Our spring almanac 16.04.2010 – 22.04.2010
Blue and empty skies
The peaceful skies over Basingstoke and the violent eruption of a volcano in Iceland, remind us of how important the atmosphere of our planet Earth is to us all. This 7 day period begins with the skies over the UK and northern Europe empty of commercial jet aircraft. This is because dust in the dust plume from the erupting volcano in Iceland contains particles of silica that, if they enter the jet engines of an airliner in flight, will melt as glass and cause damage and even engine failure.
The size and mass of our planet Earth means that there is enough gravity to keep the air and the different layers of our thin film of atmosphere from disappearing into space.
The mass of our planet also means that it has layers of molten rock and a hot solid core, and therefore produce the volcanic eruptions that have been part of the story of how the Earth and its atmosphere has evolved. So volcanic activity is part of the story of life on Earth. The Earth’s magnetic field also plays its part in protecting the atmosphere from the harmful radiation of the solar wind.
Earth – the Goldilocks planet
The Earth has been called the Goldilocks planet because, just like in the story the story of Goldilocks and the Three Bears, in which a little girl chooses from sets of three items, ignoring the ones that are too extreme, large or small, hot or cold, and choosing the one in the middle, which is “just right”, the conditions for life on our home planet are just right.
The constellation Cygnus
Cygnus, meaning the swan, is a northern constellation, and is one of the most recognizable constellations of the summer and autumn in the northern half of our planet. The Pelican Nebula resembles a pelican in shape, hence the name, and is a large area of emission nebula in the constellation Cygnus (the Swan), close to Deneb, and divided from its brighter, larger neighbor, the North America Nebula, by a molecular cloud filled with dark dust.
The Pelican is much studied because it has a particularly active mix of star formation and evolving gas clouds. The light from young energetic stars is slowly transforming cold gas to hot and causing an ionization front gradually to advance outward. Particularly dense filaments of cold gas are seen to still remain. Millions of years from now this nebula might no longer be known as the Pelican, as the balance and placement of stars and gas will leave something that appears completely different.
Cygnus was the Constellation Logo for Kingsclere School.
One of Kingsclere School’s students came up with a brilliant new idea for the group of stars that form Cygnus – an ice cream cone!
Looking like a wide winged, long necked bird, in graceful flight, the swan In Greek mythology has been identified with several different legendary swans. Zeus disguised himself as a swan to seduce Leda, who gave birth to the Gemini, Helen of Troy and Clytemnestra; Orpheus was transformed into a swan after his murder, and was said to have been placed in the sky next to his lyre (Lyra).
Shooting stars in Lyra
This week, between the 20th and the 22nd of April, we can look for a surprisingly unpredictable meteor shower called the Lyrids. The Lyrids are called the Lyrids because the meteors appear to burst into view in the part of the night sky where we find the constellation of Lyra, the Lyre.
These meteor showers began at the beginning of our 7 day period appearing in what is called a radiant between the star pattern of Lyra and the constellation of Hercules.
Look for the constellation Lyra rising in the north east at around 22h GMT. The best time to see shooting stars will be on the 22nd April when the meteor shower will be at its maximum. Sometimes the Lyrid shooting stars burst into view in a spectacular display, sometimes all we can expect to see is less than ten shooting stars per hour.
The best time to look for these bright burning sparks of comet debris is after midnight when the night side of Earth faces into its orbit around the Sun and passes through the leftover material of a comet trail of the periodic Comet C/1861 G1 Thatcher. The Lyrids have been observed for the past 2600 years.
Kingsclere in sunshine 22.04.2010