Stars / Astronomy / Astrophotography / Telescopes / Astro

Hydrogen is a poor fuel as it has a low specific energy.
It also takes a lot of energy to compress it to a liquid,
and special alloy tanks to contain it.
There is something to be said for injecting (upto 6%) hydrogen
from electrolysis from 'surplus' wind power into the gas pipeline system.

Sounds about right, I'm no expert. The idea of passively generating zero-carbon fuel is very appealing to me but the reality is no doubt less simplistic. For cars and home heating I guess we'll be almost totally battery powered/electric before hydrogen as a fuel becomes economically viable. It might have a place in rocketry though.

motorised transport innovations

I think the phrase loses meaning when extended to space travel...

The upshot is usually just more and more travel beyond any reasonable utility that one could rationally defend

This conclusion requires predicting the future and as such I wouldn't put much on it, who knows what utility there could be from commercial space flight?

I think the phrase loses meaning when extended to space travel...

Why?

This conclusion requires predicting the future and as such I wouldn't put much on it, who knows what utility there could be from commercial space flight?

That I don't know, of course (as hinted at above), but knowing people, some of it will be stupid shit like this--the aforementioned 'wealthy' people keen on their fifteen minutes in space:

https://www.theguardian.com/science/2019/jun/07/nasa-international-space-station-commercial-access-tourism

Asteroid near miss https://astronomy.com/news/2019/07/a-large-asteroid-just-zipped-between-earth-and-the-moon-

Full moon tonight.

Just watched it rise over the medditeranian , beautiful behind some light cloud.

Anyone else think that was Saturn under Jupiter?

The Moon is reasonably near Jupiter this evening.

Around half a billion miles but then everything is relative.

The Moon is reasonably near Saturn this evening.

Had a week in the Peak District so had to take a 1,648 second shot of the Milky Way - 10mm Samyang lens on. Canon 1000d.

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Amazing picture.

What's the bright one middle right?

Thanks - that’s Vega

I read up on it. I find it interesting that it is spinning with its pole facing towards us. I always imagined all the stars were oriented same as the sun.

I always imagined all the stars were oriented same as the sun.

It's randomised around the galaxy, within a solar system then a preferential axis is likely/inevitable. Though you can still get anomalies such as Uranus which rolls around on it's side.

I do enjoy this planet-detecting stuff:

https://www.theguardian.com/science/2019/sep/11/rocky-super-earth-k2-18b-named-most-habitable-known-world-beyond-solar-system

What are you likely to see with an average telescope in a typical London garden. Is the light pollution too bad to see anything but the moon or can you still see stuff?

I was able to see the rings of Saturn and Jupiter's moons. But aside from that it wasn't much more than the moon.

Edit: This was with a 130mm Dobsonian

Depends on your Southern horizon. If you've got a decent view about 40 degrees above the horizontal then Saturn, Mars, Jupiter, Venus and the moon will be regular reasonable targets for a modest c. 200 quid telescope.

If you're thinking of nebulae and star clusters then you need to be mobile or spending money on fancy mounts.

Those two asteroids (near earth objects) past by relatively close to earth last night, right?

today i think
just 3 million miles away and twice as big as the shart

Cheers. I may be getting a garden for the first time and was curious.

Hadn't really thought about the range of vision. The garden would have big houses to the south and north so possibly not much of a view anyway.

Don't be too pessimistic, I live in a back to back terrace and the horizon is probably around 60 degrees. Still get to see some of the planets as they pass over. Generally the sky nearer the horizontal is not great fro viewing through anyway.

So saw a large star due South, got a star chart. Turns out it’s Saturn.

I have a few telescopes: in order of success for viewing...
£15 Lidl telescope - no success.
£70 telescope from camera shop, my main spotting scope for shooting - 70x70 - saw the planet and 3 moons.
Really old “GreenKat” spotting scope from the 70s. 20x50 (is that right?). Planet, 3 moons, but sharper than before, and the slight glow of rings going round the planet. Rings inclined at about 15 degrees.

First time I’ve ever seen any thing like this, so I’m very happy to have done it with basic kit from my flat window. What else could I go for?

Jupiter is just off to the west of Saturn.

A decent pair of binoculars might help...