Artist's rendering of a Mars opposition, when the Red Planet and the sun sit on exact opposite sides of the Earth. Distances are not to scale.
UPDATE: See our latest skywatching tips to see Mars at opposition here: Mars Visible
Artist's rendering of a Mars opposition, when the Red Planet and the sun sit on exact opposite sides of the Earth. Distances are not to scale.
UPDATE: See our latest skywatching tips to see Mars at opposition here: Mars Visible in Night Sky, But Its 2 Moons Are Hard to Spot
Mars will make a close approach to Earth Saturday (March 3), and interested skywatchers can follow the action live online.
Every 26 months, the orbits of Earth and Mars align such that the two planets form a relatively straight line with the sun. This cosmic event is called an opposition, because the Red Planet sits on the exact opposite side of Earth from the sun.
Mars will be in opposition to Earth Saturday, and it will be visible even to stargazers under the cloudiest of skies. That's because the online Slooh Space Camera will broadcast a free, real-time feed of the Mars opposition, beginning at 11:00 p.m. EST (0400 GMT on March 4).
Slooh will provide footage from multiple observatories around the world, including Arizona and the Canary Islands off the coast of Africa. The broadcast can be accessed at Slooh's homepage, found here: http://events.slooh.com/
Though the opposition occurs Saturday, the Red Planet's actual closest approach to Earth won't come until Monday (March 5), when the two bodies are separated by about 62.6 million miles (100.7 million kilometers). This discrepancy in dates is caused by Mars' elliptical path around the sun. [Amazing Mars Photos]
The Red Planet's oval orbit also dictates that some oppositions bring it much closer to Earth than others. Saturday's opposition isn't one of the closer ones, because it occurs when Mars is near aphelion, or the farthest it gets from the sun during an orbit.
The Mars opposition of 2003, on the other hand, occurred when the Red Planet was near perihelion, or its closest distance to the sun. During that approach, Mars came within about 34.8 million miles (56 million kilometers) of our planet — the closest the two planets have been in nearly 60,000 years.
Skywatchers who want to observe the Mars opposition the old-fashioned way can find the Red Planet in the constellati