*** The Official Astronomy & Universe Thread ***

[Stu999]

NASA solar eclipse feed. Happens in about an hour.

The Ring of Fire: 2023 Annular Solar Eclipse (Official NASA Broadcast)

Watch live with us as a “ring of fire” eclipse travels across the United States on Oct. 14, 2023, from Oregon to Texas. This event occurs when the Moon passe...

www.youtube.com

 

[Malevolence]

 

[jpaul]

Seems the Northern lights might be on again this evening - might be worth a trip to Norfolk coast,
haven't found a geographically local forecast, just V

Northern lights could be visible in some states Sunday, forecasts show

A geomagnetic storm could bring the northern lights as far south as Iowa, forecasts show.

thehill.com

The current Earth-directed CME was sparked by a filament eruption on Friday, the SWPC says. It is expected to impact us late Sunday, causing G1-level geomagnetic storms (the lowest level on the five-point scale). G2 storms are likely for Monday.

The SWPC’s current forecast shows Canada and Alaska, blanketed in red in the image below, have the greatest likelihood of seeing the northern lights on Sunday. NOAA predicts the southern extent of the auroras — depicted by the red line on the image below — could reach as far south as northern Nebraska and central Iowa.

Northern lights turn skies magenta over Norfolk and Suffolk

The aurora lights up the skies across the East of England to the delight of photographers.

www.bbc.co.uk

 

[AlphariusOmegan]

got the telescope out again last night and came away with this, rather pleased although only managed to image half the night due to a cable issue, still learning pixinsight to process the images

 

[Rannoch]

I could have purchased that scope but common sense and portabilty won

 

[BananaDunka]

Always fascinated by Venus, so close, in distance and size, yet so mysterious.

 

[Pooh]

Venus - Runaway global warming

 

[Blackjack Davy]

The remains of the mars-sized planet that crashed into the earth and created the moon early in its history lives deep within the earth according to scientists

https://edition.cnn.com/2023/11/03/world/earth-moon-theia-collision-llvps-scn/index.html

Venus - Runaway global warming

The Earth in about 1 billion years if you want to know our future maybe sooner if we carry on the way we are

 

[BananaDunka]

Yeah Mars was also once like Earth before its atmosphere got stripped away more than likely due to an extreme solar event. Venus is much closer to the Sun so whilst in its early days the conditions would have allowed for Earth-like features, that was only going to last so long. Both Mars and Venus are great candidates to see what Earth will be like through one of two scenarios, an equally mega CME rips away our atmosphere, or time takes its toll on this planet and it sees the same fate as Venus. The Venus outcome will happen regardless of if a natural event doesn't wipe us out, so best be living off-planet by then

Thoughts on planet 9 too? Primordial black hole or nearly 8000 year orbit of the Sun planet yet to be discovered with modern astronomy due to its distance in the darkness of space?

https://www.bbcearth.com/news/uncovering-the-mystery-of-planet-nine

I think the black whole theory tracks the best, if it was a planet then at least some telescopes would have picked up something by now, which then would have redirected JWST to point its cold sensor to get a physical image of it. But a black hole laying dormant out there amongst all the black, much harder to detect and its gravity would quietly just pull on the bodies in our solar system as is being observed.

 

[Penfold101]

I think the black whole theory tracks the best, if it was a planet then at least some telescopes would have picked up something by now, which then would have redirected JWST to point its cold sensor to get a physical image of it. But a black hole laying dormant out there amongst all the black, much harder to detect and its gravity would quietly just pull on the bodies in our solar system as is being observed.

A planet in that sort of orbit would be incredibly difficult to detect at any wavelength - space is massive and you would have to be looking in exactly the right place. JWST wouldn't fare much better as the resolution is about the same as Hubble's and a planet that far out is likely going to be very cold indeed. In summary - I'm not sure how they're going to find it (if it's there) except with exhaustive surveys looking for things moving at incredibly slow speeds. It may even be buried in some data already, just overlooked due to the insignificant changes betwwen observations.

 

[Pooh]

Yeah Mars was also once like Earth before its atmosphere got stripped away more than likely due to an extreme solar event. Venus is much closer to the Sun so whilst in its early days the conditions would have allowed for Earth-like features, that was only going to last so long. Both Mars and Venus are great candidates to see what Earth will be like through one of two scenarios, an equally mega CME rips away our atmosphere, or time takes its toll on this planet and it sees the same fate as Venus. The Venus outcome will happen regardless of if a natural event doesn't wipe us out, so best be living off-planet by then

Thoughts on planet 9 too? Primordial black hole or nearly 8000 year orbit of the Sun planet yet to be discovered with modern astronomy due to its distance in the darkness of space?

https://www.bbcearth.com/news/uncovering-the-mystery-of-planet-nine

I think the black whole theory tracks the best, if it was a planet then at least some telescopes would have picked up something by now, which then would have redirected JWST to point its cold sensor to get a physical image of it. But a black hole laying dormant out there amongst all the black, much harder to detect and its gravity would quietly just pull on the bodies in our solar system as is being observed.

