What’s Up With the Weather? Created by Dr. A. Dávila

Autumnal Equinox

Equinox (direct rays)

The Big Dipper isn't really a constellation The Big Dipper isn't really a constellation? It's an asterism, which is a special, recognizable group of stars. The star Polaris is in another constellation called the 'Little Bear', or Ursa Minor.

The picture is seen from above, turned on its side The picture is seen from above, turned on its side. The north rotational pole of the earth points toward Polaris. But this star is 300 light years from Earth, or about 3000 trillion kilometers, or 3,000,000,000,000,000 km

Sun rays directed toward the southern hemisphere (winter solstices)

Sun rays directed toward the northern hemisphere (summer)

Equinoxes Equinoxes are days in which day and night are of equal duration. The two yearly equinoxes occur when the Sun crosses the celestial equator.

Equinoxes The autumnal equinox occurs on September 22 or 23 (this is the beginning of fall in the Northern Hemisphere and the beginning of spring in the Southern Hemisphere).

Equinoxes The vernal equinox occurs on March 20 or March 21 (this is the beginning of spring in the Northern Hemisphere and the beginning of fall in the Southern Hemisphere).

Varying Seasons Birthdays

SPRING begins March 20

SUMMER begins June 20

WINTER begins December 21

AUTUMN begins September 22

December 21 March 20 September 22 June 20

Night-time Daylight

Night-time Daylight

Daylight and night-time are the same (equinox)