In 2029 an asteroid bigger than the Eiffel Tower will pass by Earth in an event that until recently scientists feared could herald a catastrophic collision.

Now researchers hope to scrutinize in 99942 Apophis as it makes its passage, in order to strengthen our defenses against other space rocks.

According to the European Space Agency, a spacecraft will travel to Apophis to gather information about its size, shape, mass and how it rotates as it moves through space. The mission will also shed light in the composition and internal structure of Apophis, as well as its orbit, and will investigate how the asteroid changes as it passes within 20,000 miles (32,000 kilometers) of Earth – about one-tenth the distance from the Moon – on Friday, April 13, 2029.

“The passage it makes with Earth is absolutely unique,” said Dr. Holger Krag, the head of Esa’s space safety program office, adding that no asteroid is expected to come this close to Earth for several thousand years. “If the sky is clear, you should be able to see it with the naked eye.”

Apophis will pass closer to Earth than the geostationary satellites used for television broadcasting, GPS and weather forecasting. At that distance, Kragg said, the asteroid will begin to interact with Earth.

“It’s the Earth’s gravitational field that will actually slightly reshape the asteroid, causing it to change its shape,” he said, adding that the gravitational pull could also cause landslides on the asteroid’s surface.

Krag said the information they have from Ramses will help scientists understand the asteroid and the danger such space rocks pose. “Our goal in planetary defense is not to do science on asteroids, but to characterize them in a way that one day we can deflect them when they become dangerous,” he said.

Professor Monica Grady of the Open University said that while most asteroids were in fairly safe orbits and they didn’t come close to our planet, Earth-crossing asteroids like Apophis were something else.

“They come close to Earth and there is a chance that one day one of them will hit Earth and cause great destruction. We think this happened 65 million years ago, when all the dinosaurs went extinct.”he said. “And if it’s a big asteroid and it hits us, it will be a disaster that will destroy humanity” completed.

After its discovery in 2004, Apophis kept scientists awake at night with concerns that it could collide with Earth as it orbits the Sun. While NASA ruled out an impact as Apophis approaches Earth in 2029 and 2036, experts said that a crash was not expected for at least the next 100 years.

However, the space agencies are not leaving the safety of the planet to chance, instead they are researching ways to deal with Earth-bound asteroids.

The ‘Ramses’ mission is not the only mission preparing to check Apophis. Following NASA’s successful Osiris-Rex mission last year, which discovered 4.6-billion-year-old pieces of space rock from the asteroid Bennu, the same spacecraft will visit Apophis in 2029 with a new mission title, Osiris-Apex.

While Ramses will reach Apophis before his close encounter with Earth, Osiris-Apex is expected to arrive later.