Astronomer and co-recipient of this year’s Nobel Prize in physics Didier Queloz doesn’t think we can escape the effects of climate change by moving to another planet. Habitable planets—if they even exist—would be very far away. He added, “We are a species that has evolved and developed for this planet. We are not built to survive on any other planet than this one.”

Even if a suitable planet was found, getting there would be quite a challenge. A couple of recent articles about medical issues in astronauts merely orbiting the earth are concerning. Astronaut Scott Kelly spent 340 days on the International Space Station. During that mission, he collected blood and urine samples and did mental and reaction tests. His twin brother Mark, also an astronaut, stayed on the ground and served as a control.

Scott experienced DNA mutations and immune system and microbiome changes, some of which have not disappeared since his return to earth. He also had lower cognitive test scores which have not returned to baseline. It’s not clear whether the continued intellectual problems are related to his experience in space or due to pain and sleep disturbances after landing.

The DNA mutations may have been cells repairing radiation injury. He was exposed to 48 times more radiation in space than the average person on earth during the same period.

A recent paper found that 6 of 11 ISS astronauts had in-flight ultrasonography showing stagnant or retrograde blood flow in their internal jugular veins. Two of them developed internal jugular vein clots, one occlusive and one partial. Lower body negative pressure counteracted the flow reversal in over half of the subjects.

Those are just a few of the medical issues associated with space travel. In response to a 2014 story about NASA’s attempt to develop robots that could perform surgery inside the human body, I blogged about the challenges of performing surgery in space. Five years later, we are not any closer to conquering the many obstacles which include personnel, equipment, anesthesia, recovery, blood contaminating the air in the spacecraft, spacecraft air contaminating the operative field, and more. The time lag for data transmission to or from Mars is about 20 minutes which would preclude having a surgeon on earth robotically performing an operation on a patient 140 million miles away.

More medical difficulties remain unsolved.

Zero or low gravity environments cause kidney stones and decreased bone density which might lead to untreatable fractures in space or on Mars.

In order to grow enough food to sustain human life, the number of plants that would have to be cultivated will produce more oxygen than humans can safely live in. However, decreasing the amount of plant food grown to keep the atmospheric oxygen level similar to that of earth will result in starvation of the Mars colonists.

Psychological issues related to confinement in a small space with only a few companions may occur.

In early 2015, reported that the private nonprofit project Mars One had chosen 100 finalists from over 200,000 applicants to crew its planned one-way trip to Mars. However, the Mars One website has not issued a press release since February 2019 when one of its companies was placed in administration [bankruptcy protection] by a Swiss court.

Don’t pack your bags just yet.

Other sources:

Listverse, NASA, EarthSky.