In preparation for NASA's journey to Mars, scientists deployed a group of mice to the Atlantis space shuttle, in order to observe how long-term space living can affect the body. As a result, they found out that the mice showed signs of early liver damage upon their return to earth.

According to Science Daily, the University of Colorado found out the mice were showing signs of liver disease after their long-term stay at the space shuttle, Atlantis. Karen Jonscher, PhD, an associate professor of anesthesiology and a physicist at the University of Colorado said, "Prior to this study, we really didn't have much information on the impact of space flight on the liver... We knew that astronauts often returned with diabetes-like symptoms, but they usually resolved quickly."

For the study, the mice spent 13 and a half days inside the space shuttle. The researchers collected samples and they found that the space flight caused specialized liver cells that can cause long term damage to the organ. "We saw the beginning of nascent liver damage in just 13.5 days...The mice also lost lean muscle mass. We have seen this same phenomenon in humans on bedrest -- muscles atrophy and proteins break down into amino acids." Jonscher said.

In addition to that, the researchers found out that space flight caused increased fat storage in the mice's liver. It can be attributed to the loss of specific minerals responsible for the breaking down of fats.

Because of the result of this study, some say that the long-term space journey to Mars could be more dangerous that originally thought. Daily Mail reported that the results have an implication on NASA's journey to Mars because the same process affecting the mouse livers can also happen to humans, the only difference is how long before it affects men.

The journey to Mars would take about a year; the mice spent less than 14 days before the damage manifested. The same report said, "The mice showed signs of non-alcoholic fatty liver disease (NAFLD) and potential early indicators for the beginnings of fibrosis, the first stage of liver scarring."

Researchers are keen to find out more about this mechanism so that they can protect the astronauts who will be involved in NASA's journey to Mars.