Astronomical News

Comfortably Numb

Antediluvian
Joined
Aug 7, 2018
Messages
6,413
Reaction score
10,042
Points
279
Location
Phone
The case of the missing dark matter: new suspect found in galactic mystery

Source: phys.org
Date: 27 November, 2020

A faraway galaxy with almost no dark matter has threatened to break our theory of galaxy formation. New evidence suggests the galaxy isn't an anomaly—but a victim of theft.

Dark matter—an invisible substance as enigmatic as its name suggests—is a key ingredient in helping galaxies form and stay alive.

It creates the strong gravity needed to spark galaxy formation and keep existing galaxies structurally intact.

But astronomers have been puzzled since last year's discovery of 'NGC1052-DF4', a stable and long-lived galaxy with almost no dark matter. How can the galaxy exist without this important ingredient? Are our theories about galaxy formation wrong?

Today, an international study led by UNSW Sydney suggests the dark matter was there to begin with—it's just been stolen by a greedy neighbour.

"The dark matter isn't there because it's already been removed," says Dr. Mireia Montes, lead author of the study and astronomical researcher at UNSW Science and the Space Telescope Science Institute.

"We found that the gravitational pull from the nearby massive galaxy NGC1035 is removing its stars—and dark matter."

The research, published today in The Astrophysical Journal, provides an explanation for why so much dark matter is missing from the galaxy without contradicting our existing understanding of galaxy formation.

https://phys.org/news/2020-11-case-dark-galactic-mystery.html
 

Comfortably Numb

Antediluvian
Joined
Aug 7, 2018
Messages
6,413
Reaction score
10,042
Points
279
Location
Phone
Our Solar System Is Going to Totally Disintegrate Sooner Than We Thought

Source: sciencealert.com
Date: 29 November, 2020

Although the ground beneath our feet feels solid and reassuring (most of the time), nothing in this Universe lasts forever.

One day, our Sun will die, ejecting a large proportion of its mass before its core shrinks down into a white dwarf, gradually leaking heat until it's nothing more than a cold, dark, dead lump of rock, a thousand trillion years later.

But the rest of the Solar System will be long gone by then. According to new simulations, it will take just 100 billion years for any remaining planets to skedaddle off across the galaxy, leaving the dying Sun far behind.

Astronomers and physicists have been trying to puzzle out the ultimate fate of the Solar System for at least hundreds of years.

"Understanding the long-term dynamical stability of the solar system constitutes one of the oldest pursuits of astrophysics, tracing back to Newton himself, who speculated that mutual interactions between planets would eventually drive the system unstable," wrote astronomers Jon Zink of the University of California, Los Angeles, Konstantin Batygin of Caltech and Fred Adams of the University of Michigan in their new paper.

[...]

https://www.sciencealert.com/our-so...o-totally-disintegrate-sooner-than-we-thought
 

charliebrown

Junior Acolyte
Joined
Nov 2, 2020
Messages
84
Reaction score
60
Points
18
Location
Earth
OK, this is not my field, but when scientists claim that dark matter makes up 95% of our universe how can that be?

Dark matter has never been seen, or proven, or measured, so I think this is “ fake news “ .

I personally think the universe is a living entity.
 

Comfortably Numb

Antediluvian
Joined
Aug 7, 2018
Messages
6,413
Reaction score
10,042
Points
279
Location
Phone
Astronomers Just Mapped 1 Million Previously Unknown Galaxies, And You Can Take a Tour

Source: sciencealert.com

AIDAN HOTAN, THE CONVERSATION
1 DECEMBER 2020

Astronomers have mapped about a million previously undiscovered galaxies beyond the Milky Way, in the most detailed survey of the southern sky ever carried out using radio waves.

The Rapid ASKAP Continuum Survey (or RACS) has placed the CSIRO's Australian SKA Pathfinder radio telescope (ASKAP) firmly on the international astronomy map.

While past surveys have taken years to complete, ASKAP's RACS survey was conducted in less than two weeks - smashing previous records for speed. Data gathered have produced images five times more sensitive and twice as detailed as previous ones.

Modern astronomy is a multi-wavelength enterprise. What do we mean by this?

Well, most objects in the Universe (including humans) emit radiation over a broad spectrum, called the electromagnetic spectrum. This includes both visible and invisible light such as X-rays, ultraviolet light, infrared light and radio waves.

To understand the Universe, we need to observe the entire electromagnetic spectrum as each wavelength carries different information.

Radio waves have the longest wavelength of all forms of light. They allow us to study some of the most extreme environments in the Universe, from cold clouds of gas to supermassive black holes.

