Definitions and frames of reference For an observer on the North Pole, the sun reaches the highest position in the sky once a year in June. The day it happens is called the June solstice day. Similarl ...
The solstice itself may have been a special moment of the annual cycle of the year even during neolithic times. Astronomical events, which during ancient times controlled the mating of animals, sowing ...
For most purposes, the Geographic South Pole is defined as the southern point of the two points where the Earth's axis of rotation intersects its surface (the other being the Geographic North Pole). H ...
Overall may tend to be slightly milder than those in the Northern Hemisphere at similar latitudes except in the Antarctic which is colder than the Arctic. This is because the Southern Hemisphere has s ...
A common misconception is that the polar shortest day is totally dark everywhere inside the polar circle. In places very close to the poles it is completely dark, but regions located at the inner bord ...
Relatively few people live north of the Arctic Circle due to the severe climate. Areas have been settled for thousands of years by indigenous peoples. Tens of thousands of years ago, waves of people m ...
List of continents Continents of the Northern Hemisphere all of continental Europe excluding overseas territories in the Southern Hemisphere and Eastern Hemisphere.all of North America, Central Americ ...
Ecologically speaking, a season is a period of the year in which only certain types of floral and animal events happen (e.g.: flowers bloom—spring; hedgehogs hibernate—winter). So, if we can observe ...
Axis tilt The seasons result from the Earth's axis of rotation being tilted with respect to its orbital plane by an angle of approximately 23.5 degrees. (This tilt is also known as "obliquity of the e ...
The Orion arm contains a number of Messier objects:The Butterfly Cluster (M6)The Ptolemy Cluster (M7)Open Cluster M23Open Cluster M25The Dumbbell Nebula (M27)Open Cluster M29Open Cluster M34Open Clust ...
The galactic plane is the plane in which the majority of a disk-shaped galaxy's mass lies. The directions perpendicular to the galactic plane point to the galactic poles. Most often, in actual usage, ...
As defined by the IAU, the light-year is the product of the Julian year (365.25 days as opposed to the 365.2425-day Gregorian year) and the speed of light (299792458 m/s). Both these values are includ ...
Main articles: Observable universe § Large-scale structure, Galaxy filament and Galaxy groups and clustersDeep sky surveys show that galaxies are often found in relatively close association with othe ...
The word galaxy derives from the Greek term for our own galaxy, galaxias (γαλαξ?α?, "milky one"), or kyklos ("circle") galaktikos ("milky") for its appearance as a lighter colored band in the ...
When observing the night sky, the term “Milky Way” is limited to the hazy band of white light some 30 degrees wide arcing across the sky. Although all of the individual stars that can be seen in the ...
