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ArabiaWeather – NASA announced a historic achievement using an advanced laser communications system, as a video was broadcast from space showing a cat called “Taters” from a distance of 19 million miles (31 million kilometers) from Earth. This achievement is considered an important step in communication technologies. Satellite, and represents one of the historical landmarks.

This success comes within a technical project by NASA that aims to broadcast high-resolution video clips and transmit other data from deep space, with the aim of enabling future human missions to be sent outside Earth’s orbit. Pam Milroy, NASA’s Deputy Administrator, said:

“This achievement reflects our commitment to developing optical communications as an essential component of meeting our future data transmission needs.”

Historic test video… “Taters” the space cat takes broadcasts from space

NASA has put together an amazing demonstration that continues 15 secondsWhere he was the hero Cat “Taters”which belongs to a JPL employee, was photographed “Taters” Satellite video clips were transmitted using advanced and unique technology. An aviation laser transmitter and receiver was used in this innovative display, and the video signal took 101 seconds Reaching Earth, where it was successfully decrypted, resulting in a successful video stream from deep space.

Laser communication technology is designed to achieve efficient data transmission from deep space, and successfully passed the testing phase with NASA’s Psyche mission on October 13. This technology provides data transmission rates greater than… 10 to 100 times Compared to modern radio frequency systems currently used in deep space missions.

Ryan Rogalin, project receiver electronics lead at JPL, noted that the process of receiving the video at Palomar and transmitting it to JPL over the Internet was successful, as the signal arrived from deep space at a speed faster than conventional signals.

Why cat video?

The historical connection is evident in this context, according to what was reported by the Jet Propulsion Laboratory. In light of the increasing interest of the United States in visual communication methods in the 1920s, broadcast “Statue of Felix the Cat” To be a demo that represents a test image.

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ArabiaWeather – In 2015, David Hall was excavating in Maryborough Provincial Park near Melbourne, Australia. Carrying out a metal detector, he discovered something unusual – a very heavy red rock resting in some yellow clay.

The Maryborough meteorite. (Museums Victoria)

He took it home and tried everything to open it, and confirmed that there was a nugget of gold inside the rock – after all, Maryborough Park is located in the Goldfields, where the Australian gold rush reached its peak in the 19th century.

To break down his find, Hall used a rock saw, an angle grinder, a drill, and even doused the object in acid. However, even a heavy hammer couldn’t create a crack. That’s because what he was trying so hard to open wasn’t a solid block of gold.

As he discovered years later, it was a rare meteorite.

Dermot Henry, a geologist at the Melbourne Museum, told the Sydney Morning Herald in 2019: “He had a chiseled, winked look.”

“This is formed when they pass through the atmosphere, melt outside, and are sculpted by the atmosphere.”

Hall was unable to open the “rock,” but remained fascinated, taking the nugget to the Melbourne Museum to identify it. “I’ve looked at a lot of rocks that people think are meteorites,” Henry told Channel 10 News. In fact, after 37 years of working at the museum and examining thousands of rocks, Henry said only two of the offerings turned out to be real meteorites.

This was one of the two.

The Maryborough meteorite, with a slab cut from the mass. (Melbourne Museum)

“If you saw a rock like this on the ground, and you picked it up, it shouldn’t be that heavy,” Bill Birch, a geologist at the Melbourne Museum, explained to the Sydney Morning Herald. The researchers published a scientific paper describing the 4.6 billion-year-old meteorite, which they named Maryborough after the town near where it was found.

It weighs 17 kilograms (37.5 pounds), and after using a diamond saw to cut a small slice, researchers discovered that its composition contains a high percentage of iron, making it an ordinary H5 chondrite.

Once opened, you can also see tiny crystalline droplets of metallic minerals throughout it, called chondrules.

“Meteorites provide the cheapest form of space exploration,” Henry said. “They transport us back in time, providing clues about the age, composition and chemistry of our solar system (including Earth).” Some of them offer a glimpse into the deep interior of our planet. In some meteorites, there is “stardust” older than our solar system, which shows us how stars form and evolve to form the elements of the periodic table.

