four ways to get energy from a black hole. The most famous is a 1969 study by the physicist Roger Penrose, who won the Nobel Prize in 2020.

His theory says that matter should be placed in the ergosphere – a chaotic space-time located beyond the event horizon of a black hole. The substance will fall into two parts. One will be absorbed by the black hole, and the second will “bounce” back. According to calculations, as a result of this process, more energy can be obtained than was originally invested.

Penrose considered only one particle, which splits in two. Recent studies are looking at astronomical plasma that occurs in an accretion disk around a black hole. Since plasma has a huge number of particles, it can provide a huge amount of energy.

The authors of the new study noted that they plan to study all available theories about obtaining energy from black holes. They intend to determine which one is more effective.

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In 200 light years from us, six planets emit an amazing “melody”

In 200 light years from us, six planets emit an amazing "melody" 100

Astronomers have discovered a system of six exoplanets orbiting a star with a specific orbital resonance.

The star system known as TOI-178 is located about 200 light years from us and includes six planets, five of which form a resonant chain, that is, they revolve around the central star in a strictly specified rhythm, and their densities, on the contrary, do not follow the regularity we are used to, according to Forbes.

In the video, the melody plays when the planet passes either full orbit or half of it, and when they line up at these points, they begin to play in resonance. TOI-178 is a really strange star system. Its innermost planet orbits in two days, while the slowest in 20. 

A similar orbital resonance is observed, for example, in the satellites of Jupiter: Io, Europa and Ganymede. While the farthest, Ganymede makes one complete revolution, Europa makes two, and the closest to Jupiter Io – four. This means that they play the same melody in different octaves. 

However, the planets orbiting the TOI-178 star are in a much more complex resonance circuit, obeying the 18: 9: 6: 4: 3 rule. This is the longest resonant pattern known among planetary systems.

Only after the discovery of a kind of “melody” of the TOI-178 star system, astronomers discovered the sixth planet. They used resonance rhythm to calculate where the additional planet would be in its orbit. 

An amazing “rhythm dance” was discovered with the Very Large Telescope (VLT) of the European Southern Observatory (ESO) in Chile. However, this is not just an orbital curiosity. 

“The orbits in this system are very strictly ordered. This tells us that since its formation, it has developed extremely smoothly and calmly,” – Yann Alibert explained, co-author of the study at the University of Bern. 

But even if the arrangement of the orbits in the system is so delicately ordered, everything is much worse with the densities of the planets.

“Here we see that a planet as dense as the Earth is located in the neighborhood of a“ bloated ”one, which has a density half that of Neptune. And after it comes a planet with a density like Neptune. not what we’re used to,” Nathan Hara notes, another study author at the University of Geneva.

However, in addition to the fact that astronomers talk a lot about how TOI-178 was formed, they hope that further study of it will provide important clues about how planets form and evolve in planetary systems.

“This contrast between the rhythmic harmony of orbital motions and the disordered densities of planets completely contradicts our understanding of the formation and development of planetary systems,” Adrien Leleu added, an astrophysicist at the University of Bern in Switzerland who led the study. 

map, constellation Sculptor
This map shows the location of the planetary system TOI-178 in the constellation Sculptor. The map includes most of the stars visible to the naked eye under good conditions, and the location of the system is indicated by a red circle.[ – ]+Photo: ESO, IAU AND SKY & TELESCOPE

The article even argues that resonances and density variations found in the TOI-178 star system could make it the “Rosetta Stone” in understanding the formation and evolution of planets. 

If researchers manage to find planets in the “habitable zone” of a star, where liquid water can exist on their surface, this will be an important and turning point for science. 

Scientists hope that by continuing the resonance chain and using ESO’s upcoming Extremely Large Telescope, they will be able to find more planets and capture them. 

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KOI-5Ab, the curious planet that orbits in a system of three suns

KOI-5Ab, the curious planet that orbits in a system of three suns 101
Photo: (Caltech / R. Hurt (IPAC))

To us, the Sun alone seems perfectly normal, but our solar system is actually a strange exception.

Most stars in the Milky Way galaxy have at least one companion star. In a system 1,800 light-years away, astronomers have finally confirmed the existence of a gas giant planet orbiting stars in a triple star system.

Called KOI-5, the system is located in the constellation Cygnus, and the exoplanet was confirmed ten years after it was first detected by the Kepler space telescope.

In fact, the planet – now known as KOI-5Ab – was discovered by Kepler when it began operations back in 2009.

“KOI-5Ab was dropped because it was difficult and we had thousands of other candidates,” astronomer David Siardi of NASA’s Exoplanet Science Institute said.

“There were lighter dives than the KOI-5Ab, and every day we learned something new from Kepler, so the KOI-5 was almost forgotten.”

Exoplanet hunters tend to avoid the complexities of multi-star systems; of the more than 4,300 exoplanets confirmed to date, less than 10 percent are multi-star systems, although such systems dominate the galaxy. As a result, little is known about the properties of exoplanets in multi-star systems compared to those orbiting a lone star.

After Kepler’s discovery, Chardy and other astronomers used ground-based telescopes such as the Palomar Observatory, Keck Observatory, and the Gemini North Telescope to study the system. By 2014, they had identified two companion stars, KOI-5B and KOI-5C.

Scientists were able to establish that the planet KOI-5Ab, is a gas giant that is about half the mass of Saturn and 7 times the size of Earth, and is in a very close five-day orbit around KOI-5A. KOI-5A and KOI-5B, both of roughly the same mass as the Sun, form a relatively close binary system with an orbital period of about 30 years.

KOI-5Ab, the curious planet that orbits in a system of three suns 102

A third star, KOI-5C, orbits the binary system at a much greater distance, with a period of about 400 years – slightly longer than Pluto’s 248-year orbit.

“By studying this system in more detail, perhaps we can understand how planets are created in the universe.”

The discovery was announced at the 237th meeting of the American Astronomical Society.

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