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The Chinese lunar rover finds a strange substance in the moon’s hidden face

The Yutu-2 Chinese lunar rover of the Chinese mission Change 4, which carries out a study of the hidden face of the Moon, found a substance “that looks like gel” and is distinguished from other materials observed on the surface of the natural satellite of the earth.

Chinese lunar rover

Crater where the strange substance was found.

According to the “navigation diary” of Yutu-2, on August 17 a project specialist examined images taken by the camera of the rover’s and observed a strange substance in a crater. Then, the scientists decided to postpone the operations that the device had to carry out before entering hibernation during the eighth lunar day of the mission and ordered him to analyze not only the discovery itself, but the territory near the crater in question.

The rover examined the area with its near and visible infrared spectrometer (VNIS), which detects the light scattered or reflected by the materials to reveal its nature.

Chinese lunar rover

The rover going to investigate the crater with the substance.

So far, mission scientists have not given an explanation about the mysterious substance, just saying that its constitution resembles that of a “gel” and has an “unusual color” that highlights it from its surroundings. Some researchers have suggested that it could be melted glass created from the impact of one or more meteorites on the lunar surface.

However, and looking for precedents of something similar, it can be concluded that the recent discovery of Yutu-2 is not the first surprise of this kind. Harrison Schmitt, astronaut and geologist of the Apollo 17 mission, found an orange substance on the surface near the landing site in 1972 (Taurus-Littrow). The lunar geologists eventually concluded that it was a soil created during a volcanic explosion in the satellite about 3.6 billion years ago.

Orange soil discovered by the Apollo 17 mission.

The ‘gel’ was said to stand out because it was different in shape, colour and texture to the rest of the crater.

Yutu-2, also referred to as the Jade Rabbit 2, examined the crater with its Visible and Near-Infrared Spectrometer (VNIS).

This technology is able to determine the chemical composition of a substance by analysing the light that reflects from its surfaces.

It won’t be able to tell for sure if the substance is a squishy gel or hardened molten though so further analysis is still needed.

Yutu-2 is still exploring the dark side of the Moon for new discoveries.

China’s Chang’e-4 probe landed on the moon Credit: Alamy Live News

It was released on the Moon back in January when China’s Chang’e 4 lander reached the “dark side” of the lunar surface.

It is popularly called the “dark side” because it can’t be seen from Earth and is relatively unknown, not because it lacks sunlight.

In other news, a bonkers lift from Earth to the Moon has been proposed by scientists in a mad bid to cut the cost of space travel.

Nasa’s chief wants Pluto to be classified as a planet again.

And, an Earth-sized rocky planet has been found orbiting a nearby star – and there is a chance it could be habitable.

Will it be the same in the main case of this news or will it be something else?

Source: Space.com

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Visiting interstellar comet is caught on camera

Image Credit: Gemini Observatory / NSF / AURA

A two-color composite image of the visiting comet. 

Astronomers have revealed that comet 2I/Borisov is remarkably similar to comets from our own solar system.

First observed on August 30th, the comet, which is the second confirmed interstellar visitor to our solar system, was announced last month by the Minor Planet Center (MPC) at Harvard University.

The first, an object known as ‘Oumuamua, was discovered back in 2017.

Perhaps the most remarkable thing about 2I/Borisov however is just how unremarkable it actually is.

“This is the first comet known to science that arrived from outside the solar system, and it is completely similar to those we see inside the solar system,” said astronomer Michal Drahus.

Its discovery suggests that there are several nearby solar systems very much like our own and that comets like those we find in our local neighborhood are not uncommon elsewhere in the universe.

Observations using the William Herschel Telescope on La Palma, Spain and the Gemini North telescope on Mauna Kea, Hawaii have shown that 2I/Borisov has a distinctive and familiar coma (a billowing cloud of gas and dust) as well as a short, fat tail.

Its nucleus is thought to be 2km wide .

“This appears to be a completely unremarkable comet on a very remarkable orbit,” said astronomer Colin Snodgrass from Edinburgh University.

“It’s very interesting that this interstellar comet looks like our own ones.”

“It implies that some of the formation processes we are trying to figure out with detailed observation of comets and asteroids, or space missions like Rosetta, are common between stars.”

Source: Guardian

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Study Reveals Six Galaxies Undergoing Sudden, Dramatic Transitions

Galaxies come in a wide variety of shapes, sizes and brightnesses, ranging from humdrum ordinary galaxies to luminous active galaxies. While an ordinary galaxy is visible mainly because of the light from its stars, an active galaxy shines brightest at its center, or nucleus, where a supermassive black hole emits a steady blast of bright light as it voraciously consumes nearby gas and dust.

