A tiny space rock is due to scrape past Earth today in what will be the closest asteroid approach in quite a while, NASA has announced.
Today's celestial visitor is a near-Earth asteroid known as 2019 WJ4. The object doesn't boast hefty proportions, as data from NASA's Center for Near-Earth Object Studies (CNEOS) only places it within a size range of between 18.3 feet and 42.6 feet in diameter. At the lower end of that size estimate, the asteroid is no bigger than an average-sized car. At the upper end of NASA's size estimate, the rock is still 1.5 times smaller than the famous Chelyabinsk meteor that penetrated Earth's atmosphere in 2013, exploding in the sky over Russia.
While it may not be the largest rock to traipse through our cosmic neighborhood in recent weeks -- the rock doesn't hold a candle to the huge 632-foot asteroid that shot past Earth yesterday from 2.3 million miles away -- what it lacks in size, it more than makes up for in speed. The rock is hurtling through the void of space at breakneck speeds and is expected to approach Earth at a velocity of a little over 41,200 mph. As an added bonus, the asteroid will venture extremely close to the planet's surface, flying even closer than the moon.
The swift asteroid will buzz the planet in the afternoon, reaching its closest point to Earth at 3:05 p.m. ET. As it swoops in for its close -- but perfectly safe -- flyby of Earth, 2019 WJ4 will come within 195,300 miles of the terrestrial surface. By comparison, the moon sits at an average distance of 238,900 miles from our planet. To put that into perspective, the rock will pass at 0.85 times the distance to the moon.
The last time that an asteroid crept in closer to Earth was at the beginning of the month, on November 2. At the time, a similarly-sized space rock zoomed past our planet from just 65,100 miles away -- or 0.28 times the lunar distance.
Less than three hours after its close brush with Earth, asteroid 2019 WJ4 will swing by the moon for another close encounter. The rock will skim the moon from as little as 37,200 miles away, barreling past the lunar surface at more than 43,200 mph.
Just like yesterday's much larger celestial visitor, 2019 WJ4 is part of a recently discovered group of near-Earth asteroids that have only been on NASA's radar for a few days. The rock was first spotted a mere four days ago, on November 26. According to a recent report from NASA's Jet Propulsion Laboratory (JPL), the object circles the sun once every 1,187 days, or 3.25 years, and is classified as an Apollo-type asteroid -- a class of space rocks that can not only approach Earth, but also intersect the planet's orbit.
Today's close encounter with Earth will be the first time that asteroid 2019 WJ4 passes through our corner of space. The rock is not expected to make a return trip for the foreseeable future. The asteroid will make a close pass by Jupiter in 2021, as it treks the outer solar system in its journey around the sun.