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Observers of Mars are scattered throughout the world. This provides the opportunity to have continuous coverage of Mars since it is always night somewhere and thus Mars can (at least potentially) be constantly observed. There is a bit of a gap in the Pacific area, though, and Kwajalein [in the Republic of the Marshall Islands] is situated to fill this gap. I could monitor activity on Mars when others could not and it so happened that I was able to image around the beginning of the planet-wide dust storm. These images were used by others in their analysis of the dust storm.
Kent DeGroff, Astrophotographer
Now is the very best time to look for Mars from nightfall until dawn! The red-orange planet is the brightest it has been since 2005. It is approaching the brilliance of Jupiter, which is visible high in the southwest at dusk, before Mars rises in the southeast.
On the 16th, sunset is at 8:07 in the west-northwest and Mars rises in the southeast at 8:38pm. Sunrise is at 5:37 on the 17th and Mars sets at 6:02. The planet rises earlier each successive evening, making it easier to see as it climbs above buildings and other obstructions at nightfall. But it sets earlier, too, becoming a challenge to observe before sunrise.
Wishing to see the planetary show at dawn, but sure that I wouldn’t get outdoors by 5 o’clock on a recent morning that was predicted to be clear, I looked out of a southwest-facing window when I was awakened at 3 o’clock. What a sight! The luminous, ruddy planet seemed to be an ember in the dark sky, yellowish Saturn to its left, both atop the beautiful Scorpion constellation. The planets are visible from the ground or a high-rise building even where city lights limit stargazing.
On the 22nd, Mars will be at “opposition” in Earth’s skies: sun and planet will be approximately opposite each other. Mars will rise in the southeast at 8:05pm as the sun sets in the west-northwest at 8:12pm. Mars sets in the southwest on the morning of the 23rd at 5:30 as the sun rises at 5:32 in the east-northeast. The namesake of the god of war will shine at its greatest magnitude, -2.06, on a scale where the smaller the number the more luminous the celestial object. After opposition, Mars slowly decreases in brilliance and rises and sets earlier – all the while continuing to stir our interest.
While we enjoy contemplating the prominence of Mars in spring skies, I have the privilege of sharing astrophotographer Kent DeGroff’s images of a 2001 dust storm on the red planet, with informative comments.
I asked Kent why dust storms on Mars are of interest to scientists. He replied, “Monitoring the planet for dust storms provides data used to determine what kind of weather patterns exist there and the effects on the planet. Besides the raw science, it helps to evaluate how certain planned activities will be affected. For example, there are potential negative effects for the Opportunity rover currently on the surface since visibility would be reduced and there is a possibility of damage. The wind and dust also have an impact on the design of Mars landers, especially ones with parachutes. If and when a manned mission is sent to Mars, dust storms will obviously be an important factor in planning.”
Just a bit of explanation: the images are in order and show a period of 8 days during which the dust storm developed significantly. The planet rotates in 24 hours 37 minutes, so each night at a given observer location, the surface details will appear to move but, even so, you can see the dust moving over the areas that are visible. If you compare the images using the dark marking at the 8 o’clock position in the first image, you can see the progression. That marking also gets less apparent as the dust moves in. It is nearly at the right hand edge in the last image. Pole caps and clouds at the edge of the disk can also be seen.
Kent DeGroff
https://www.flickr.com/photos/whiskey_creek_observatory/
About Mars http://mars.nasa.gov/ |