Long wavelengths pass through clouds, dust and the atmosphere with ease, but need to be received with large antennas. Australia's wide open (but relatively low-altitude) spaces are the perfect place to build large radio telescopes.

We have some of the most spectacular views of the centre of the Milky Way from our position in the Southern Hemisphere. Indigenous astronomers have appreciated this benefit for millennia.

Radio astronomy is a relatively new field of research, dating back to the 1930s.

The first detailed 30cm radio map of the southern sky - which includes everything a telescope can see from its location in the Southern Hemisphere - was Sydney University's Molonglo Sky Survey. Completed in 2006, this survey took almost a decade to observe 25 percent of the entire sky and produce final data products.

Our team at CSIRO's Astronomy and Space Science division has smashed this record by surveying 83 percent of the sky in just ten days.

[...]

https://www.sciencealert.com/take-a-virtual-tour-of-a-million-previously-undiscovered-galaxies
 

Comfortably Numb

Antediluvian
Joined
Aug 7, 2018
Messages
6,413
Reaction score
10,042
Points
279
Location
Phone

maximus otter

Recovering policeman
Joined
Aug 9, 2001
Messages
7,185
Reaction score
14,446
Points
309
A Mysterious Object Is Hurtling Towards Earth, and Scientists Don't Know What It Is

A mysterious object will fly past the Earth tomorrow and scientists still aren't quite sure what it is.

The object, dubbed 2020 SO by astronomers, will come within "just" 31,605 miles of our planet at 3:50 a.m. ET on December 1, according to NASA's Center for Near Earth Object Studies

The object, which is estimated to measure between 15-33 feet across, was discovered by the Pan-STARRS survey based in Maui, Hawaii, on September 17, 2020. This find was confirmed two days later by the Minor Planet Center, which is responsible for the designation of minor bodies in the solar system.

Initial observations suggested that the object was an asteroid. But scientists at CNEOS soon began to suspect that 2020 SO was not a normal asteroid.

"We are not sure it is an asteroid—that is, a natural body," Masi wrote on the Virtual Telescope Project website.

CNEOS director Paul Chodas subsequently suggested that 2020 SO may not be an asteroid at all, tentatively identifying it as the Centaur rocket booster from NASA's failed Surveyor 2 lunar mission, which launched on September 20, 1966.



He came to this conclusion after turning back the clock and running the object's orbit backwards using a computer model to work out its past trajectory through space.

Chodas found that the object had already passed relatively close to Earth several times over the past decades, including one moment that indicated it could have actually launched from Earth, according to NASA.

"One of the possible paths for 2020 SO brought the object very close to Earth and the Moon in late September 1966," Chodas said in a statement. "It was like a eureka moment when a quick check of launch dates for lunar missions showed a match with the Surveyor 2 mission."

The object's low relative velocity and orbital plane also supported the argument that the object was potentially not of natural origin.

2020 SO was captured by Earth's gravity on November 8, and calculations show it will remain in orbit around our planet as a temporary satellite until March 2021 before it escapes back into a new orbit around the sun.

https://www.newsweek.com/mysterious-object-earth-nasa-asteroid-1551202

maximus otter
 

Comfortably Numb

Antediluvian
Joined
Aug 7, 2018
Messages
6,413
Reaction score
10,042
Points
279
Location
Phone
Not since 1623 Jupiter and Saturn will be next to each other on December 21st, the first day of winter.

Is this a good sign or a bad sign?
It's most certainly a sign of the times and some detail in the following article.

We're About to Witness a Super-Rare Planetary Alignment Not Seen in 800 Years

Source: sciencealert.com
Dare: 1 December, 2020

Star-gazers are in for a treat over Christmas, as Jupiter and Saturn will get closer to each other in Earth's night sky than they have been for nearly 800 years. Set up your telescope, hope for a clear night, and get ready.

The celestial synchronisation has been in the works since summer as Jupiter and Saturn have been moving closer together in the night sky, and between 16-25 December they'll be separated by only 1/5th the diameter of a full moon.

While the planets won't physically be close to each other at all, of course, they'll look like a single point of bright light to anyone looking up at the night sky.

"Alignments between these two planets are rather rare, occurring once every 20 years or so, but this conjunction is exceptionally rare because of how close the planets will appear to one another," says astronomer Patrick Hartigan from Rice University.

[...]

https://www.sciencealert.com/the-pl...k-for-a-rare-spectacle-not-seen-in-800-years/
 

Comfortably Numb

Antediluvian
Joined
Aug 7, 2018
Messages
6,413
Reaction score
10,042
Points
279
Location
Phone
Well this is intriguing and certainly a somewhat oblique facet of astronomy.

