Photos: The greatest hits from Mars

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  1. The face of Mars

    The Hubble Space Telescope focuses on the full disk of Mars, with a head-on view of a dark feature known as Syrtis Major. Hubble astronomers could make out features as small as 12 miles wide. (AURA / STSCI / NASA) Back to slideshow navigation
  2. Red, white and blue planet

    Two decades before Pathfinder, the Viking 1 lander sent back America's first pictures from the Martian surface. This 1976 picture shows off the lander's U.S. flag and a Bicentennial logo as well as the planet's landscape. (NASA) Back to slideshow navigation
  3. Grand canyon

    This is a composite of Viking orbiter images that shows the Valles Marineris canyon system. The entire system measures more than 1,875 miles long and has an average depth of 5 miles. (NASA) Back to slideshow navigation
  4. Red rover

    A mosaic of eight pictures shows the Pathfinder probe's Sojourner rover just after it rolled off its ramp. At lower right you can see one of the airbags that cushioned Pathfinder's landing on July 4, 1997. (NASA) Back to slideshow navigation
  5. Twin Peaks at their peak

    The Pathfinder probe focuses on Twin Peaks, two hills of modest height on the Martian horizon. Each peak rises about 100 feet above the surrounding rock-littered terrain. (NASA) Back to slideshow navigation
  6. Blue horizon

    A Martian sunset reverses the colors you'd expect on Earth: Most of the sky is colored by reddish dust hanging in the atmosphere, but the scattering of light creates a blue halo around the sun itself. (NASA / JPL) Back to slideshow navigation
  7. Two-faced Mars

    The image at left, captured by a Viking orbiter in the 1970s, sparked speculation that Martians had constructed a facelike monument peering into space. But the sharper image at right, sent back in 1998 by Mars Global Surveyor, spoiled the effect. (NASA) Back to slideshow navigation
  8. Put on a happy face

    The "Happy Face Crater" - officially named Galle Crater - puts a humorous spin on the "Face on Mars" controversy. This image was provided by the Mars Global Surveyor orbiter. (MSSS / NASA) Back to slideshow navigation
  9. A monster of a mountain

    Mars' highest mountain, an inactive volcano dubbed Olympus Mons, rises as high as three Everests and covers roughly the same area as the state of Arizona. Mars Global Surveyor took this wide-angle view. (MSSS / NASA) Back to slideshow navigation
  10. Pockmarked moon

    Mars Global Surveyor snapped this picture of Phobos, the larger of Mars' two potato-shaped moons. Phobos' average width is just 14 miles. The image highlights Phobos' 6-mile-wide Stickney Crater. () Back to slideshow navigation
  11. From Mars with love

    This valentine from Mars, as seen by Mars Global Surveyor, is actually a pit formed by a collapse within a straight-walled trough known in geological terms as a graben. The pit spans 1.4 miles at its widest point. (MSSS / NASA) Back to slideshow navigation
  12. Sandy swirls

    An image taken by Mars Global Surveyor shows a section of the northern sand dunes on Mars' surface. The dunes, composed of dark sand grains, encircle the north polar cap. (JPL / NASA) Back to slideshow navigation
  13. Curls of clouds

    Global Surveyor focuses on a storm system over Mars' north polar region. The north polar ice cap is the white feature at the top center of the frame. Clouds that appear white consist mainly of water ice. Clouds that appear orange or brown contain dust. (MSSS / NASA) Back to slideshow navigation
  14. Swiss cheese

    Global Surveyor captured images of a frost pattern at Mars' south polar ice cap that looks like Swiss cheese. The south polar cap is the only region on the Red Planet to contain such formations. (NASA / JPL / Malin Space Science) Back to slideshow navigation
  15. Purple Planet

    A false-color image from the Opportunity rover, released Feb. 9, 2004, accentuates the differences between a green-looking slab of Martian bedrock and orange-looking spheres of rock. Scientists likened the "spherules" to blueberries embedded within and scattered around muffins of bedrock. The spherules are thought to have been created by the percolation of mineral-laden water through the bedrock layers. (NASA / JPL / Cornell University) Back to slideshow navigation
  16. Dunes of Mars

