General Astronomy

[Suranis]

Photo from the far side of the Moon was captured by the Chinese Chang'e 5-T1 spacecraft in 2014.

Credit: Chinese Space Agency

Moon.jpg (14.3 KiB) Viewed 1174 times

[RTH10260]

The grave of all cryptocurrencies?

Supermassive black hole at heart of ancient galaxy ‘far larger than expected’
Discovery of GS-9209, one of the furthest from the Milky Way, adds to evidence that large black holes prevent star formation, astronomers say

Ian Sample Science editor
Fri 26 May 2023 18.11 BST

A supermassive black hole discovered at the heart of an ancient galaxy is five times larger than expected for the number of stars it contains, astronomers say.

Researchers spotted the immense black hole in a galaxy known as GS-9209 that lies 25bn light-years from Earth, making it one of the most distant to have been observed and recorded.

The team at Edinburgh University used the James Webb space telescope (JWST) to observe the galaxy and reveal fresh details about its composition and history.

Dr Adam Carnall, who led the effort, said the telescope – the most powerful ever built – showed how galaxies were growing “larger and earlier” than astronomers expected in the first billion years of the universe.

“This work gives us our first really detailed look at the properties of these early galaxies, charting in detail the history of GS-9209, which managed to form as many stars as our own Milky Way in just 800m years after the big bang,” he said.

Carnall said the “very massive black hole” at the centre of GS-9209 was a “big surprise” that lent weight to the theory that such enormous black holes are responsible for shutting down star formation in early galaxies.

“The evidence we see for the supermassive black hole was really unexpected,” said Carnall. “This is the kind of detail we’d never have been able to see without JWST.”

[RTH10260]

BUT... BUt... but... where is the planet that rains cats and dogs?

Planet where it rains sand revealed by Nasa telescope
Planet Wasp-107b also has scorching temperatures, raging winds and the burnt-matches scent of sulphur dioxide

Hannah Devlin Science correspondent
Wed 15 Nov 2023 17.22 CET

Nasa’s James Webb space telescope has revealed a planet where specks of sand fall as rain, in groundbreaking observations.

The planet, Wasp-107b, lies 200 light years away in the Virgo constellation and had already caught the attention of astronomers because it is very large but very light, earning it the nickname the “candy floss” planet. The latest observations give an unprecedented glimpse of a strange and exotic world beyond our solar system that features silicate sand clouds and rain, scorching temperatures, raging winds and the distinct burnt-matches scent of sulphur dioxide.

“Our knowledge of other planets is based on what we know from Earth,” said Prof Leen Decin, of the Catholic Institute (KU) Leuven and first author of the research. “That’s a very restricted knowledge.”

The planet was discovered in 2017 after astronomers spotted a telltale periodic flickering of light from its host star each time the planet passed in front of it. “It’s like a fly in front of a street lamp,” said Decin. “You see a slight dimming of the light.”

James Webb takes these observations to the next level by measuring starlight that is filtered through the planet’s atmosphere. Because different elements absorb different wavelengths of light, the spectrum of starlight indicates which gases are present.

Wasp-107b is similar in mass to Neptune but almost the size of Jupiter, and its vast, diffuse nature allows the James Webb telescope to peer deep into its atmosphere.

“It’s a great target because it’s really fluffy. It’s one of the fluffiest planets out there and they’re the ones we can get these big signals when we look at their atmosphere,” said Dr Joanna Barstow, a planetary scientist at Open University who is working on separate JWST measurements of the same planet. “We’ve been working on predictions for the past 10 years but nothing has quite prepared us for what we’re actually seeing – both what we’re finding out and the quality of the data. It’s been really exciting.”

The latest observations, published in Nature, reveal evidence of water vapour and sulphur dioxide, which would give the atmosphere a smell of burnt matches. It is also the first time the chemical composition of clouds on another planet has been identified – in this case, silicate sand.

The planet’s atmosphere would feature something akin to Earth’s water cycle, but instead with sand cycling between solid and gaseous states. From the hotter, lower levels of the atmosphere, with temperatures close to 1,000C, silicate vapour would rise up, cool and form microscopic grains of sand, too small to see. Eventually, these clouds of sand dust would become dense enough that they begin to rain back down to the lower layers of the atmosphere. Below a certain level, the sand would sublime back into vapour, completing the cycle.

“The clouds would be like a hazy dust,” said Decin. “And these sand particles are streaming around at extremely high velocity. A few kilometres per second.”



https://www.theguardian.com/science/202 ... -wasp-107b

[RTH10260]

James Webb Space Telescope Captured Spectacular Images

SEA OF COSMOS
28 Dec 2023

to be viewed on YT

https://youtu.be/qYFqLZiJFww

[AndyinPA]

Stunning!

[John Thomas8]

[AndyinPA]

https://www.space.com/nasa-voyager1-spa ... ion-glitch

It has been several months since one of humanity's most accomplished spacecraft, the Voyager 1 probe, stopped talking to us — and though they remain somewhat hopeful, Voyager mission scientists are preparing for the worst: A goodbye.

