It's been a while since a comet has been visible to observers without optical aid, but that moment has come again, as Comet Hartley is expected to reach magnitude 5 during October.
Comet Hartley in October
Comet Hartley comes its closest to Earth and the sun in October. The comet was discovered in 1986 by Malcolm Hartley in Australia. Comet Hartley makes an orbit around the sun once every six and a half years, but previous passes did not bring the comet as close to Earth as it will be this time. The comet will be just 0.12 astronomical units from Earth. (This is still about 47 times farther away from Earth than the moon.)
The comet has already been viewed by large scope owners as fuzzy and greenish. As the comet gets closer, more reports will roll in as to whether a tail is visible. Comet Hartley begins the months in the constellation Cassiopeia and will track south and end the month crossing from Gemini into Monoceros. The Southern Hemisphere gets a chance to see the comet in November as it continues to sink southward.
Learn more about How to See Comet Hartley.
The Planets in October
Venus is still a stunning magnitude -4.8 and lingering in the sunset's glow. By mid-October, Venus will disappear with the sun and soon after it will reappear in the morning sky.
Once Venus leaves the evening sky, Jupiter will be the brightest point of light in the night. Jupiter is in the southeast, shining at magnitude -2.9. Uranus is still close to Jupiter, but they will begin to separate a bit until they close the space again at the end of the year. Jupiter starts the month closer to Uranus and in the same constellation, Pisces, but by the end of the month Jupiter is in Aquarius.
All four of Jupiter's largest moons are easy to spot as they orbit the planet. The satellites reconfigure themselves each evening. On October 23, Europa is in front of Jupiter in the early evening and Io is behind it, making it appear that there are only two moons (Ganymede and Callisto). But a few hours later both moons will come back into view as first Europa joins the other two planets on one side and then Io slips out from behind the moon on the other side. Our own moon joins the view on October 19 as its waxing gibbous phase can be seen not far above Jupiter.
Mars is also in the evening sky but difficult to see. The Red Planet shines at magnitude 1.4 in the southwest at sunset. On October 9, a thin crescent moon lies right above Venus and right below Mars.
The Hunter's Moon
This October the full moon is called the Hunter's Moon, and it occurs on October 22 at 7:37 p.m. MDT. This will spoil the Orionid meteors, which peak the night before. On October 24 and 25, find the waning moon near the Pleiades star cluster in Taurus.
Source: Celestron's The Sky Software
Kelly Whitt - I have been a professional writer for more than a decade, covering many topics from science-based articles to do-it-yourself home ...
