Sky Watch: October 2013

September 30, 2013
Sky Watch

Here are the monthly sky watch highlights. Each month, we share the wonders of the universe to help you explore the night sky from your own backyard. (Note: Times listed below are ET.)

October 2013

by Bob Berman, as featured in
The Old Farmer's Almanac

Saturn is getting quite low in the west, joining horizon-hugging Venus, which, though still a mere 10 degrees up in fading twilight, brightens to magnitude –4.5 this month. Green Uranus reaches opposition at magnitude 5.7 in Pisces on the 3rd. It’s an easy target in binoculars and faintly visible to the naked eye in dark skies, especially during this moonless period. The thin crescent Moon hovers between Mercury and Saturn on the 6th, a low conjunction visible to southern observers. The Moon is to the right of Venus on the 7th and to the right of Jupiter on the 24th. The giant planet now rises by 11:00 P.M. and can be well observed after midnight.

Sky Map October 2013

by Jeff DeTray
Visit Jeff's site at

Astronomer Jeff DeTray has created the sky map below to help you navigate the night sky.

This month's highlight: Two planets, the Twins, and a comet you can't see … YET!

Although we usually think of sky gazing as something to be done in the evening, the pre-dawn hours are every bit as rewarding. October offers early risers some delightful treats.

The brightest object on this month's map is the planet Jupiter, a bit more than halfway up from the horizon. Jupiter is currently located in the constellation Gemini, the Twins, brothers Castor and Pollux. In mythology, Castor was mortal and Pollux immortal. When Castor was killed, Pollux asked Zeus for permission to share his immortality with his twin brother, and they now reside together, forever in the night sky. On this month's map, the twins are reclining, heads down, with their legs stretched out toward the bright star Betelgeuse. The stars Castor and Pollux represent the twins' heads, and they are often depicted holding hands, a symbol of true brotherly love.

Nearer the horizon, look toward bright Regulus in the constellation Leo, the Lion, and you'll see the planet Mars just to its left. Notice the color difference between the two. Regulus is very white, while slightly dimmer Mars has a warmer, yellowish hue. Mars, of course, is known as the Red Planet, but we see it as yellowish unless we're looking through a powerful telescope.

Very near Mars and Regulus is Comet ISON, but the comet is currently too faint to be seen with the unaided eye. Why mention it at all? Because Comet ISON may become a spectacular bright comet later in the year.

Comet ISON is named after the International Scientific Optical Network, one of whose telescopes was used to discover it. The comet has been watched by astronomers for more than a year as it falls toward the Sun from the deep reaches of our solar system. Like most comets, ISON will brighten as it approaches the Sun. By November, it may brighten enough to become visible to the unaided eye. The key word is “may.” The brightness of comets is notoriously difficult to predict. Sometimes, a comet will brighten to a certain point, then brighten no further.

What's exciting about Comet ISON is that we will get a viewing opportunity in November, and perhaps another chance in December. It all depends what happens on November 28 – Thanksgiving Day in the United States. On that day, Comet ISON will reach the Sun, pass very close to it, swing around it, and then … well, no one is quite sure what will happen! The possibilities include:

1. The comet will be vaporized by the Sun, never to be seen again.
2. The Sun's gravity will break the comet into small fragments that will drift apart, and none of the fragments will be very bright.
3. The comet will break into fragments that will remain close together and therefore reasonably bright.
4. Comet ISON will withstand the Sun's energy, remain intact, and emerge from the encounter greatly brightened, with a lovely long tail of dust and gas.

At this point, we just don't know. We'll have more information about Comet ISON next month. In the meantime, if you have large binoculars or a small telescope, you may be able to see Comet ISON as a faint smudge near Mars in mid-October. Let's all hope for a brighter view in the months ahead!

OCTOBER Sky Map: Click to View PDF

October 2013 Sky Map

Sky map produced using Chris Marriott's Skymap Pro

Explore the sky night from your own backyard. A printable black and white map is provided below!

October 2013 Sky Map PrintableClick for Printable Sky Map (PDF)
Just click, print, and bring outside!


Reader Comments

Leave a Comment

Hi Cassandra, If you were

The Editors's picture

Hi Cassandra,

If you were looking toward the west-southwest, you may have seen the planet Venus as it was slowly setting. However, no planet or star would suddenly change speed as you describe.

My guess is that you saw Venus and that by coincidence, an aircraft flew into the same part of the sky just as Venus was setting. This could make it seem that Venus itself had suddenly changed speed.

Jeff DeTray

On October 5&6 of 2013. My

On October 5&6 of 2013. My spouse and I from Victorville, CA. Witnessed a bright star in the sky. we've kept watch on it from 5pm to 9pm. We watched it slowly move down and then suddenly it began to move fast and it disappered. We would like to know exactly what it was we were seeing.

The speeding up part could be

The speeding up part could be part of an optical illusion. The closer your star got to the horizon the faster it looks like it is moving.