The distance from Earth to Mars (the 3rd and 4th planets from the Sun, respectively) varies greatly because Earth’s orbit around the sun is much smaller than Mars’ orbit.
The minimum distance from the Earth to Mars is about 54.6 million kilometers (33.9 million miles). The farthest apart they can be is about 401 million km (249 million miles). The average distance is about 225 million km (140 million miles). To compare, the circumference of our Earth is only 40,075 km or 24,901 miles.
On January 4, 2004, NASA’s Spirit, a robotic MER-A (Mars Exploration Rover), landed successfully on the planet Mars at 04:35 Ground UTC.
Three weeks later, Spirit’s twin, Opportunity (MER-B), landed on the other side of Mars.
This YouTube video is a clip from the IMAX movie “Roving Mars” from 2006. I recommend you watch the video in Full Screen mode!
Before Spirit became stuck in late 2009, the rover already had completed its planned 90-sol mission, functioning effectively over twenty times longer than NASA planners had expected. Spirit logged 4.8 mi)of driving instead of the planned 0.4 mi, allowing more extensive geological analysis of Martian rocks and planetary surface features. Initial scientific results from the first phase of the mission (the 90-sol prime mission) were published in a special issue of the journal Science.
On May 1, 2009 (5 years, 3 months, 27 Earth days after landing; 21.6 times the planned mission duration), Spirit became stuck in soft soil. This was not the first of the mission’s “embedding events” and for the following eight months NASA carefully analyzed the situation, running Earth-based theoretical and practical simulations, and finally programming the rover to make extrication drives in an attempt to free itself. These efforts continued until January 26, 2010 when NASA officials announced that the rover was likely irrecoverably obstructed by its location in soft soil, though it continued to perform scientific research from its current location.
The rover continued in a stationary science platform role until communication with Spirit stopped on sol 2210 (March 22, 2010). A formal farewell was planned at NASA headquarters after the Memorial Day holiday and was televised on NASA TV.
H/t FOTM’s Ken L.
~Eowyn