    A false-color view from NASA's Opportunity rover, released Aug. 6, 2004, shows the dune field at the bottom of Endurance Crater. The bluish tint indicates the presence of hematite-containing spherules ("blueberries") that accumulate on the flat surfaces of the crater floor. (NASA / JPL / Cornell University) Back to slideshow navigation
  17. Alien junkyard

    The Opportunity rover looks at its own heat shield, which was jettisoned during the spacecraft's descent back in January 2004, on Dec. 22, 2004. The main structure from the heat shield is at left, with additional debris and the scar left by the shield's impact to the right. The shadow of the rover's observation mast is visible in the foreground. (NASA / JPL) Back to slideshow navigation
  18. Devil on Mars

    This image shows a mini-whirlwind, also known as a dust devil, scooting across the plains inside Gusev Crater on Mars, as seen from the Spirit rover's hillside vantage point on April 18, 2005. (NASA / JPL) Back to slideshow navigation
  19. Rub al Khali

    The tracks of NASA's Opportunity rover are visible in a panoramic picture of a desolate, sandy stretch of Martian terrain in Meridiani Planum, photographed in May 2005 and released by NASA on July 28. "Rub al Khali" (Arabic for "Empty Quarter") was chosen as the title of this panorama because that is the name of a similarly barren, desolate part of the Saudi Arabian desert on Earth. (NASA / JPL / Cornell University) Back to slideshow navigation
  20. Double moons

    Taking advantage of extra solar energy collected during the day, NASA's Spirit rover spent a night stargazing, photographing the two moons of Mars as they crossed the night sky. The large bright moon is Phobos; the smaller one to its left is Deimos. (NASA / JPL / Cornell / Texas A&M) Back to slideshow navigation
  21. Mars in the round

    A 360-degree panorama shows a stretched-out view of NASA's Spirit rover and its surroundings on the summit of Husband Hill, within Mars' Gusev Crater. The imagery for the panorama was acquired in August, and the picture was released on Dec. 5. (NASA) Back to slideshow navigation
  22. Fossil delta

    Scientifically, perhaps the most important result from use of the Mars Orbiter Camera on NASA's Mars Global Surveyor has been the discovery in November 2003 of a fossil delta located in a crater northeast of Holden Crater. (NASA / JPL / MSSS) Back to slideshow navigation
  23. Underneath the ice

    This view taken in January 2005 shows sharp detail of a scarp at the head of Chasma Boreale, a large trough cut by erosion into the Martian north polar cap and the layered material beneath the ice cap. (NASA / JPL / MSSS) Back to slideshow navigation
  24. Celestial celebration

    Controllers at NASA's Jet Propulsion Laboratory in Pasadena, Calif., cheer on Friday after hearing that Mars Reconnaissance Orbiter successfully made it into orbit around the Red Planet. (Phil McCarten / Reuters) Back to slideshow navigation
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By
updated 1/22/2010 4:22:39 PM ET 2010-01-22T21:22:39

If you head outside around 8 p.m. this week and face due east, you'll see a brilliant, fiery-colored, non-twinkling "star" that immediately will attract your attention. It's not a star, however, but the planet Mars.

Mars, the most Earthlike planet of all the planets, has been absent from our evening sky for well over a year. Now it's coming back. Here's why:

Earth and Mars are in an eternal dance with the two parties sometimes close, sometimes very far apart. Both worlds orbit the sun, with Earth doing so more quickly on the inner path. Every 2.1 years, Earth laps Mars, like a race car on the inside track. At that moment, the sun, Earth and Mars are all lined up. Astronomers call it opposition.

During much of January we've been speeding toward Mars in our orbit by an average of 3 miles per second; so Mars has been gradually getting brighter and larger in apparent size.

Mars will pass closest to the Earth at 2:01 p.m. EST during the American afternoon of Jan. 27, just two days before its Jan. 29 opposition, (when it will appear to rise at sunset and set at sunrise and will be visible all night). As a bonus, on opposition night, the Moon, just hours before officially turning full, will sit well off to the right of Mars as they climb the early evening eastern sky.

