Some daily events in the changing sky for October 5 – 13.
Friday, October 5
Saturday, October 6
Sunday, October 7
Monday, October 8
Tuesday, October 9
Wednesday, October 10
Thursday, October 11
Friday, October 12
Saturday, October 13
Want to become a better amateur astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope. For an easy-to-use constellation guide covering the whole evening sky, use the big monthly foldout map in each issue of Sky & Telescope, the essential magazine of astronomy. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).
Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of maps; the standard is Sky Atlas 2000.0) and good deep-sky guidebooks (such as Sky Atlas 2000.0 Companion by Strong and Sinnott, the even more detailed Night Sky Observer's Guide by Kepple and Sanner, or the enchanting though somewhat dated Burnham's Celestial Handbook). Read how to use them effectively.
More beginners' tips: "How to Start Right in Astronomy".
This Week's Planet Roundup
Mercury (about magnitude +0.5) is very deep in the glow of sunset and fading now. Early in the week, try looking for it with binoculars about 20 minutes after sundown just above the west-southwest horizon. Good luck.
Venus (magnitude –4.7, in Leo) blazes high in the east before and during dawn. Near it are Saturn and Regulus — and on the mornings of the 6th and 7th, so is the crescent Moon. A telescope shows that Venus itself is a crescent, thickening from week to week even as the planet shrinks into the distance.
Mars (magnitude –0.2, in the feet of Gemini) rises around 10 p.m. daylight saving time and shines very high toward the south at dawn — near the zenith, in fact, for mid-northern observers. Compare Mars's fiery color with that of Betelgeuse — which is off to its right or lower right after they rise, and below it in early dawn.
In a telescope, Mars appears gibbous and 10 to 10.5 arcseconds in diameter. It will reach 16" diameter around its Christmas-season opposition. The Martian dust storms of July and August have abated, and while the planet's atmosphere is still bright and hazy with dust, surface features are showing through somewhat better. But they're still low-contrast.
Jupiter (magnitude –2.0, in southern Ophiuchus) glares in the southwest during and after twilight. It sets by midevening. Antares, much less bright, sparkles redly 7° or 8° below it.
Saturn (magnitude +0.7) is the brightest "star" near dazzling Venus in the dawn. Fainter Regulus (magnitude +1.4) is right there too; it's upper right of Saturn.
Uranus (magnitude 5.8, in Aquarius) and Neptune (magnitude 7.9, in Capricornus) are well placed in the southeast to south during evening. Finder charts for them are in the July Sky & Telescope, page 60, and online. With a big scope you can shoot for their faint moons! See the October Sky & Telescope, page 69.
Pluto (magnitude 14.0, in Sagittarius) is sinking in the southwest at dusk.
All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's midnorthern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America. Eastern Daylight Time (EDT) equals Universal Time (UT, UTC, or GMT) minus 4 hours.
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