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Amateur astronomer Jane Houston Jones with one of her homemade telescopes.
Image credit: Morris Jones
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Mars is the only planet with a surface that can be easily seen through amateur telescopes. Despite its small size, which is about half the size of Earth, Mars has higher mountains, larger rift valleys, and larger impact basins than Earth. Most of these intriguing geologic features are covered with dust, which obscures the view from amateur telescopes. What we mostly see through telescopes is darker cratered terrain in the south and lighter smooth plains in the north.
What will Mars look like in your telescope? It depends. You may be able to see different color markings on the planet clearly, depending on such variables as the quality and cleanliness of your telescope optics and magnification strength and quality of your eyepieces. Weather and atmospheric conditions, both on Earth and Mars impact your view too. If you are observing Mars at low power through a small 60mm - 100mm aperture telescope, Mars will look like a small orange disk or sphere, and you may see some markings. Larger telescopes will reveal not only details on the planet, but also some haze on the limbs or edges of the sphere.
During closest approach in 2007, the apparent diameter of Mars will be more than 4 arcsec smaller than it was at the same period in 2005; however, it will be 10 degrees higher in the sky - much better for observing the Red Planet - helping to make up for the smaller size.
June 2007 through April 2008 are the prime Mars observing months. Mars remains a morning planet for most of 2007 until its opposition on December 24. The best time to view Mars will be several hours after it rises, when it is highest in the sky. By December, we'll be able to enjoy Mars viewing in the mid-evening hours, but amateur astronomers will wait even later for the best views of the red planet.
| January 2007: |
Mars begins 2007 having passed behind the sun. Mars doesn't rise until the glow of sunrise begins to brighten the morning sky. |
| February 2007: |
Mars rises 1½ hours before the Sun. It is low in the east-southeast at dawn. |
| March 2007: |
Mars still rises 1½ hours before the Sun. It is getting a little brighter but still not prominent. On March 16, Mars is just north of the moon in the morning sky. |
| April 2007: |
Mars brightens to magnitude 1 this month, comparable to some of the brighter stars of spring, such as Regulus in Leo, and Castor and Pollux, the Gemini twins, stars you'll see in the early evening. Mars is still too small to distinguish features visually (through a telescope). Mars now rises 2 hours before the Sun. Its diameter is 1/3 that of Venus. |
| May 2007: |
Mars rises 2½ hours before the sun this month. It enlarges a bit, too. |
| June 2007: |
Mars rises by 2:00 a.m. by late June. It is still quite small - only a quarter the apparent diameter of Saturn and one quarter the diameter of Venus. Compared to Jupiter, which is still visible in the sky, Mars is about 9 times smaller in apparent diameter. |
| July 2007: |
Mars rises at about 1:30 a.m. this month. Watch as it nears the Pleiades cluster this month. It is still too small to see features through most amateur telescopes this month. |
| August 2007: |
Mars finally rises before midnight this month. But viewing is still best several hours later when the planet is higher in the sky. On August 8th early risers will see Mars, the crescent moon, and the Pleiades at 5:00 a.m. just before sunrise. It grows a little bigger in apparent size as it nears Earth, but is still too small for viewers to see any features. The orangey color begins to be more apparent now. |
| September 2007: |
Mars now rises in the late evening. In late September, Mars comes within 1 AU (93 million miles) of Earth, brightens, and grows larger. The best time to view Mars is still around morning twilight when Mars is high in the south for mid-northern latitudes. |
| October 2007: |
Mars brightens and appears larger in diameter this month, as it approaches its December 24, 2007 opposition. It is now possible to see some features on the planet through telescopes. It rises in the mid-evening. On October 4, Mars passes by a beautiful open cluster, M-35, near the foot of the constellation Gemini. You can point out the pumpkin-colored planet to trick-or-treaters on Halloween. |
| November 2007: |
Mars begins its retrograde loop this month. It will "appear" to halt its direct motion (eastward relative to the backgound stars) and begin creeping westward. It rises at about 8 p.m. and transits (reaches its highest point in the sky) at 3:00 a.m., which is the best time for viewing planets. The southern hemisphere of Mars is slightly inclined towards Earth. But since summer is ending on Mars in December the south polar ice cap will be tiny, if visible at all. Some of the dramatic features such as Syrtis Major, Solis Lacus will be visible through telescopes this month. |
| December 2007: |
Mars Opposition! Mars will not be this close to Earth again until 2016: at a distance of 0.60 AU, or 56 million miles from Earth. Mars rises just after twilight in December. This month, Mars reaches its largest angular diameter of nearly 16 arcseconds. For comparison, Saturn, minus, its rings, spans about 18 arcseconds in apparent diameter this month. Compare the two planets. Mars is 0.6 AU from Earth, while Saturn is 9.2 AU (855 million miles) from Earth. Mars outshines the brightest star in the sky - Sirius, in the constellation Canis Major. On December 23, look for Mars near the full moon. North American observers can glimpse the dark feature Syrtis Major this month, while southern observers can view Solis Lacus. Mars is extremely favorable for telescopic observing this month. From now until April 2008, Mars will be great to view all night long. |
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