Αναρτήσεις

Προβολή αναρτήσεων από Ιανουάριος, 2022

Look up! Huge asteroid (7482) 1994 PC1 race by Earth at 43,000 miles per hour

Εικόνα
A large stony asteroid safely pass Earth today January 18, 2022. Its estimated size is around 3,280 feet (about 1 km or .6 of a mile), around 2 1/2 times the height of the Empire State Building. As you can see from this asteroid’s label – (7482) 1994 PC1 – we’ve known about it since 1994. It is classified as a Potentially Hazardous Asteroid due to its size and relatively close flybys of our planet. An asteroid of this size strikes Earth approximately every 600,000 years. But we have nothing to fear from 1994 PC1 at its 2022 close approach. And … a plus … amateur astronomers with backyard telescopes might catch a glimpse of it as it sweeps past. 1994 PC1 orbits the Sun at a distance of 0.9–1.8 AU once every 1 years and 7 months (572 days). Its orbit has an eccentricity of 0.33 and an inclination of 33° with respect to the ecliptic. On 17 January 1933, it passed 811,350 km (504,150 mi) from the Moon and then about a hour later made its closest known approach to Earth of 1,125,400 km (699...

The Nervous System of Harriet Cole

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This story, set in 1880s post Civil War America, particularly appealed to me due to my love of anatomy. The two main players in this unusual tale are very different individuals indeed. The first, Harriet Cole, was an African-American woman who worked as a cleaning lady at Hahnemann Medical College (now the Drexel University College of Medicine) in Philadelphia. The second, Dr Rufus B. Weaver, was the Medical College’s leading Professor of Anatomy. Together this odd couple would be responsible for the creation of one of the world’s most captivating and astonishing medical specimens. Harriet’s demise and generous donation In 1888, at just 35 years of age, Harriet Cole died from tuberculosis. Having worked for some time at the Medical College, she agreed to leave her body to Dr Weaver and requested that it be used for the benefit of science and medicine. It is very doubtful that Harriet knew what Dr Weaver would do with her body though, and the extraordinary legacy that she would leave be...

Glaucus Atlanticus

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Glaucus atlanticus is a sea slug, a pelagic nudibranch. At the taxonomic level it is a mollusc of the Gastropoda class, in the family Glaucidae and the only species of the genus Glaucus. Usually, they live in the Atlantic Ocean, although specimens have been found in all oceans. It prefers mainly temperate and tropical waters, which is why its sighting is more frequent in Mozambique and South African waters. Its camouflage is one of its best adaptations to survive The sea swallow inhabits the shallowest part of the water, which is the most dangerous area for a prey. In the part seen from the sky they are almost invisible, because their bright blue color camouflages them with the sea, being exactly the same color as it and therefore, avoiding being seen by birds. At the bottom they are silver, achieving the same mimicry effect so that fish do not see them. On the back it has two lines of a deeper blue that go through its body to the tip of its tail. In between, there is a thicker one th...