Last week, the Mars Reconnaissance Orbiter (MRO) celebrated ten years since its launch from Cape Canaveral Air Force Station on August 12, 2005. It took nine long months for the spacecraft to reach its destination – the red planet. Getting to Mars was the easy part. It was achieving orbital insertion that kept MRO’s team on the edge of their seats.
“The most crucial event after launch was orbit insertion on March 10, 2006,” said JPL’s Dan Johnston, MRO project manager. “The 27-minute burn of the spacecraft’s main engines, necessary for orbit capture, was scheduled for completion while the spacecraft was behind Mars, so we had to wait in suspense for confirmation that it went well. It did.”
MRO’s initial orbit was highly elliptical. In the five months after the March 10 insertion, the spacecraft used aerobraking – dipping into the upper fringe of Mars’ atmosphere – to get the orbit into a circular shape.
In November 2006, the MRO began its primary science mission. It used six instruments over two years to gather information about Mars’ surface, subsurface and atmosphere. During this two-year period, the orbiter made several incredible discoveries.
Mars Reconnaissance Orbiter Discoveries
Using radar measurements, results published in 2009 indicated Mars’ north pole has a total volume of water ice of 821,000 cubic kilometers. For a closer to home comparison, that equals about 30% of Earth’s Greenland ice sheet.
Pane ‘e’ shows the thickness of the icy layers below Mars’ north pole. Credit: NASA
In a pair of images, one captured in October 2008 and another in January 2009, the Mars Reconnaissance Orbiter revealed frozen water hiding below the surface of mid-latitude Mars.
A recent meteor impact uncovered ice that can be easily seen in the 2008 image. Three months later and the ice was nearly gone as it transitioned from a solid to a gas, also known as sublimation.
“This ice is a relic of a more humid climate from perhaps just several thousand years ago,” said Shane Byrne of the University of Arizona, Tucson.
I’m saving MRO’s craziest discovery for last. On February 19, 2008, the orbiter was able to capture four Martian avalanches happening in real-time. Talk about right place at the right time.
Usually, scientists only see changes at a seasonal level. It’s incredibly rare to see something like this happening in real-time. The only other active changes I can think of are dust devils.
The cloud in the image above is about 590 feet across. It extends roughly 625 feet from the base of the cliff to the left. NASA scientists believe the avalanche pictured above was triggered at the steepest section of the cliff where it appears blocks of rock are pulling away from the cliff wall.
As for what triggered the avalanche? Scientists aren’t sure. There are a variety of possible explanations. A nearby meteorite impact, seismic activity or the movement of ice in the area could have caused it.
MRO Keeps Tabs on other Mars missions
When it wasn’t making its own discoveries, the MRO was also watching landers descend through Mars’ atmosphere. Check out the extraordinary images below.
May 25, 2008 – Phoenix Lander. It looks like the Phoenix lander is heading right for the large crater, but it lands 12 miles in front of it.
August 6, 2012 – Curiosity Rover. Check out Curiosity in the Martian sky about one minute before it touched down.
Opportunity Rover tracks on the Martian surface
What’s next for the MRO
Ten years later and the Mars Reconnaissance Orbiter is still going strong. And, NASA plans to use it for many years to come. Today, it still conducts science operations but it also plays a major support role for other missions. It provides communication relay services to other missions and helps NASA determine landing sites for potential rovers in the future.
Next year it will provide communications support for the InSight mission.
Image credits: NASA