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Ravenous

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About Ravenous

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  1. All show, no go! The idea is OK, but it is massively overpriced - over two thousand Euro for a 7 Kg all-in small refractor and mount. I think the more technically minded astrophotography experts on this very forum could demonstrate a similar system for much less. Might be OK for the iPhone generation though.
  2. We'd all be getting far fewer point on our licences... (kidding)
  3. Well, if there were NO other life sources in the universe, we would never truly "discover" that as we would have to search pretty much for ever to prove it. I'm 50/50 on the matter. It's common for people to say the chances are there's almost certainly lots of suitable planets, but I'd also accept an argument that life getting started is actually massively unlikely, and we're the only planet that ever developed it. Both cases are pretty mindblowing (not terrifying), but logically one of them must be true. I don't mind which as they both have something interesting to say.
  4. Impossible - because a ball of wool running backwards through time is one very confused sheep!
  5. Yes also the ISS is definitely going to be decommissioned eventually (no firm date yet), so what should the next major project be? A station further out (with more radiation exposure than low earth orbit), a longer Moon stay (perhaps for a few months), or an asteroid rendezvous maybe? (These are the sorts of choice I've heard debated recently anyway.)
  6. Oh I wouldn't dare ask him that - bear in mind he's ex-military, he can probably still hospitalise a man with his bare hands!
  7. By the way Hadfield did "Desert island Discs" on Radio 4 a while back (probably still downloadable). I don't usually listen to these things but he told an interesting story about hitting a large bird on a high speed/low level test run, in I think an F-15. His test pilot career must have had a few interesting moments as well as his space days!
  8. A few months ago I heard someone on the radio ask Tim Peake a question - and he sounded more impressed than usual about its originality. (I guess they don't often get unique questions.) The question was (basically): if Isaac Newton turned up today, which one thing would you tell him about? (Not sure if I'd go for general relativity, or the modern interpretation of light - both Newton's subjects.)
  9. I'm having a hard time seeing this. I'm sure the standard Crayford is sufficient; based on the kinematic principles Hugh mentioned earlier. You can constrain a plane with three contact points. (It'll be free to slide in two dimensions and rotate in one) You can constrain a sphere with three contact points (It'll be free to rotate in three axes) To constrain a cylinder, you need four contact points. (It'll be free to slide in one axis and rotate around one direction.) (For completeness, I should mention all three cases need a flexible constraint from "above" to prevent the
  10. I believe the real reason Messier logged M1 was because he realised it was easily mistaken for a comet. So he wanted to log it so people wouldn't make that mistake. He must have been aware of lots of other, brighter nebulae (M42, M45 etc were probably known of in the stone age!)
  11. As @Zakalwe has already said, heat can be radiated away on earth too, when exposed to a clear, dark sky. In the right circumstances the ground can lose heat and cool faster than the air above it. You can end up with a temperature inversion, where there's a layer of cold air in contact with the (also cold) ground, and warmer air above it. This is why morning mist can briefly form thin layers around dawn. Quite fascinating stuff we often have no idea is going on around us until we think about it...
  12. If it's your eyepieces that are attracting condensation during a session - put them in a closed box (even a cardboard box will do) at the start of the session, put each one back when you change eyepieces, and keep the lid closed. That might keep them "warm" enough to prevent condensation gathering on them. (It's usually the cold that encourages the condensation.)
  13. I'll add my vote to a few items that people have already mentioned: Hale-Bopp - great two-tailed comet. M57 - my first view of it through a 100mm reflector. Sure I know how these things form, but I still can't quite believe it.
  14. Don't worry, that's not likely! M42 is a big splat below the "belt" of Orion, and quite easy with binoculars. M78 is a very faint thing, small, but I mentioned it because (once your eye's had some practice) it does show a vague shape with a 100mm scope - under good conditions. There's a finder chart for both on the page here: https://freestarcharts.com/messier-78
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