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    #76
    Anyone for an astronomy thread?

    The theory is - I think - that your alien's giant superstructure would be solar panels, so it would be very thin while occluding the sunlight, and therefore not need to be particularly high mass.

    Of course it's much more likely that it's entirely natural.

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      #77
      Anyone for an astronomy thread?

      Maybe they're building a Dyson Sphere.

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        #78
        Anyone for an astronomy thread?

        How far is this thing away? I couldn't find a figure.

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          #79
          Anyone for an astronomy thread?

          About 1,400 light years, or 8 quadrillion (billion billion) miles.

          It'd be a long hop in a Ford Focus.

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            #80
            Anyone for an astronomy thread?

            Nipping round the shops feels like a long hop if you're in a Ford Focus. Relativity, innit?

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              #81
              Anyone for an astronomy thread?

              If they do point SETI at this thing and discover it buzzing with alien radio signals, what message do you think we should send to them?

              I think it should be "come and have a go, if you think you're hard enough".

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                #82
                Anyone for an astronomy thread?

                If you sent a message there around the time of the traditional founding of Rome (753BC), we could be getting a reply sometime in the next decade or so.

                Edit - just checked its 1480 light years away, so it would be another couple of centuries. If we do send a message, I'm not waiting up.

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                  #83
                  Anyone for an astronomy thread?

                  New Enceladus flyby pics!

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                    #84
                    Anyone for an astronomy thread?

                    About 1,400 light years, or 8 quadrillion (billion billion) miles.
                    I think that's out by a factor of 1000, Rogin, if by billion you mean a thousand million (i.e. 10^9): the thing is only about 1 per cent as far away in miles. (If you meant the old-fashioned British billion, or 10^12, then you'd be out by a factor of around 1000 million.)

                    1 light year = a little under 6 million million miles, so 1400 light years = approx 8,000 million million miles, or around 8 x 10^15 miles, whereas 8 billion billion (the US billion now virtually standard over here also) = 8 x 10^18 miles and 8 billion billion trad. British would be 8 x 10^24.

                    Bizarrely, a "quadrillion" seems to have alternate meanings of 10^15 and 10^24 (see link below): the latter would, like British "billion billion", overstate the distance by a factor of 1000 million, while the former would be correct (but not a "billion billion" on either basis, so ....).

                    https://en.wikipedia.org/wiki/Quadrillion

                    High time we did away with these "...illion" words to get rid of confusion. In German, "Billion" means 10^12 (as they use "Milliarde" for US billion 10^9), which must cause untold confusion between Germans and Americans. I reckon we should adopt the international scientific scaling prefixes, calling a million of something "mega...", a (US) billion "giga..." and so on.

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                      #85
                      Anyone for an astronomy thread?

                      Ah, I got as far as working out the 10^15, then skipping to 'billion billion' I got it wrong - a quadrillion is a 'million billion', isn't it, yes. Or a thousand trillion.

                      Anyway, this week's apparently all about a near-conjunction of Mars, Jupiter and Venus. Have to get up early to see it though (just before dawn) and cross fingers for clear weather.

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                        #86
                        Anyone for an astronomy thread?

                        GY, that Enceladus photo is fantastic.

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                          #87
                          Anyone for an astronomy thread?

                          All Enceladus photos are fantastic.

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                            #88
                            Anyone for an astronomy thread?

                            Rogin the Armchair Fan wrote: Ah, I got as far as working out the 10^15, then skipping to 'billion billion' I got it wrong - a quadrillion is a 'million billion', isn't it, yes. Or a thousand trillion.

                            Anyway, this week's apparently all about a near-conjunction of Mars, Jupiter and Venus. Have to get up early to see it though (just before dawn) and cross fingers for clear weather.
                            I've seen this on the Eastern horizon the past few mornings.

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                              #89
                              Anyone for an astronomy thread?

                              And another flyby.

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                                #90
                                Anyone for an astronomy thread?

