Weather Glossary - Y
The interval required for the earth to complete one revolution around the sun. A sidereal year, which is the time it takes for the earth to make one absolute revolution around the sun, is 365 days, 6 hours, 9 minutes and 9.5 seconds. The calendar year begins at 12 o'clock midnight local time on the night of December 31st-January 1st. Currently, the Gregorian calendar of 365 days is used, with 366 days every four years, a leap year. The tropical year, also called the mean solar year, is dependent on the seasons. It is the interval between two consecutive returns of the sun to the vernal equinox. In 1900, that took 365 days, 5 hours, 48 minutes, and 46 seconds, and it is decreasing at the rate of 0.53 second per century. This decrease is due to the slow precession of the Earth's axis of rotation.
Backyards in Queanbeyan and parts of Canberra have been covered with "golf-ball sized" hailstones and the roof of a supermarket has partially collapsed after a storm hit the region.
A western Queensland church has raised more than $90,000 for a scheme to keep rural contractors in work during the ongoing drought.
Much of southeastern Australia is experiencing its sunniest week since spring and skies have been staying clear at night, effectively giving planet gazers a fine-tuned view of a rare feature.