FOUR asteroids will skim past Earth tomorrow in a series of close flybys, according to Nasa.

The space rocks are travelling up to 57,000mph and the largest of the bunch is as tall as the Empire State Building.

2 Four asteroids will zip past Earth on Saturday Credit: Getty - Contributor

Nasa has classed the asteroids as "near-Earth objects" (NEOs) and is keeping them under constant supervision.

Tens of thousands of NEOs are tracked by scientists to ensure they don't collide with our planet. One small change to their trajectories could spell disaster for our planet.

The first of Saturday's asteroids is called 2020 GM1.

It will pass Earth at around 7.15am BST at a distance of 2.3million miles - around nine times the distance between Earth and the Moon.

2 The space rocks are travelling up to 57,000mph and the largest of the bunch is as tall as the Empire State Building Credit: Getty - Contributor

That may sound far, but it's relatively close in space terms: Nasa considers anything passing within 120million miles of Earth a NEO.

The first of tomorrow's asteroids is also the fastest, clocking speeds of 57,000 miles per hour.

The other Easter weekend asteroids are 2020 GU1 (8:48am), 2020 GG (3:21pm) and 2004 FG11 6pm).

At 1,246ft long, the largest, 2004 FG11, is as big as the Empire State Building.

Astronomers are currently tracking nearly 2,000 asteroids, comets and other objects that threaten our pale blue dot - and new ones are found every day.

What's the difference between an asteroid, meteor and comet? Here's what you need to know, according to Nasa... Asteroid: An asteroid is a small rocky body that orbits the Sun. Most are found in the asteroid belt (between Mars and Jupiter) but they can be found anywhere (including in a path that can impact Earth)

An asteroid is a small rocky body that orbits the Sun. Most are found in the asteroid belt (between Mars and Jupiter) but they can be found anywhere (including in a path that can impact Earth) Meteoroid: When two asteroids hit each other, the small chunks that break off are called meteoroids

When two asteroids hit each other, the small chunks that break off are called meteoroids Meteor: If a meteoroid enters the Earth's atmosphere, it begins to vapourise and then becomes a meteor. On Earth, it'll look like a streak of light in the sky, because the rock is burning up

If a meteoroid enters the Earth's atmosphere, it begins to vapourise and then becomes a meteor. On Earth, it'll look like a streak of light in the sky, because the rock is burning up Meteorite: If a meteoroid doesn't vapourise completely and survives the trip through Earth's atmosphere, it can land on the Earth. At that point, it becomes a meteorite

If a meteoroid doesn't vapourise completely and survives the trip through Earth's atmosphere, it can land on the Earth. At that point, it becomes a meteorite Comet: Like asteroids, a comet orbits the Sun. However rather than being made mostly of rock, a comet contains lots of ice and gas, which can result in amazing tails forming behind them (thanks to the ice and dust vapourising)

Earth hasn't seen an asteroid of apocalyptic scale since the space rock that wiped out the dinosaurs 66million years ago.

However, smaller objects capable of flattening an entire city crash into Earth every so often.

One a few hundred feet across devastated 800 square miles of forest near Tunguska in Siberia on June 30, 1908.

Luckily, Nasa doesn't believe any of the NEOs it keeps an eye on are on a collision course with our planet.

That could change in the coming months or years, however, as the space agency constantly revises objects' predicted trajectories.

"Nasa knows of no asteroid or comet currently on a collision course with Earth, so the probability of a major collision is quite small," Nasa says.

"In fact, as best as we can tell, no large object is likely to strike the Earth any time in the next several hundred years."

Even if they were to hit our planet, the vast majority of asteroids would not wipe out life as we know it.

"Global catastrophes" are only triggered when objects larger than 3,000 feet smash into Earth, according to Nasa.

Shocking clip reveals what 500km asteroid hitting Earth would look like – unleashing fiery cataclysm across planet

TOP STORIES IN SCIENCE HIPPY CROC Boffins win Ig Nobel Prize for giving alligator helium to see how it sounded APOCALYPSE WOW Stunning new Jupiter photo shows 9,800-mile MEGA storm bigger than Earth HORROR-SCOPE You've been reading the wrong horoscope for years because the stars have moved SPACE NEIGHBOURS? Signs of LIFE on Venus in extraordinary discovery for Brit scientists ALIEN INVASION Strange footage of a 'UFO' hovering over New Jersey sends alien-hunters wild PLAN-IT Jupiter is so bright you can see it from the UK with the naked eye TONIGHT

In other news, it recently emerged that an asteroid obliterated early human civilisations in a catastrophic collision with Earth 13,000 years ago.

Scientists recently discovered a "Super-Earth" 31 light-years away that humans could one day colonise.

And, distant planets may host even more life than we have here on Earth, according to one shock study.

Are you worried about asteroid strikes? Let us know in the comments!

We pay for your stories! Do you have a story for The Sun Online Tech & Science team? Email us at tech@the-sun.co.uk