December 13, 2012
NASA’s Curiosity Can Find Its Position With Martian Eclipses
Lee Rannals for redOrbit.com — Your Universe Online
Researchers say that if Curiosity ever loses its location on the surface of Mars, it could use eclipses to help it find its way.
Researchers at the Complutense University of Madrid (Spain) have developed a method for helping Curiosity find its way around Mars by using Martian moons.
"Observing these events offers an independent method for determining the coordinates of Curiosity," Gonzalo Barderas, researcher at UCM and coauthor of the study, said in a statement.
Curiosity must have a camera or sensor capable of sending data about an eclipse in order for this method to work.
"It could prove especially useful when there is no direct communication with Earth that allows for estimation of its position using radiometric dating or images provided by orbiters," Barderas said.
The team wrote in the Monthly Notices of the Royal Astronomical Society journal that the initial objective of the group was to create a mathematical tool for predicting Phobos eclipses from the surface of Mars.
They said their method also proved useful for locating the precise location of any spacecraft that are also capable of observing eclipses, such as Curiosity.
The NASA rover kept its eye on eclipses last September as the Martian moon Phobos made its transit in front of the sun. The team's model predicted partial eclipses that took place on September 13 and 17, which were captured by Curiosity's MastCam.
Researchers also used Curiosity's Spanish REMS instrument, the vehicle's environmental station, to detect a reduction in ultraviolet solar radiation during the eclipses.
Simulations and the real end images coincided with a precision of one-second. In order to make the calculations, the team considered the initial predicted landing area for Curiosity.
With just two minutes of observations and using the start and end times of Phobos' contact with the Sun, the scientists are able to determine Curiosity's position with an error of just a few feet to a few miles.
The next movements of the Martian moon will take place between August 13 and 20 2013, and between August 3 and 8 2014. Curiosity will have its chance to observe the eclipses again, and the scientists will be able to confirm their new method for navigation.
"In any case, this method can be applied to other space probes operating on the surface of Mars that have the ability to make optical observations or that have instruments that measure solar radiation," Luis VÃ¡zquez, one of the authors, said in the statement.