Snipfact:

          Stars appear to twinkle because we see them through the layers of the Earth’s atmosphere. Light is distorted a it passes through these layers, so that the amount we see constantly. Stars nearest the horizon seem to twinkle the most because the light is passing through a greater depth og atmosphere. Stars do not twinkle when viewed from space, so telescopes in space, such as the Hubble, give the best possible view of distant stars and galaxies.

  Work on NASA’s new lunar lander, codenamed Altair, begins in 2009. Tha aim to put humans on the Moon by 2018 – 46 years after the last Apollo mission. This artist’s impression of the Altair (the name of a bright star) shows how the lander will look.

  Most of the world’s countries and cultures use the Gregorian calendar, but some base their calendars on more ancient systems. Other countries have adopted an alternative calendar at some point in their history. 3761 BC   Jewish calendar starts 2637 BC   Original chinese calendar starts 45 BC   Julian calendar adopted by Roman Empire AD 1 Christian calendar starts 79   Hindu calendar starts 597   Julian calendar adopted in Britain 622   Islamic calendar starts 1582   Gregorian calendar introduced in Catholic countries 1752   Julian calendar abandoned, Gregorian calendar adopted in Britain and its           colonies, including America 1873   Japan adopts the Gregorian calendar 1949   China adopts the Gregorian calendar

  The Islamic year is about 11days shorter than a year in the Gregorian calendar. The Islamic calendar started 622 years later than the Gregorian so its date is behind. But because the year is shorter, the Islamic calendar is gradually gaining on the Gregorian. The two will eventually coincide –in the year 20874.

     The Hebrew (Jewish) and Islamic (Muslim) calendars are based on the lunar (Moon) cycle. Every months starts approximately on the day of a new Moon, or when a crescent moon is first seen. The visibility of the moon varies according to the weather so the start date cannot be determined in advance. Printed calendars may vary by a few days. Tishri /Muharram corresponds approximately with September/October in the Gregorian calendar, Heshvan/safar with October/November, and so on.     Hebrew               Islamic 1 Tishri                   Muharram*(30 days) 2 Heshvan               safar (29 days) 3 Kislev                   Rabi’a I (30 days) 4 Tevet    ...