Sitting somewhere on the spectrum between ordinary and active galaxies is another class, known as low-ionization nuclear emission-line region (LINER) galaxies. While LINERs are relatively common, accounting for roughly one-third of all nearby galaxies, astronomers have fiercely debated the main source of light emission from LINERs. Some argue that weakly active galactic nuclei are responsible, while others maintain that star-forming regions outside the galactic nucleus produce the most light.

A team of astronomers observed six mild-mannered LINER galaxies suddenly and surprisingly transforming into ravenous quasars–home to the brightest of all active galactic nuclei. The team reported their observations, which could help demystify the nature of both LINERs and quasars while answering some burning questions about galactic evolution, in the Astrophysical Journal on September 18, 2019. Based on their analysis, the researchers suggest they have discovered an entirely new type of black hole activity at the centers of these six LINER galaxies.

“For one of the six objects, we first thought we had observed a tidal disruption event, which happens when a star passes too close to a supermassive black hole and gets shredded,” said Sara Frederick, a graduate student in the University of Maryland Department of Astronomy and the lead author of the research paper. “But we later found it was a previously dormant black hole undergoing a transition that astronomers call a ‘changing look,’ resulting in a bright quasar. Observing six of these transitions, all in relatively quiet LINER galaxies, suggests that we’ve identified a totally new class of active galactic nucleus.”

All six of the surprising transitions were observed during the first nine months of the Zwicky Transient Facility (ZTF), an automated sky survey project based at Caltech’s Palomar Observatory near San Diego, California, which began observations in March 2018. UMD is a partner in the ZTF effort, facilitated by the Joint Space-Science Institute (JSI), a partnership between UMD and NASA’s Goddard Space Flight Center.

Changing look transitions have been documented in other galaxies–most commonly in a class of active galaxies known as Seyfert galaxies. By definition, Seyfert galaxies all have a bright, active galactic nucleus, but Type 1 and Type 2 Seyfert galaxies differ in the amount of light they emit at specific wavelengths. According to Frederick, many astronomers suspect that the difference results from the angle at which astronomers view the galaxies.

Type 1 Seyfert galaxies are thought to face Earth head-on, giving an unobstructed view of their nuclei, while Type 2 Seyfert galaxies are tilted at an oblique angle, such that their nuclei are partially obscured by a donut-shaped ring of dense, dusty gas clouds. Thus, changing look transitions between these two classes present a puzzle for astronomers, since a galaxy’s orientation towards Earth is not expected to change.

Frederick and her colleagues’ new observations may call these assumptions into question.

© R. Buta (University of Alabama/Image enhancement: Jean-Baptiste Faur Spiral Seyfert Galaxy NGC 3081: Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable.

© R. Buta (University of Alabama/Image enhancement: Jean-Baptiste Faur
Spiral Seyfert Galaxy NGC 3081: Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable.

“We started out trying to understand changing look transformations in Seyfert galaxies. But instead, we found a whole new class of active galactic nucleus capable of transforming a wimpy galaxy to a luminous quasar,” said Suvi Gezari, an associate professor of astronomy at UMD, a co-director of JSI and a co-author of the research paper. “Theory suggests that a quasar should take thousands of years to turn on, but these observations suggest that it can happen very quickly. It tells us that the theory is all wrong. We thought that Seyfert transformation was the major puzzle. But now we have a bigger issue to solve.”

Frederick and her colleagues want to understand how a previously quiet galaxy with a calm nucleus can suddenly transition to a bright beacon of galactic radiation. To learn more, they performed follow-up observations on the objects with the Discovery Channel Telescope, which is operated by the Lowell Observatory in partnership with UMD, Boston University, the University of Toledo and Northern Arizona University. These observations helped to clarify aspects of the transitions, including how the rapidly transforming galactic nuclei interacted with their host galaxies.

“Our findings confirm that LINERs can, in fact, host active supermassive black holes at their centers,” Frederick said. “But these six transitions were so sudden and dramatic, it tells us that there is something altogether different going on in these galaxies. We want to know how such massive amounts of gas and dust can suddenly start falling into a black hole. Because we caught these transitions in the act, it opens up a lot of opportunities to compare what the nuclei looked like before and after the transformation.”

Unlike most quasars, which light up the surrounding clouds of gas and dust far beyond the galactic nucleus, the researchers found that only the gas and dust closest to the nucleus had been turned on. Frederick, Gezari and their collaborators suspect that this activity gradually spreads from the galactic nucleus–and may provide the opportunity to map the development of a newborn quasar.

