2019 Total Solar Eclipse Event at ESO’s La Silla Observatory in Chile
On 2 July 2019 one of nature’s most impressive phenomena will be visible from ESO’s La Silla Observatory in Chile — a total solar eclipse. As these are very rare — the next one visible from La Silla will occur in 212 years — ESO is organising a campaign of observing and outreach activities on site, allowing the general public to experience this spectacular event. Tickets to participate will be available from 13:00 CEST/07:00 CLT on Friday 13 July 2018.
Urania’s Mirror; or, a view of the Heavens is a set of 32 astronomical star chart cards, first published in November 1824. They had illustrations based on Alexander Jamieson’s A Celestial Atlas, but the addition of holes punched in them allowed them to be held up to a light to see a depiction of the constellation’s stars. They were engraved by Sidney Hall, and were said to be designed by “a lady”, but have since been identified as the work of the Reverend Richard Rouse Bloxam, an assistant master at Rugby School.
The cover of the box-set showed a depiction of Urania, the muse of astronomy, and came with a book entitled A Familiar Treatise on Astronomy… written as an accompaniment. Peter Hingley, the researcher who solved the mystery of who designed the cards a hundred and seventy years after their publication, considered them amongst the most attractive star chart cards of the many produced in the early 19th century.
Polar stratospheric clouds or PSCs, also known as nacreous clouds, are clouds in the winter polar stratosphere at altitudes of 15,000–25,000 meters (49,000–82,000 ft). They are best observed during civil twilight when the sun is between 1 and 6 degrees below the horizon as well as in winter and in more northerly latitudes. They are implicated in the formation of ozone holes. The effects on ozone depletion arise because they support chemical reactions that produce active chlorine which catalyzes ozone destruction, and also because they remove gaseous nitric acid, perturbing nitrogen and chlorine cycles in a way which increases ozone destruction.
source / images: x, x, x, x, x, x, x, x
Conjunction: Venus and Moon
Image credit: Roger Hutchinson & Michael DeWoody
Halo (optical phenomenon)
Halo is the name for a family of optical phenomena produced by light interacting with ice crystals suspended in the atmosphere. Halos can have many forms, ranging from colored or white rings to arcs and spots in the sky. Many of these are near the Sun or Moon, but others occur elsewhere or even in the opposite part of the sky. Among the best known halo types are the circular halo (properly called the 22° halo), light pillars and sun dogs, but there are many more; some of them fairly common, others (extremely) rare.
The ice crystals responsible for halos are typically suspended in cirrus or cirrostratus clouds high (5–10 km, or 3–6 miles) in the upper troposphere, but in cold weather they can also float near the ground, in which case they are referred to as diamond dust. The particular shape and orientation of the crystals are responsible for the type of halo observed. Light is reflected and refracted by the ice crystals and may split up into colors because of dispersion. The crystals behave like prisms and mirrors, refracting and reflecting light between their faces, sending shafts of light in particular directions.
images: x, x, x, x, x, x, x, x, x, x
Aurora Over Alaska
Credit: Joshua Strang, USAF, Wikipedia
Image Credit: NASA, ISS Expedition 40, Reid Wiseman
Earthshine – Jan 14, 2013
Abandoned building from the early 1900’s, with the moon captured through the window.
By Dewald Van Rensburg