APOD 2.1: Iridescent Cloud Edge Over Colorado

 

When watching the eclipse on October 23, spotters in Colorado suffered from cloud coverage. Unexpectadely, the clouds tarted to show iridescence, the diffraction of sunlight around a thin screen of nearly uniformly-sized water droplets. Different colors of the sunlight become deflected by different angles and come to the observer from slightly different directions. The white streak on the right are the trails of an airplane.

APOD 1.8: Auroral Corona Over Norway

 

Auroras rarely reach below 60 kilometers off the ground, and can range up to 1000 kilometers. Auroras are made from prtons and electrons striking differeent atoms and molecules in the Earth's atmosphere. the uncommon auroral corona can happen when aurora happens directly above or is taken from directly under. This green and purple aurora exhibition occurred last month above Kvaløya, Tromsø, Norway. The Sessøyfjordenfjord runs through the foreground, while numerous stars are visible far in the distance. 

APOD 1.7: Eclipse At Moonset

 

     This half eclipsed moon lies over a bed of clouds covering the Pacific ocean and Chilean coast line. The curved edge of the earths shadow cuts across the middle as the Moon sinks lower in towards the western hemisphere. This eclipse began at the time of moonset and sunrise on October 8, it could only be followed for about an hour on the far west due to clouds.

Christian Severin, “Longomontanus”

b. Longberg, Jutland, Denmark, 4 October 1562; d. Copenhagen, Denmark, 8 October 1647

            Christian Severin was the son of two peasants, Søren Poulsen and Maron Christensdatter.  After Severin’s father died, his mother could now afford for him to go to school continuously, in result, having Severin finish school when he was twenty six. After servicing Tycho Brahe until 1597, he received an MA at the University of Rostock. He then returned home and became a college professor in 1607, teaching science and mathematics at the University of Copenhagan. He remained there until his death in 1647. When Tycho died in 1601, his program for the restoration of astronomy was unfinished. Two tasks were left: the selection and integration of the data of the motions of the planets, and the presentation of the results of the entire program in the form of a treaty. Severin, Tycho’s closest, assumed the responsibility and fulfilled both tasks in his Astronomia danica in 1662. Although Severin worked and wrote in the era of Kepler and Galileo, he didn’t believe in ellipses, heliocentrism, the telescope, and logarithms. Regardless of his knowledge as an astronomist, Severin’s reputation suffered in comparison to Kepler’s achievements. Severin’s prestige attached to his work saw it through two reprintings despite the appearance of Kepler's Tabulae Rudolphinae in 1627. In Severin’s honor, there is a massive inpact crater named after him, Longomontanus, located southwest of Tycho, another crater.

APOD 1.6 : The Butterfly Nebula From Hubble

 

This nebula has an estimated surface tempurature of 250,000 degrees C, named the butterfly nebula fot its dying center, making it look like two butterfly wings. this picture was taken in 2009 by the Hubble Space Telescope's Wide Field Camera 3 an has had its colors reprosessed. NGC 6302 lies about 4,000 light-years away in the constellation, Scorpion (Scorpius).