The first thing that comes to mind when thinking about a telescope is probably a scientific instrument housed within a dome or similar structure on a secluded plateau, or a radio antenna in some remote location. However, astronomers at Stratospheric Observatory for Infrared Astronomy (SOFIA) are doing something that is uncommon – observing from a 2.5 metre telescope in a modified Boeing B747SP aircraft. Ms Karina Leppik, SOFIA Mission Director gave a public lecture on 3 February 2020 titled: ‘What do you get when you mix a telescope with an airplane?’
The focus of the public lecture was on SOFIA’s flight planning and execution (how to point at a specific star or object in the sky). She began her talk by introducing the audience to the electromagnetic spectrum and the different layers of the Earth’s atmosphere, putting emphasis on the Stratosphere, which is the layer where SOFIA flies in. She mentioned that SOFIA flies at an altitude of 39,000-45,000 feet, placing it above 99 percent of obscuring water vapour. This means that it flies above the weather and below space, enabling it to better observe the infrared radiation that celestial objects emit. According to Dr Leppik, this allows astronomers to observe objects that cannot be seen from Earth due to dust particles and other factors that hinder astronomical observations.
“An infrared telescope allows us to observe very fine details of celestial objects better than with a telescope that operates in the visible light”, she said.
She gave detailed information on the major components of the aircraft and of the various instruments used, depending on what celestial object they want to observe. She also gave an outline of the flight path, plan, and of challenges often encountered in flight planning. She pointed out a major flight planning challenge as getting to the right place at the right time, due to the fact that the exact location of the occultation is not well known until hours before the event. Moreover, she has displayed some of the most remarkable images captured through the telescope, including infrared images of the center of our Milky Way galaxy spanning 600+ light-years across, the Orion Nebula, Swan Nebula, and the Epsilon Eridani Planetary System.
SOFIA is the largest airborne observatory in the world and is a joint project of the United State’s National Aeronautics and Space Administration (NASA) (80%) and the German Aerospace Center (20%). To learn more about the SOFIA telescope, please visit https://www.nasa.gov/mission_pages/SOFIA/overview/index.html