
Taken near the entrance of Hawai`i Volcanoes National Park (which is now closed) on May 15, 2018, at 11:28 am.
MORTON GNEISS
Morton, Minnesota
Oldest Rock in the United States — 3.524 billion years old
MORTON GNEISS
Morton, Minnesota
Oldest Rock in the United States — 3.524 billion years old
Kilauea Volcano
10 Questions About the Earth—
and the Geology of North America.
Science — History — Biography
13. The first attempt to photograph a total solar eclipse was made by Giovanni Alessandro Majocchi in Milan, Italy, on July 8, 1842. He succeeded in photographing the partial phase of the eclipse, but the chemicals on his photographic plate (a daguerreotype) were not sensitive enough to record the corona. The exposure time was 2 minutes.
The first successful photograph of a total solar eclipse was made by Johann Julius Friedrich Berkowski at an observatory in Königberg, Prussia (now Kaliningrad, Russia). His photograph was also a daguerreotype, meaning the image was recorded on a copper plate that had been coated with silver iodide, which he developed by holding the plate over mercury vapor. The exposure time was 84 seconds. The image of the eclipsed Sun on the daguerreotype has a diameter of about 0.3 inch.