Astronomy & Cosmology

[Wuwei]

The latest Scientific American, August, has an article,
Is Dark Matter Real?
It is not available unless you buy the magazine or pay for a download.

The article is about a modified Newtonian dynamics (MOND) which has been further modified to be consistent with General Relativity. Excerpts:

Astrophysicists have piled up observations that are difficult to explain with dark matter. It is time to consider that there may be more to gravity than Einstein taught us.

...Scientists can make [dark matter] simulations fit the data, but they must insert many parameters that have to be carefully chosen. Modified gravity, in stark contrast, simply predicts this correlation.

… Although [MOND]works across a huge range of different galaxy types, it cannot explain the motion of galaxy clusters very well. And on the behavior of the cosmos as a whole, modified gravity is mute.​

Although it is mute, that doesn't mean it's wrong. It's just that there is no underlying theory yet. I always thought that the dark matter hypothesis was a bit of a kludge. Hopefully MOND is the answer.

 

[Stryder50]

So it's been awhile for this thread, but couldn't see reason to start a new one on essentially the same topic. I'm resurrecting here for purpose of parking items of interest of general astronomical news and knowledge.

Astronomers spot possible moon-forming region for the first time​

Astronomers spot possible moon-forming region for the first time

 

[Stryder50]

NASA’s Insight Has Just Given Us a View of What’s Inside Mars​

NASA’s Insight Has Just Given Us a View of What’s Inside Mars

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NASA's InSight Mars lander just gave scientists an unprecedented look at the guts of the red planet. Here's how they compare to Earth's.​

NASA's InSight Mars lander just gave scientists an unprecedented look at the guts of the red planet. Here's how they compare to Earth's.

 

[Stryder50]

NEO

Asteroid That Could Be Bigger Than the Washington Monument to Speed by Earth This Weekend​

Asteroid That Could Be Bigger Than the Washington Monument to Speed by Earth This Weekend

 

[ClaireH]

I’ve always been interested in Astronomy.

Fncceo- I have a feeling you’re joking with the swami looking picture unless that’s really you but I’ve always had a fascination with astronomy and with astrology for that matter. I don’t subscribe that the stars force people to act in certain ways- we always have a choice. What I find interesting is there are generalizations that can be made for instance if you were to say you are a Taurus I could come back and give you maybe 3 to 5 of your basic traits…. or not lol The old “well it depends on where all of the other constellations are and what do you have rising at time of birth and all of that… I don’t know enough about downsizing to fit more in that respect but I do find it interesting still.

 

[Stryder50]

A global dust storm on Mars canceled winter on the red planet​

...
In June 2018, a number of small dust storms on Mars converged to form one massive, swirling squall that engulfed the entire planet, practically hiding its entire surface from the view of spying orbiters. Now researchers say the mega-storm also squashed an entire season, bringing the southern winter to an abrupt and early end.
...

A global dust storm on Mars canceled winter on the red planet

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Wait a minute!
Mars has "global warming/climate change" and there are no humans there to cause it?
Where's "the science", and "science funding" in all this alternate case of ACC/AGW?

 

[there4eyeM]

A global dust storm on Mars canceled winter on the red planet​

...
In June 2018, a number of small dust storms on Mars converged to form one massive, swirling squall that engulfed the entire planet, practically hiding its entire surface from the view of spying orbiters. Now researchers say the mega-storm also squashed an entire season, bringing the southern winter to an abrupt and early end.
...

A global dust storm on Mars canceled winter on the red planet

~~~~~~~~~~~~~~~~~~~~
Wait a minute!
Mars has "global warming/climate change" and there are no humans there to cause it?
Where's "the science", and "science funding" in all this alternate case of ACC/AGW?

What about those probes humans sent?

 

[Stryder50]

What about those probes humans sent?

May have to wait until the dust clears to see if they can transmit and their solar panels not too covered in dust to function.

Meanwhile, check #23 above ...

 

[there4eyeM]

May have to wait until the dust clears to see if they can transmit and their solar panels not too covered in dust to function.

Meanwhile, check #23 above ...

But, humans have intervened.

 

[Stryder50]

But, humans have intervened.

There are no humans up there to sweep dust off the solar panels so they'll work to best efficiency.
The few probes landed there, functional and "dead now" have little effect upon the total planetary ecology/environment.

 

[Stryder50]

Epic Nova Eruption From Rare Star Is So Bright You Can See It With The Naked Eye​

If you look carefully into the night sky, you might see a star that wasn't visible last week.
...
In the equatorial constellation of Ophiuchus, a star named RS Ophiuchi about 4,566 light-years away has just had an epic eruption. This nova was so bright that the star is now visible to the naked eye, at a magnitude of around 4.8 – a whopping seven magnitudes brighter than its usual 12th magnitude dimness.

Novae are rare enough to spot at the best of times, but what makes this occasion so special is the rarity of the star. RS Ophiuchi is what is known as a recurrent nova – a star that erupts periodically – and only 10 of these stars have ever been discovered in the Milky Way.

RS Ophiuchi typically erupts every 15 years or so. Its last nova was in 2006, so the new burst is right on schedule, and was first reported on 8 August 2021 by Irish amateur astronomer Keith Geary. That detection was rapidly followed by reports of others around the world.
...

Epic Nova Eruption From Rare Star Is So Bright You Can See It With The Naked Eye