By the way, that big thing that hit Earth is called Theia. It also blasted a big hole in the surface. That big hit sent a huge amount of dust and rubble into orbit. Most scientists think that that rubble, in time, became our Moon. As Earth orbits the Sun, its tilted axis always points in the same direction.
It is summer in June in the Northern Hemisphere because the Sun's rays hit that part of Earth more directly than at any other time of the year. It is winter in December in the Northern Hemisphere, because that is when it is the South Pole's turn to be tilted toward the Sun. And, believe it or not, aphelion when Earth is farthest from the Sun occurs in July, and perihelion when we are closest occurs in January.
For those of us who live in the Northern Hemisphere where it's summer in July and winter in January, that seems backwards, doesn't it? During the summer, the Sun tracks more directly overhead, rising in the east, overhead at noon, and setting in the west. If you live in the Southern Hemisphere, the Sun will be more northerly in the sky during the winter that is, June, July, and August. So if you go to South Africa for the winter holidays, bring your swimsuit and leave your skis at home.
Weather Forecasting. The Short Answer:. Earth has seasons because its axis is tilted. The specific dates for this occurrence are different for different latitudes. On the day of the equinox, the geometric center of the Sun's disk crosses the equator, and this point is above the horizon for 12 hours everywhere on the Earth.
However, the Sun is not simply a geometric point. Sunrise is defined as the instant when the leading edge of the Sun's disk becomes visible on the horizon, whereas sunset is the instant when the trailing edge of the disk disappears below the horizon.
At these times, the center of the disk is already below the horizon. Furthermore, atmospheric refraction or bending of the Sun's rays cause the Sun's disk to appear higher in the sky than it would if the Earth had no atmosphere.
Thus, in the morning, the upper edge of the disk is visible for several minutes before the geometric edge of the disk reachs the horizon.
Similarly, in the evening, the upper edge of the disk disappears several minutes after the geometric disk has passed below the horizon. For observers within a couple of degrees of the equator, the period from sunrise to sunset is always several minutes longer than the night.
At higher latitudes in the Northern Hemisphere, the date of equal day and night occurs before the March equinox. Daytime continues to be longer than nighttime until after the September equinox. In the Southern Hemisphere, the dates of equal day and night occur before the September equinox and after the March equinox. The chart shown below shows the dates and times for the equinoxes and solstices through Times listed are in Eastern Time.
Subtract one hour for Central Time. Source: U. Naval Observatory. The answer is YES. However, you can stand an egg on end, with a large amount of patience, on any day of the year.
This idea seems to pop up every year around the equinox. The thought that an egg can only stand on end on the spring equinox due to gravitational forces of the sun being aligned with the earth sounds like science, but it isn't. According to Chinese tradition, an egg can be made to stand on end at the precise moment winter ends and spring begins.
But, the Chinese calendar had this transition occurring at a variable time each year, determined partly by the Chinese lunar month, usually in early February. More recently, this thought became fixed to the time of the spring equinox. The underlying assumption relating to standing eggs on end is that there must exist some special gravitational balance.
There are many forces acting on an egg when you try to stand it on end on a flat surface.
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