On February 11th of this year, NASA launched the Solar Dynamic Observatory (SDO). The spacecraft was launched with a mission to investigate the Sun over a period of five years. Through SDO’s observations, researchers hope to learn more about how the Sun’s magnetic field is generated and how magnetic energy is stored and released in the form of solar wind, energized particles and sunlight.
While much of that data may not be very interesting to the common person, what SDO looks like might be:
What’s even cooler is the image at the top. The spacecraft was able to capture a solar eclipse, but not the kind we normally see from Earth. When most people think of a solar eclipse, they think of the Moon passing between the Earth and the Sun causing sunlight to be blocked for a short time. The type of eclipse captured by SDO actually occurs when Earth’s own shadow is cast on the Sun. SDO is able to see this shadow twice a year when the spacecraft slips behind Earth for up to 72 minutes a day. Instead of the shadow being a well-defined shape like we see when the Moon slips in front of the Sun, Earth’s shadow is less defined due to the fact that it has an atmosphere with varying degrees of density. Brighter spots on the Sun’s surface also help to breakup the shadow.
Making the photo even more striking are the solar events captured where it looks as if flames are shooting out of the Sun’s surface. These events are caused by varying magnetic fields which sometimes result in the release of solar flares when there is a sudden release of magnetic energy stored in the Sun’s corona. Strong solar flares which reach Earth can present a hazard to spacecraft and astronauts in orbit at the time.