Astronomy Picture of the Day——20180803

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2018 August 3

Eclipseover the Gulf of Poets

Image Credit & Copyright: Paolo Lazzarotti

Explanation:The total phase of the July 27 lunar eclipse lasted for an impressive 103minutes. That makes it the longest total lunar eclipse of the 21st century. TheMoon passed through the center of Earth's shadow while the Moon was nearapogee, the most distant point in its elliptical orbit. From start to finish,the entire duration of totality is covered in this composite view. A dreamlikescene, it includes a sequence of digital camera exposures made every threeminutes. The exposures track the totally eclipsed lunar disk, accompanied onthat night by bright planet Mars, as it climbs above the seaside village of Tellaro, Italy. In the foreground lies the calm mediteranean Gulf of La Spezia,known to some as the Gulf of Poets. In the 3rd century BCE, heliocentricastronomer Aristarchus also tracked the duration of lunar eclipses, thoughwithout the benefit of digital clocks and cameras. Using geometry he devised away to calculate the Moon's distance from the eclipse duration, in terms of theradius of planet Earth.