Perhaps more deserving in another thread, or indeed one of its own!?

An Astronomer Has Searched The Universe For a Potential Message From Its Creator

Source: sciencealert.com
Date: 2 December, 2020

The Universe is a mysterious place. We don't know why it exists, and there are a lot of unanswered questions as to the how. But what if it was created, on purpose, by an intelligent entity? Is there some way we could find out?

In 2005, a pair of physicists proposed that if there was a Creator, they could have encoded a message in the background radiation of the Universe, left over from when light was first unleashed to flow freely through space. This light is called the cosmic microwave background (CMB).

Now, astrophysicist Michael Hippke of Sonneberg Observatory in Germany and Breakthrough Listen has gone looking for this message, translating temperature variations in the CMB into a binary bitstream.

What he recovered appears to be utterly meaningless.

Hippke's paper describing his methods and findings has been uploaded to pre-print server arXiv, (and is thus yet to be peer-reviewed); the work includes the extracted bitstream so other interested parties can study it for themselves.

The cosmic microwave background is an incredibly useful relic of the early Universe. It dates back to around 380,000 years after the Big Bang. Prior to this, the Universe was completely dark and opaque, so hot and dense that atoms couldn't form; protons and electrons were flying around in the form of ionised plasma.

As the Universe cooled and expanded, those protons and electrons could combine to form neutral hydrogen atoms in what we call the epoch of recombination. Space became clear, and light could move freely through it for the first time.

This first light is still detectable today, albeit very faintly, suffusing all known space. That's the CMB. Since the early Universe was not uniform, density variations at the epoch of recombination manifest today in very slight fluctuations in the temperature of the CMB.

Because of this ubiquity, theoretical physicists Stephen Hsu of the University of Oregon and Anthony Zee of the University of California, Santa Barbara argued - entirely theoretically - that the CMB would make the perfect billboard on which to leave a message that would be visible to all technological civilisations in the Universe.

"Our work does not support the Intelligent Design movement in any way whatsoever," they wrote in their 2006 paper, "but asks, and attempts to answer, the entirely scientific question of what the medium and message might be IF there was actually a message."

They proposed that a binary message could be encoded in the temperature variations in the CMB. This is what Hippke has attempted to find - first by addressing the claims made by Hsu and Zee, and then by using the data to try and find a message.

[...]

https://www.sciencealert.com/is-the...-s-creator-in-the-cosmic-microwave-background
 

EnolaGaia

I knew the job was dangerous when I took it ...
Staff member
Joined
Jul 19, 2004
Messages
19,347
Reaction score
26,121
Points
309
Location
Out of Bounds
A Mysterious Object Is Hurtling Towards Earth, and Scientists Don't Know What It Is
Initial observations suggested that the object was an asteroid. But scientists at CNEOS soon began to suspect that 2020 SO was not a normal asteroid. ...
CNEOS director Paul Chodas subsequently suggested that 2020 SO may not be an asteroid at all, tentatively identifying it as the Centaur rocket booster from NASA's failed Surveyor 2 lunar mission, which launched on September 20, 1966.
Based on telescopic observations NASA has now confirmed the mystery object is indeed a Centaur rocket booster.
NASA: Mystery object is 54-year-old rocket, not asteroid

A mysterious object temporarily orbiting Earth is a 54-year-old rocket, not an asteroid after all, astronomers confirmed Wednesday.

Observations by a telescope in Hawaii clinched its identity, according to NASA’s Jet Propulsion Laboratory in Pasadena, California. ...

Chodas was proven right after a team led by the University of Arizona’s Vishnu Reddy used an infrared telescope in Hawaii to observe not only the mystery object, but — just on Tuesday — a Centaur from 1971 still orbiting Earth. The data from the images matched. ...
FULL STORY: https://apnews.com/article/asteroids-hawaii-dc318b7880005a32f7829afc05a55c12
 

WeeScottishLassie

Ephemeral Spectre
Joined
May 19, 2020
Messages
260
Reaction score
666
Points
93
Astronomers Just Mapped 1 Million Previously Unknown Galaxies, And You Can Take a Tour

Source: sciencealert.com

AIDAN HOTAN, THE CONVERSATION
1 DECEMBER 2020

Astronomers have mapped about a million previously undiscovered galaxies beyond the Milky Way, in the most detailed survey of the southern sky ever carried out using radio waves.

The Rapid ASKAP Continuum Survey (or RACS) has placed the CSIRO's Australian SKA Pathfinder radio telescope (ASKAP) firmly on the international astronomy map.

