Simulated effects of microgravity, created by 60 days of constant bed rest, severely disrupts rhythmic gene expression in humans, according to a new study from the University of Surrey published in iScience.

Astronauts exposed to microgravity experience changes to physiology, including immune suppression, increased inflammation, and reduced muscle mass and bone density. With the increase in human spaceflight, it is important to understand changes in the molecular mechanisms underlying these changes.

Lead author Professor Simon Archer, Professor of Molecular Biology of Sleep at the University of Surrey, said, "This unique study represents the largest longitudinal dataset of time series gene expression in humans. Human gene expression varies rhythmically over the 24-hour day, and it is important to collect time series data rather than from just single time points to get a full picture of what occurs in the body when exposed to simulated microgravity.

"It also raises questions about the impact of constant bed rest on our bodies as we have identified a dramatic effect on the temporal organization of human gene expression.

For nearly 50 years, NASA's Voyager 1 mission has competed for the title of deep space's little engine that could. Launched in 1977 along with its twin, Voyager 2, the spacecraft is now soaring more than 15 billion miles from Earth.

On their journeys through the solar system, the Voyager spacecraft beamed startling images back to Earth—of Jupiter and Saturn, then Uranus and Neptune and their moons. Voyager 1's most famous shot may be what famed astronomer Carl Sagan called the "pale blue dot," a lonely image of Earth taken from 6 billion miles away in 1990.

But Voyager 1's trek could now be drawing to a close. Since December, the spacecraft--which weighs less than most cars--has been sending nonsensical messages back to Earth, and engineers are struggling to fix the problem. Voyager 2 remains operational.

Fran Bagenal is a planetary scientist at the Laboratory for Atmospheric and Space Physics (LASP) at CU Boulder. She started working on the Voyager mission during a summer student job in the late 1970s and has followed the two spacecraft closely since.

To celebrate Voyager 1, Bagenal reflects on the mission's legacy—and which planet she wants to visit again.