Zermelo

You can get 12V hairdryers with two power settings. The higher one will be in the region of 10A-15A but the lower will be more gentle on your power supply (and mirrors).

So the little cubesat LICIACube has just checked in with this: (Didymos lower and Dimorphos top, just after impact) (Image credit: NASA/ASI) https://www.space.com/dart-asteroid-crash-first-photos-liciacube

This one?

Some forecasts were reasonable for this evening, so I set up and managed to align, saw a few targets but most of the sky was cloudy and it was very slow to move. In the clear patches the seeing wasn't great either, so I've called it a night.

Nice report. Mars opposition is December 8th. Of course, in terms of the apparent size, Mars benefits from opposition more in relative terms than the other planets. And then, specifically this year, it is in a better area of the sky (Taurus) than either Jupiter or Saturn, and so it will benefit from higher maximum altitudes (and in December, it will be at a more convenient time of the evening, in northern latitudes). I agree about the double cluster, I had a similar view last time out with my Skymax and a 24mm UFF, it frames them very nicely.

As for the F/12 vs F/12.1, well: - as pointed out above, the actual diameter is moot - with Maks, since the mirror moves when you focus, it's hard to be precise about the focal ratio in use - and that's without any changes at the back end So I've only ever assumed that mine is closer to F/12 than F/11 or F/13

There was certainly ice visible, so it may have been that: (06:00 BST 21/09/22, N at bottom)

The jet stream has passed off to the East now, so tonight with the Mak was a big improvement on Friday. Although for the first hour things were very jumpy and murky, so I think there was some high level cloud coming and going. But after a while it settled down and became really very good. Doubles included Sigma Cas, Alkurah, SAO 110099, HD16694 and HD 9817 (1.8"). The Little Dumbell was just visible, and the double cluster fitted nicely into the 24mm UFF. But the highlights were the planets. For the first time I saw all the outer planets in one session. Saturn was not well placed above rooftops and a little unsteady, though I identified Titan, Rhea and Dione. Mars appeared late above the fence and showed atmospheric fringeing, but I did see some darker areas, and was that a white cap on the North pole? I've only seen one on the South pole before*. Uranus looked very green in the Nirvana 4mm, and Neptune distinctly blue. For the first time, I could make out an actual disc for Neptune. Jupiter was perhaps the best, once it had risen to a decent angle and the sky had calmed. The first view was just as Io was clearing the limb, which looked impressive. When I returned later on, I could see some nice detail in the NEB/SEB, a further two bands to the South and one to the North. The BCO 10mm and Morpheus 9mm were both excellent on planets and doubles tonight, and in the end I couldn't separate them. [EDIT: *yes, it probably was the North polar cap, as it was quite prominent at the time I was observing: (from https://skyandtelescope.org/observing/interactive-sky-watching-tools/mars-which-side-is-visible/#)]

Baader really do have a widget for everything

So the seeing has really suffered with the jet stream tonight, and there seemed to be some patches of high cloud affecting the views. Nothing would seem to take any kind of magnification. Doubles under 2" were far too jumpy to split. Jupiter and Saturn were OK at low mags, but showed very little detail. Open clusters at low powers were unaffected, so I stuck to them. The double cluster was nicely framed in the 24mm UFF and contrast was not too bad. IC4756 in Serpens was also very pleasant. M39, NGC7209 and Stock 2 were also decent in the UFF, but the very loose Collinder 463 was less inspiring. The Wild Duck benefitted from a bit more magnification, being so small. The 30mm NPL also gave very respectable views, though with less contrast at its lower mag. Even my cheap Svbony 23mm aspheric performed very well (admittedly at F12+), with good colour rendering, sharp stars and no soft edges. It looks like we might get a couple more clear nights, with the jet stream moving off to the East and the moon rising later, so I may manage to improve on tonight.

Hello, and welcome to SGL. Have you seen this recent thread? A different scope, but similar budget. Your 25mm would give you around 50x I think. A Starguider 12mm would give you around 100x, which you could later double with a Barlow.

Welcome to SGL, Rich. You've already done two of the most useful things as a beginner - signing on here, and joining your local club. Good luck with your next step!

Some info here: https://stargazerslounge.com/topic/287169-altitude-of-the-planets-for-the-next-few-years/ 2025 looks good.

Visual astronomy is an intriguing mix of technology, biology and psychology. As a beginner, one of the areas I was keen to understand was the weakest point in the optical chain from star to brain. In particular, were the mirrors in my very average scopes showing me the best that they could, and would better (=more expensive) eyepieces make any noticeable difference? No, they weren't, and yes, they could. So far, each of the steps: MA stock>BST Starguider>ES 82°>Morpheus has shown an improvement, though the size of the enhancement (in my judgement) has diminished each time, while the cost increments have increased. Improvements have been of two kinds: (a) objectively identifiable and (in principle, at least) quantifiable changes: the FOV is larger, the stars are sharper, tighter doubles can be split; and (b) more subjective changes: the view just seems more pleasant, though I can't always say why, and possibly others would disagree. Al Nagler talked about a "majesty factor" to measure the ineffable. Of course, there are many other ways to improve the pleasure and effectiveness of the visual experience, sometimes less obvious, and often less expensive than a new eyepiece. Flocking helped a bit, so did using a dew shield to control light ingress. Possibly the most surprising improvement for me was the introduction of an observing seat. Honestly, I already have too many eyepieces. I make that judgement on coming in from a long session on a cold evening, uncapping all the eyepieces in my cases and realizing that I've probably used only four or five of them. But there are very few that I regret buying: I value the learning experience that each has provided, and I think I would have missed something if I had taken short-cuts. As for collecting eyepieces for their own sake, well, at the outset I certainly didn't get excited about a 10mm modified achromat; it was a means to an end and nothing more. Whereas a Morpheus, well that is a thing of beauty.

