February 11, 2015 marks five years in space for NASA’s Solar Dynamics Observatory or SDO, which provides incredibly detailed images of the Earth-facing side of the sun 24 hours a day. Capturing an image almost once per second, SDO has provided an unprecedentedly clear picture of how massive explosions on the sun grow and erupt ever since its launch on Feb. 11, 2010. The imagery is also captivating, allowing one to watch the constant ballet of solar material through the sun’s atmosphere, the corona.
In honor of SDO’s fifth anniversary, NASA has released two videos showcasing highlights from the last five years of sun watching. The first is a time lapse of the past five years. Different colors represent different wavelengths of extreme ultraviolet light, ultraviolet light, and visible light, which in turn correspond to solar material at different temperatures. Additionally SDO returns solar magnetic field data that helps scientists study solar activity.
The second video showcases highlights from the last five years. Watch the movie to see giant clouds of solar material hurled out into space, the dance of giant loops hovering in the corona, and huge sunspots growing and shrinking on the sun’s surface.
The imagery in both videos is an example of the kind of data that SDO provides to scientists. By watching the sun in different wavelengths – and therefore different temperatures – scientists can watch how material courses through the corona, which holds clues to what causes eruptions on the sun, what heats the sun’s atmosphere up to 1,000 times hotter than its surface, and why the sun’s magnetic fields are constantly on the move. SDO also measures fluctuations in the sun’s extreme ultraviolet output, which provides the majority of energy for heating Earth’s upper atmosphere.
“There have now been more than 2,000 scientific papers published based on SDO data,” said Dean Pesnell, project scientist for SDO at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “SDO has also led to wonderful international collaborations, with the data being shared and used all over the world.”
Five years into its mission, SDO continues to send back tantalizing imagery to incite scientists’ curiosity. For example, in late 2014, SDO captured imagery of the largest sun spots seen since 1995 as well as a torrent of intense solar flares. Solar flares are bursts of light, energy and X-rays. They can occur by themselves or can be accompanied by what’s called a coronal mass ejection, or CME, in which a giant cloud of solar material erupts off the sun, achieves escape velocity and heads off into space. In this case, the sun produced only flares and no CMEs, which, while not unheard of, is somewhat unusual for flares of that size. Scientists are looking at that data now to see if they can determine what circumstances might have led to flares eruptions alone.
This mission has touched us on many levels; it evokes a sense of wonder when we see these beautiful images;” said Lika Guhathakurta, SDO program scientist at NASA Headquarters in Washington, DC. “It stokes our curiosity and it connects us personally to the deepest mysteries—from the warmth we feel on our skin when we walk outside on a sunny day to the distant reaches of the cosmos.”
Goddard built, operates and manages the SDO spacecraft for NASA’s Science Mission Directorate in Washington, D.C. SDO is the first mission of NASA’s Living with a Star Program. The program’s goal is to develop the scientific understanding necessary to address those aspects of the sun-Earth system that directly affect our lives and society.