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Дата изменения: Thu Jun 23 13:25:08 2005 Дата индексирования: Tue Oct 2 04:06:19 2012 Кодировка: Поисковые слова: europa |
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From: TerryMoselaol.com Date: Tue, 21 Jun 2005 20:29:02 EDT Subject: Longer nights, ISS, Nice conjunction, Jupiter Hi all, 1. Good news for all astronomers - the nights are getting longer again - at least for those of us in the N. Hemisphere! The effect doesn't really become noticeable until about mid-July, but every little helps! But the latest sunset of the year, in our latitudes, does not occur until 25 June. 2. The ISS is now giving another series of night-time passes above Ireland, at first just in the early mornings (i.e. after midnight), but soon those will extend into the late evenings, at least by clock time (BST). Get details for your location from www.heavens-above.com. 3. A CLOSE CALL! One of the best planetary conjunctions for many years to come is getting under way. As from tonight, Saturn, Venus and Mercury will all lie within a circle only 5 degrees across low in the evening twilight. And they will gradually get closer, with Venus and Mercury in particular having a VERY close pass. Brilliant Venus currently lies in the middle, with brightish Mercury to its right, and fainter Saturn further away to its left, all three in a straight line. Mercury and Saturn then both close in on Venus, from opposite directions. You'll almost certainly need binoculars to see Saturn, and they'll help for Mercury too. DO NOT observe with binocs or a telescope anywhere near the Sun in the sky! If you want to try to observe these planets before sunset, stand somewhere from where the Sun is hidden, e.g. by a building or tree. Here are some details, for June evenings in Ireland: 22nd: Mercury, Venus & Saturn now within 5 degrees of each other. 24th: All are closer, Saturn is starting to dip below the original straight line. 25th: Venus and Mercury now very close, Saturn starting to pass below and left of Venus. 26th: Mercury, Venus & Saturn inside a circle about 1.5° across, Saturn vertically below the other pair. 27th, 18 30: Mercury & Venus closest, about 4' apart, and still only about 6' apart later in the evening twilight; Saturn lies 2.25 degrees to the lower right. 28th: Mercury now lies close to the left of Venus; much fainter Saturn is now 3.25 degrees to the lower right of Venus, and probably very hard to see in the bright twilight. The Mercury-Venus conjunction is a very close one: even in the later twilight on the 27th, when they have passed their closest point, they will still be only about 1/5 of a moon diameter apart! Telescopes and cameras at the ready, everybody! 4. Giant planet JUPITER gives a grand finale performance with a series of satellite events on 27/28 June. There are 4 events, with two sets of triple overlaps. How many can you see before Jupiter gets too low? For convenience, I'll give the times in BST: 22.00: Io transit starts. 22.18: Europa transit starts 23.15: Io shadow transit starts 00.11: Io transit ends 00.54: Europa shadow transit starts 01.01: Europa transit ends 01.25: Io shadow transit ends 03.23 Europa shadow transit ends. The latter will be too late for anywhere in Ireland, but observers in the far SW should just be able to catch all the others, and even in the North end of the island it will theoretically be possible to see at least part of all four events. Send any observations of this, and of anything else, particularly photos of the ISS and the planetary conjunction, to Andy McCrea for STARDUST andrew
mccreaa.freeserve.co.uk and to John Hall for the website Jimmyaquarius
btinternet.com Clear skies, Terry Moseley
Last Revised: 2005 June 23rd
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