'Curiosity' can be positioned with eclipses

Dec 13, 2012
'Curiosity' can be positioned with eclipses
This image shows Phobos in transit last September. Credit: NASA/JPL-Caltech/MSSS

Observations from 'Curiosity' when Mar's moon Phobos crosses in front of the sun, like in September, help us to understand exactly where the rover is on the red planet. Researchers at the Complutense University of Madrid (Spain) have developed a method for achieving precisely this.

The exact location of Curiosity on the surface of Mars is determined using data transmitted from its antennas as well as the space probes that orbit the . It is very unlikely that these systems would fail but in such an eventuality there would be an alternative for determining the location of the rover: 'ask it' what it sees.

"Observing these events offers an independent method for determining the coordinates of Curiosity," explains Gonzalo Barderas, researcher at the Complutense University of Madrid (UCM) and coauthor of the study.

For this method to be used the robot must have a camera or sensor capable of sending data about an eclipse. "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," outlines the researcher.

The initial objective of the UCM group was to create a for predicting Phobos eclipses from the surface of Mars. But their method also proved useful in locating the precise location of any spacecraft that are also capable of observing eclipses from there. The details have been published in the '' journal.

The model predicted partial eclipses that took place on the 13 and 17 September. The MastCam camera that Curiosity carries in its mast captured them without any problems. The Spanish REMS instrument, namely the vehicle's environmental station, also detected a reduction in ultraviolet solar radiation during the eclipses (5% in the first case).

The initial simulations and the real end images coincided with a precision of one second. In order to make their calculations, the scientists considered the initial predicted landing area for Curiosity: an ellipse of 7 x 20 km2.

In addition, with just two minutes of observations and using the start and end times of Phobos' contact with the Sun, error can be reduced in the rover coordinates from an order of magnitude of kilometres to another of metres.

According to the model, the next movements of the Martian moon will take place between the 13 and 20 August 2013 and between the 3 and 8 August 2014. will have the chance to observe eclipses again and the Spanish scientists will be able to confirm the validity of their tool.

"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," outlines Luis Vázquez, one of the authors.

In fact, under the scientific management of Vázquez, this study forms part of a Spanish project associated to the joint Russian, Spanish and Finnish MetNet mission to distribute small meteorological stations across Mars.

Explore further: NASA's IceCube no longer on ice

More information: G. Barderas, P. Romero, L. Vázquez, J. L. Vazquez-Poletti, I. M. Llorente. "Opportunities to observe solar eclipses by Phobos with the Mars Science Laboratory". Monthly Notices of the Royal Astronomical Society 426 (4): 3195-3200, October 2012. Doi: 10.1111/j.1365-2966.2012.21939.x

add to favorites email to friend print save as pdf

Related Stories

A Martian eclipse, captured by Curiosity

Sep 18, 2012

Yes, Mars gets eclipses too! This brief animation, made from ten raw subframe images acquired with Curiosity's Mastcam on September 13—the 37th Sol of the mission—show the silhouette of Mars' moon Phobos ...

Curiosity's sundial carries a message of hope

Aug 23, 2012

While Curiosity is definitely loaded up with some of the most high-tech instruments ever made to investigate the surface of Mars, it also carries a very low-tech instrument: a sundial, which can be used to ...

Recommended for you

NASA's IceCube no longer on ice

35 minutes ago

NASA's Science Mission Directorate (SMD) has chosen a team at NASA's Goddard Space Flight Center in Greenbelt, Maryland, to build its first Earth science-related CubeSat mission.

Tidal forces gave moon its shape, according to new analysis

14 hours ago

The shape of the moon deviates from a simple sphere in ways that scientists have struggled to explain. A new study by researchers at UC Santa Cruz shows that most of the moon's overall shape can be explained by taking into ...

User comments : 5

Adjust slider to filter visible comments by rank

Display comments: newest first

Royale
1 / 5 (3) Dec 13, 2012
Mar's moon?
I was unaware we found a new plan't.
marble89
3 / 5 (4) Dec 13, 2012
You are kidding of course
tscati
2.3 / 5 (3) Dec 14, 2012
How do you get an ellipse of 7 x 20 square kilometres? I can understand an ellipse of 7 x 20 kilometres, or an ellipse of 42.4 square kilometres...
ScottyB
2.3 / 5 (3) Dec 14, 2012
Im pretty sure they meant "Mars" not "Mar's" lol
Royale
3.7 / 5 (3) Dec 17, 2012
And we both get down-voted for no apparent reason. haha. Other than someone has no sense of humor.