NASA's Solar Dynamics Observatory (SDO) is tasked to observe the sun 24/7. In a recent activity, SDO captured a partial solar eclipse. Capturing eclipses are a welcome break from the otherwise seemingly boring job of the SDO.

The partial solar eclipse occurred last May 25. The moon passed in the space between SDO and the sun. It was brief but no less astonishing partial eclipse. The moon crossing the sun is called a lunar crossing or lunar transit. It lasted for an hour where the moon blocked about 89 percent of the sun during the peak of the eclipse, according to Space.com.

An image of the partial eclipse captured by NASA SDO was released by the agency last May 26. It started at 2:24 om EDT and ended 3:17 pm.

"The moon's crisp horizon can be seen from this view because the moon has no atmosphere to distort the sunlight," NASA said in the image caption. "While the moon's edge appears smooth in these images, it's actually quite uneven."

The interesting part is that during the partial solar eclipse, the surface of the moon was visible. It appeared to be rugged with craters, valleys and mountains. If observed closely, the bumpy outline of the topography features.

But NASA experts say that the partial solar eclipse is just a prelude to a more interesting phenomenon. SDO is expected to witness lunar transit this coming Aug. 21. At the same time, a total eclipse will be visible from Earth also known as the Great American Solar Eclipse.

Solar Probe Plus

Aside from that, NASA is inching towards reaching the Sun's surface. On May 31, the agency will make an announcement about its Solar Probe Plus. The probe is also called its mission to "touch the sun" because of its ambitious target proximity to the center of the Solar System. The mission will launch in the summer of 2018 and is designed to reach an orbit at about only four million miles away from the sun's surface.