Quarks to Quasars

Mars Now at Most Extreme Distance from the Sun

• Mars is at its farthest point from the sun in its approximate 2-year orbit.
• Coincidentally, Mars is also fast-approaching opposition, the period in its orbit that brings the planet closest to Earth.

Wednesday (Feb. 15), the red planet Mars swings to aphelion — its farthest point from the sun in its approximate two-year orbit. This chart helps to illustrate Mars, the fourth planet outward from the sun, at aphelion.

In their order going outward, the four inner rocky planets planets are Mercury, Venus, Earth and Mars. The four outer gas giant planets — Jupiter, Saturn, Uranus and Neptune — lie well outside chart.

You can see Mars this evening — or any evening in the coming months — for yourself. The best time to see Mars in this two-year period is almost here, with Earth due to pass between Mars and the sun on March 3, 2012.

Wednesday night, Mars rises above the eastern horizon around 8 to 9 p.m. (local time, as seen from around the globe). The planet is located now in front of the constellation Leo the Lion. Mars, the fourth planet outward from the sun and the next planet outward from Earth, should be fairly easy to spot because the distance between our two worlds is nearly at its least now for this two-year period. Because it’s relatively close, Mars looks like a bright reddish star.

On March 3, 2012, Earth will pass in between the sun and Mars, bringing Mars to opposition. Because Mars stands opposite the sun in our sky at opposition, Mars will rise in the east at sunset and set in the west at sunrise, to stay out all night long in early March 2012. At present, Mars shines from evening until morning dawn.

This 2012 opposition of Mars nearly coincides with Mars at aphelion — Mars’ greatest distance from the sun. Because of this close coincidence of aphelion and opposition, the year 2012 gives us Mars’ farthest and dimmest opposition since its opposition on Feb. 12, 1995. Looking ahead, we won’t see a more distant opposition again until Feb. 19, 2027.

As a general rule, Mars reaches opposition every other year, and far-distant Martian oppositions recur every 15 to 17 years. Extra-close oppositions, whereby an opposition closely aligns with perigee — Mars’ closest point to the sun — also happen in cycles of 15 to 17 years. The last extra-close opposition took place on Aug. 28, 2003, and the next one will be on July 27, 2018.

But any opposition of Mars — whether it’s near or far — counts as extra special. It’s at or near opposition that Earth comes closest to Mars for the year, and that Mars, in turn, shines most brightly in our sky. Watch for Mars to brighten these February 2012 nights, in spite of the fact that this upcoming opposition will be the most distant one in years.