NASA is keeping a close eye on a bus-sized asteroid that is expected to skim past Earth Saturday at a distance only slightly father away than the moon.

Officials at the space agency's Jet Propulsion Laboratory (JPL) and and Center for Near-Earth Object Studies (CNEOS) estimated that the space rock is between 28 and 62 feet wide, and will shoot past our planet at a speed of roughly 29,300 mph.

It will come within 273,000 miles of Earth. By comparison, the average distance between our planet and the moon is roughly 238,900 miles.

The close encounter is expected to take place in the early morning hours, but the asteroid poses no threat to Earth.

The space rock, called 2024 VK3, is just one of five asteroids that will fly by our planet this weekend. 

Three are as roughly big as commercial airplanes and one is about the size of a house, according to NASA JPL. 

The next-closest encounter will be made by the airplane-sized asteroid 2024 VZ2, which will come within 790,000 miles of our planet. 

The others will maintain distances of over a million miles away with house-sized asteroid 2024 UC5 being 2,580,000 miles away at its closest point to Earth. 

All of these asteroids are considered Near Earth Objects (NEOs) because they are within approximately 30 million miles of our planet. 

NASA has observed, documented and classified around 36,000 objects in the solar system as NEOs.

The space agency tracks NEOs primarily to identify asteroids that could potentially collide with Earth, and assess the threat they pose.

NASA uses a variety of methods to survey nearby space rocks, including both ground-based and space-based telescopes.

One key tool is the Near-Earth Object Surveyor, an infrared space telescope used to discover and characterize Potentially Hazardous Asteroids (PHAs).

PHAs are asteroids that have a high probability of making a close approach to Earth and are large enough to cause significant damage if they made impact. 

Technically, that means any space rock that comes within 0.05 astronomical units - or roughly 4,647,790 miles - of Earth's orbit, and has an absolute brightness of 22.0 or less. 

Absolute brightness is an indirect measurement of an asteroid's size. Lower values of magnitude indicate greater brightness, and thus larger objects. 

None of the asteroids that will fly by Earth this weekend are considered PHAs.

But NASA is preparing for the unlikely event that a PHA hurtles towards our planet in the future.

The agency's Planetary Defense Coordination Office (PDCO) is developing technologies and strategies that could safe Earth from a catastrophic asteroid impact. 

Established in 2016, PDCO is tasked with the mission of finding, tracking and better understanding asteroids and comets that could pose an impact hazard to Earth. 

In 2021, the office launched the Double Asteroid Redirection Test (DART), which slammed a spacecraft into the asteroid Dimorphos and successfully changed the space rock's orbital trajectory. 

This mission was a test of the 'kinetic impact' asteroid deflection strategy, which could one day be used to redirect a PHA on a collision course with Earth. 

In October, the European Space Agency launched the second phase of this mission, called Hera.

The Hera spacecraft is currently on its way to Dimorphos to perform a detailed post-impact survey of Dimorphos. This will help experts solidify kinetic impact into a well-understood and repeatable planetary defense technique.