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Perhaps you’ve already noticed the dazzling red dot dancing in the night sky. That’s Mars, our planetary neighbor. And for the past few weeks it has been growing brighter as it slowly approaches a state that astronomers call opposition, when it and the sun are on opposite sides of Earth. It’s like we’re in between the two right now in a cosmic game of monkey in the middle.
This will occur on Friday, July 27, and everyone in the world can watch, weather permitting.
How often does Mars opposition occur?
Earth and Mars align with the sun in opposition about once every two years.
But truly jaw-dropping midnight views of Mars happen every 15 to 17 years. That’s when opposition occurs when Mars is at perihelion, or its closest position to the sun, according to Rich Zurek, project scientist for NASA’s Mars Reconnaissance Orbiter. This upcoming opposition will be one of those moments.
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When does Mars reach its closest approach?
Mars will be at its closest to Earth before sunrise on July 31 at around 4 a.m. Eastern Time, according to EarthSky.org.
Because Mars and Earth have elliptical orbits rather than perfectly circular ones, opposition and the closest approach between the two planets do not happen at the same time. Mars’s orbit around the sun takes about two Earth years to complete. If the two planets orbited the sun along perfectly circular orbits that were in the same plane, then Mars’s closest approach would happen on the same day as opposition.
In 2003, Mars was at its closest approach to Earth in about 60,000 years, Dr. Zurek said. At that point, it was only about 34.65 million miles away from Earth, according to EarthSky.org.
On average, Mars is about 140 million miles from Earth, according to NASA, and at the farthest, they are about 250 million miles apart, according to Space.com. The close approach happening this month will be the closest since 2003, at a distance of about 35.8 million miles away from Earth, according to NASA.
NASA tends to launch its space missions to Mars during times of closest approach, or every two years. For example, the Mars Exploration Rovers, Opportunity and Spirit, were launched in 2003, the Mars Reconnaissance Orbiter in 2005 and the Mars Phoenix Lander in 2007.
The next closest approach will be in October 2020, and the next super-close opposition will be in September 2035.
Far into the future, Earth and Mars will have another record-breaking meet-up in 2287, when the two will be about 34.60 million miles apart.
What will opposition and closest approach look like?
During these events, Mars will appear as a brilliant crimson orb sticking out amid the white stars that sprinkle the heavens. It will be slightly brighter during opposition than during its closest approach because of the angle at which the sunlight is hitting it.
After the moon, Venus is the brightest object in the night sky, followed by Jupiter. But during this period, Mars will appear as bright or brighter than the gas giant, according to Dr. Zurek.
How can I see it?
Just look up. Mars has been extra bright all month, and it will remain that way for about a month following Opposition. After that it will fade back to its normal glow as it gets farther from Earth. Mars will be at its brightest between July 27 and July 30, according to NASA.
What will I see with a telescope?
Mars is in the middle of a planet-consuming dust storm. Normally, when people gaze upon the red planet’s surface through a powerful telescope, they can discern its dark spots, like the Syrtis Major region, and lighter areas, too. Early astronomers once confused these features for oceans and continents.
But the dust storm is shrouding the surface. Because the dust particles are flying high in the atmosphere, they will reflect sunlight and make Mars look as if it has more bright spots than it normally does, Dr. Zurek said.
“It’s going to be a hazy object and they won’t see some of the classically dark markings that are so prominent on the planet,” he said. Though some skygazers may be disappointed, the colossal dust storm is rare — and the worst NASA scientists have seen on the planet.
The harsh conditions have silenced the Opportunity Rover, which is facing the most serious struggle of its 14-year mission. The solar-powered robot last made contact with NASA in June, and some scientists are concerned they may never hear from it again.
A lunar eclipse, too
For part of the world, Mars won’t be the only orb shining red on the night of July 27.
People living in Africa, Asia and the Middle East will get an extra treat: a lunar eclipse. The moon will turn a copper color as it moves into Earth’s shadow. It will be the longest lunar eclipse of this century, lasting about an hour and 43 minutes in its complete stage, according to EarthSky.org. That’s almost half an hour longer than the lunar eclipse that occurred in January.
But for most of us in the Western Hemisphere and all of us in North America, we’ll miss out on the eclipse and have to settle for just one beautiful red marble in the night sky.