Archives for September 2007
Seeing Mercury this week
Published on 30 Sep 2007 at 12:21 pm.
1 Comment.
Filed under astronomy, skywatching.
Mercury swings around the Sun very quickly. It takes only 88 days to make a complete orbit. Being quite a bit closer to the Sun than the Earth, Mercury never seems to stray far from the Sun in the sky. However, it is now about 25° to the east of the Sun […]
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Planetary Symbols
Published on 28 Sep 2007 at 11:43 pm.
4 Comments.
Filed under planets, sky lore.
When I am writing equations in my astronomy class, the students often find that I am using some odd symbols now and then rather than spelling out the names of the planets of the Solar System. Well, that is because in some cases it is easier to just put the symbol in the equation […]
Harvest Moon
Published on 26 Sep 2007 at 1:25 pm.
4 Comments.
Filed under astronomy, sky lore, skywatching.
Full Moon occurs today at 19:45 UT (2:45 pm Central Daylight Time). You may have gone out to look at the Moon the last few nights and thought that it looked full, but really it was not quite full. The Full Moon is defined by the moment that the Moon is most nearly […]
Wolf 359
Published on 25 Sep 2007 at 10:17 pm.
4 Comments.
Filed under stars.
Located in Leo, somewhat south of the classic figure of the Lion, almost on the ecliptic, is a very tiny star called Wolf 359.
Wolf 359 is not very impressive to look at. First of all, it is dim. Shining with a visual magnitude of about 13.46, Wolf 359 is nearly 1000 times dimmer […]
Stellarium
Published on 24 Sep 2007 at 7:05 pm.
15 Comments.
Filed under amateur astronomy.
Last week, I had a couple of posts where I posted a sky view created using computer software. When I was first learning astronomy, this tool was not available. We had star charts, for sure, but you had to do all the work yourself looking at star charts to try to imagine what […]
Equinox ≠ Equal Nights
Published on 23 Sep 2007 at 2:57 pm.
1 Comment.
Filed under astronomy.
This morning, at 09:51 UT (4:51 CDT), the Autumnal Equinox occurred. The term “equinox” has as its root meaning in Latin “equal nights.” Many introductory books about astronomy, and virtually all K - 12 books, say that the equinox is the day that days and nights are equal length: 12 hours of […]
2008 Regolith Excavation Challenge
Published on 22 Sep 2007 at 2:00 pm.
1 Comment.
Filed under space exploration.
One of NASA’s Centennial Challenges is the Lunar Regolith Excavation Challenge, hosted together with the California Space Authority. The proposed rules for the 2008 challenge are now available for comment. The prize for winning the competition is $750,000. No doubt, most teams would spend at least that much, if not considerably more, […]
