The countdown to the April 8 total solar eclipse is on, and eclipse-chasers have been waiting months - even years - to catch a glimpse of the Moon crossing the Sun in our sky.
But did you know you can see the effect of a total solar eclipse every day, courtesy of a NASA/ESA solar observatory?
The Solar and Heliospheric Observatory (SOHO) is a joint NASA and European Space Agency spacecraft that orbits the Sun and continuously captures images of our host star.
Solar eclipses and solar science
Total solar eclipses are a magnificent sight, but they're also a great chance for solar scientists to observe our host star in detail.
This is because during a total solar eclipse, the Moon covers the entirety of the solar disk.
It's a coincidence of nature that the Moon is just the right size and just the right distance from Earth for this to happen.
When the Moon does block out the Sun's disk, this makes the Sun's corona - its outermost layer - more visible.
During a total solar eclipse, astronomers can better observe wisps of the Sun's extended atmosphere as hot gas from the Sun streams into space.
Just as holding up your hand to block the Sun on a sunny day helps you see what's in front of you, the Moon blocking the Sun during a total solar eclipse helps solar scientists see the corona.
SOHO's coronagraph
This is the premise behind the Solar and Heliospheric Observatory's observations of our Sun.
It uses a device called a 'coronagraph', which creates an artificial solar eclipse by blocking out light from the Sun, the same way the Moon does.
This enables astronomers to see parts of the Sun's atmosphere that would normally be drowned out by its powerful brightness.
It's also the technique being used by the ESA Proba-3 mission, which will see two spacecraft fly in formation, one acting as the coronagraph.
And it's possible for anyone to observe these artificial solar eclipses by using the online Helioviewer Eclipse Watch tool.
It provides eclipse-like images captured over 100 times a day by the Large Angle and Spectrometric Coronagraph Experiment (LASCO) instrument on the SOHO spacecraft.
You can also see this by accessing SOHO's realtime data of the Sun.
Just refresh the page to see the latest artificial eclipse captured by SOHO.
Solar eclipses and the Solar Cycle
The Sun goes through periods of being very active, and periods of being very quiet. These peak and trough in a roughly 11-year cycle called the Solar Cycle.
Solar scientists can learn a lot about the Sun's activity during a solar eclipse, but can get a view of an eclipse effect every day, courtesy of the SOHO spacecraft.
LASCO observes the solar corona, and especially coronal mass ejections, which erupt from the Sun during periods of solar activity.
In the Helioviewer Eclipse Watch tool, an image of the Moon has been transposed for scale.
This shows how the Moon actually covers a smaller portion of the Sun's disk than SOHO's coronagraph, meaning that on the day of a total solar eclipse, solar scientists get the chance to see more of the Sun's outer atmosphere than usual.
Total solar eclipses are not just beautiful; they're a chance to learn so much more about our host star and the changing face of the Solar Cycle.
