The giant rock – known as Asteroid 2012 DA14 – was identified last February by Spanish astronomers. Today it was hurtling towards Earth at around 17,400 miles per hour.
DA14 is expected to conduct a rare fly-by of planet earth at around 5pm GMT today, at its closest speeding over Indonesia around 17,200 miles from the Earth's surface. The fly-over is set to be the closest on record for an asteroid of this size.
Scientists insist there is no risk DA14 will hit Earth and say even a collision with a satellite is highly unlikely.
"There is no chance it might collide with Earth," a statement on Nasa's homepage read on Friday.
But that has not stopped an outbreak of largely tongue-in-cheek global nervousness contaminating the internet, fuelled by reports that meteorite fragments had crashed to Earth over western Siberia on Friday morning injuring around 500.
"Meteorite shower in Russia, 2012 DA14 over Indonesia. They are coming! The end is nigh!" tweeted Marin Purgar, from Cakovec in northern Croatia.
"The Russia meteorite crash is like a prelude to the DA14," wrote one micro-blogger from Singapore.
On Friday morning, the UK Space Agency rejected any link, claiming the meteor incident over the Ural Mountains in Russia was "not related to asteroid 2012 DA14".
Mexico's Agencia Espacial also sought to reassure concerned followers, tweeting that there was "no connection" between the two events.
But the speculation continued. Some linked the approach of DA14 to unfulfilled predictions of a "Mayan Apocalypse" on December 21 last year, suggesting the Mayans had only been a few weeks off.
"DA14 is getting close to the earth today – but which side will it go past on? Oh God!" tweeted Elaine Banhara, from the Brazilian city of Campinas in Sao Paulo state.
Were DA14 to crash into Earth, the asteroid – which is around half the size of a football pitch – would likely inflict major damage.
One precedent came with the so-called "Tunguska Event" of 1908 when a similar-sized asteroid exploded over Siberia, lighting up the sky and leaving a trail of destruction that stretched for around 825 square miles.
Experts, however, dismissed fears of a repeat. Nasa – which is laying on a live feed of the asteroid – said the flyby was actually a blessing that would "provide a unique opportunity for researchers to study a near-Earth object up close."