SOFIA the Boeing 747 flying telescope

The word SOFIA stands for (Stratospheric Observatory for Infrared Astronomy) it  is Nasa’s first airborne telescope nested in a Boeing 747.

(Watch the SOFIA explanation video below)

Because the Earth’s atmosphere absorbs light wavelengths it is difficult for astronomers closer to the sea level to detect lower spectrums of infrared and ultraviolet radiation.  This created the necessity to reach for higher altitudes above earths lower atmosphere the troposphere to see the stars with less distortion in between caused by turbulence, water vapor and the ozone layer.

SOFIA is based on a Boeing 747SP wide-body aircraft that has been modified to include a large door in the aft fuselage that can be opened in flight to allow a 2.5 meter diameter reflecting telescope access to the sky. This telescope is designed for infrared astronomy observations in the stratosphere at altitudes of about 41,000 feet (about 12 km). SOFIA’s flight capability allows it to rise above almost all of the water vapor in the Earth’s atmosphere, which blocks some infrared wavelengths from reaching the ground. At the aircraft’s cruising altitude, 85% of the full infrared range will be available.

The SOFIA telescope hatch opened in mid-flight
The SOFIA telescope hatch opened in mid-flight

Stars don’t twinkle in the stratosphere

SOFIA does its astronomic observation at the stratosphere which is one of Earth’s largest atmospheric layers.  It is a 40km layer situated  above  10 to 13 km (30,000–40,000 ft; 6–8 mi) above sea level.  At the stratosphere stars don’t twinkle due to the lack of air turbulence at these high altitudes these conditions are ideal for observing star formation which emits low levels of radiation which can be detected from the stratosphere.