Some daily celestial sights among the ever-changing stars and planets
Friday, October 3
As evening twilight fades away, look very far to the lower left of the Moon for Fomalhaut, the Autumn Star, already climbing up from the southeast horizon.
Saturday, October 4
The W pattern of Cassiopeia 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 live in the mid-northern latitudes. As far south as San Diego and Jacksonville, the Dipper will lie partly below the horizon.
Sunday, October 5
Look above the gibbous Moon this evening for the Water Jar asterism of Aquarius. It's not bright; you may need binoculars.
Monday, October 6
As twilight fades, look for Arcturus, the Spring Star, twinkling in the west to west-northwest. It's still pretty easy to see. But how much later into the fall, as it sinks away, will you be able to keep it in view?
Tuesday, October 7
Total eclipse of the full Moon happens before dawn Wednesday morning for North and Central America; Wednesday evening for Australia and eastern Asia. See our article, Wake Up to a Total Lunar Eclipse on October 8.
Earlier in the evening for North America, look above the bright full Moon for the Great Square of Pegasus tipped onto one corner.
Wednesday, October 8
Altair is the brightest star high in the south at nightfall. Very far to its lower left (about six fist-widths) is Fomalhaut, almost as bright.
Thursday, October 9
Mars still shines low in the southwest at nightfall. Look to its left, by about two fist-widths at arm's length, for the fist-sized Teapot of Sagittarius. (You'll need an open view toward the south-southwest.) As the season advances and the Teapot moves lower, it tips ever farther to pour out its last drops.
Friday, October 10
The waning gibbous Moon is up in the east by 9 or 10 p.m. Look left of it (by about a fist-width at arm's length) for the Pleiades. Much farther left, in the northeast, shines Capella in Auriga.
High above the Moon and Capella, forming a big triangle with them, is the naked-eye eclipsing variable star Algol. It should be at its minimum light, magnitude 3.4 instead of its usual 2.1, for a couple hours centered on 12:36 a.m. tonight EDT; 9:36 p.m. PDT. Algol takes several additional hours to fade and to recover. Info and comparison-star chart.
Saturday, October 11
The Moon late this evening shines near Aldebaran amid the Hyades. Take a look with binoculars. This will be a challenging scene to photograph (use a long lens), what with the Moon's brilliance and the Hyades stars' faintness.
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).
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
Mercury is hidden in the glare of the Sun.
Venus (magnitude –3.9) has sunk away deep into the sunrise.
Mars (magnitude +0.8) is low in the southwest during dusk. Look for twinklier orange Antares (magnitude +1.0) ever farther to Mars's lower right.
Jupiter (magnitude –1.9, at the Cancer-Leo border) rises in the east-northeast around 2 or 3 a.m. It shines brightly high 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 Antares, which is lower right of Mars.
Uranus (magnitude 5.7, in Pisces) and Neptune (magnitude 7.8, in Aquarius) are high in the southeast and south, respectively, by 10 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.