There are different theories and explanations for this, but the most widely accepted one is that Mars was stripped of its atmosphere by the solar wind and radiation not an extreme event.

Essentially Mars lost its magnetic field and that's when the problems began.

Mars used to have a thick atmosphere that could have supported life billions of years ago. It also had a substantial magnetic field that protected it from the harmful effects of the Sun. However, around 4 billion years ago, Mars lost its magnetic field and became vulnerable to the solar wind and radiation.

Solar wind is a stream of charged particles that flows from the Sun and can ionize gas molecules in the upper atmosphere of a planet. This means that the gas molecules lose or gain electrons and become electrically charged. The charged particles can then be carried away by the magnetic field of the Sun, causing the atmosphere to erode over time. Radiation from the Sun can also break down gas molecules into lighter atoms that can escape the gravity of the planet more easily.

 

[Penfold101]

There are different theories and explanations for this, but the most widely accepted one is that Mars was stripped of its atmosphere by the solar wind and radiation not an extreme event.

Essentially Mars lost its magnetic field and that's when the problems began.

Mars used to have a thick atmosphere that could have supported life billions of years ago. It also had a substantial magnetic field that protected it from the harmful effects of the Sun. However, around 4 billion years ago, Mars lost its magnetic field and became vulnerable to the solar wind and radiation.

Solar wind is a stream of charged particles that flows from the Sun and can ionize gas molecules in the upper atmosphere of a planet. This means that the gas molecules lose or gain electrons and become electrically charged. The charged particles can then be carried away by the magnetic field of the Sun, causing the atmosphere to erode over time. Radiation from the Sun can also break down gas molecules into lighter atoms that can escape the gravity of the planet more easily.

To add to this, off the top of my head, it's down to the core needing to be liquid to generate the magnetic field - over billions of years the core cools and starts to solidify, and slowly the magnetic field dissipates allowing the atmosphere to vanish as described above. Earth is much larger than Mars, and so will retain heat in the core a lot longer.

 

[BananaDunka]

That is true, I'd still call it an extreme event though on the face of it!

The core doesn't have to be fluid though, there just needs to be fluid motion going on down there with the planet spinning fast enough for that to happen. So if the inner core is solid, but outer core is molten, then as long as convection currents are possible then a magnetic field would be generated. A number of things can stop that process, a large enough asteroid impact can slow down a planet's spin causing the loss/weakening of its magnetic field, the gravity from a neighbouring planet can slowly pull it further into danger over time, natural geology can cause the molten inner to become more solid or lose convection currents with the same outcome etc - All pretty extreme events one way or other really.

 

[Penfold101]

That is true, I'd still call it an extreme event though on the face of it!

The core doesn't have to be fluid though, there just needs to be fluid motion going on down there with the planet spinning fast enough for that to happen. So if the inner core is solid, but outer core is molten, then as long as convection currents are possible then a magnetic field would be generated. A number of things can stop that process, a large enough asteroid impact can slow down a planet's spin causing the loss/weakening of its magnetic field, the gravity from a neighbouring planet can slowly pull it further into danger over time, natural geology can cause the molten inner to become more solid or lose convection currents with the same outcome etc - All pretty extreme events one way or other really.

I've seen my early-2000's disaster movies - I know my ****...

 

[Pooh]

Absolutely an extreme event on a planetary timescale.

Would be fascinating if you could jump start a core and then terraform.

 

[BananaDunka]

Absolutely an extreme event on a planetary timescale.

Would be fascinating if you could jump start a core and then terraform.

There's a documentary proving it can be done!

 

[BUDFORCE]

That is true, I'd still call it an extreme event though on the face of it!

The core doesn't have to be fluid though, there just needs to be fluid motion going on down there with the planet spinning fast enough for that to happen. So if the inner core is solid, but outer core is molten, then as long as convection currents are possible then a magnetic field would be generated. A number of things can stop that process, a large enough asteroid impact can slow down a planet's spin causing the loss/weakening of its magnetic field, the gravity from a neighbouring planet can slowly pull it further into danger over time, natural geology can cause the molten inner to become more solid or lose convection currents with the same outcome etc - All pretty extreme events one way or other really.

I'd imagine after enough time the rotational energy of the spinning core will dissapate anyway. But given how unimaginably huge the amounts of energy are involved, it will take a VERY long time.

Makes you shudder at the though of the amounts of energy involved in whatever started it off in the first place.

To add to this, off the top of my head, it's down to the core needing to be liquid to generate the magnetic field - over billions of years the core cools and starts to solidify, and slowly the magnetic field dissipates allowing the atmosphere to vanish as described above. Earth is much larger than Mars, and so will retain heat in the core a lot longer.

Yup basically my understanding as well.

 

[Penfold101]

I'd imagine after enough time the rotational energy of the spinning core will dissapate anyway. But given how unimaginably huge the amounts of energy are involved, it will take a VERY long time.

Makes you shudder at the though of the amounts of energy involved in whatever started it off in the first place.

That would be gravity!

 

[Pooh]

There's a documentary proving it can be done!

Bit disapointed that the Martians of the day didn't seek advice from their film makers on how to save their planet. Bit short sighted of them.

 

[Malevolence]