Have you ever wondered: can astronauts see stars in space?
With only the black vastness around them, it seems like the night sky should be full of twinkling lights. However, the reality is more complex and fascinating.
Understanding why stars can disappear when viewed from space gives us insight into how human vision works and the nature of the universe.
Can Astronauts See Stars in Space? The Short Answer
The short answer is yes, astronauts can see some stars from space, but not nearly as many as we can see from Earth. The main factor impacting star visibility is the brightness of the sun. In space, the sun shines much brighter than on Earth, making it harder for astronauts’ eyes to adjust to see the relatively dimmer stars. Additionally, the Earth’s atmosphere acts like a filter, blocking some of the sun’s light and allowing more stars to be visible. Without this filtering effect, space appears darker with fewer visible stars.
Why Stars Are Not Visible in Most Pictures of Astronauts
Most photographs of astronauts in space don’t show any visible stars. This is mainly because the camera exposure settings required to take a properly lit picture of a brightly lit astronaut and space station cause the faint stars to be too dim to appear. To capture stars, the camera would have to be set for a long exposure, which would cause everything else in the image to be completely washed out.
The bright sun illumination reflecting off the Earth and space station surfaces further compound this effect. So in reality, the reason we don’t see stars in astronaut pictures is simply a limitation of photography in bright light, not because the stars aren’t visible to the astronauts’ own eyes.
Seeing Stars From the Moon
Unlike in space near Earth, the stars are visible from the surface of the Moon. With no atmosphere on the Moon, sunlight is not scattered to fill the sky with light. This means space appears black even during the lunar daytime, allowing the stars to be seen.
Astronauts who walked on the Moon during the Apollo missions described the view of the stars from the lunar surface as spectacular. Without the filtering effects of Earth’s atmosphere, the sky was filled with many more visible stars than we can see from Earth. Close to the horizon, the sun’s light was filtered through lunar dust, giving the sky a darkened hue that made the stars stand out even more clearly.
Viewing Stars From the International Space Station
Astronauts aboard the International Space Station (ISS) can see stars from their unique vantage point in low Earth orbit. Unlike the Moon, the ISS still has the Earth’s atmosphere surrounding it. This means the sky appears blue during the day instead of black. However, when orbiting on the night side of the planet, astronauts can see stars from the space station’s cupola observatory modules.
Without the interference of city lights, the view offers incredible visibility. Astronauts have described seeing shooting stars and the Milky Way galaxy from the space station. When the ISS passes into the Earth’s shadow, the sudden darkness reveals a sky bursting with stars and planets. This offers a rare chance for astronauts to stargaze from space.
Astronauts Accounts of Seeing Stars During Spacewalks
Floating outside the International Space Station during spacewalks offers astronauts an even more immersive view of the stars. Without the station windows or walls blocking their line of sight, astronauts can take in a full 360-degree view of space. Many have commented on how bright and numerous the stars appear, unfiltered by the Earth’s atmosphere.
One striking account came from astronaut Kjell Lindgren during a 2015 spacewalk. He described seeing shooting stars and the Milky Way with incredible clarity. Lindgren even spotted the Andromeda galaxy over 2 million lightyears away. He said “It’s amazing just how much brighter the stars are” without the atmosphere in the way. Experiences like this remind astronauts of the vastness of space when they are outside the confines of the space station.
The Factors Affecting Star Visibility for Astronauts in Space
Several key factors determine how clearly astronauts can see stars from the space station or during spacewalks. The main one is lighting conditions – astronauts see stars best when the space station is positioned on the night side of the Earth. The station’s orbit means it experiences 16 sunrises and sunsets per day.
When the sun is up, light scatters and overpowers the tiny pinpricks of starlight. The station’s position relative to the Sun also impacts temperatures. During colder periods, there may be less water vapor on external visors which can otherwise cause a foggy effect. The location of the Earth and Moon is also a consideration, as the reflected light from these bodies can make stars harder to spot during periods of a full moon or when the Earth is in view.
Will Star Visibility Improve for Future Deep Space Missions?
As astronauts travel farther from Earth during deep space missions, they will enjoy much better views of the stars. On the Moon, stars can be seen even during the lunar day. Future missions to Mars or asteroids will offer astronauts a vastly improved stellar vista compared to the International Space Station. With no atmosphere and no nearby large celestial bodies reflecting light, the darkness of deep space allows for spectacular observation of constellations, galaxies, nebulae and more. There will still be some limitations, as spacecraft lighting and reflective surfaces can interfere with star gazing. But overall, the further from Earth astronauts travel, the more stars they will be able to see from their vehicles and spacesuits.
FAQ
Can Astronauts See Stars in Space?
Yes, they can, but fewer than we see from Earth due to the sun’s brightness and lack of Earth’s atmospheric filter.
Why Aren’t Stars Visible in Astronaut Photos?
Camera exposure settings optimized for bright objects (like astronauts) make faint stars too dim to capture.
Are Stars More Visible From the Moon or the ISS?
Stars are clearer from the Moon due to no atmosphere. On the ISS, stars can be seen, especially on the night side, but Earth’s atmosphere slightly affects the view.
Conclusion
Yes, astronauts can see stars from space under the right conditions. The key points are that stars are visible when astronauts are in the shadow of the Earth or moon, away from bright surfaces, and their eyes have adjusted to the darkness. Light pollution from the sun and reflected light off the Earth or moon can make stars hard to see. But when astronauts are situated in the right viewing conditions, and let their eyes adjust, the stars are bright and plentiful.