Date:30 September 2015
This week the world has been abuzz with NASA’s discovery of water on Mars. But that didn’t happen just overnight – so we take a look back at the nine years the Mars Reconnaissance Orbiter spent orbiting the red planet.
In 2005, NASA launched the Mars Reconnaissance Orbiter (MRO), an exploration and investigational spacecraft designed to relay information about the history and possible persistence of water on Mars. The MRO explored the surface of Mars from orbit, capturing close-up photographs and analysing the climate, geology, atmosphere and presence of water on the planet’s surface, using a variety of instruments built for the mission.
To find water on Mars, the MRO was equipped with three cameras: a high resolution imaging camera to capture geologic detail, a weather camera to monitor clouds and dust storms and a contextual camera to provide wide-area views.
The MRO was also fitted with a spectrometer to identify minerals on the planet’s surface (especially minerals likely to have been formed in the presence of water), a climate sounder to detect variations in dust, temperature and water vapour concentration, and radar sounding probes to detect whether ice might be present below the surface of Mars.
Since the MRO’s arrival into orbit in March 2006, the spacecraft followed a strict mission timeline, relaying details of specific points of interest back to Earth. Between March and November 2006 it captured details of Mars’ atmospheric density.
From November 2006 until November 2008, the MRO observed the atmosphere, surface and subsurface of Mars, while also offering support to the Phoenix Mars Scout.
The next step in the MRO’s timeline was to capture images of the surface of Mars, including possible habitable zones and details of internal and external ice structures. This mission concluded in December 2010. Thereafter the MRO observed the seasonal and surface changes until September 2012.
At this point of the timeline, the spacecraft started to target new surface locations and followed up on earlier discoveries. It is during this phase that it was discovered that there might be water on Mars.
Researchers detected signatures of hydrated minerals, as captured by the MRO’s spectrometer, on slopes with dark streaks (pictured above). NASA scientists found that the streaks “appear to ebb and flow over time”, meaning that the streaks sppear to flow down steep slopes during “warm seasons” and fade during cooler seasons. These streaks also appear in a variety of locations on the planet.
Astronaut and associate administrator of NASA’s Science Mission Directorate, John Grunsfeld, commented: “Our quest on Mars has been to ‘follow the water’, in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected.”
Grunsfeld adds that the discovery is a “significant development” that appears to confirm that there is water on Mars.
Image credit: NASA/JPL/University of Arizona