NASA's Curiosity rover ticks off one Martian year on the Red Planet
Tuesday, June 24, 2014, 3:06 PM - Today - June 24, 2014 - the 687th day since NASA landed a 1-ton, atomic-powered robot rover named 'Curiosity' in Gale Crater, on the surface of Mars, marks exactly one Martian year since that incredible accomplishment, and the rover has wracked up an impressive amount of science so far on the Red Planet.
Given our somewhat limited perspective here on Earth, we humans (understandably) tend to keep track of things like anniversaries based on our 365-days-per-year calendar. Going by that metric, we're roughly six weeks shy of celebrating the 2nd anniversary of when NASA's Mars Science Laboratory, aka Curiosity, touched down on the surface of the Red Planet. Shifting our perspective to that of the rover, however, the planet that's underneath Curiosity's wheels is 1.38 times (just over 78 million kilometres) further from the Sun than Earth is, and thus it takes the planet about 1.88 longer to complete one orbit around the Sun (aka one year) - that's 686 days, 23 hours, 18 minutes and 14.4 seconds to be exact. Technically, though, that's still using Earth time. If we want to switch over completely to the Martian perspective, the length of a Martian day (also called a Sol) is 24 hours and 40 minutes, so the Martian year is exactly 668 Sols, 14 hours, 22 minutes and 42.24 seconds long. Perhaps some day in the future, colonists may redefine the other Martian units of time, but for now that's as close as we're going to get.
Either way, though, if we count out that many days or Sols from when Curiosity touched down from its 'seven minutes of terror' landing, that brings us to today!
In that time, Curiosity has wowed us with amazing images of the Martian surface, of Phobos and Deimos, the two tiny moons that orbit the planet, and even a look at our own home from its location on Mars. Even more importantly, though, it has accomplished some amazing science since it arrived. In fact, it's already completed its primary mission, determining that Mars once had surface conditions - with fresh water and a thicker atmosphere - that would have been favorable for microbial life, and it did so before it even reached the focus of its travels - Mt. Sharp, the 5.5 km-high mountain in the middle of Gale Crater.
Some of its other scientific achievements:
- sampling the current Martian atmosphere to give us clues as to where the thicker atmosphere of the past went
- determining that there is little methane - a possible by-product of organic life - in the air there, clearing up previous speculation (at least for Curiosity's location)
- measuring the radiation at the surface of Mars, giving us an idea of what colonists would face while living there
- giving us the first estimates of exactly when Mars' environment was more suitable for life, by dating surface rocks and determining how long they've been exposed to harmful solar radiation
- examining some of the complex geology of sediments in Gale Crater, revealing what could be evidence for multiple periods of melting in the past
With the regular image updates that the rover sends back to Earth, NASA has pieced together time-lapse videos of Curiosity's journeys on Mars, which was presented in a recent Timelapse Tuesday:
To see more of what Curiosity is up to on the surface of Mars, you can check out some favourite images of the rover's team (click here) and the raw images it snaps with its cameras - organized by Sol - (click here), and the NASA team provides regular news updates about the mission on their website (click here).