Illustration courtesy Caltech/NASA

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The Mars Rover Curiosity approaches the red planet in an artist's conception.

Illustration courtesy Caltech/NASA

Sky Show Sunday: Planets to Align for Mars Rover Landing

See Mars, Saturn, and the bright star Spica form "Martian Triangle."

A striking pregame show featuring Mars, Saturn, and the star Spica will set the stage Sunday for the landing of the Curiosity rover. (Pictures: Mars Rover's "Crazy" Landing, Step by Step.)

Hours before Curiosity's touchdown, "the stellar trio will be visible high above the southwest horizon after sunset and together form what is called the Martian Triangle," said Jim Todd, planetarium manager at the Oregon Museum of Science and Industry. (Get the basics on the Mars Curiosity rover.)

See video: Mars Landing Sky Show

"Shining bright ... Mars will be visible towards the right of Saturn, while Spica is below the two planets."

Visible to the naked eye, the bodies will appear separated by only five degrees on each side—equal to the width of a fist. Yet their proximity is only an optical illusion, as they are at considerable distances from each other, Todd said.

Fortuitous Conjunction

Called a conjunction—when celestial objects get close to each other in the sky—this eye-catching equilateral triangle is not rare. But its timing with the Mars rover is fortuitous.

At about 1:24 a.m. ET on Sunday, Curiosity's entry capsule will slam into Mars's upper atmosphere in what has been dubbed the seven minutes of terror: the rover's entry, descent, and landing.

With the cosmic trio sinking below the local western horizon shortly before the Mars mission lands, there will be plenty of time to soak in both space events. "After the Martian Triangle sets, go inside and turn on NASA TV for the historic Mars landing," Todd suggests.

Colorful Martian Triangle Easy to See

While this cosmic grouping can be enjoyed with the naked eye, the event makes for a great opportunity to get a closeup view of the planets, he said. Even the smallest of backyard telescopes will reveal the rings around Saturn and the tiny, but distinctly orange-hued, disk of Mars. (Available now: the new National Geographic e-book Mars Landing 2012.)

Particularly pretty through binoculars will be the color contrast among golden-yellow Saturn, orange-red Mars and whitish-blue Spica—the lead star in the constellation Virgo, he said.

Sky-watchers will have an added treat on August 21, he added, when the waxing crescent moon will hang below the cosmic trio as Mars switches places with Saturn.

On TV: Martian Mega Rover, Thursday, August 9, 2012, at 10 p.m. ET/PT