Mars Closest Encounter With Earth

[bioginz]

Hey Guys,

Im just curious... can you show me the actual computations as when the next closest encounter of Mars and Earth will commence?...Ive read it would be on year 2287 if I am not mistaken...thanx in advance..

DANDYBOY

 

[russ_watters]

The calculations are extremely accurate. Mars and Earth have a ~2.1 year cycle of close encounters (oppositions), but due to the fact that the orbits are elliptical, they have an ~15 year cycle of closer and further oppositions. And there are still longer cycles:

There will be thus a favorable opposition every approximately 15 years, after 7 oppositions, but one will approach the starting configuration still better everye 32 years, 47 years, 79 years, 284 years, or 363 years. Of course these calculations are approximate, because they do not take account of the deformation of the orbits.

http://www.imcce.fr/en/observateur/support/opposition_mars/index.php

As you can see, though, it doesn't ever get much under 56 million km. Yes, the next time it will be closer than in 2003 (55.758), is 2287 (55.688), but in 2050 it will be 55.957. The total spread there is smaller than the distance between the Earth and moon, about 385,000 km, or about half a percent.