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Astronomers find ‘most distant’ galaxy

An international team of astronomers has detected the most distant galaxy yet.

The galaxy is about 30 billion light-years away and is helping scientists shed light on the period that immediately followed the Big Bang.

It was found using the Hubble Space Telescope and its distance was then confirmed with the ground-based Keck Observatory in Hawaii.

The study is published in the journal Nature.

Because it takes light so long to travel from the outer edge of the Universe to us, the galaxy appears as it was 13.1 billion years ago (its distance from Earth of 30 billion light-years is because the Universe is expanding).

Lead researcher Steven Finkelstein, from the University of Texas at Austin, US, said: “This is the most distant galaxy we’ve confirmed. We are seeing this galaxy as it was 700 million years after the Big Bang.”

The far-off galaxy goes by the catchy name of z8_GND_5296.

Astronomers were able to measure how far it was from Earth by analysing its colour.

Because the Universe is expanding and everything is moving away from us, light waves are stretched. This makes objects look redder than they actually are.

Astronomers rate this apparent colour-change on a scale that is called redshift.

They found that this galaxy has a redshift of 7.51, beating the previous record-holder, which had a redshift of 7.21.

This makes it the most distant galaxy ever found.

Galaxy
z8_GND_5296 is churning out stars at a remarkable rate, say astronomers

The system is small: about 1-2% the mass of the Milky Way and is rich in heavier elements.

But it has a surprising feature: it is turning gas and dust into new stars at a remarkable rate, churning them out hundreds of times faster than our own galaxy can.

It is the second far-flung galaxy known that has been found to have a high star-production rate.

Prof Finkelstein said: “One very interesting way to learn about the Universe is to study these outliers and that tells us something about what sort of physical processes are dominating galaxy formation and galaxy evolution.

“What was great about this galaxy is not only is it so distant, it is also pretty exceptional.”

He added that in the coming years, astronomers are likely to discover even more distant galaxies when Nasa’s James Webb Space Telescope (JWST) is launched and other ground-based telescopes come online.

Commenting on the research, Dr Marek Kukula, Public Astronomer at the Royal Observatory Greenwich, told BBC News: “This, along with some other evidence, shows that there are already quite surprisingly evolved galaxies in the very early Universe .

“This high star-formation rate maybe is a clue as to why these galaxies can form so quickly.”

Prof Alfonso Aragon-Salamanca, from the University of Nottingham, added: “This is an important step forward, but we need to continue looking for more.

“The further away we go, the closer we will get to discovering the very first stars that ever formed in the Universe. The next generation of telescopes will make this possible.”

But Dr Stephen Serjeant from the Open University said: “Chasing ultra-high redshift galaxies is a very exciting but equally very difficult game, and many claims of extremely distant galaxies have since turned out to be more nearby interlopers.”

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Space

An inconceivably ancient cosmic object was discovered

An international group of astronomers from the United States, Germany, China and Chile reported the discovery of a largest quasar called Poniua’ena, which in Hawaiian means “an invisible rotating source of creation surrounded by radiance.”

The object is located at a distance of about 30 billion light years, which corresponds to the age of the Universe at 710 million years. A preprint of the article, which will be published in the Astrophysical Journal Letters, is available on the arxiv website.

The light from the quasar J1007 + 2115 flew 13 billion years, however, due to the accelerated expansion of the Universe, its redshift is z = 7.515, which corresponds to the actual distance to it, equal to 29.3 billion light years. Astronomers see the object as it was in the era of reionization, when the first stars appeared, ionizing hydrogen atoms with their light.

Poniua’ena contains a supermassive black hole whose mass reaches 1.5 billion solar masses, making the quasar the largest object in the early Universe. According to Jinyi Yang, lead author of the work from the University of Arizona, this is the earliest object of such a monstrous size known to scientists.

Its existence poses a problem for theoretical models of the formation of supermassive black holes, according to which, J1007 + 2115 simply would not have time to grow in 710 million years if it had originally arisen as a result of the collapse of the star.

Instead, astronomers believe, a hundred million years after the Big Bang, there was already a black hole with a mass of 10 thousand Suns, which was formed as a result of direct gravitational collapse of clouds of cold hydrogen gas.

Poniua’ena is currently the second oldest quasar found to date. In 2018, the quasar J1342 + 0928 was discovered, which is two million years older than J1007 + 2115, but at the same time half as massive.

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Space

Wormholes. To anywhere in the universe in a minute

Wormholes or tunnels in the fabric of spacetime are terribly unstable. As soon as at least one photon hits them, the wormhole closes instantly. A new study suggests that the secret to a stable wormhole is in their form.

Wormholes, if they exist, will allow us to travel from point A to some extremely distant point B without worrying about travel time. The transition would be incredibly fast. Real cheat code of the universe. See a star for millions of light years? You could reach it in just a few minutes if you had a wormhole leading to it. No wonder this is a very popular science fiction theme.

But wormholes are not just a figment of our imagination, created to carve out all the boring scenes of interstellar travel (and this is centuries and millennia). We learned about them through Einstein’s general theory of relativity: matter and energy bend and deform the fabric of space-time, the curvature of which tells matter how to move.

Therefore, when it comes to wormholes, you just need to ask yourself: is it possible to deform space-time so that it overlaps itself, forming a tunnel between two distant points? The answer was given in the 1970s – yes.

