Star Trak: October 2013

  • Oct. 2, 2013


BLOOMINGTON, Ind. -- Venus will brighten considerably during October and reach its greatest elongation from the sun on Nov. 1. It will set more than two hours after the sun for viewers around 40 degrees north latitude, but it will still be only about 10 degrees above the southwest horizon 45 minutes after sunset, the best time to view it with a telescope.

On Oct. 16, the bright red-orange star Antares will be about 1 degree below the brilliant white planet an hour after sunset. Venus will be more than 100 times brighter than Antares, the brightest star in the constellation Scorpius.

Mars will rise around 3 a.m. EDT at the start of October and a half hour earlier by month’s end. On the morning of Oct. 15, the red-orange planet will pass very close to the bright blue-white star Regulus in the constellation Leo the Lion. Binoculars will give a good view of the enhanced colors of the two objects, the easiest way to tell them apart.

An impressive companion of Mars will be Comet Ison as the two objects travel together across the morning sky during the first half of October. Astronomers expect the comet to be within range of small telescopes early in the month and visible in binoculars by month’s end. 

Jupiter will rise shortly after midnight at the beginning of the month and in late evening by midmonth. The strikingly bright planet will be high in the southeast by the start of morning twilight, the best time for viewing it with a telescope. Jupiter will be 25 times brighter than Pollux, the brightest star in the constellation Gemini the Twins, which will form the backdrop for the planet this month. Any telescope will show Jupiter’s four brightest moons, and this month will be especially favorable for viewing the movements of these moons as they pass in front of the planet and behind it.

For those in the Northern Hemisphere, Saturn and Mercury will be close to the western horizon during October, so low in bright evening twilight that binoculars will probably be needed to see them.

Meteor shower

The Orionid meteor shower will peak before the first light of dawn on the night of Oct. 20-21. The Orionids typically produce up to 25 meteors per hour, which appear to originate from the constellation Orion the Hunter, but this time bright moonlight will wash out the fainter meteors. Orion will rise before midnight in the east-southeast, and the number of meteors will increase as it gets higher above the horizon.

The shower will be active for most of October, with the number of meteors gradually increasing from the start and declining after the peak. The Orionid meteors are dust particles from Halley's Comet, left behind in the comet's orbit.

Moon phases

The moon will be new on Oct. 4, at first quarter on Oct. 11, full on Oct. 18 and at third quarter on Oct. 26.

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