The asteroid, named 2002 AJ129, is expected to come within just over 2 million miles of Earth, which is relatively close by space standards. Space debris that enters the Earth’s atmosphere are called meteors, one of which was recently seen in Michigan. In this case, the asteroid is invisible to the naked eye. Astronomers will need powerful radio waves and a telescope to study it.

Here’s what you need to know about the approaching asteroid and whether you should take cover:

1. How big is the asteroid?

Asteroid 2002 AJ129 is 1,600 and 4000 feet in diameter (480 m – 1.1 km), which International Business Times notes is larger than the world’s tallest building Burj Khalifa. According to NASA’s Center for Near Earth Object Studies, it will be one of the larger NEOs to fly by Earth in 2018. “Note that a ‘close’ passage astronomically can be very far away in human terms: millions or even tens of millions of kilometers,” according to the NASA website.

2. What is the asteroid made of?

The asteroid is described as a near-Earth object, which are defined by NASA as “comets and asteroids that have been nudged by the gravitational attraction of nearby planets into orbits that allow them to enter the Earth’s neighborhood.” While comets are mostly water ice and dust, asteroids are rocky objects that orbit the sun.

3. Is the asteroid dangerous?

Though this asteroid is expected to come no closer than 2.6 million miles from Earth, its distance and size are still enough for NASA to deem it a “potentially hazardous asteroid.” Any asteroid that is within 4,650,000 miles from Earth with a diameter larger than 500 feet is deemed “potentially hazardous.” To get a sense of scale, our moon is approximately 238,855 miles from Earth.

Despite the categorization, it is very unlikely that the asteroid will hit Earth.

4. What do NASA astronomers think?

NASA astronomers are excited to use telescopes plus powerful radar get a glimpse of 2002 AJ129 and learn more about its shape, rotation speed, size, and internal components. Lance Benner, a NASA astronomer, told Newsweek that the agency has booked the Goldstone Radio Telescope, located in California, to study nearly 40 asteroids in 2018.