NASA is preparing the probes orbiting the planet Mars for a close comet flyby in October. Great concerns for the safety of the spacecrafts orbiting the planet, including one due to arrive shortly before Comet C/2013 A1 Siding Spring, has prompted NASA to take action.
The comet’s nucleus is expected to miss Mars by about 82,00 miles, but it will also shed materials hurtling at about 35 miles per second.
“The hazard is not an impact of the comet nucleus, but the trail of debris coming from it,” said Rich Zurek, chief scientist for the Mars Exploration Program at NASA’s Jet Propulsion Laboratory. “Using constraints provided by Earth-based observations, the modeling results indicate that the hazard is not as great as first anticipated. Mars will be right at the edge of the debris cloud, so it might encounter some of the particles — or it might not.”
With the danger so close to the orbiters , NASA has made plans to ensure they are somewhat safe from that debris by maneuvering the orbiters, including the one that will arrive there in September, onto the far side of the planet, minimizing the risks. This is very important because even a particle just 1/50th of an inch in size (half a millimeter) could cause significant damage.
The Mars Reconnaissance Orbiter recently made one orbit-adjustment maneuver on July 2 to begin the repositioning the spacecraft for the October 19 flyby. Another maneuver is scheduled for August 27. The Odyssey orbiter is planning a maneuver on August 5 to prepare as well. That leaves the Mars Atmosphere and Volatile Evolution ( MAVEN ) spacecraft, which isn’t expected to arrive until September 21. It will conduct a precautionary maneuver on October 9 prior to beginning it’s main science phase in early November.
Not to miss an opportunity, NASA intends to study the comet as it passes. Researchers plan to use several instruments on the orbiters to study the nucleus, the coma that surrounds it, and the tail of the comet. They will also monitor any possible effects it has on the Martian atmosphere.
MAVEN will study the gases that come off the comet’s nucleus into the coma as it is warmed by the Sun, and look for effects on the upper atmosphere of Mars. Odyssey will study thermal and spectral properties of the coma and tail. MRO will monitor Mars’ atmosphere for possible temperature increases and clud formation, as well as changes in electron density at high altitudes. Down on the planet, the rovers may be used to watch for meteors during the flyby.