• This October, Mars and the Earth will be on opposite sides of the sun
  • It's called solar conjunction, which happens every two years
  • Gases expelled by the sun can interfere with radio signals
  • NASA will pause from sending commands for two weeks

The Mars missions will go quiet for about two weeks in October because of the "solar conjunction." However, that doesn't mean the spacecraft will be idling on the red planet.

For about two weeks every two years, the Earth and Mars are obscured from each other as they are positioned at opposite sides of the sun. During this period, called the "solar conjunction," the two planets are "temporarily invisible to each other," NASA noted.

During this time, spacecraft on Mars is essentially "incommunicado" and engineers don't attempt to send new instructions or communicate with them because the ionized gas that the sun expels can interfere with the radio signals, NASA explained in a news release. This year, the "commanding moratorium" will be from Oct. 2 to 16.

According to the agency, it is "impossible to predict" which information could get lost due to the interference.

"That could corrupt commands and result in unexpected behavior from our deep space explorers," the agency noted.

As such, the engineers instead send two weeks' worth of instructions to the spacecraft on Mars before the solar conjunction.

"Each mission has been given some homework to do until they hear from us again," Roy Gladden, manager of the Mars Relay Network at NASA's Jet Propulsion Laboratory, said in the news release.

For instance, the Perseverance rover will capture new sounds with its microphones and look for dust devils using its cameras while the Ingenuity Mars Helicopter will remain some 575 feet from Perseverance but will relay a weekly status to it.

"I'm parked in a sweet spot between dunes and a rock outcrop, ready for a 2-week solar conjunction, when the Sun blocks signals to and from Mars," the Perseverance Rover Twitter account noted.

The older Curiosity Rover will join the Perseverance in looking for dust devils and also take various measurements with its instruments while the InSight Lander and three NASA orbiters also have tasks of their own.

"Like parents who raise youngsters to be responsible and let them go on a short vacation with their friends, they've done all they can to ensure the voyagers will be healthy and safe," NASA said.

NASA's Perseverance became the fifth rover to successfully land on Mars since 1997, launching shortly after China's Tianwen-1
NASA's Perseverance became the fifth rover to successfully land on Mars since 1997, launching shortly after China's Tianwen-1 NASA/JPL-Caltech/MSSS / Handout