A massive asteroid, nearly as big as a whale, skimmed past the Earth but was only detected a day later.

The space rock, named 2017 VL2, was observed by scientists using the Mauna Loa observatory on 10 November. However, it was only after analysing its speed and trajectory, astronomers found that the asteroid had narrowly missed the Earth when it flew by on 9 November.

The asteroid, which measures around 50-100ft across, was about 117,480km away from our planet – a third of the distance separating the Earth and Moon.

At this distance, 2017 VL2 skimmed the Earth safely. However, in the event of a collision, the massive size of the space rock coupled with its estimated speed of 9km/second could have resulted in serious damage.

As the Daily Mail reports, the impact from this asteroid could have obliterated life within a diameter of 6km. According to Bended Reality, which cited the Purdue University's Impact Earth calculator, its impact would have been 15 times stronger than the atomic bomb dropped on Hiroshima during World War II.

It was one of the seven largest asteroids that zoomed past our planet this year, as per a report in the Watchers.

But for now, there's no reason to worry as 2017 VL2 will not make a close pass any time before 2125.

The space rock belongs to the Apollo group of asteroids, which has over 8,000 members. Of these, some 1,500 are large enough and potentially capable of threatening Earth during close flybys.

Next week, another potentially hazardous asteroid – 5km wide or nearly half as big as the one that annihilated the dinosaurs – will whizz past Earth, according to Nasa. The asteroid, which goes by the name 3200 Phaethon, will come within three million kilometres of our planet and will not return until 2093.