While past surveys have taken years to complete, ASKAP's RACS survey was conducted in less than two weeks - smashing previous records for speed. Data gathered have produced images five times more sensitive and twice as detailed as previous ones.

Modern astronomy is a multi-wavelength enterprise. What do we mean by this?

Well, most objects in the Universe (including humans) emit radiation over a broad spectrum, called the electromagnetic spectrum. This includes both visible and invisible light such as X-rays, ultraviolet light, infrared light and radio waves.

To understand the Universe, we need to observe the entire electromagnetic spectrum as each wavelength carries different information.

Radio waves have the longest wavelength of all forms of light. They allow us to study some of the most extreme environments in the Universe, from cold clouds of gas to supermassive black holes.

Long wavelengths pass through clouds, dust and the atmosphere with ease, but need to be received with large antennas. Australia's wide open (but relatively low-altitude) spaces are the perfect place to build large radio telescopes.

We have some of the most spectacular views of the centre of the Milky Way from our position in the Southern Hemisphere. Indigenous astronomers have appreciated this benefit for millennia.

Radio astronomy is a relatively new field of research, dating back to the 1930s.

The first detailed 30cm radio map of the southern sky - which includes everything a telescope can see from its location in the Southern Hemisphere - was Sydney University's Molonglo Sky Survey. Completed in 2006, this survey took almost a decade to observe 25 percent of the entire sky and produce final data products.

Our team at CSIRO's Astronomy and Space Science division has smashed this record by surveying 83 percent of the sky in just ten days.

[...]

https://www.sciencealert.com/take-a-virtual-tour-of-a-million-previously-undiscovered-galaxies
That's wicked! :D
 

Comfortably Numb

Antediluvian
Joined
Aug 7, 2018
Messages
6,413
Reaction score
10,042
Points
279
Location
Phone
Arecibo has completely collapsed.
Drone catches Arecibo Observatory's last moments

Source: livescience.com
Date: 3 December, 2020

The exact moment of Arecibo Observatory's final collapse — when the cables supporting its instrument platform broke — was caught on video by a drone doing a routine inspection flyby, according to a new video released by the observatory Thursday (Dec. 3).

The footage, taken just before 8 a.m. local time in Puerto Rico on Dec. 1, shows what at first appears to be a peaceful, blue-sky morning. Then, one of the main cables holding up the suspended platform over the radio dish gives way, and the entire platform swings downward, breaking apart as it twists toward the ground.

The footage may help scientists understand what went wrong at the famous alien-searching observatory, known not just to astronomers and science enthusiasts but also to moviegoers who watched the 1995 James Bond hit "GoldenEye" and the 1997 film "Contact," based on Carl Sagan's novel.

[...]

https://www.livescience.com/drone-footage-arecibo-observarory.html
 

Comfortably Numb

Antediluvian
Joined
Aug 7, 2018
Messages
6,413
Reaction score
10,042
Points
279
Location
Phone
Ghostly circles in the sky can't be explained. And astronomers are excited.

Source: livescience.com
Date: 3 December, 2020

Are they 'throats' of wormholes?

In September 2019, my colleague Anna Kapinska gave a presentation showing interesting objects she’d found while browsing our new radio astronomical data. She had started noticing very weird shapes she couldn’t fit easily to any known type of object.

Among them, labeled by Anna as WTF?, was a picture of a ghostly circle of radio emission, hanging out in space like a cosmic smoke-ring. None of us had ever seen anything like it before, and we had no idea what it was. A few days later, our colleague Emil Lenc found a second one, even more spooky than Anna’s.

Anna and Emil had been examining the new images from our pilot observations for the Evolutionary Map of the Universe (EMU) project, made with CSIRO’s revolutionary new Australian Square Kilometre Array Pathfinder (ASKAP) telescope.

EMU plans to boldly probe parts of the Universe where no telescope has gone before. It can do so because ASKAP can survey large swathes of the sky very quickly, probing to a depth previously only reached in tiny areas of sky, and being especially sensitive to faint, diffuse objects like these.

I predicted a couple of years ago this exploration of the unknown would probably make unexpected discoveries, which I called WTFs. But none of us expected to discover something so unexpected, so quickly. Because of the enormous data volumes, I expected the discoveries would be made using machine learning. But these discoveries were made with good old-fashioned eyeballing.

Our team searched the rest of the data by eye, and we found a few more of the mysterious round blobs. We dubbed them ORCs, which stands for “odd radio circles”. But the big question, of course, is: “what are they?”

[...]

https://www.livescience.com/ghostly-circles-puzzle-astronomers.html
 
Top