Follow astronaut Scott Kelly’s record-breaking 12-month mission on the International Space Station, from launch to landing, as NASA charts the effects of long-duration spaceflight.
Artificial selection is one example, eyes another, of the well-documented and inescapable process of evolution--change in a population of species over time--by natural selection. These are some of the things that molecules do.
In 2014, the International Space Station had to move three times to avoid lethal chunks of space debris and there is an increasing problem of satellites mysteriously breaking down. With first-hand accounts from astronauts and experts, Horizon reveals the scale of the problem of space junk. Our planet is surrounded by hundreds of millions of pieces of junk moving at 17,000 miles per hour. Now the US government is investing a billion dollars to track them, and companies around the world are developing ways to clear up their mess - from robot arms to nets and harpoons. Horizon investigates the science behind the hit film Gravity and discovers the reality is far more worrying than the Hollywood fiction.