“Other rare meteorites contain organic molecules such as amino acids, which are the building blocks of life.”

A slab cut from the Maryborough meteorite. (Birch et al., PRSV, 2019)

Although researchers don’t yet know where the meteorite came from or how long it spent on Earth, they do have some guesses.

Our solar system was a pile of dust and chondrite rocks. Eventually gravity pulled much of this material together to form planets, but the remains mostly ended up in a massive asteroid belt.

Henry said: “This particular meteorite most likely comes out of the asteroid belt between Mars and Jupiter, and it was pushed out of there due to some asteroids colliding with each other, and then one day it collided with Earth.”

Carbon dating suggests that the meteorite was on Earth between 100 and 1,000 years ago, and there were a number of sightings of the meteorite between 1889 and 1951 that could correspond to its arrival on our planet.

Researchers believe that the Maryborough meteorite is much rarer than gold, which makes it more valuable to science. It is one of only 17 meteorites ever recorded in the Australian state of Victoria, and is the second largest chondrite mass, after a massive 55-kilogram specimen identified in 2003.

“This is only the 17th meteorite found in Victoria, while thousands of gold nuggets have been found,” Henry said.

“Given the chain of events, it is arguably astronomical that it was discovered at all.” It’s not even the first meteorite that takes a few years to reach the museum.

In a particularly astonishing story covered by ScienceAlert in 2018, a space rock took 80 years, two owners, and a stint as a doorstop before it was finally revealed for what it is. Now might be as good a time as any to check your backyard for rocks. Heavy and hard to break – you may be sitting on a metaphorical goldmine.

Source: sciencealert

Arabia Weather – It’s hard to imagine, but the Sahara Desert was a green forest a few thousand years ago.

The desert turns into fertile land every 21 thousand years

It may seem as if the sand dunes and rocky plateaus of the Sahara are as old as time, but that could be far from the truth. As a new study shows, this vast strip of North Africa turns from barren desert to lush green forests every 21,000 years or so.

The last period when the Sahara was a green forest occurred between 15,000 and 5,000 years ago. This latest research confirms that this was not just a curious blob, but part of a cyclical transition that changed the region from arid to wet about every 21,000 years.

Dr. Edward Armstrong, the study’s lead author and a climate scientist at the University of Helsinki and the University of Bristol, said in a report: “The cyclical transformation of the Sahara into different ecosystems and forests is one of the most notable environmental changes on the planet.”

“Our study is one of the first climate modeling studies that simulates African wet periods at a similar magnitude to what paleoclimate observations indicate, and reveals why and when these events occur.”

The new research looks to better understand what is called “Wet periods in North Africa” over the past 800,000 years using a recently developed climate model.

Their work confirmed the idea that periodic wet phases in the Sahara were driven by changes in the Earth’s orbit around the sun. It is generally agreed that “Greening“The Sahara Desert is due to the Earth’s oscillation on its axis, which affects seasonality and determines the amount of energy that part of the planet receives. This ultimately affects the strength of the African monsoon, which helps control the amount of vegetation spread across this vast region.

However, their work also suggests that this cycle may be influenced by distant ice sheets at high latitudes in the Northern Hemisphere. Wet periods did not occur during ice ages when most of the Earth’s high latitudes were covered by thick ice sheets.

Experts speculate that these ice sheets helped cool the atmosphere like a refrigerator, limiting the African monsoon system and suppressing the growth of plant life in the Sahara.

The cyclical shift in North Africa is not only a big problem for the Sahara, but it also has huge implications for our story. After all, some of humanity’s greatest early achievements – migrations out of Africa – were largely dictated by the condition of the Sahara. Depending on his “mood”, it can serve as a harsh obstacle or a welcoming path.

The gate was open when the desert was green, and it was closed when deserts prevailed

Mika Talavara, co-author and assistant professor of hominin ecology at the University of Helsinki, explained: “The Sahara region serves as a gateway that controls the spread of species between North and Sub-Saharan Africa, and within and beyond the continent.”

