At around 1.8 million kilometres away, the asteroid has been classed as a near Earth object (NEO) and is nearly five times the distance between our planet and the moon.
NASA has released radar images of the peanut-shaped asteroid which were obtained in the early hours of Tuesday morning by its 70-meter (230-foot) antenna at the Goldstone Deep Space Communications Complex in California.
2014 JO25's size combined with its reflective surface will likely make it visible to stargazers who possess small optical telescopes. The last time such a huge space rock came this nearby was in 2004.
Astronomers will closely monitor The Rock as it comes within 4.6 lunar distances from Earth at 1.24pm United Kingdom time on Wednesday. As member station KQED notes, 1999 AN10 is expected to buzz by Earth in 2027 at a distance roughly equivalent to the space between Earth and the moon.
It's the closest this asteroid has come to Earth for at least the past 400 years and will be its closest approach for at least the next 500 years. The feed for 2014 JO25 will begin at noon on Wednesday. But it does fall within the category of "potentially hazardous asteroids" that astronomers monitor for safety, Pascal Descamps, an astronomer at the Paris Observatory told AFP by phone.
Estimates of its size vary but experts put it between 650 metres (2,132ft) and 1.4 kilometres (0.87 miles) in length.
The good news is that scientists have identified at least 90 percent of these flying hazards within our solar system.
"This one is close, but not uncomfortably close", she said.
The rock is around one kilometre long.
Earth hasn't been greeted by this asteroid for centuries, according to NASA. NASA says, calling it an "outstanding opportunity to study this asteroid".
Watch an animated calculation below of the asteroid's orbit calculated a year ago by Ron Baalke, a space scientist.
Given the vastness and darkness of the universe, it can be incredibly hard for astronomers to track potentially unsafe objects that could be on a collision course with Earth.
So far, however, funding has not been approved.