“It’s surprising that any galaxy can change its look on human time scales. These changes are taking place much more quickly than we can explain with current quasar theory,” Frederick said. “It will take some work to understand what can disrupt a galaxy’s accretion structure and cause these changes on such short order. The forces at play must be very extreme and very dramatic.”

In addition to Frederick and Gezari, UMD-affiliated co-authors of the research paper include Adjunct Associate Professor of Astronomy Bradley Cenko, former Neil Gehrels Prize Postdoctoral Fellow Erin Kara and astronomy graduate student Charlotte Ward.

More information: Sara Frederick et al, A New Class of Changing-look LINERs, The Astrophysical Journal (2019). DOI: 10.3847/1538-4357/ab3a38

Eureka Alert
Headline Image: © (Left; infrared & visible light imagery): ESA/Hubble, NASA and S. Smartt (Queen’s University Belfast); (Right; artist’s concept): NASA/JPL-Caltech

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Giant black hole at centre of Milky Way exploded ‘recently’ – and blast was felt 200,000 light-years away

THE SUPERMASSIVE black hole at the centre of the Milky Way exploded 3.5million years ago, according to astronomers.

This is considered to be ‘astonishingly recent’ in galactic terms and is changing what scientists thought they knew about our galaxy.

This artist’s impression shows the huge bursts of radiation exploding from the centre of the Milky Way and reaching the Magellanic Stream

Professor Lisa Kewley, who worked on the study, said: “This is a dramatic event that happened a few million years ago in the Milky Way’s history.

“A massive blast of energy and radiation came right out of the galactic centre and into the surrounding material.

“This shows that the centre of the Milky Way is a much more dynamic place than we had previously thought. It is lucky we’re not residing there!”

The cataclysmic blast ripped through our galaxy and was likely felt 200,00 light years away in the Magellanic Stream.

The diameter of the Milky Way itself is thought to be up to 200,000 light years in size

It is considered to be a recent event because when it happened the dinosaurs had already been wiped out for 63million years and human ancestors were already walking on Earth.

This black hole blast phenomenon is known as a Seyfert flare.

The astronomers think it would have created two enormous ‘ionisation cones’ that would have sliced through the Milky Way.

They think it was caused by nuclear activity in the gigantic black hole, known as Sagittarius A.

It is estimated to have lasted for around 300,000 years, which is extremely short in galactic terms.

Co-author Magda Guglielmo from the University of Sydney said: “These results dramatically change our understanding of the Milky Way.

“We always thought about our Galaxy as an inactive galaxy, with a not so bright centre.

“These new results instead open the possibility of a complete reinterpretation of its evolution and nature.

“The flare event that occurred three million years ago was so powerful that it had consequences on the surrounding of our Galaxy.

“We are the witness to the awakening of the sleeping beauty.”

The research was led by by Professor Joss Bland-Hawthorn from Australia’s ARC Centre of Excellence for All Sky Astrophysics in 3 Dimensions (ASTRO 3D).

During the study, data was gathered by the Hubble Space Telescope and used to calculate when and how the explosion took place.

It will soon be published in The Astrophysical Journal.

What is a black hole? The key facts

Here’s what you need to know…

What is a black hole?

  • A black hole is a region of space where absolutely nothing can escape
  • That’s because they have extremely strong gravitational effects, which means once something goes into a black hole, it can’t come back out
  • They get their name because even light can’t escape once it’s been sucked in – which is why a black hole is completely dark

What is an event horizon?

  • There has to be a point at which you’re so close to a black hole you can’t escape
  • Otherwise literally everything in the universe would have been sucked into one
  • The point at which you can no longer escape from a black hole’s gravitational pull is called the event horizon
  • The event horizon varies between different black holes, depending on their mass and size

What is a singularity?

  • The gravitational singularity is the very centre of a black hole
  • It’s a one-dimensional point that contains an incredibly large mass in an infinitely small space
  • At the singularity, space-time curves infinitely and the gravitational pull is infinitely strong
  • Conventional laws of physics stop applying at this point

How are black holes created?

  • Most black holes are made when a supergiant star dies
  • This happens when stars run out of fuel – like hydrogen – to burn, causing the star to collapse
  • When this happens, gravity pulls the centre of the star inwards quickly, and collapses into a tiny ball
  • It expands and contracts until one final collapse, causing part of the star to collapse inward thanks to gravity, and the rest of the star to explode outwards
  • The remaining central ball is extremely dense, and if it’s especially dense, you get a black hole

Source newsamed.com

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