The gate was open when the desert was green, and it was closed when deserts prevailed. This alternation between wet and arid phases has had serious consequences for the dispersal and evolution of species in Africa. Being able to model wet periods in North Africa is a major achievement and means we are now better able to model human distributions and understand the evolution of our species in Africa.

Source: iflscience

nature

Arabia Weather – Strange things happen inside planets, where familiar materials are exposed to intense pressure and heat. It is possible that vibrational movements of iron atoms will occur within the solid inner core of the Earth, and it is also possible for the formation of heavy, hot black ice, which is both solid and liquid at the same time, inside Uranus and Neptune, the two giant gas planets rich in water.

Five years ago, scientists recreated this strange ice, called superionic ice, for the first time in laboratory experiments; Four years ago, they confirmed its existence and crystal structure. Then just last year, researchers at several US universities and the Stanford Linear Accelerator Center Laboratory in California (SLAC) discovered a new phase of super-ionized ice.

Their discovery deepens our understanding of why Uranus and Neptune have irregular magnetic fields with multiple poles.

From our terrestrial surroundings, you would be forgiven for thinking that water is a simple molecule consisting of a single oxygen atom bonded to two hydrogen atoms that settle into a fixed position when the water freezes. But highly ionized ice is strangely different, yet it may be among the most abundant forms of water in the universe, supposedly filling not only the interiors of Uranus and Neptune, but also similar exoplanets.

A strange type of ice except at very high temperatures

These planets have extreme pressures two million times Earth’s atmospheric pressure, and their interiors are as hot as the surface of the Sun, which is where water becomes alien.

In 2019, scientists confirmed the predictions of physicists who worked in 1988, discovering that highly ionized ice consists of a skeletal structure containing a rigid cubic lattice that traps oxygen atoms, while ionized hydrogen atoms are released and flow through that lattice in a manner similar to the flow of electrons through metals. . This highly ionized structure gives the ice its electrically conductive properties and keeps its melting point low, maintaining a frozen state even at extreme temperatures.

This gives highly ionized ice its conductive properties. It also raises its melting point so that frozen water remains solid at extreme temperatures. In this latest study, physicist Ariana Gleason of Stanford University and her colleagues bombarded thin strips of water, sandwiched between two layers of diamond, with some ridiculously powerful lasers.

Successive shock waves raised pressures to 200 gigapascals (2 million atmospheres) and temperatures of about 5,000 K (8,500 degrees Fahrenheit) — hotter than the temperatures of the 2019 experiments, but at lower pressures.

Researcher Gleason and her team explained in their paper, which they published in January 2022: “Understanding water-rich exoplanets similar to Neptune requires careful analysis of the state of water under conditions of pressure and temperature associated with the internal composition of each planet.”

X-ray diffraction then revealed the crystalline structure of the hot, dense ice, where pressure and temperature conditions were maintained for a short period of about a fraction of a second.

The resulting diffraction patterns also confirmed that the ice crystals were in fact a new phase distinct from the superionized ice observed in 2019. The newly discovered superionized ice, Ice XIX, has a body-centered cubic structure and increased conductivity compared to its predecessor from 2019, Ice XVIII. . .

Electrical conductivity is important here because moving charged particles generate magnetic fields. This is the basis of dynamo theory, which describes how conductive fluids, such as the Earth’s mantle or the interior of another celestial body, give rise to magnetic fields. If more of the interior of a Neptune-like ice giant were sucked in by a soft solid, and less by a rotating liquid, that would change the type of magnetic field produced. If the planet has two superionic layers with different conductivities, as Gleason and his colleagues suggest, the magnetic field generated by the outer liquid layer would interact with each of them differently, making things even stranger.

Here, Gleeson and his colleagues conclude that the enhanced electrical conductivity of a layer of superionized ice similar to Ice

If so, it would be a satisfying result more than 30 years after NASA’s Voyager 2 space probe, launched in 1977, flew by the two ice giants in our solar system and measured their unusual magnetic fields.