Wormholes are entirely possible and not forbidden by the general theory of relativity. But the wormholes are very unstable, because, in essence, they consist of two black holes in contact with each other and forming a tunnel. That is, we are talking about points of infinite density, surrounded by areas known as the event horizon – one-sided space barriers. If you cross the event horizon of a black hole, you will never go back.

To solve this problem, the entrance to the wormhole must be outside the event horizon. Thus, you can cross the wormhole without touching the barrier. But as soon as you enter a wormhole located between huge masses, the gravity of your presence will distort the wormhole tunnel, collapsing it. Slammed shut, the tunnel will leave two lonely black holes, separated by a space in which the remains of your body will hang.

But it turns out there is a way to place the entrance to the wormhole away from the event horizon and make the tunnel stable enough for you to get through it. For this, material with a negative mass is needed. This is an ordinary mass, but with a minus sign. And if you put together enough negative mass in one place, you could use it to keep the wormhole open.

As far as we know, a substance with a negative mass does not exist. In any case, there is no evidence that it exists. Moreover, if it were, it would violate many laws of the Universe, such as inertia and conservation of momentum. For example, if you kicked a ball with a negative mass, it would fly backward. If you place an object with a negative mass next to an object with a positive mass, they will not be attracted. On the contrary, objects will repel each other, instantly accelerating.

Since negative mass seems like a myth, it can be assumed that wormholes are unlikely to exist in the universe. But the idea of ​​wormholes is based on the mathematics of the general theory of relativity – our current understanding of how gravity works. More precisely, our current, incomplete understanding of how gravity works.

We know that the general theory of relativity does not describe all the gravitational interactions in the universe. She gives in to strong gravity with a small body size. For example, before the bowels of black holes. To solve this problem, we need to turn to the quantum theory of gravity, which would combine our understanding of the world of subatomic particles with our broader understanding of gravity. But every time scientists try to put it together, everything just falls apart.

However, we have some clues on how quantum gravity can work, and we can understand wormholes. It is possible that a new and improved understanding of gravity will show that we do not need negative mass matter at all, and that stable, passable wormholes are real. A couple of theoreticians from Tehran University in Iran have published a new study of wormholes.

They applied some methods that allowed them to understand how quantum mechanics can change the standard general picture of relativity. Scientists have found that passable wormholes can exist without a substance with negative mass, but only if the entrance does not represent an ideal sphere, but is slightly elongated.

The results are interesting, but there is one snag. These hypothetical passable wormholes are tiny. Very tiny. Wormholes will be only 30% longer than Planck’s length – 1.6 x 10 ^ 35 meters. The traveler should be the same size. Yes, in addition, this microscopic traveler should fly at almost the speed of light. Despite emerging problems, the study opens a small crack, so to speak, for a look at the existence of wormholes, which can be expanded in the course of further research.

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Space

Scientists believe that Europa’s underground ocean is habitable: The secrets that Jupiter’s satellite hides

K. Retherford/Southwest Research Institute

The dream of Mankind is the existence of celestial bodies that can host life, initially in our own solar system as the Earth is considered that in the near future will not be able to sustain the growing population.

Scientists claim that Europa, the satellite of the planet Jupiter, has the necessary conditions for the development of life and characterize the large ocean’s underground ocean as “potentially habitable”.

When we say life development we mean organisms that are based on the “function” of carbon biochemistry.

This theory has been developed for several years and Europa, along with the planet Mars, is considered to be the two celestial bodies to which humanity could “escape”.

It is worth adding that the delicate atmosphere of Europa consists mainly of … oxygen!

Of course, living conditions will not be the same as on Earth, but they are considered to be “tolerable” for a start.

According to scientific observations, this vast expanse of water may have been able to develop and support the growth of microbes in the past, perhaps even in the present period.

Europa, with an ocean hidden beneath a thick ice shell that surrounds its surface, has long been considered a possible habitat for extraterrestrial life in our solar system, along with other candidates such as Mars and Saturn’s moon, Egelados. A new study presented Wednesday at a geo-scientific conference underscores Europa’s potential to develop life, even at the microbial level.

“We believe that the ocean of Europa may have been habitable early on when it was formed, because our models show that the composition of the ocean may have been only slightly acidic, containing carbon dioxide and some sulfates,” Mohit Melwani Daswani said, the planetary scientist and head of the study of NASA’s Jet Propulsion Laboratory.

“The availability of liquid water is the first step towards sustainability. In addition, the exchange of chemicals between the ocean and the rocky interior may have been significant in the past, so the potential life may have been able to use chemical energy to survive, “  he added.

Daswani said the germs resemble some of the Earth’s bacteria that use carbon dioxide for energy and could have survived using ingredients available in Europa’s early oceans.

Europa is slightly smaller than the Earth’s moon. The ocean of Europa, with a possible depth of 65 to 160 km, may contain twice as much water as the Earth’s oceans!

The study assessed whether Europa was previously habitable and did not examine its current inhabitability, a question that researchers are investigating by examining all the data collected from space missions and observations from telescopes.

According to many, in order for Humanity to be able to diffuse into space (the so-called scattering), it needs to create bases in its own solar system.

Most likely, terrafoming (geoengineering) methods will be used to completely change any “compatible” celestial bodies. A process that can take centuries.

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