‘Naked-eye planets’ align for ‘exciting’ spectacle

IOWA CITY - He's used to getting incredulous looks from students when he suggests they head outdoors before dawn to stargaze.

But University of Iowa astronomy professor Steven Spangler said the view this next month could be worth it - even in the subzero temperatures that have settled across Eastern Iowa of late.

For the first time in more than a decade, all of the 'naked-eye planets” - from Mercury to Saturn - will be visible together in the predawn sky. The unique alignment has to do with the planetary orbits, and the last time Mercury, Venus, Mars, Jupiter, and Saturn were configured in a row - or arc, as it be - was January 2005, according to EarthSky.org.

Although the spectacle technically will be visible from now until late February, Spangler said, peak viewing will occur between Jan. 28 and Feb. 5 - in part because a waning moon will transition across the sky into a crescent moon, eventually positioning itself near the planetary lineup.

'That will be exciting to see,” he said.

Stargazers should look to the southeast horizon between 6:30 a.m. and sunrise for the planets, which will shine in an imperfect line from left to right, starting with Mercury, Venus, Saturn, Mars, and Jupiter. Venus will be the easiest to spot, as it's the brightest, and Mercury will be the most difficult.

Some stars could appear planetary at first glance, Spangler said.

'But these planets should be brighter,” he said.

UI astronomy professor Robert Mutel suggested this tip.

'You can easily tell the difference between a planet and a star by looking for twinkling,” he said in an email to The Gazette. 'A star twinkles, whereas a planet doesn't. (Or at least not as much.)”

Mutel, who is on an observing trip in Arizona and said he plans to check out the planetary event during his all-night watches, provided a few more observing tips.

Mercury is

the most challenging to see because it's never very far from the Sun and so is very low on the horizon just before dawn.

One bright

star - called Spica - could be confused for a planet, as it sits along the planetary arc between Mars and Jupiter. But, he said, it should be discernible because it will twinkle.

All five

planets will be whitish in color, except Mars, which will have a faint copper hue.

'Since the planetary arc will slowly change over the next several weeks, it's not important to watch it on a particular morning,” he said.

Mutel and Spangler said the event holds no scientific consequence or opportunity.

'Although it's a beautiful sight to see five planets in an arc across the sky, there is no deep astronomical significance,” Mutel said.

But Spangler said, as an astronomer, he still plans to check out 'these beautiful objects.”

'We enjoy going out and seeing them as much as any other person,” he said.

Although some mythology and even current Internet-fueled debate has suggested planetary alignment could affect weather, gravity, or continental movement, Mutel and Spangler said there is no correlation.

'Pre-modern societies would view these things as having some kind of importance,” Spangler said. 'But what they thought it meant would have differed from one culture to the next.”