Mars was at Its Biggest and Brightest for a Decade

Here’s how to get prime views of the red planet as it gets the closest it’s been to Earth since 2005.

By Andrew Fazekas
Photographs By NASA, ESA, the Hubble Heritage Team (STScI/AURA), J. Bell (ASU), and M. Wolff (Space Science Institute)

The red planet was the closest it has come to Earth since November 2005.

At exactly 10:00 a.m. UT on May 22, Mars reached what astronomers call opposition. This is when the sun, Earth, and Mars are aligned in a straight path so that Mars appears to rise in the east just as the sun sets in the west, making the sunlit side of the planet visible all night long.

Mars also makes its closest approach to Earth on May 30, coming just 46.7 million miles away. These two events so close together mean that the red planet will appear unusually large and bright through telescopes for the next few weeks.

While you shouldn’t expect Mars to be as big as the full moon, as many online hoaxes in past years have suggested, this opposition will be your best bet to see the red planet until 2018.

That’s because Mars reaches opposition only once every 26 months, when Earth manages to overtake the planet in its tighter track around the sun. But unlike Earth’s more circular orbit, Mars’s path is fairly elliptical. That means the distance between the two worlds varies, making some oppositions better than others.

The previous best encounter occurred back in August 2003, when Mars was a record-breaking 35 million miles distant. Such ideal conditions won’t happen again until 2287.

While we weren't as close for this opposition, Mars will still outshine most of the brightest springtime stars and rode high in our sky.

In addition to offering beautiful views, opposition has traditionally set the stage for robotic invasions of Mars. Because of Mars’s proximity and alignment with our planet, the time around opposition is the best for sending spacecraft, saving travel time and fuel costs.

This year, the European Space Agency's ExoMars Trace Gas Orbiter launched in March and is now heading for Mars, and plans for possible future human missions will also be timed around opposition.

Mars and Company

Many keen-eyed onlookers noticed the fiery planet growing brighter in our night skies the past few months before the event, making it easy to spot with nothing more than the naked eye as one of the brightest starlike objects in the heavens.

This opposition favored observers in the Southern Hemisphere, because the planet will travel through the southern constellations of Ophiuchus, Scorpius, and Libra. But observers in more northerly locations across the globe got impressive views.

The full moon made a spectacular pairing with Mars on the night of May 21, making the red planet even easier to hunt down. The two brilliant objects dominated the overnight hours, traveling together while appearing to be separated by only five degrees, equal to the width of three middle fingers held at arm’s length.

Adding to the cosmic spectacle, Mars was joined by the yellow-colored ringed planet Saturn and the red giant star Antares.

Red Planet Up Close

Most of the time Mars is not much to look at through a telescope, because it's just a tiny, fuzzy, orange-hued dot; however, all that changes during opposition, when the planet becomes a disk filled with tantalizing features.

Even a small telescope with about a six-inch mirror can tease out surface details like the southern white ice cap and distinct, dark regions that are windswept rocky fields.

As we step outside this weekend and look up, it's amazing to think that the ruddy color of Mars we can see with just our unaided eyes is caused by sunlight reflecting off the iron-rich dust covering this barren but intriguing world.

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