35.8 million miles is definitely not what most of us would consider “close.” But in planetary terms, close is definitely relative! On July 31, Mars will be 35.8 million miles from Earth, which is the closest it has been to Earth in 15 years. What does this mean for sky watchers? It means the Red Planet will appear super bright, and with its orange-red color, will be hard to miss in the nighttime sky. From July 27-30, the point in Mars’ orbit will come closest to Earth, and will be closest to Earth before sunrise Eastern Time on July 31.
What defines a “close approach?” The minimum distance from the Earth to Mars is about 33.9 million miles and does not happen very often. Because Earth and Mars have elliptical orbits and are slightly tilted to each other, all close approaches are not equal. When Mars slowly approaches what astronomers call opposition, it and the Sun are on opposite sides of the Earth. Earth and Mars align in opposition about every two years (fun fact: this is why most NASA missions to the Red Planet are at least two years apart – to take advantage of the closer distance). Opposition to Mars is at its closest to the Sun every 15 to 17 years, when excellent views of the Red Planet from Earth can occur. This is what is happening on the early morning hours of July 31.
Is 35.8 million miles the closest Mars has ever been to Earth? Nope. In 2003, Mars was 34.6 million miles from Earth and the closest it had been in nearly 60,000 years. This type of proximity won’t occur again until 2287. But, there will be another close approach in October 2020 when the distance between the Red Planet and Earth will be 38.6 million miles.
Now that we’ve gotten all of that out of the way, what does this mean for you, the novice astronomer or general sky-watcher? It means that if you have clear skies where you live, go outside on the overnight hours of July 30 or early morning hours of July 31 and look up. The planet will be brighter than usual and will have an orange or red haze. You can also look through a telescope. If weather is bad where you are, NASA will be streaming live from the Griffith Observatory.
The graphic below illustrates the five planets as they are visible, with the naked eye, from Huntsville, Alabama. It shows their positions in the sky around 6:30 AM during the week of January 18 and continuing for the next few days. Mercury will be close to the Sun, over in the East, and Jupiter will be over in the West, with Venus, Saturn, and Mars between the two. Pluto is near Mercury, but is invisible to the eye, requiring a telescope for viewing.
The last time an alignment such as this occurred was about 10 years ago. This pre-sunrise configuration will be similar for other northern latitudes.
In the graphic, the yellow line is the ecliptic, which is the plane of the Earth’s orbit. The orbits of the major planets lie close to this plane, which is why they appear close to the ecliptic in the night sky.
Dust off your telescope and prepare for a spectacular viewing opportunity of Mars in the night sky. The Earth will fly between the sun and Mars on April 8, 2014, and, for the several weeks around that time, Mars will be rising in the east when the sun is setting in the west. Mars will be at its brightest and best fiery red color.
Now is a good time to start watching for Mars in the night sky. Mars will look like a bright red star, although it shines with a steadier light than the twinkling stars. Mars rises in the east at mid-to-late evening. By the time April rolls around, Mars will be shining from dusk till dawn.
Make note on April 13 and April 14 on your calendar. A bright waxing gibbous moon will pair up with the red planet on the night of April 13-14; the totally eclipsed full moon will couple up with Mars on the night of April 14-15.
Mars with its mysterious dark markings and a white polar cap will be easily visible in April’s night sky. Image Credit: NASA
With a complicated launch manifest on the range in Florida, LRO/LCROSS has already had to wait its turn behind other launches. The latest space shuttle mission to the International Space Station delayed LRO and LCROSS launch once more with a leaking hydrogen valve. Summer weather at Cape Canaveral is fraught with thunderstorms that could challenge a launch, but with any luck, technology and weather will cooperate and the lunar missions will get to take off just a couple of days behind schedule.
Even so the moon is back in our sights. We know many facts about the moon, more than we know about any world beyond our own except perhaps Mars, yet we have barely begun to solve its countless mysteries. Our nearest neighbor is a witness to 4.5 billion years of solar system history, and it has recorded that history more completely than any other planetary body. Nowhere else can we see back with such clarity to the time when Earth and other terrestrial planets were formed and life emerged. Since we’ve already been to the moon, why go back? Most don’t realize that we’ve only scratched the surface as far as our closest celestial neighbor is concerned.
Whatever happens with launch this week, there is high anticipation for these first NASA steps back to the moon in many years. They are the precursors to a much broader knowledge of our neighbor and a potential human return to the moon. It won’t be long before we can look up at the moon, and who doesn’t nearly every day, and know that LRO is bathing the companion of our night sky with its laser altimeter and opening the wide eyes of its cameras for what are sure to be astounding views. And we can look forward to an October fireworks show as LCROSS impacts the moon and exposes minerals that have been hiding for billions of years. Even if you don’t live in an area where the impact is visible, the streaming images online are going to be amazing.
Only by returning to the moon to carry out new scientific explorations and prepare for a potential human return can we hope to narrow the gaps in understanding and learn the secrets that the moon has kept for eons.