Mercury, our solar system’s innermost planet, is just visible above the western horizon shortly after sunset.
Due to the shallow angle of the ecliptic (apparent path of the sun and planets across the sky) at this time of the year, Mercury does not rise very high above the horizon, Though fairly bright (mag. -0.1), you’ll need an unobstructed view and good seeing conditions to spot this planet this month.
You’ll also need binoculars or a scope to spot Saturn (mag. 0.6) this month. One of your best opportunities to see Saturn (and Mercury) will be on the evening of Oct. 6. Look for Saturn slightly above the thin, two-day old, crescent moon. Mercury will be to the lower left of the moon. By the third week of October, both planets are lost in the glare of the setting sun.
Venus continues to shine brilliantly in the SW sky just after sunset all month long. On the evening of Oct. 7, the waxing, crescent moon sits to the right of Venus. The next evening, the moon will appear to the upper left of Venus. Brightening slightly from mag. -4.2 to -4.5 this month, Venus will be an easy object to spot each clear evening.
Jupiter (mag. -2.3) rises shortly after midnight as October opens, and during the late evening by mid-month. High in the SE as the morning twilight begins, Jupiter and its four largest moons — Io, Europa, Callisto and Ganymede — will present good viewing targets.
Mars (mag. 1.6) joins Jupiter in the eastern, pre-dawn sky, rising around 3 a.m. as October starts and about a half hour later by month’s end. Though not a vivid observing object right now, Mars will draw a lot of attention in October, due to its travelling companion this month, Comet ISON.
All eyes will turn to the pre-dawn, eastern sky this month as Comet ISON makes its long-awaited debut in our northern skies. The comet will track alongside of Mars during the first half of October. As the month opens, Comet ISON will sit approximately 2 degrees (4 times the diameter of the full moon) north of Mars.
By the middle of the month, this distance will be only 1 degree. Much is expected of this virgin comet as its makes its maiden voyage through our solar system. It remains to be seen whether it lives up to all the hype and becomes the “comet of the century” as everyone is hoping. We won’t get a true picture of what Comet ISON’s performance might be until the end of the month, when the comet makes its perihelion (closest approach to the sun) swing around the sun, and reappears in our sky.
If it survives its trip around the sun, the best views will come in November and December. For the latest updates and tracking paths of the comet, either Google Comet ISON or go to www.skyandtelescope.com, www.astronomy.com or skypub.com/ison.
With this year’s Orionid meteor shower (radiant in Orion - the Hunter) being washed out by the gibbous moon during its peak in the pre-dawn hours of Oct. 21, meteor buffs will have to settle for the Southern Taurid (radiant in Taurus - the Bull). This minor meteor shower peaks in the pre-dawn Oct. 10 sky. The crescent moon will have set earlier in the evening, so conditions should be good, weathering permitting. Though few in number on an hourly rate at peak (five to 10 per hour), the Taurids more than make up for it by their bright, slow trails across the sky, making for good astro-photos.
October’s full moon on Oct. 18 is often referred to as the Hunter’s Moon.
Until next month, clear skies and good comet hunting.
Oct. 4 — New moon; 9:35 p.m.
Oct. 10 — Southern Taurid meteor shower peaks in pre-dawn sky; Moon at perigee (closest to Earth); 367,667 kms.; 8:14 p.m.
Oct. 11 — First quarter moon; 8:02 p.m.
Oct. 18 — Full (Hunter’s) moon; 8:38 p.m.
Oct. 25 — Moon at apogee (farthest from Earth); 402,208 kms.; 11:24 a.m.
Oct. 26 — Last quarter moon; 8:40 p.m.
Glenn K. Roberts is a member of the Charlottetown Centre of the Royal Astronomical Society of Canada (RASC). His column appears in The Guardian once a month. He welcomes comments from readers. Anyone who would like to comment on his column is encouraged to email him at email@example.com.