An ‘off year’ by Mars standards
This year's apparition of Mars is actually one of the poorer and more distant ones in the planet's 15-year cycle of oppositions near and far. This is due chiefly to the fact that just over two months after opposition, Mars will arrive at aphelion (its farthest point from the sun) in its eccentric orbit. So we will come no closer than 61,720,695 miles (99,329,830 km) to it on this occasion. Shining with a yellow-orange hue, it will attain a peak brightness of -1.3; just a trifle fainter than Sirius, the brightest star in the sky. (On this scale, smaller number represent brighter objects, and the brightest get negative rankings.)

Mars will also be almost twice as far away from Earth compared to its historic approach to Earth back on Aug. 27, 2003. On that date the red planet made the closest approach to ours in nearly 60,000 years. As compared to 2003, the 2010 approach of Mars will provide telescopic viewers with a very small disk even at high magnification. This will actually be its second farthest opposition; the next one, on March 3, 2012, will be the farthest.

Top 10 images of the world at night

So this month's peak brilliance and very modest disk size will be the best that Mars achieves until April 2014.

On opposition night, the season is early spring in Mars' northern hemisphere. The Martian north polar cap, tipped 12 degrees toward us, will therefore shrink noticeably in the weeks that follow.

Mars is never easy to study, and this season its small diameter presents special challenges. The best telescope for studying the red planet is a large, high quality refractor or a large aperture Dobsonian reflector. But usually the limiting factor is the atmospheric seeing, which can change literally from minute to minute. Studying the planets always means spending a lot of time watching and waiting for elusive moments of steady seeing. Just as important, the more you look the better trained your eye will become. So plan to spend lots of time behind your eyepiece.

This week Mars become just large enough to show touches of dark surface detail and perhaps occasional white clouds or limb hazes in medium-sized amateur telescopes at the best moments on those steady nights when it's high up.

Speaking of high ...
And now a positive note: This part of Mars' orbit rides fairly high in the sky for Northern Hemisphere observers; from the southernmost parts of the United States such as south Texas and the Florida Keys, Mars will appear to climb to a point almost directly overhead. This week, the planet is in the midst of performing a backwards (retrograde) loop — during which it's carried closest to us — against the faint stars of Cancer.

Moving from left to right against the background stars, Mars will pass 3-degrees north of the famous Beehive star cluster on Feb. 6, a pretty sight in binoculars.

It then slows to a standstill around March 11 and moves back toward the east. We're then leaving it behind, and henceforth it will appear to travel in a long straight line around the sky, becoming steadily farther and smaller. It will pass the Beehive again (just 1 degree north of the cluster) on April 16.

Then on June 6 it slides less than a degree north of the bright bluish star, Regulus, a pretty conjunction easily seen in the middle of the evening sky. By then, however, Mars will have shrunk to an ochre dot even in large telescopes.

The Mars e-mail hoax
Now for something a bit different: Over the past six years, people have received an e-mail titled "Mars Spectacular" which has circulated widely on the Internet from an anonymous source. In turn, this message has ended up being passed along to others who simply couldn't resist forwarding it to their entire address book; a snowball rolling down a hill is a good analogy.

This e-mail declares that on Aug. 27, Mars will be closer to Earth than it has in the past 60,000 years, thereby offering spectacular views of the Red Planet. The commentary even proclaims, with liberal use of exclamation marks, that Mars will appear as bright as (or as large as) the full Moon.

The problem is that "Aug. 27" actually refers to Aug. 27, 2003. As I've already noted, Mars did indeed make a historically close pass by Earth on that night. But, to the naked eye Mars merely appeared like a brilliant yellowish-orange star, certainly not anything like the full Moon!

So this Mars e-mail is totally bogus. Yet it now seems that every year in the late spring or summer, this "Mars chain letter" gets revived.

So ... I would like to make a request: If later this year you find yourself a recipient of this dubious Mars e-mail message, I would suggest that rather than forward it on to others, you simply hit the "Delete" button on your computer keyboard; better yet, why not forward this column to the person who may have passed the e-mail on to you. In this way, you'll be providing an antidote to this Mars computer virus.

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