25 of the most mind-boggling natural phenomena on Earth

That's right, volcanoes can produce lightning.

It's pretty hard to study, but researchers have a few ideas about what causes it. One of the most common is that during an eruption, ash picks up so much friction that the build-up of static electricity causes lightning.

Like fire rainbows, halos require just the right formation of ice crystals in clouds high above the surface of the Earth to bend light from the sun into a perfect ring.

The same phenomenon can also happen with moonlight, although moon halos are usually white and sun halos can be rainbow-colored, like this one.

It's pretty clear how this phenomenon got its nickname: It looks like a tornado, but it's made of fire. They form when wind patterns twist an active fire into a column.

Fire tornadoes have been reported to grow as wide as 1,000 feet. 

These ice spikes, called penitentes, form in high altitudes, where sunlight turns ice directly into water vapor, rather than melting it to water.

Sunbeams vaporize small dimples in the snow's surface. Then, the uneven surface directs the sun into the dips and away from the peaks, exacerbating the trend.

Penitentes can grow as tall as 15 feet.

Wind can catch individual droplets of lava from a volcanic eruption and stretch them into long, thin glass wires. These strands  — which are called Pele's hair — can reach as long as 6 feet.

In Hawaii,the phenomenon is named for Pele, the goddess of volcanoes. It's also found in Norway, where it's known as Witch's Hair.

Periodical cicadas are insects that emerge as broods every 13 or 17 years. They spend most of their life underground, sucking the juice out of plant roots — in fact, they're North America's longest-living insect.

Once a brood emerges, they're singing to mates, mating, laying eggs, and dying, all over the course of a few short weeks.

Salar de Uyuni in Bolivia is both the world's largest salt flat (it's about 4,000 square miles) and the home of half the planet's lithium, a key component in most batteries.

The wet season turns the salt flat into a perfectly reflective lake.

Some lakes are so chock-full of methane that you can light them on fire. 

Thermokarst lakes are usually found in areas that have been stuck in permafrost for millennia. As these lakes melt, they belch highly-combustible methane that rises to the surface, meaning with a well-placed spark, you can set these lakes on fire. 

But it's not all fun and games. Scientists worry that as more of these lakes thaw, they'll release more methane, which is a potent greenhouse gas. 

Wildfires can be so hot that thunderstorms can appear in the clouds of smoke billowing above them. 

So-called pyrocumulonimbus clouds can create their own lightning. 

Bismuth is a dense, super-shiny grey metal that is found in predictable places like safety valves and paintings, but also Pepto-Bismol.

Blood Falls, in one of the driest regions of Antarctica, is fed by an underground lake. It's full of bacteria scientists want to study because they fuel themselves with sulfates.

The water has so much iron in it that it literally rusts when it meets air, giving the waterfall its trademark color.

Hailing from the Philippines and Indonesia, the rainbow eucalyptus, also known as the rainbow gum, is probably the most colorful tree on Earth. Its striped look is caused by bark turning colors and peeling away as it ages.

The youngest bark is bright green because it contains chlorophyll (usually found in leaves), then turns first purple then red then brown as it gets older, loses chlorophyll, and picks up tannins (also found in wine).

In an ironic twist, huge amounts of rainbow eucalyptus wood pulp are turned into white paper every year.

Formally known as the "Richtat structure," the Eye of the Sahara is in Mauritania. Scientists think it's the eroded remains of a giant dome of rock. 

Each band of the ring is made of a different type of rock that erodes at a different speed. It's also the "almost home" signal for astronauts landing in Florida. In fact, astronauts are mostly responsible for teaching us there's something there in the first place, since the formation is difficult to recognize when you walk over it.

Tens of thousands of harmless snakes waiting out the winter in underground limestone dens in Manitoba, Canada, home to the highest concentration of snakes in the world, according to National Geographic.

In May, they slither out of their nests to mate, with dozens of smaller male snakes lurking, waiting to ambush larger females.

Lake Natron, in Tanzania, can hit 140 degrees Fahrenheit. Thanks to a nearby volcano, it has alkalinity at the level of pure ammonia.

That means it's almost deserted, except for a particularly hardy fish, the microbes that make it look red, and flamingos. The birds actually use the lake as their only breeding ground because there aren't very many predators around to eat the chicks.

But animals that do die in the lake end up so coated in baking soda and similar chemicals that they look like they've been turned to stone.

Waterspouts look like liquid tornadoes, but while they can form during storms, they can also develop on calm, open ocean — swirling towers of wind climbing up from the water to the sky.

They are most common in the Florida Keys, although they've also been spotted on the Great Lakes.

What looks like a forest is actually a singular tree. This grove, nicknamed Pando, in found in central Uthal. It is one of the oldest and largest organisms in the world.

Although the grove looks like its made up of 47,000 trees from above, it is actually a collection of shoots that all come from a single organism, called the quaking aspen, named after its fluttery leaves. 

The quaking aspen usually grows into groves of identical clones, although it can reproduce sexually on special occasions.

All of the shoots are actually connected underneath the soil by a dense network of roots.

Lake Maracaibo in Venezuela sees more lightning strikes than anywhere else on Earth: In fact, the lake is struck by lightning more than 200 times a year, most commonly between the hours of midnight and 5 a.m. in late spring and autumn.

In upstate New York, near the Canadian border, there is a small waterfall hiding a big surprise: a shoot of fire about eight inches tall.

Behind the waterfall is a natural gas seep that feeds the flame.

It's sheltered enough by the waterfall to stay lit pretty reliably, although hikers do re-light it if they see it's been blown out. (We should note that it's not 100% natural — but too cool to skip.)

These burning gas seeps are actually fairly common, but this one is more interesting and younger than most — and very photogenic.

Canada's Spotted Lake's water actually every summer leaving behind large spots, which are colorful deposits of a dozen minerals.

Moroccan goats have learned to climb trees in order to better snack on their tasty Argan fruit.

Local farmers like the goats so much that they've brought more goats in to enjoy the buffet.

Waves can glow with brilliant colors at night during a bioluminescent bloom. 

This natural phenomenon is caused by phytoplankton a type of algae that emits bright light when they are agitated. 

It can be spotted in select locations all around the world, from California to Hong Kong. 

Usually spotted only near the poles, nacreous clouds form very high in the atmosphere where the air is particularly cold and dry.

The colorful shine comes from the setting sun being lower in the sky than the cloud. As the clouds reflect the sunbeams back toward Earth, they diffract the light. 

This probably isn't what comes to mind when you dream of tropical beaches. Papakolea, also known as Green Sand Beach in Hawaii is one of only a couple beaches in the world with green sand.

The remarkable hue comes from olivine rock that was formed during eruptions of the nearby volcano.

Hundreds or thousands of starlings together turn into an incredible dance known as a murmuration and nicknamed a "black sun."

The flocks can be seen in the US and Europe, particularly in England.

The flock's complex choreography boils down to just a couple simple rules, like follow your neighbor.