(FOX CAROLINA) -- A very big asteroid with its own little moon is going to zip past Earth tonight.
This moon-and-asteroid system, called 1999 KW4, is made up of two rocks.
The big one is about 0.8 miles (1.3 kilometers) wide, according to NASA, and shaped like a spinning top.
The smaller one is more elongated and stretches 0.35 miles (0.57 km) along its longest dimension. It points lengthwise toward its much larger twin.
The two asteroids will pass closest to Earth at 7:05 pm EDT (1105 GMT), when they'll be just 3,219,955 miles (5,182,015 km) from the planet's surface.
That's more than a dozen times the distance between the Earth and the moon in its orbit around our planet, and much too far for the space rocks to pose any threat.