The 1.7 mile-long asteroid 1998 QE2 will be making its closest approach for at least the next 200 years on May 31.
It doesn't sound very close - it will get about 3.6 million miles away - but astronomers will be able to get a good look at it fly by.
Space.com said that 3.6 million miles is about 15-times the distance between the Earth and moon.
NASA will observe the rock using two telescopes in California and Puerto Rico.
"We will also use new radar measurements of the asteroid's distance and velocity to improve our calculation of its orbit and compute its motion farther into the future than we could otherwise," Lance Benner of NASA's Jet Propulsion Laboratory in a statement.
RT pointed out that QE2 is not only interesting for its size but also the mystery of its origins.
One guess is that it came apart from a comet that got quite close to the sun, giving it a blackened color.
It may also have popped out of an asteroid belt that circles Mars and Jupiter.
The asteroid was discovered by scientists 15-years ago.