The National Aeronautics and Space Administration revealed that the Solar Dynamics Observatory (SDO) saw a partial solar eclipse in space when it caught Moon passing in front of Sun on May 25. According to reports, the lunar transit lasted almost an hour, between 2.24 and 3.17 pm EDT. The moon covered about 89 per cent of the Sun at the peak of its journey across the Sun's face.

Although in several images the moon's edge appears to be smooth, but, it is actually quite uneven. The surface of Moon is rugged, sprinkled with craters, valleys and mountains. A close look at the image will make you notice the subtle, bumpy outline of these topographical features.

The authorities said that SDO will witness another lunar transit on August 21. But, this time the moon will only barely hide part of the Sun. However, on the same day, a total eclipse will be observable from the earth.

A total solar eclipse, a situation in which the Moon completely obscures Sun, will cross the United States on a 70-mile-wide ribbon of land stretching from Oregon to South Carolina. A partial eclipse will be visible throughout the rest of North America and even in parts of South America, Africa, Europe and Asia.

Apart from this, NASA also said that the rugged terrain of Moon leads to what we see on Earth during total solar eclipse. The light rays stream through lunar valleys along Moon's horizon and form Baily's beads, bright points of light that signal the beginning and end of totality.

The scientists also say that the surface of the moon shapes the shadow, which is better known as umbra. It races across the path of totality: Sunlight peeks through valleys and around mountains, adding edges to the umbra. These edges warp even more as they pass over Earth's own mountain ranges.

The data from NASA's Lunar Reconnaissance Orbiter, or LRO along with NASA topographical data of Earth were used by visualisers to precisely map the upcoming eclipse in unprecedented detail. According to the study, the umbral shape varies with time, and is not simply an ellipse, but an irregular polygon with slightly curved edges.