Now I'm trying to remember when it was we showed the kids an impressive display of sunspots. The morning sun just happened to be shining through the stairs landing window onto the white-painted kitchen door about 5m away, so I stood at the window holding the binoculars (one lens capped), projecting the sun's image onto the door. I think the kids were almost as impressed at the sight as we were. Eeh, must have been 15+ years ago.
Daughter and I were sitting out in the garden last night watching Perseid meteors (and at one point rather excruciatingly pretending neither of us could hear the neighbours having noisy sex) and I did think the light pollution/haze seemed to come and go rather quickly; much faster than light cloud would pass over. I failed to put two and two together and realise it was probably the aurora.
Astronomy and Space
Re: Astronomy and Space
I read that there were over 200 sunspots on the visible face of the sun over the weekend. This is the most there has been for over 20 years.Martin Y wrote: ↑Tue Aug 13, 2024 10:53 amNow I'm trying to remember when it was we showed the kids an impressive display of sunspots. The morning sun just happened to be shining through the stairs landing window onto the white-painted kitchen door about 5m away, so I stood at the window holding the binoculars (one lens capped), projecting the sun's image onto the door. I think the kids were almost as impressed at the sight as we were. Eeh, must have been 15+ years ago.
Given that the solar sunspot cycle is about 11 years, it would most likely to have been nearer 20 than 15 years.
My avatar was a scientific result that was later found to be 'mistaken' - I rarely claim to be 100% correct
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
Re: Astronomy and Space
A bit - what? what!
https://x.com/tw__astro/status/1829495132791648518
https://x.com/tw__astro/status/1829495132791648518
My avatar was a scientific result that was later found to be 'mistaken' - I rarely claim to be 100% correct
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
Re: Astronomy and Space
A recent (April 2024) discovery by the Juno spacecraft that has only just come to my attention is Steeple Mountain on Io.
An incredibly narrow and sharply pointed mountain, with a prominence of 5000m to 7000m above the surrounding surface, isolated a long way from other mountains in extensive flat plains, it looks like something out of a sci-fi art graphic, not something that could actually be real. I can't imagine the geological processes that can create such a formation. Moreover, it must be rather unstable. I wonder how quickly such things form and the collapse. We can see a lot of landslide debris around the base.
You can see a "fly-around" view of it if you click the short animation on the Wikipedia page here.
Smaller planetary bodies with weaker gravity enable taller mountains to form than on earth. The tallest mountain on Io is about 17,500m. The mountains of Iapetus, a moon of Saturn, are quite extraordinary - it has an equatorial ridge 1,200km long, generally about 13,000m high with individual peaks to 20,000m, on a moon of 1,500km diameter.
Which makes it a little odd to learn that Io has relatively flat relief in comparison to other major Jovian moons, despite all the volcanism throwing lava around, seemingly creating relief. There may be some very big and very pointy mountains, but much of the moon has extensive plains. Craters and valleys tend to get filled up with lava. It may also be that mountain ranges are not as well supported by the underlying crust as you would expect for the amount of gravity, given the tendency of the crust to melt into lava.
An incredibly narrow and sharply pointed mountain, with a prominence of 5000m to 7000m above the surrounding surface, isolated a long way from other mountains in extensive flat plains, it looks like something out of a sci-fi art graphic, not something that could actually be real. I can't imagine the geological processes that can create such a formation. Moreover, it must be rather unstable. I wonder how quickly such things form and the collapse. We can see a lot of landslide debris around the base.
You can see a "fly-around" view of it if you click the short animation on the Wikipedia page here.
Smaller planetary bodies with weaker gravity enable taller mountains to form than on earth. The tallest mountain on Io is about 17,500m. The mountains of Iapetus, a moon of Saturn, are quite extraordinary - it has an equatorial ridge 1,200km long, generally about 13,000m high with individual peaks to 20,000m, on a moon of 1,500km diameter.
Which makes it a little odd to learn that Io has relatively flat relief in comparison to other major Jovian moons, despite all the volcanism throwing lava around, seemingly creating relief. There may be some very big and very pointy mountains, but much of the moon has extensive plains. Craters and valleys tend to get filled up with lava. It may also be that mountain ranges are not as well supported by the underlying crust as you would expect for the amount of gravity, given the tendency of the crust to melt into lava.
Re: Astronomy and Space
I managed to get this published in an astronomy magazine - two half images of the Sun, taken in late June (close to the time when the Earth is furthest from the Sun) and in January (close to the time when it's closest).
About 3% difference in size
I have plans to repeat this in May and December with the Moon
About 3% difference in size
- Perihion and Aphelion.png (323.96 KiB) Viewed 2806 times
My avatar was a scientific result that was later found to be 'mistaken' - I rarely claim to be 100% correct
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
Re: Astronomy and Space
What's the difference from May to December? 
Re: Astronomy and Space
About 16% at full moon.
My avatar was a scientific result that was later found to be 'mistaken' - I rarely claim to be 100% correct
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
Re: Astronomy and Space
Like the full moon, that went over my head (never found it much of a 'com')
My avatar was a scientific result that was later found to be 'mistaken' - I rarely claim to be 100% correct
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
ETA 5/8/20: I've been advised that the result was correct, it was the initial interpretation that needed to be withdrawn
Meta? I'd say so!
Re: Astronomy and Space
I love that, hope the moon photo gets published tooGfamily wrote: ↑Mon Mar 03, 2025 11:06 pmI managed to get this published in an astronomy magazine - two half images of the Sun, taken in late June (close to the time when the Earth is furthest from the Sun) and in January (close to the time when it's closest).
About 3% difference in size
Perihion and Aphelion.png
I have plans to repeat this in May and December with the Moon
where once I used to scintillate
now I sin till ten past three
now I sin till ten past three
Re: Astronomy and Space
On whether humanity will colonise Mars (Spoiler: No)
Move-a… side, and let the mango through… let the mango through
Re: Astronomy and Space
Latest attempt to put Wallace and Gromit's gas oven on the moon has arrived but it may be having a lie down.
https://www.bbc.co.uk/news/articles/c871eeez0yzo
https://www.bbc.co.uk/news/articles/c871eeez0yzo