What a week this is for Mars. In the next four days, the planet attains all-night visibility and will be located very near the full moon - the closest moon to Earth since 2008. Even better, Mars will become brighter and closer (61.7 million miles from Earth) than it will again for more than four years.

To the naked eye, Mars will be the bright, golden-orange and steady-shining point of light in the eastern sky each day at nightfall. On Wednesday, there is a free event at Rowan University in southern New Jersey where you can look through telescopes at the globe of Mars itself - or hear talks on Mars if the weather is bad.

Mars at opposition and at its closest: The best view of any planet farther from the sun than Earth occurs when that planet is opposite from the sun in our sky. This arrangement is called opposition, and when it happens, the planet rises at sunset, is highest at about midnight and sets at about sunrise. Earth only catches up to the slightly slower Mars for an opposition once in a little more than 2 years. The next opposition of Mars occurs Friday.

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Opposition does not just make a planet visible all night. When opposition occurs, we have a lineup of the sun, Earth and the other planet in space, therefore the planet is typically closest, biggest and brightest.

The time Mars is closest to Earth and exactly how close it comes deviates considerably due to an interesting fact: the orbit of Mars is far less circular than Earth's. As a result, during some oppositions of Mars - like the one in 2003 - Mars comes almost twice as close as it does during other oppositions - like the one this week.

The lopsidedness of Mars' orbit also means Mars can come closest several days before or after opposition. This year, Mars is closest on Wednesday, two days before opposition, on the same night of a free open house for the Mars event at Rowan University in Glassboro, Gloucester County.

Mars viewing and talks at Rowan: The open house at Rowan's Science Hall on Wednesday will offer short planetarium shows at 6:30 p.m. and 7:30 p.m. and the opening of the rooftop observatory at 7 p.m., weather permitting. If the weather is cloudy, the planetarium shows will still be held, along with a number of indoor talks about Mars. I hope to see some of you readers there.

Mars and the closest full moon: When Mars reaches opposition Friday, it will rise to the left of the moon. The moon will also be at opposition to the sun - and it will be a full moon. What's more, this will be the closest, biggest moon since the rare one seen Dec. 12, 2008.

The exact moment of the full moon will be 1:18 a.m. Saturday. The exact moment of perigee, or the moon's closest approach to Earth, will be only 2.7 hours later (very high tides are expected). The moon will then be only 221,600 miles away - less than 7 percent of its average distance from Earth.

Fred Schaaf is a local author and astronomer. He can be reached at:


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