"Sad and frustrated to have the spacecraft still working, but muted," Bruce Waggoner, the Voyager mission assurance manager, told Space.com of the group's present morale. "Even though we know the end could come at any time, it's never easy to lose a spacecraft. Especially one like Voyager 1."

For more than 45 years, this boxy machine with a pearly white, conical disk that sort of makes it look like a giant loudspeaker in space has been sending back stunning data. And I mean stunning. Not only is it the first craft to enter interstellar space (and therefore the farthest human-made object ever), but it's also responsible for the identification of new Jovian moons, the discovery of yet another Saturnian ring and the solar system's first and only "family portrait" that includes our eclectic gang of planets.

Sad, but it has had a wonderful journey and shared a lot of it with us.

[Suranis]

Ya. They have been talking about doing a final shut down for almost 2 decades though. It might be time to just let the old girl go.

[RTH10260]

Munching on our background radiation

Astronomers discover universe’s brightest object – a quasar powered by a black hole that eats a sun a day
Light from the celestial object, which is 500tn times brighter than our sun, travelled for more than 12bn years to reach Earth

Tory Shepherd
Tue 20 Feb 2024 00.12 EST

The brightest known object in the universe, a quasar 500tn times brighter than our sun, was “hiding in plain sight”, researchers say.

Australian scientists spotted a quasar powered by the fastest growing black hole ever discovered. Its mass is about 17bn times that of our solar system’s sun, and it devours the equivalent of a sun a day.

The light from the celestial object travelled for more than 12bn years to reach Earth.

Australian National University scientists first spotted it using a 2.3-metre telescope at the university’s NSW Siding Spring Observatory in Coonabarabran. They then confirmed the find using the European Southern Observatory’s (ESO’s) Very Large Telescope, which has a primary mirror of 8 metres.

The findings by the ANU researchers, in collaboration with the ESO, the University of Melbourne, and France’s Sorbonne Université have been published in Nature Astronomy.

The lead author and ANU associate professor, Christian Wolf, said it was the most luminous known object in the universe, and that its incredible rate of growth meant a “huge release of light and heat” – and that he doubted its record would ever be beaten.

The light is emitted from an “accretion disc” that is seven light years in diameter. That disc is where material is getting dragged into and spiralling around the black hole, before it crosses the event horizon.

As that material smashes into other material it creates vast amounts of light and heat.

“It looks like a gigantic and magnetic storm cell with temperatures of 10,000 degrees Celsius, lightning everywhere and winds blowing so fast they would go around Earth in a second,” Wolf said.

“This storm cell is seven light years across, which is 50% more than the distance from our solar system to the next star in the galaxy, Alpha Centauri.”

Co-author, Dr Christopher Onken said it was surprising it had remained undetected for this long, and that it was “hiding in plain sight”.

Wolf said he had two distinct feelings about the discovery.



https://www.theguardian.com/science/202 ... -sun-a-day

[RTH10260]

Astronomers detect ‘waterworld with a boiling ocean’ in deep space
Exclusive: Significant discovery, made by James Webb telescope, provokes disagreement over conditions on planet’s surface

Hannah Devlin Science correspondent
Fri 8 Mar 2024 08.00 CET

Astronomers have observed a distant planet that could be entirely covered in a deep water ocean, in findings that advance the search for habitable conditions beyond Earth.

The observations, by Nasa’s James Webb space telescope (JWST), revealed water vapour and chemical signatures of methane and carbon dioxide in the atmosphere of the exoplanet, which is twice Earth’s radius and about 70 light years away. This chemical mix is consistent with a water world where the ocean would span the entire surface, and a hydrogen-rich atmosphere, according to researchers from the University of Cambridge, although they do not envisage a balmy, inviting seascape.

“The ocean could be upwards of 100 degrees [Celsius] or more,” said Prof Nikku Madhusudhan, who led the analysis. At high atmospheric pressure, an ocean this hot could still be liquid, “but it’s not clear if it would be habitable,” he added.

This interpretation is favoured in a paper published in the journal Astronomy and Astrophysics Letters, but is disputed by a Canadian team that made additional observations of the same exoplanet, which is known as TOI-270 d. They detected the same atmospheric chemicals but argue the planet would be too hot for liquid water – possibly 4,000C – and instead would feature a rocky surface topped by an incredibly dense atmosphere of hydrogen and water vapour.

Whichever view wins out, these latest observations showcase the stunning insights James Webb is giving into the nature of planets beyond our solar system. The telescope captures the starlight that has been filtered through the atmospheres of orbiting planets to give detailed breakdowns of the chemical elements present. From this, astronomers can build up a picture of conditions at a planet’s surface – and the likelihood of life being able to survive there.

The evidence for TOI-270 d’s ocean is based on the absence of ammonia, which basic chemistry predicts should occur naturally in a hydrogen-rich atmosphere. But ammonia is highly soluble in water and so would be depleted in the atmosphere if there were an ocean down below. “One interpretation is that this is a so-called ‘hycean’ world – with a water ocean under a hydrogen-rich atmosphere,” said Madhusudhan.

Conditions would be very different from those on Earth. TOI-270 d is tidally locked, meaning one side permanently faces its star and the other is bathed in eternal darkness, creating an extreme temperature contrast.



https://www.theguardian.com/science/202 ... deep-space