Why do astronauts in space age slower than people on Earth?

Produced by: BT Desk

Astronauts age a tiny bit slower than people on Earth because of time-dilation effects --- time moves slower as gravity increases. Time passes slower for objects closer to the center of Earth where gravity is stronger.

The other factor is "relative velocity time dilation" where time moves slower as you move faster. When scientists launched an atomic clock into orbit- while keeping an identical one on Earth - it returned running behind the Earth clock.

Complication happens when gravitational time dilation and relative velocity time dilation happen at the same time.

Astronauts on the International Space Station experience both weaker gravity and higher velocity, resulting in slightly slower ageing compared to people on Earth.

The European Space Agency (ESA) in a post in X said “after spending six months on the ISS, astronauts have aged about 0.005 seconds less than the rest of us.”

To calculate your age on other planets, divide your age in Earth years by the length of the planet’s year in Earth years. This is your new age. For instance, a 24-year old on Earth is only two years old on Jupiter (24/12 = 2).

Daily life aboard the ISS moves fast. Traveling at approximately 17,000 miles per hour, 300 miles above the Earth, astronauts watch 16 sunrises and sunsets every day