Nature — Page 3
Natural phenomena
204 facts
Morning Glory clouds form in Australia and can be up to a thousand kilometres long.
Morning Glory clouds are cylindrical rolls that form in the Gulf of Carpentaria, Australia, and can stretch for more…
The smell of wet earth after rain is called petrichor.
Petrichor is caused by a mixture of compounds, including geosmin, produced by soil bacteria, and ozone brought by the…
A rainbow is actually a full circle.
From the ground, we only see the upper half of a rainbow. From above, for example from an aeroplane or a mountain, it…
Cactus spines are modified stems.
Cactus spines are modified leaves. Over the course of evolution, the leaves became spines to reduce water loss and…
Fireflies produce light without heat, with over 90 percent efficiency.
Fireflies produce light through a chemical reaction called bioluminescence, in which the enzyme luciferase acts on…
The Rafflesia is the largest flower in the world and smells like rotting flesh.
Rafflesia arnoldii can measure more than a metre across and weigh up to 11 kilograms. The flower releases a strong…
The largest waterfall in the world is Niagara Falls.
The largest waterfall in the world is the Denmark Strait cataract, an underwater waterfall between Greenland and…
The Venus flytrap can count to five before closing.
The Venus flytrap closes its traps when sensory hairs are touched twice within 20 seconds. But to start digestion, it…
Sunflowers follow the Sun throughout their entire life.
Young sunflowers exhibit heliotropism, turning their heads to follow the Sun from east to west. At night, they turn…
Snowflakes are ice crystals with six sides.
Snowflakes are ice crystals with six sides, because the molecular structure of water forms hexagons. No two…
The baobab stores water in its trunk and can survive extreme droughts.
The baobab, native to Madagascar and Africa, has an enormous trunk that can store up to 120,000 litres of water. This…
A saguaro cactus can live more than 150 years and grow 12 metres tall.
The saguaro, native to the Sonora Desert, is the tallest cactus in the United States. It grows very slowly, reaching…
Water is the only substance that expands when it freezes.
Water is one of the few substances that expands when it freezes. Unlike most liquids, water solidifies into an open…
The pyrosome is a colony of creatures that glows in the ocean.
The pyrosome is a cylindrical colony of small organisms called zooids, which join together to form a larger creature…
The fairy circles in Namibia are caused by ants.
The fairy circles in Namibia are circles of bare earth surrounded by grass, whose origin is debated. Hypotheses…
A lunar rainbow only appears during the new moon.
The lunar rainbow, or moonbow, appears during the full moon, when moonlight is refracted by raindrops. It is much…
Petrified wood is wood that has turned to stone.
Petrified wood forms when wood is buried in volcanic ash or silica-rich sediments. Over time, minerals replace the…
The red rain of Kerala was caused by animal blood.
In 2001, red rain fell in the state of Kerala, India. After several hypotheses, scientists concluded that the colour…
Some sand dunes produce sound when the wind makes them slide.
Singing dunes, such as those in the Mojave Desert, emit a low-pitched sound similar to distant thunder when the sand…
Orchids of the genus Ophrys imitate the scent of female bees to attract males.
Ophrys orchids produce pheromones identical to those of female bees. Males, attracted by the smell, try to mate with…
Most tornadoes last less than 15 minutes.
Most tornadoes last less than 15 minutes, although some can last more than an hour. The longest tornado ever recorded…
Auroras are always green.
Auroras can be green, red, blue or purple, depending on the gas and altitude. Oxygen at different altitudes produces…
A lichen is a partnership between a fungus and an alga or cyanobacterium.
Lichens are organisms composed of a fungus and an alga or cyanobacterium. The fungus provides shelter and minerals…
Volcanic lightning is a rare phenomenon observed only on Mount Etna.
Volcanic lightning, also called dirty thunderstorms, occurs in many volcanic eruptions around the world. It is caused…