1. Aurora Borealis
Undoubtedly one of the most beautiful events to occur in our world, the Aurora Borealis, also known as the Northern Lights, has both astounded and amazed people since it was first discovered. This phenomenon ocurrs when the sun gives off high-energy charged particles (also called ions) that travel out into space at speeds of 300 to 1200 kilometres per second. A cloud of such particles is called a plasma. The stream of plasma coming from the sun is known as the solar wind. As the solar wind interacts with the edge of the earth’s magnetic field, some of the particles are trapped by it and they follow the lines of magnetic force down into the ionosphere, the section of the earth’s atmosphere that extends from about 60 to 600 kilometers above the earth’s surface. When the particles collide with the gases in the ionosphere they start to glow, producing the spectacle that we know as the auroras, northern and southern.
2. Mammatus Clouds
Also known as mammatocumulus, meaning "bumpy clouds", they are a cellular pattern of pouches hanging underneath the base of a cloud. Composed primarily of ice, Mammatus Clouds can extend for hundreds of miles in each direction, while individual formations can remain visibly static for ten to fifteen minutes at a time. True to their ominous appearance, mammatus clouds are often harbingers of a coming storm or other extreme weather system.
3. Red Tides
More correctly known as an algal bloom, the so-called Red tide is a natural event in which estuarine, marine, or fresh water algae accumulate rapidly in the water column and can convert entire areas of an ocean or beach into a blood red color. This phenomena is caused by high levels of phytoplankton accumulating to form dense, visible clouds near the surface of the water. While some of these can be relatively harmless, others can be harbingers of deadly toxins that cause the deaths of fish, birds and marine mammals. In some cases, even humans have been harmed by red tides though no human exposure are known to have been fatal. While they can be fatal, the constituent phytoplankton in ride tides are not harmful in small numbers.
4. Penitentes
These amazing ice spikes, generally known as penitentes due to their resemblance to processions of white-hooded monks, can be found on mountain glaciers and vary in size dramatically: from a few centimetres to 5 metres in height. Initially, the sun’s rays cause random dimples on the surface of the snow. Once such a dimple is formed, sunlight can be reflected within the dimple, increasing the localized sublimation. As this accelerates, deep troughs are formed, leaving peaks of ice standing between them.
5. Sailing Stones
The mysterious moving stones of the packed-mud desert of Death Valley have been a center of scientific controversy for decades. Rocks weighing up to hundreds of pounds have been known to move up to hundreds of yards at a time. Some scientists have proposed that a combination of strong winds and surface ice account for these movements. However, this theory does not explain evidence of different rocks starting side by side and moving at different rates and in disparate directions. Moreover, the physics calculations do not fully support this theory as wind speeds of hundreds of miles per hour would be needed to move some of the stones.
