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Spellbinding Planets
In the early morning sky, Venus and Jupiter will have a spellbinding close encounter on Nov. 4 and 5.

Two bright planets on opposite sides of the sky--that's nice.

Two bright planets together in the same constellation--even better.

Two bright planets less than one degree apart--that's spellbinding.

Prepare to be spellbound. On Thursday morning, November 4, just before sunrise, you can see the two brightest planets side by side. Near the eastern horizon, shining brighter than the brightest stars, Venus and Jupiter will be less than one degree apart.

Hold your pinky finger at arm's length. The fingertip is about one degree wide. On Nov. 4 you could cover both Venus and Jupiter with the end of your pinky. When two planets appear so close together, they grab your brain's attention. Why? Because they tickle your fovea--a special part of the human eye.

The eastern sky just before sunrise on Thursday, Nov. 4.

Above: The eastern sky just before sunrise on Thursday, Nov. 4. More sky maps: Nov. 2, Nov. 3, Nov. 4, Nov. 5, Nov. 6.

"Your eye is like a digital camera," explains Dr. Stuart Hiroyasu, O.D., of Bishop, California. "There's a lens in front to focus the light, and a photoarray behind the lens to capture the image. The photoarray in your eye is called the retina. It's made of rods and cones, the organic equivalent of electronic pixels."

Near the center of the retina lies the fovea, a patch of tissue 1.5 millimeters wide where cones are extra-densely packed. "Whatever you see with the fovea, you see in high-definition," he says. The fovea is critical to reading, driving, watching television. The fovea has the brain's attention!

cut-away view of the eye

Right: The fovea is responsible for our central, sharpest vision. [More]

The field of view of the fovea is only about five degrees wide. If two objects are going to grab your attention at the same time, they need to fit inside that narrow angle. That's precisely what will happen on Thursday morning: Venus and Jupiter will be so close together that they can beam into the fovea, both at once.

The best time to look is between 5:30 and 6:00 a.m. local time ("local time" is the time where you live). Step outside and face east, toward the rising sun. You can't miss them: Venus and Jupiter are bright enough to see even after the sky begins to turn morning blue. Venus is the brighter of the two.

If you oversleep on Thursday, try again on Friday morning. The pair will be drifting apart, but still close enough to mesmerize.

So early in the morning, so sleepy, so cold! Once your attention gets fixed on Venus and Jupiter you might not notice. Your biggest problem will be forgetting to go back inside. Eventually the sun will rise and break the spell: time for work or school, after a better beginning than usual.

More Information
Don't Miss Next Week's Super Close Meeting Of The Two Brightest Planets Followed By An Exquisite Visit To Each By A Very Old Moon -- from Jack Stargazer

Spaceweather.com -- get the latest news about what's happening in the sky

Venus -- Earth's twin is a hellish world with sulfuric-acid clouds and a smothering atmosphere.

Jupiter -- the biggest planet in the solar system

Close encounters between Jupiter and Venus happen often enough, every year or so. Some, though, are better than others. For instance, on June 17, 2 B.C., the pair drew so near -- just 6 arcseconds (0.002 deg.) apart -- that they merged into a single dazzling point of light. Some scholars believe that was the Star of Bethlehem mentioned in the Bible.

Macular Degeneration -- the fovea is part of the macula. Macular degeneration is a common cause of vision loss among people older than 60 years.

Try this: "Carefully observe the eyes of a friend while he or she is reading a book, and you will see the two eyes rotating from side to side with each line of text. Your eyes are moving in the same way as you read this article. To understand how important this eye movement is, try reading this sentence at a normal distance while keeping your gaze fixed on one word. You will be able to read the words within about two centimeters of the center of your gaze but not the words farther away." The words you can read are the ones that fit inside the field of view of your fovea. This passage comes from a 2001 Scientific America article "The Challenge of Macular Degeneration" by Hui Sun and Jeremy Nathans.

The Mammal Eye and Vision in Mammals
Feature Author: Dr. Tony Phillips
Feature Production Editor: Dr. Tony Phillips
Feature Production Credit: Science@NASA