A huge asteroid almost 100 metres wide is hurtling towards Earth.
NASA said the asteroid, scientifically called 2013 WV44, will fly past at around 2pm on Wednesday (NZ time) at a speed of 11.81 kilometres per second.
The rock is estimated to be 91 metres wide, and although it is speeding towards us it won't get closer than 0.02334 astronomical units, or 3.49 million kilometres.
While this sounds like it's far away from us, it's still classed as a close approach and means NASA will keep an eye on it.
"Near-Earth objects are comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth's neighbourhood," NASA said.
"Composed mostly of water ice with embedded dust particles, comets originally formed in the cold outer planetary system, while most of the rocky asteroids formed in the warmer inner solar system between the orbits of Mars and Jupiter.
"The scientific interest in comets and asteroids is due largely to their status as the relatively unchanged debris from the solar system formation process some 4.6 billion years ago."
An asteroid is defined as a near-Earth object when it comes within 1.3 astronomical units of the sun and is therefore within 0.3 astronomical units, or about 45 million kilometres, of Earth's orbit.
NASA lists the five next upcoming close approaches on its online tracker and shows asteroids that are getting closer to Earth.