Next week, a relatively small asteroid — one thought to be no larger than 98 feet across — will venture extremely close to our planet, passing between Earth and the moon. Known as asteroid 2019 SP3, the space rock was discovered exactly one week ago and is expected to skim Earth closer than the moon on Thursday, scientists at NASA’s Jet Propulsion Laboratory (JPL) announced yesterday.
The asteroid flyby comes just three days after another, slightly smaller 95-foot asteroid will shoot past Earth at a little over two times the distance to the moon.
First spotted on September 22, asteroid 2019 SP3 has been kept under a close watch by the JPL over the past week. After gauging out its orbit around the sun, the JPL team classified the rock as a near-Earth object (JPL) and established it to be an Apollo-type asteroid.
To qualify for the NEO designation, a celestial object — be it a comet or an asteroid — needs to orbit the sun at a distance between approximately 91 million and 121 million miles. This means that, in their journey around the sun, NEOs can venture as far as roughly 30 million miles away from Earth’s orbit and as close to the planet’s surface as a few times the distance to the moon — or even closer, as is the case for asteroid 2019 SP3.
While the “NEO” label indicates proximity to our planet, the rock’s classification as an Apollo asteroid reveals an important clue about its orbit. As an Apollo asteroid, 2019 SP3 has the potential of being “Earth-crossing,” which means that the rock zips through the solar system on an orbital path that allows it to occasionally cross the orbit of Earth.
The space rock will swoop in for a very close shave of Earth on Thursday morning, skimming the planet from only a couple hundred miles away. Barreling through space at a cruising speed of more than 19,300 mph — or about 25 times the speed of sound — the asteroid will buzz Earth in the pre-dawn hours, quietly shooting past us at 2:33 a.m. ET on October 3.
During its close flyby of Earth, the rock will creep in as close as 223,200 miles from the planet’s surface. To put that into perspective, the moon sits at an average distance of 238,900 miles from Earth. As such, the rock will slip in at 0.97 times the distance to the moon when it cruises by Earth next week.
Before its close brush with Earth, asteroid 2019 SP3 will first swing by the moon as it makes its way toward our planet. The rock will buzz the moon in the late hours of Wednesday night, darting past its cratered surface from 325,500 miles away.
The upcoming close encounter with Earth and the moon will mark the first-ever trip through the inner solar system for asteroid 2019 SP3. The rock is not expected to return for the foreseeable future.