Our summer almanac 09.07.2010 – 15.07.2010
The Pinwheel Galaxy (also known as Messier 101 or NGC 5457) is a face-on spiral galaxy distanced 23 million light-years away in the constellation Ursa Major.
M101 is a relatively large galaxy compared to the Milky Way. With a diameter of 170,000 light-years it is nearly twice the size of the Milky Way. It has a disk mass on the order of 100 billion solar masses, along with a small bulge of about 3 billion solar masses.
Exploring the Milky Way
July 10 saw Europe’s Rosetta space probe fly past the Asteroid Lutetia, returning a stream of scientific data for analysis. The rock – some 120km (75 miles) in its longest dimension – is the biggest asteroid yet visited by a satellite.
Pictures showed Lutetia to be quite irregular in shape, its surface marked by a number of wide impact craters and even some intriguing grooves.
Asteroid Lutetia has been revealed as a battered world of many craters. ESA’s Rosetta mission has returned the first close-up images of the asteroid showing it is most probably a primitive survivor from the violent birth of the Solar System.
The flyby was a spectacular success with Rosetta performing faultlessly. Closest approach took place at 18:10 CEST, at a distance of 3162 km. The images show that Lutetia is heavily cratered, having suffered many impacts during its 4.5 billion years of existence. As Rosetta drew close, a giant bowl-shaped depression stretching across much of the asteroid rotated into view. The images confirm that Lutetia is an elongated body, with its longest side around 130km.
Rosetta’s encounter with the asteroid occurred some 454 million km from Earth, beyond the orbit of Mars.
Martyrdom of the Báb
The Bahá’í Faith is a monotheistic religion founded by Bahá’u'lláh in nineteenth-century Persia, emphasizing the spiritual unity of all humankind. There are an estimated five to six million Bahá’ís around the world in more than 200 countries.
This major holy day is celebrated on the 9th July at noon and commemorates the events surrounding the death of the Báb in 1850. The Báb (a title meaning ‘the Gate’) had many followers but his beliefs did not meet with approval from the leaders of the state religion in Persia, and they decided he should be taken from prison and put to death.
One of his young followers begged to be allowed to share his fate, and this wish was granted. An Armenian firing squad lined up and shot at the Báb and his follower, but when the smoke cleared, the young follower remained there unharmed and the Báb had gone. The Báb was found back in his cell, and the soldiers were so shaken by the ‘miracle’ that they refused to try to kill him again so a new regiment had to be called for. This time, when the squad opened fire the Báb and the follower died, and their bodies were thrown into a moat outside the town. The remains of the Báb were brought secretly from Iran to the Holy Land and were eventually interred in the tomb built for them in a spot specifically designated by Bahá’u'lláh. The Báb’s tomb, located in Haifa, Israel, is an important place of pilgrimage for Bahá’ís.
To commemorate this day, Bahá’ís read special prayers at noon, which is the time the execution was scheduled for. This is also a day of rest, when Bahá’ís should not work.
Nineteen months make a year
The Bahá’í calendar is based upon the calendar established by the Báb. The year consists of 19 months, each having 19 days, with four or five intercalary days, to make a full solar year. The Bahá’í New Year corresponds to the traditional Persian New Year, called Naw Rúz, and occurs on the vernal equinox, March 21, at the end of the month of fasting. Bahá’í communities gather at the beginning of each month at a meeting called a Feast for worship, consultation and socializing. Each of the 19 months is given a name which is an attribute of God; some examples include Bahá’ (Splendour), ‘Ilm (Knowledge), and Jamál (Beauty). The Bahá’í week is familiar in that it consists of seven days, with each day of the week also named after an attribute of God. Bahá’ís observe 11 Holy Days throughout the year, with work suspended on 9 of these. These days commemorate important anniversaries in the history of the religion.
St Swithin’s Day (Christian )
Swithin (or Swithun) was a Saxon bishop in the 9th century. Legend has it that the weather on his feast day, 15 July, will determine the weather for the next 40 days.
Saint Swithin was a Saxon bishop. He was born in the kingdom of Wessex and educated in its capital, Winchester. He was famous for charitable gifts and building churches. His feast day is 15 July and his emblems are rain drops and apples.
Swithin was chaplain to Egbert, the 802-839 king of Wessex. Egbert’s son Ethelwulf, whom Swithin educated, made him bishop of Winchester in 852.
Only one miracle is attributed to Swithin while he was alive. An old lady’s eggs had been smashed by workmen building a church. Swithin picked the broken eggs up and, it is said, they miraculously became whole again.
Swithin died on 2 July 862. According to tradition, he had asked to be buried humbly. His grave was just outside the west door of the Old Minster, so that people would walk across it and rain fall on it in accordance with Swithin’s wishes.
On 15 July 971, though, Swithin’s remains were dug up and moved to a shrine in the cathedral by Bishop Ethelwold. Miraculous cures were associated with the event, and Swithin’s feast day is the date of the removal of his remains, not his death day.
However, the removal was also accompanied by ferocious and violent rain storms that lasted 40 days and 40 nights and are said to indicate the saint’s displeasure at being moved. This is probably the origin of the legend that if it rains on Saint Swithin’s feast day, the rain will continue for 40 more days.
Saint Swithin is still seen as the patron of Winchester Cathedral.
Our weather this summer is dominated by the Polar Front Jet Stream, a strong band of winds in the upper atmosphere that effectively controls the weather in high latitudes in the northern hemisphere. It is the mechanism for forming high and low pressure systems at the surface of the Earth, and consequently has a major influence on the Atlantic depressions that bring the UK much needed year round rainfall.
Meteorologists studying the upper atmosphere above the northern hemisphere have drawn a link between the wildfires raging across western Russia and the dramatic flooding in northern Pakistan, pinning the blame on an unusual ‘kink’ in the polar jet stream that has remained frozen in place for more than a month.
A jet stream is a fast-moving current of air that wiggles around the world at an altitude of around 10 and 12 kilometres above ground. There’s two branches usually in place in the northern hemisphere at this time of year — a strong “subtropical” jet blowing over the Mediterranean and central Asia, and a weaker northern “polar” jet that blows over northern Europe (and carries with it the low pressure areas that bring the UK most of its rain).
Weather forecasters use the polar jet to predict medium-term temperatures, because it acts as a barrier between cold Arctic air and warmer tropical air. If the polar jet moves north then areas just south of it will be warmer and drier than normal. If it moves south, then areas just to the north will be cooler and wetter.
During this July 2010, an exceptionally strong polar jet stream has shot up to the north of Moscow, and then plunged back south towards Pakistan. This brought hot air north over western Russia, and stopped low pressure systems from dropping their rain on the region, where harvests normally depend on it.