This Week’s Sky at a Glance, Sept. 26 – Oct. 4

Moon passing Saturn, Mars and Antares

The waxing crescent Moon works its way eastward above the star-and-planet display low in the southwestern twilight. (These scenes are plotted for the middle of North America.)

Friday, September 26

As early as 8 or 9 p.m. now look for Fomalhaut, the lonely 1st-magnitude Autumn Star, twinkling on its way up from the southeast horizon. It will be highest due south around 11 or midnight (depending on your location).

Saturday, September 27

Low in the southwest in twilight, Mars and Antares are passing 3° apart this evening and Sunday evening, as shown above. Meanwhile, off to their right, the waxing crescent Moon floats a couple degrees to the lower right of Saturn (for North America).

Sunday, September 28

Spot the Moon in the southwest as twilight fades. Use it as your guide to Saturn far to its lower right, and the Mars-Antares pair to its left (as shown above).

Monday, September 29

The thick waxing crescent Moon now stands above Mars and Antares at dusk (as shown above).

Tuesday, September 30

Arcturus is the bright star due west at nightfall. It's an orange giant 37 light-years away. Off to its right in the northwest is the Big Dipper, most of whose stars are about 80 light-years away. They're both sinking lower every week now.

Wednesday, October 1

First-quarter Moon (exact at 3:33 p.m. EDT). The Moon shines above the Sagittarius Teapot in the south at nightfall.

Thursday, October 2

Look high above the Moon at nightfall for Altair. Crossing the zenith (for the mid-northern latitudes) are the other two stars of the Summer Triangle: Vega and Deneb.

Friday, October 3

As early as 8 p.m. now look for Fomalhaut, the Autumn Star, on its way up from the southeast horizon. This evening it's very far lower left of the Moon.

Saturday, October 4

The W of Cassiopeia now stands vertically (on its dimmer end) high in the northeast around 10 or 11 p.m., depending on your location. By then the Big Dipper is lying level just above the north-northwest horizon — if you're in the mid-northern latitudes. As far south as San Diego and Jacksonville, the Dipper will lie partly below the horizon.

Make your plans for catching the total eclipse of the Moon next Wednesday, October 8th. It will happen before or during dawn for North America, and on the evening of the 8th local date for Australia and the Far East. Uranus will be near the eclipsed Moon. See the October Sky & Telescope page 50, or the version online: Wake Up to a Total Lunar Eclipse on October 8, 2014.


Want to become a better astronomer? Learn your way around the constellations. They're the key to locating everything fainter and deeper to hunt with binoculars or a telescope.

This is an outdoor nature hobby; for an easy-to-use constellation guide covering the whole evening sky, use the big monthly map in the center of each issue of Sky & Telescope, the essential guide to astronomy. Or download our free Getting Started in Astronomy booklet (which only has bimonthly maps).

Pocket Sky Atlas

The Pocket Sky Atlas plots 30,796 stars to magnitude 7.6 — which may sound like a lot, but it's still less than one per square degree on the sky. Also plotted are many hundreds of telescopic galaxies, star clusters, and nebulae.

Once you get a telescope, to put it to good use you'll need a detailed, large-scale sky atlas (set of charts). The standards are the little Pocket Sky Atlas, which shows stars to magnitude 7.6; the larger and deeper Sky Atlas 2000.0 (stars to magnitude 8.5); and once you know your way around, the even larger Uranometria 2000.0 (stars to magnitude 9.75). And read how to use sky charts with a telescope.

You'll also want a good deep-sky guidebook, such as Sue French's Deep-Sky Wonders collection (which includes its own charts), Sky Atlas 2000.0 Companion by Strong and Sinnott, the bigger Night Sky Observer's Guide by Kepple and Sanner, or the beloved if dated Burnham's Celestial Handbook.

Can a computerized telescope replace charts? Not for beginners, I don't think, and not on mounts and tripods that are less than top-quality mechanically (able to point with better than 0.2° repeatability, which means fairly heavy and expensive). As Terence Dickinson and Alan Dyer say in their Backyard Astronomer's Guide, "A full appreciation of the universe cannot come without developing the skills to find things in the sky and understanding how the sky works. This knowledge comes only by spending time under the stars with star maps in hand."


This Week's Planet Roundup

Jupiter and Regulus before dawn, October 2014

It's only October, but already you can spot the Sickle of Leo before dawn. Jupiter marks the way.

Mercury (magnitude +0.2) has sunk deep into the glow of sunset.

Venus (magnitude –3.9) has sunk deep into the sunrise.

Mars (magnitude +0.8) is low in the southwest during dusk, passing above similarly colored but twinklier Antares (magnitude 1.0). They'll be 3° apart on September 27th and 28th, then will start to widen as Mars moves east.

Jupiter (magnitude –1.9, at the Cancer-Leo border) rises around 2 or 3 a.m. and shines brightly in the east before and during dawn. It forms a big triangle with Pollux above it (by about two fists at arm's length) and Procyon to their right. Look below Jupiter and a bit left for Regulus.

Saturn (magnitude +0.6, in Libra) is sinking away into the afterglow of sunset. Look for it well to the right of the Mars-Antares pair, and probably a little lower depending on your latitude.

Uranus (magnitude 5.7, in Pisces) and Neptune (magnitude 7.8, in Aquarius) are high in the southeast and south, respectively, by 10 or 11 p.m. See our Finder charts for Uranus and Neptune online or in the September Sky & Telescope, page 50.


All descriptions that relate to your horizon — including the words up, down, right, and left — are written for the world's mid-northern latitudes. Descriptions that also depend on longitude (mainly Moon positions) are for North America.

Eastern Daylight Time (EDT) is Universal Time (UT, UTC, or GMT) minus 4 hours.


“This adventure is made possible by generations of searchers strictly adhering to a simple set of rules. Test ideas by experiments and observations. Build on those ideas that pass the test. Reject the ones that fail. Follow the evidence wherever it leads, and question everything. Accept these terms, and the cosmos is yours.”

— Neil deGrasse Tyson, 2014.


 

One thought on “This Week’s Sky at a Glance, Sept. 26 – Oct. 4

  1. mary bethmary beth

    Wow! What a beautiful sight to see Mars and Antares dangling from the crescent moon! I had to double check to make sure I knew which one was Mars :)!

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