By Amy Oliver
Daily Mail Online
Did the Earth move for you last night?
If so, it may be down to the solar system's second largest asteroid hurtling rather close to Earth.
Asteroid '433 Eros', which is 400 times the City of London, came within 16.6million miles of our planet yesterday evening.
The massive hunk of rock posed no threat, but is the closest an asteroid of its size has come to Earth in a long time.
The last time Eros got up close and personal was 37 years ago in 1975. Its next visit won't be until 2056.
Stargazers who missed the fly-by can now aim their telescopes in the direction of constellations Leo, Sextans and Hydra, where the asteroid will be until February 10, according to researchers
Eros orbits the Sun every 642.9 days and rotates once every five hours and 16 minutes.
It was discovered in 1898 by Gustav Witt in Germany and Auguste Charlois in France.
A smaller bus-sized asteroid passed even closer to Earth last week.
Asteroid 2012 BX34, came within 36,750miles of Earth at about 3.30pm on Friday, according to NASA's Asteroid Watch programme.
Even though this is more than five times closer than the moon, at 11 meters wide, it didn't pose any threat.
‘It wouldn't get through our atmosphere intact even if it dared to try,’ Asteroid Watch scientists tweeted.
Nevertheless, with NASA estimating there are almost 1,000 asteroids over one kilometre in length and 19,500 over 100-metres, scientists at the Institute of Planetary Research are trying to find a way to protect Earth.
The EU-funded NEOShield project will look for a way to protect earth from the space rocks, expected to take three years to complete.
Some of the ideas being tossed around at the moment include repelling asteroids with projectiles or explosives or using gravity to change its course.