                                Moon meeting Jupiter at 0630 GMT:
                                https://astronomynow.com/2015/12/02/see-the-moon-meet-planet-jupiter-on-the-morning-of-4december/

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                                  #91
                                  Anyone for an astronomy thread?

                                  Latecomer to this thread, but, I saw the ISS above, and outside the window on the 18th Nov, for about 3 minutes (cloudy), but only because I was looking for it.

                                  It's really big. Or, fast, one or the other.

                                  That picture above this, sorry, that's one of Saturn's? Shit, life (or not) is fucking wonderful.

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                                    #92
                                    Anyone for an astronomy thread?

                                    Incidentally, how do I change the time to another time zone on here? (It isn't 6am)

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                                      #93
                                      Anyone for an astronomy thread?

                                      Or, am I just moving faster, by being slightly higher than you all?

                                      I remember the first time I saw Brian Cox, in one of those old Science Channel (RIP) things, and he explained about how if you are on the highest floor of a building, that time goes less fast, than being on the ground floor.

                                      I assume that is still true?

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                                        #94
                                        Anyone for an astronomy thread?

                                        Apparently for the next three weeks, from an hour before dawn, you can see all five naked eye planets lined up from just above the eastern horizon across to Jupiter in the north. The fact they are in a line isn't that rare an occurrence (all of them orbit on the same plane, after all) but it's unusual for them all to be the same "side" of the Sun as us (and thus visible in our night sky at the same time). Alas, the chances of there being a clear night in Lancashire to see them i nthe next three weeks are rarer still, so I won't be setting an alarm. Should be some good views taken from the southern hemisphere.

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                                          #95
                                          Anyone for an astronomy thread?

                                          The existence of this would be very interesting. Would this be the much-hypothesised body that occasionally swings by and slings comets into the inner solar system?

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                                            #96
                                            Anyone for an astronomy thread?

                                            Rogin the Armchair Fan wrote: The existence of this would be very interesting. Would this be the much-hypothesised body that occasionally swings by and slings comets into the inner solar system?
                                            So they found Planet X?

                                            [Goes home to prepare for the end of the world]

                                            Part of me thinks, 'how can you miss an entire planet?' The other has only a rudimentary grasp of astronomy.

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                                              #97
                                              Anyone for an astronomy thread?

                                              If it exists, it's dark and a really REALLY long way away. (20 times the distance from the sun as Neptune.) And in the scheme of things, not very big. It's about 10 times as massive as the earth, so what, 3 times the size?
                                              Given that Pluto was a few pixels in our best telescopes until last year, it's no great surprise.
                                              The fact that it needed to be inferred from the gravitational disturbances on tiny objects demonstrates how hard these things can be to find.
                                              For comparison, the Earth is 93,000,000 miles from the sun. That's 1 astronomical unit (AU.)
                                              The perihelion of this planet would be 200 - 300 AUs. The aphelion could be 1000 - 1400 AUs.
                                              That's between 2 and 8 light days away. Which is bloody miles. (130,099,626,101 bloody miles, roughly.)

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                                                #98
                                                Anyone for an astronomy thread?

                                                Hopefully, with gravitational inference they can pin it down somewhat.

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                                                  #99
                                                  Anyone for an astronomy thread?

                                                  So even at 700 times further from the Sun than us this thing would still only be 4 light-days away. Another reminder of just how phenomenally far away a light year is.

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                                                    Anyone for an astronomy thread?

                                                    After listening to a recent episode of the always excellent In Our Time about Saturn, I learned at least 100 things I didn't know. Hearing all about Cassini and the plan for its final plunge, I was intrigued and took a look at the mission website.

                                                    Naturally, I then "lost time" for the next hour here.

                                                    Meat and drink to the astronomers I'm sure, but I'm not one and it's all mind-blowing. I'm going to catch up on the various other planetary missions in future, so there should never be a dull moment again.

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