- Vine was created by Nasa astronaut Reid Wiseman over the weekend
- Timelapse condenses 92-minute orbit into the span of around six seconds
- Sun never sets because ISS’ orbit is in alignment with the ‘terminator’ line
- Terminator line marks barrier between light and dark on Earth’s surface
- This happens up to four times a year but is most common around the time of the summer solstice
Astronauts on the International Space Station (ISS) can see as many as 16 sunrises and sunsets in a 24-hour period.
But on some occasions, the location of the station means the sun never sets at all, providing stunning views for the crew on board.
Now, Nasa astronaut Reid Wiseman has revealed this incredible sight from orbit, in the first ever Vine video to be sent from space.
The timelapse condenses a 92-minute orbit into the span of around six seconds showing the space station hurtling around the planet at 17,500 mph (27,600 km/h).
WHAT CAUSES A NEVER-SETTING SUN?
In certain orbits of the Earth, the sun never sets on the ISS because the space station is in alignment with the day/night terminator line.
This line marks the barrier between light and dark on the surface of the Earth.
In this scenario, something known as the ‘beta angle’ increases. This is the imaginary line between the sun and the path of the ISS around Earth.
When beta angle exceeds 69º, it is in constant sunlight. This happens two to four times a year and is most extreme near the summer solstice on June 21.
The timelapse condenses a 92-minute orbit into the span of around six seconds showing the space station hurtling around the planet at 17,500 mph (27,600 km/h).
The sun never sets because the space station’s orbit comes into alignment with the day and night terminator line.
This marks the barrier between light and dark on the surface of the Earth.
In this scenario, something known as the ‘beta angle’ increases. This is the imaginary line between the sun and the path of the ISS around Earth.
Writing in the Weather Centre blog, Tony Rice explained that as the beta angle gets higher, the time the ISS is in sunlight also increases.
The sun never sets because the space station’s orbit comes into alignment with the day and night terminator line. This marks the barrier between light and dark on the surface of the Earth
During this period, the so-called ‘beta angle’ increases. This is the imaginary line between the sun and the path of the ISS around Earth. As the beta angle gets higher, the time the ISS is in sunlight increases. When beta angle exceeds 69º, it is in constant sunlight
‘When beta angle exceeds 69º, it is in constant sunlight, and mission control keeps an even closer around-the-clock watch on power production and temperatures,’ he said.
‘This happens two to four times a year but is most extreme near the summer solstice coming on June 21.’
Previous space shuttles would enter something known as a ‘barbeque mode’ which would cause them to do slow barrel rolls to avoid overheating.
On the ISS, an Active Thermal Control System transfers heat through to large radiators extending under the station that can then be released into space.
Reid Wiseman from Baltimore (pictured) is currently serving as flight engineer aboard the International Space Station for Expedition 41. Wiseman’s space Vine has gained over 4,000 likes and nearly 2,000 retweets since it was posted on Saturday
‘1st Vine from space! Single Earth orbit. Sun never sets flying parallel w/terminator line,’ Wiseman explained in the clip, which he shared over the weekend.
Vine is a mobile service that creates short looping videos which are six seconds or less. So far, Wiseman’s Vine has gained over 4,000 likes and nearly 2,000 retweets.
The 38-year-old from Baltimore is currently serving as flight engineer aboard the International Space Station for Expedition 41.
The last time Twitter saw a space ‘first’ was when astronaut Mike Massimino sent the first tweet from orbit in 2009.
‘My parents were waving in Maryland at sunrise, so I took a picture of them,’ Wiseman wrote with this shot
Source:::: y ELLIE ZOLFAGHARIFARD in Daily Mail Australia
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