If you’re on the Red Planet right now, a word of warning. You’re about to hear nothing for us for more than a week. Apologies.
That’s going to occur because Mars is moving almost behind the Sun relative to Earth, as both planets continue their dance around the Solar System. From July 22 to August 1, communications will be hampered by the pesky Sun.
So NASA has decided not to send any commands to any of its rovers or spacecraft at Mars during that time, to eliminate the risk of signals received being distorted by the Sun. NASA’s fleet consists of the Curiosity and Opportunity rovers on the ground, and the Mars Odyssey, Mars Reconnaissance Orbiter, and MAVEN spacecraft in orbit.
"Out of caution, we won't talk to our Mars assets during that period because we expect significant degradation in the communication link, and we don't want to take a chance that one of our spacecraft would act on a corrupted command," said Chad Edwards, manager of the Mars Relay Network Office at NASA's Jet Propulsion Laboratory in California, in a statement.
Mars won’t actually go directly behind the Sun. But it will go close enough that ionized gas from the Sun’s corona (its outer atmosphere) could cause issues. This occurrence is known as Mars solar conjunction.
Don’t worry too much though, because the various teams that work on each mission have been planning for this. This moratorium happens roughly every 26 months, owing to the particulars of how our two planets orbit the Sun, so scientists are prepared.
Most of the missions have experienced this many times before. For Mars Odyssey, it’s the eighth conjunction, Opportunity the seventh, MRO the sixth, Curiosity the third, and MAVEN the second.
(Note, we don't know if other countries with missions around Mars – India and Europe – are going to be doing the same thing as NASA, but we have asked each agency and will update when we hear back.)
The teams have already sent commands to the various missions so they can continue operating, even without regular contact with Earth. NASA also will still receive data back from its Mars missions during this time. Anything that’s corrupted will then be re-sent back later, when the planets have an obstructed view of each other again.
"The vehicles will stay active, carrying out commands sent in advance," said Mars Program Chief Engineer Hoppy Price, of JPL. "Orbiters will be making their science observations and transmitting data. The rovers won't be driving, but observations and measurements will continue."