28 August

Today's entries are mainly political and scientific. Way back, on 28 August 1619,  Ferdinand II was  elected emperor of the Imperium Romanum Sacrum, the Holy Roman Empire. 

More than two centuries later, the Slavery Abolition Act of  1833 enacted by the British Parliament outlawed slavery in the British Empire, thus liberating around 700 000 people. 

And talking about empires and spheres of influence, on 28 August 1867  the United States took possession of the tiny Midway Atoll (only slightly more than 6 km² ) in the North Pacific Ocean.  A century later the Battle of Midway (1942)  became an important naval milestone of World War II when the US  Navy defeated a Japanese attack.

Another empire collapsed on 28 August 1991, when  Mikhail Gorbachev resigned as General Secretary of the Soviet Communist Party of the then Soviet Union.  On the same day, the Ukraine declared its independence from the USSR.

Here, courtesy of the British Library,
is the original score of Herschel's Symphony No 15   

On this date in 1789 William Herschel, the German-born British astronomer who was also a prolific composer, discovered one of my favourite moons in the Solar System - Saturn's beautiful Enceladus. Herchel is, of course, perhaps best known as the astronomer who discovered the planet Uranus in 1781. Currently we are learning more about Enceladus and other moons in the Saturn system via the Jet Propulsion Laboratory's Cassini mission.  

The first issue of Scientific American magazine was published on 28 August 1845.  It is now the oldest continuously published monthly magazine in the US with  

among others also an online version at http://www.scientificamerican.com/ and a dedicated YouTube channel at    https://www.youtube.com/user/SciAmerican.

On 13:00 on 28 August 1941, the Dominion Observatory time became Canada's official time. 

Finally, something for the UK Royals watchers:  on this date in 1996 the divorce of  Charles, Prince of Wales and Diana, Princess of Wales became final.

 Saturn's moon Enceladus reflects sunlight brightly while the planet and its rings fill the background of this Cassini view.Enceladus is one of the most reflective bodies in the solar system because it is constantly coated by fresh, white ice particles.Photograph and caption:  NASA/JPL-Caltech/Space Science Institute  The mission's dedicated website is here: http://saturn.jpl.nasa.gov/index.cfm    

 Dramatic plumes, both large and small, spray water ice out from many locations along the famed "tiger stripes" near the south pole of Enceladus. The tiger stripes are fissures that spray icy particles, water vapour and organic compounds. More than 30 individual jets of different sizes can be seen in this image and more than 20 of them had not been identified before. This mosaic was created from two high-resolution images that were captured by the narrow-angle camera when NASA’s Cassini spacecraft flew past Enceladus and through the jets on Nov. 21, 2009.  
Photo and caption: NASA/JPL-Caltech/Space Science Institute

 A quintet of Saturn's moons come together in the Cassini spacecraft's field of view for this portrait. Janus (179 kilometers, or 111 miles across) is on the far left. Pandora (81 kilometers, or 50 miles across) orbits between the A ring and the thin F ring near the middle of the image. Brightly reflective Enceladus (504 kilometers, or 313 miles across) appears above the center of the image. Saturn's second largest moon, Rhea (1,528 kilometers, or 949 miles across), is bisected by the right edge of the image. The smaller moon Mimas (396 kilometers, or 246 miles across) can be seen beyond Rhea also on the right side of the image.
Photo and caption: NASA/JPL-Caltech/Space Science Institute