Posted on 07/23/2003 7:40:47 AM PDT by CFW
"Opposition" occurs when Mars is opposite the sun relative to Earth. This happens about every 25 months.
"Opposition" occurs when Mars is opposite the sun relative to Earth. This happens about every 25 months. This year, Mars' opposition occurs near the same time as the "perihelion" of Mars, which is when Mars, moving along its elliptical orbit, is closest to the sun. This combination of Mars opposition *and* perihelion, which happens at the same time about every 15 to 17 years, makes Mars favorable for viewing because it is especially close to Earth.
This year, Mars is closer to Earth than it has been for tens of thousands of years.
At 5:51 a.m. EDT on Aug. 27, 2003, Mars will be within 34,646,418 miles (55,758,006 kilometers) of Earth.
The most recent opposition in 2001 was not particularly favorable as it involved a separation between Mars and Earth of more than 41 million miles (67 million kilometers). The most recent perihelion/opposition took place in September 1988, when Mars passed to within 36.5 million miles (58.7 million kilometers) of Earth. Mars and Earth were even closer in 1971, just 34.9 million miles (56.2 million kilometers) apart. This year's 2003 approach, 34.6 million miles, is less than 1 percent closer than the one in 1971, but still a record-holder.
The next, even closer opposition occurs on Aug 28. 2287, when Mars is 34.62 million miles away (55.69 million kilometers) and another closer opposition occurs on Sep. 8, 2729, when Mars is 34.60 million miles away (55.65 million kilometers).
Mars is a smaller planet than Earth. Usually, it looks pretty small in a telescope. But during a good opposition, like the one this year, Mars can be seen beautifully up close.
Well, if "opposition" is more favorable, why don't they call it "agreement" instead of "opposition"?
Without getting into a technical explanation of visual magnitude, Mars may not be as bright as the full moon, but having viewed it the other night, I can tell you that there's no mistaking its bright red glow in the sky. Currently, those North Americans around 40 N latitude, can see it rise in the ESE around midnight, and by dawn, it will have moved across the southern sky. As we get into August, Mars will appear earlier in the evening, for a longer period of viewing.
No serious astronomical equipment is necessary to view Mars; a small pair of binoculars should provide a nice image--you'll probably be able to see a small whitish area on the southern pole--that would be one of the ice caps.
Any small telescope will provide terrific views, the ice caps, and even surface makings should be visible. As someone else posted, the Sky and Telescope site has some great references that will give more observation details.
Keep in mind as with any type of astronomical viewing, the closer Mars gets to Earth, the better chances of cloudy or inclement weather in your neighborhood! :)
Note that summer in the South of Mars is approaching, so that as the planet nears opposition with Earth, the cap will be shrinking.
Well, with a diameter of 6.8 million meters and a distance of 36 million miles, it's equivalent to observing a 7 inch ball a mile away. Do you think you could make out the features on someones face from a mile away with a small pair of binoculars ?
Mars is well up now, at 12:30 AM CDT in Chicagoland, and about 42 million miles away tonight. I just tried observing it with my Celestron 9X63 binoculars and my Bushnell 8X21's . These are 9 and 8 times magnification, with 63 mm and 21 mm objectives. The Celestron is a big magnificent pair of binoculars I got for comet observing, and the Bushnell you can enclose in one hand, but it's almost the same power.
With the 9X63's Mars looks very big, but this is an illusion caused by its brightness. If I stop down the objectives by masking them with my hands, it shrinks to pretty much a dot, although my eyes aren't the best anymore. Even the 8X21's show a false enlargement, and I can see shrinkage using the masking technique with them also.
I got a pair of 12x63mm. I'm thinking I should have gotten the 9x.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.