They are well priced for what they offer. I'll be interested to see reviews of the two new ones.

Hello, and welcome to SGL. Did you try this one? https://skyandtelescope.org/observing/interactive-sky-watching-tools/transit-times-of-jupiters-great-red-spot/

I like his decription: "like a thin snake that has swallowed a tennis ball"

With SkySafari, the number of images increases with the level/edition you buy. For V7: https://skysafariastronomy.com/skysafari-7-comparison-chart.html I agree with you that sometimes there is a DSS image, but it is "unhelpful" (e.g. framed at an unsuitable magnification).

I saw the shadow around 23.45, very nice. I couldn't make out Io itself. I found Jupiter itself a bit underwhelming and a mushy, though the shadow was very tight and sharp. It could have been seeing as you say, although I managed well with doubles earlier on.

I set up the 150mm Newt at 8.30 but I was dodging clouds for the first couple of hours, then it mostly cleared. This time, ClearOutside takes the trophy, spot on. Meteoblue and Metcheck were too pessimistic. Of course the big, bright thing was there throughout, so I split a few doubles (including λ Cygni, 0.9" at 335x) and had a look at Jupiter and Saturn. Io's shadow showed up nice and sharp, but only traces of detail in the NEB and SEB. Saturn was better than I expected, showing a faint band in the northern hemisphere. But mainly I was trying out a new Barlow, so a lot of comparisons with my other one. It performed as well, possibly better.

I remember that - came out after the TV series I think - didn't own it, but played once at a friend's house and liked it.

What is it? When did you get it? How is it played? Why did you like it? I recently came across this in the loft: "4000 A.D." by Waddingtons. When I was around 10 or 11, a family friend bought us this game for Christmas, knowing that my brother and I were "interested in space". I don't remember any other astronomy-related board games around at the time. For some reason, they managed to get hold of the English/French version that was produced for the Canadian market. It's very much a game of strategy. There isn't even a die, so no random element. It's played on a board that attempts to model a section of the galaxy (the "third dimension" here is that the red stars in each square are meant to be on a "lower level" than the yellow ones, effectively one square distant from them). Each player starts off with a "home base" star and a small fleet of spaceships, and they can use warp vessels in hyperspace (the sections on the edge of the board) to move some of them to other stars, and then use the resources so gained to build more ships. As you expand your empire, you eventually encounter the forces of your opponents, which you can engage and hope to wipe out. A sort of cross between Risk and Elite. I loved it. The combination of strategic thinking, a spatial arena, and no requirement for sharp reflexes, all with an astronomical theme was nirvana. The aspect I liked most was that when you put ships into hyperspace, their location became indeterminate: they could be anywhere on a conceptual sphere, centred on their departure point. The radius of the sphere expanded with each incremental step in hyperspace, and their actual destination became clear only when their owning player pulled them back into normal space and moved them back onto the main playing area. The other players could see the ships in hyperspace, and had to try to guess their intentions and take countermeasures. To make it more complicated, if three or four players were playing, they could form alliances against each other. Unfortunately, I was the only one that did like it. That Christmas, I press-ganged other members of the family into playing, but their initial confusion turned quickly into indifference and finally derision. My dad even won one game and then claimed afterwards that he had never actually understood the rules, and that his masterful winning manoeuvre had been a complete fluke. The game was mothballed and was never played again in anger, but I saved it from the skip when my parents downsized, and still live in hope of convincing someone to give it a go. https://en.wikipedia.org/wiki/4000_A.D. https://boardgamegeek.com/boardgame/1435/4000-d

This was reported and fixed quickly: https://github.com/mozilla/contain-facebook/issues/865 I've removed 2.33 and installed 2.34, and it's now OK.

Yes, definitely subjective. As you say, the "resolved vs. split" distinction does at least depend on the appearance of some black between the two. But I'm just interested in any opinions. Yes, I probably tweaked my simulation a bit far - I was aiming for a borderline case, but as you say, it's also about consistency and stability over time. The observer's individual confidence in a split will vary according to the particular double and their previous experience.

Today, I noticed that the text in individual SGL posts (but not in forum overviews, etc.) was not being displayed. Specifically, the text is still there, and can be revealed by selecting it, but by default it seems to be displaying unhelpfully as black on black. I'm running Firefox under Windows. This isn't happening in MS Edge. After some experimentation, I pinned it down to Firefox's Facebook Container extension, the add-on that stops your data leaking to FB from third-party sites. My copy of the extension was auto-updated to v2.3.3 earlier today. Disabling the extension restores the usual behaviour. I've no idea why it should cause this; it is also affecting the size of the text in ClearOutside, but nothing else that I can see. So possibly there's some outbound call for fonts that's now being blocked. I haven't been able to find any mention of the problem online, but in the short term, disabling the FB extension should restore the text.