Source: sciencealert

Arabia weather – when it arrives winter seasonMany people wonder about the secret of the extreme cold that surrounds us, and how the sun can appear in the winter sky and remain cold, while it comes in the summer with its warm and bright rays.

The secret of this natural phenomenon lies in a very precise mystery, linked to the movement of the Earth around the sun, which constitutes an integral part of the balance of the universe. In this article, we will explore the secret of this distinctive phenomenon, and reveal how the Earth’s tilt and its different positions during the winter affect degrees. Sunlight heat.

The temperature of the sun remains constant throughout the year, as it is a ball of fire interspersed with nuclear reactions, which makes its surface always hot. The high temperature of the sun causes the release of huge amounts of radiation in all directions and because of the sun’s release of light rays in the visible spectrum, it also includes infrared rays. Infrared and ultraviolet radiation travels through the solar system, and because of the way the momentum of light waves carries energy, it heats anything it comes into contact with.

If the sun’s temperature is constant throughout the year, how can the cold weather in winter be explained? (especially in the northern hemisphere)? This can be explained by understanding the composition and position of the Earth itself rather than any direct influence of the Sun.

Why is the sun cold in winter?

Answer: The Earth is characterized by colder regions in winter; Because of the tilt resulting from its axis, this tilt means that sunlight spreads over a larger area in winter (in cold areas)The more light spreads, the colder it gets in those areas, and the farther the Earth is from the sun in winter thanks to its tilt, but since this difference in distance is not obviously large, the Earth’s tilt remains the main factor in changing the climate in winter.

If we draw the Earth’s orbit around the sun during the year, we will find that it appears completely circular. However, a change occurs when the Earth goes through summer in the Northern Hemisphere, and despite the small change in distance (in terms of space distances)However, the naked eye cannot notice these changes.

The slope we’re talking about is a slope 23 degrees For a straight line, the axis, the line that extends from the North Pole to the South Pole, is inclined by an amount 23 degrees Far from the Earth’s orbit around the Sun, winter in the Northern Hemisphere is therefore tilted away from the Sun.

It is considered a phrase “Low winter sun” Resulting from this tilt, the sun appears in the sky in winter in the Northern Hemisphere. Because of this tilt, winter sunlight spreads more across the same area of ​​the hemisphere, which contributes to a feeling of coldness due to less spread of light energy and warmth.

The Earth’s tilt plays an important role, as it makes the Northern Hemisphere farther from the sun during the winter. Although this effect is small at distance, the Earth’s tilt remains the main factor in changing the climate in the winter.

This indicates that the differences are more pronounced in the North and South Poles, where the Sun appears less in the sky in winter at the North Pole and more at the South Pole. This results in areas of the Earth at the equator being less affected by the Earth’s tilt, and the Sun is seen at a similar amount whether In summer or winter.

So, the difference that occurs in the winter in the Northern Hemisphere only appears, while the cold weather in the winter in the Southern Hemisphere depends on the distance from the ends of the Earth and its proximity to the equator.

Effect of the Earth’s axis tilt

The Earth’s axis of rotation is tilted about 23 degrees With respect to its orbit around the sun. This leads to the northern hemisphere tilting towards the sun in the summer; The solar light is therefore more uniform and straight.

While in winter, the Northern Hemisphere is tilted away from the Sun, making the Sun appear at a low angle in the sky. This change in the angle of solar radiation causes the light to be smeared across a larger area on the Earth’s surface, reducing the amount of energy received and causing cold winters.

The phenomenon is repeated in the southern hemisphere, where they have summer when it is winter in the north, and vice versa. The temperature depends greatly on the angle of the sun’s radiation, and in areas near the poles, the sun always appears at a low angle, which leads to permanent coldness. Conversely, The sun appears at a high angle near the equator, which leads to generally higher temperatures.

In this way, the Earth’s tilt affects the angle of the sun and the amount of direct light received, forming the basis for climate variations and seasons around the world.

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