WATCH: NASA Spacecraft Observes Rare Double Eclipse
A NASA spacecraft captured a rare double eclipse - when the Earth and the moon crossed paths in front of the Sun.
NASA's Solar Dynamics Observatory (SDO) captured the rare event on Sept. 1 when the Earth completely eclipsed the Sun from SDO's perspective just as the moon started to pass across the face of the Sun. The end of the eclipse of the Earth happened just at the moment for SDO to catch the last stages of the moon's passage.
According to a press release via EurekAlert, the SDO constantly monitors the sun's activity, but during SDO's semiannual eclipse seasons, the Earth briefly blocks SDO's view each day due to SDO's geosynchronous orbit.
In a video released earlier, NASA Goddard Space Flight Center shows the rare event in detail, where both the Earth and the moon's shadows can be seen. The SDO data shows the difference between the Earth and the moon by their edges: Earth's shadow edges looked fuzzy, while the moon's were sharp and distinct. According to scientists, this is because the Earth's atmosphere absorbs the light from the sun, making its edges appear faint. The moon, on the other hand, has no atmosphere, which makes it appear crisper and clearer in the images.
According to NASA astronomers, the geometry of the Earth, the moon and the Sun resulted to a simultaneous eclipse visible from southern Africa. The eclipse, which is called an annular eclipse or a "ring of fire" eclipse, had been visible is the African countries of Tanzania, Gabon, Republic of the Congo, the Democratic Republic of Congo, Mozambique and Madagascar.
An annular eclipse happens when the moon is at a point in its orbit farther from the Earth. This makes the moon appear too distant or smaller in size, so that it does not cover the sun entirely, and instead leaves a flaming circle of light in the sky, like a ring of fire.