Best time for humans to travel to Mars is when the sun is roaring, scientists say

Maybe book your SpaceX Starship ticket for 2030 to avoid some of the worst space radiation.

Amanda Kooser
Amanda Kooser
Freelance writer Amanda C. Kooser covers gadgets and tech news with a twist for CNET. When not wallowing in weird gear and iPad apps for cats, she can be found tinkering with her 1956 DeSoto.
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Clouds and ice caps on the red planet.

NASA/ESA/Hubble Heritage Team (STScI/AURA)/J. Bell/M. Wolff (Space Science Institute)

Humanity is set on the idea of visiting Mars in person, but there's the pesky problem of hazardous radiation during long-duration spaceflights to get there. Scientists have raised concerns about brain damagegastrointestinal issues and cancer on a journey to the red planet. All in all, it sounds pretty off-putting, but it's not impossible to pull off.

A new study has some suggestions for dealing with the safety issues, and it could partly come down to strategically picking the best time to travel. 

"This study shows that while space radiation imposes strict limitations and presents technological difficulties for the human mission to Mars, such a mission is still viable," says the paper published this month in the journal Space Weather. It covers simulations that point to the optimal time to travel to Mars.

The paper calls out two main types of hazardous particle radiation: solar energetic particles (SEP) from our sun and galactic cosmic rays (GCR) from outside the solar system. The researchers point to a time known as solar maximum -- when our sun is at its highest activity level -- as an ideal time for humans to head to Mars.

"The scientists' calculations demonstrate that it would be possible to shield a Mars-bound spacecraft from energetic particles from the sun because, during solar maximum, the most dangerous and energetic particles from distant galaxies are deflected by the enhanced solar activity," UCLA said in a statement on Wednesday

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Spacecraft designers would need to focus on shielding astronauts from SEP, but there would be a reduced impact from damaging GCR during solar maximum. The team also recommends keeping a Mars round trip to less than four years in duration, though the study acknowledges this could change based on the development of new shielding materials.

The travel time to Mars can vary (it took NASA's Perseverance mission about seven months to get there), but there are a couple of prime times coming up in the mid-2030s and 2050 when shorter Earth-to-Mars journeys will coincide with periods of solar maximum. Hopefully that will help with your Martian vacation planning.

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