20 August 2017

Sol 1793: It’s Always Sunny in Gale Crater

Posted by Ryan Anderson

A subset of the Curiosity tactical planning team at JPL took a short break from planning Sol 1793 activities to view the solar eclipse from the roof of building 264.

Not to be overshadowed by other goings on in the solar system today, we planned a full day of activities for Curiosity. Unfortunately, some of the arm activities and the drive we planned over the weekend didn’t execute because Mars was slightly colder than we expected, and we didn’t heat the actuators in the arm for quite long enough. Tosol we’re therefore planning to recoup the contact science observations we had planned on sandy ripples in front of the rover. We will be taking MAHLI images of targets ‘The Shivers,’ ‘Trumpet,’ and ‘Hosmer,’ and also an APXS observation of Trumpet. Following the contact science activities, we’ll go for a drive that continues along the strategically planned route towards the area Curiosity will ascend Vera Rubin Ridge. Between the many arm activities and drive, we didn’t have time to get targeted remote sensing science in the plan, but we did plan a post-drive Mastcam clast survey, some deck monitoring, a MARDI, standard DAN and REMS activities, and a ChemCam LIBS observation of the calibration target onboard the rover.

Curiosity science team member Fred Calef’s unique pinhole viewer showing crescent shadows during the eclipse.

Back on Earth, the tactical team built a 15-minute eclipse delay into the middle of planning so that the team could go outside to observe the solar eclipse that occurred in the skies over Los Angeles and much of North America. While JPL was located substantially south of the path of totality, the partial eclipse still dimmed the Sun to a level that was approximately equivalent to what Curiosity would see on the surface of Mars. (On a clear day, Mars receives less solar insolation than Earth because it’s farther from the Sun.) Science team member Fred Calef also got particularly creative in his Curiosity themed pinhole viewer.

Solar eclipses happen on Mars too, although the Martian moons Phobos and Deimos are too small to completely cover the Sun like on Earth. Curiosity has had the opportunity to observe several of these awesome celestial events throughout the mission, including one back in 2013 when even the rover couldn’t help but take a pause in the middle of a drive to look skyward. Fortunately, with special solar filters already built into the rover’s cameras, Curiosity didn’t need to worry about ordering eclipse glasses last minute in order to capture these spectacular images.

Written by Abigail Fraeman, Planetary Geologist at NASA’s Jet Propulsion Laboratory