250 Surprising Facts: Animals, Science, Space, History & Everyday Life

By most estimates, there are more stars in the observable universe than grains of sand on all of Earth's beaches.

Sunlight takes about 8 minutes and 20 seconds to reach Earth, so you always see the Sun as it was a few minutes ago.

About 1.3 million Earths could fit inside the Sun.

Saturn is less dense than water, so in a big enough bathtub it would float.

Neptune has the fastest winds in the solar system, at more than 2,000 kilometres per hour.

Jupiter is the largest planet in the solar system, and its Great Red Spot is a storm wider than the whole Earth.

Mercury is the closest planet to the Sun, but Venus is the hottest, at around 465°C, because its thick atmosphere traps heat.

A year on Mercury lasts only 88 Earth days.

Uranus is tipped over on its side, so it seems to roll around the Sun.

The Sun is 400 times wider than the Moon, and 400 times farther away

The Sun is about 400 times wider than the Moon, and it also happens to be about 400 times farther from Earth. Because of this cosmic coincidence, the two look almost exactly the same size in our sky. That is why, during a total solar eclipse, the Moon can cover the Sun's bright disc so neatly and reveal its glowing outer atmosphere, the corona.

Venus spins in the opposite direction to most planets, so on Venus the Sun rises in the west and sets in the east.

Sunsets on Mars look blue, because fine Martian dust scatters blue light toward the viewer when the Sun is low.

Olympus Mons on Mars is the tallest volcano in the solar system, about two and a half times the height of Mount Everest.

Pluto is smaller than Earth's Moon.

The Moon has earthquakes too. They are called moonquakes.

Samples brought back from the Moon suggest it may still have had small volcanic eruptions when dinosaurs walked the Earth.

The Moon is slowly drifting away from Earth, by about 3.8 centimetres every year.

Australia is wider than the Moon. Australia stretches about 4,000 kilometres from east to west, while the Moon is about 3,475 kilometres across.

Comets smell like rotten eggs. A spacecraft that sniffed Comet 67P found gases including hydrogen sulphide and ammonia.

Footprints on the Moon could last for millions of years

The Moon has almost no atmosphere, so there is no wind or rain to wipe away marks on its surface. The footprints left by Apollo astronauts between 1969 and 1972 are likely still there today, looking almost as crisp as the day they were made. Only the slow rain of tiny meteorites will eventually wear them away, and that could take millions of years.

A teaspoon of material from a neutron star would weigh around a billion tonnes on Earth.

Space is completely silent, because there is no air to carry sound waves.

Astronauts can grow up to about 5 centimetres taller in space, as their spines stretch without gravity pressing down. They shrink back after returning to Earth.

Saturn's rings are enormous, but in many places they are only about 10 metres thick.

Earth is not a perfect sphere. It bulges at the equator, where it is about 43 kilometres wider than it is from pole to pole.

Because of that bulge, the peak of Mount Chimborazo in Ecuador, not Everest, is the point on Earth's surface farthest from the planet's centre.

Measured from its base on the ocean floor, Mauna Kea in Hawaii is more than 10,000 metres tall, which is taller than Everest.

Mount Everest is still growing by a few millimetres every year, as the Indian tectonic plate pushes into Asia.

The shore of the Dead Sea is the lowest land on Earth, at about 430 metres below sea level.

Astronauts on the ISS see about 16 sunrises every day

The International Space Station orbits about 400 kilometres above Earth at roughly 28,000 kilometres per hour. At that speed it circles the whole planet about every 90 minutes. That means the crew passes from night into day around 16 times every 24 hours. Astronauts keep to a strict schedule and use window shades to get proper sleep.

About 90% of the world's people live in the Northern Hemisphere.

Africa is the only continent that sits in all four hemispheres: north, south, east and west.

Asia is the largest continent. It covers about 30% of Earth's land and is home to around 60% of its people.

Canada is home to more than half of all the lakes in the world.

Lake Baikal in Russia is the world's deepest and oldest lake, and it holds about a fifth of the planet's unfrozen fresh surface water.

The Amazon carries more water than any other river, around a fifth of all the river water flowing into the world's oceans.

The largest desert on Earth is not the Sahara but Antarctica, because a desert is defined by how little rain or snow falls there.

The coldest temperature ever recorded on Earth's surface was −89.2°C, at Vostok Station in Antarctica in 1983.

Earth's inner core is roughly as hot as the surface of the Sun, at around 5,000°C or more.

A day on Venus is longer than its year

Venus spins extremely slowly, taking about 243 Earth days to turn once on its axis. It orbits the Sun faster than that, completing a year in about 225 Earth days. So a single Venusian day lasts longer than a whole Venusian year. Because it also spins backwards, the time from one sunrise to the next on Venus works out to about 117 Earth days.

An average fluffy cumulus cloud weighs around 500 tonnes, roughly as much as 100 elephants.

Oceans cover about 71% of Earth's surface.

Only about 3% of Earth's water is fresh water, and most of that is locked away in ice and glaciers.

Most of the deep ocean floor has never been seen by human eyes.

The Great Barrier Reef off Australia stretches for about 2,300 kilometres and is the largest structure on Earth built by living things.

Hawaii is moving slowly toward Japan, by several centimetres a year, as the Pacific Plate shifts.

Russia is the largest country in the world and spans 11 time zones.

Thanks to its overseas territories, France has 12 time zones, more than any other country.

Vatican City is the smallest country in the world, at less than half a square kilometre.

Mount Everest would disappear inside the deepest part of the ocean

The Challenger Deep in the Mariana Trench in the western Pacific is the deepest known point in the ocean, roughly 10,900 metres below the surface. If you dropped Mount Everest into it, the peak would still be more than 2 kilometres underwater. The water pressure at the bottom is over 1,000 times that at sea level. Yet in 1960, two explorers reached it in a submersible called Trieste.