An asteroid discovered just yesterday will swing by Earth tomorrow on what NASA has announced to be its closest-ever approach to our planet. Traveling through the void of space at a cruising speed of a little over 14,800 mph, the asteroid will buzz by Earth in the pre-dawn hours of Sunday morning, coming within a distance that is only a few times the length from Earth to the moon.
According to a report released today by NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, the asteroid was dubbed 2019 SE5 and bears the label of a near-Earth object (NEO).
As NASA explains, NEOs are celestial objects, such as comets or asteroids, that orbit somewhere between approximately 91 million and 121 million miles from the sun. 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.
Although asteroid 2019 SE5 was first spotted only a day ago, JPL scientists have had enough time to analyze its orbit and pinpoint the moment of its impending flyby of Earth. The study of its orbital path also revealed that the rock is an Apollo-type asteroid and that it circles the sun once every two years. In its journey around the sun, the asteroid occasionally cruises by Earth as it treks through the inner solar system. Being an Apollo asteroid, it also has the potential to cross Earth’s orbit — similar to all the other asteroids of this class, which get their name from the famous asteroid 1862 Apollo.
In terms of size, tomorrow’s celestial visitor is rather on the small side. The asteroid is thought to be at least 36 feet wide and is estimated to measure up to 82 feet in diameter, per NASA’s Center for Near-Earth Object Studies (CNEOS). At the upper end of NASA’s size estimate, the asteroid is only slightly larger than the Chelyabinsk meteor, which made headlines in 2013 when it penetrated Earth’s atmosphere and exploded in the sky above Russia.
While that particular close encounter wreaked havoc in the Russian city of Chelyabinsk — the meteor caused extensive damage, destroying more than 7,200 buildings and injuring nearly 1,500 people — this won’t be the case for asteroid 2019 SE5. NASA assures that this space rock will harmlessly pass by Earth at a safe distance from the planet’s surface.
“Scientists determine the orbit of an asteroid by comparing measurements of its position as it moves across the sky to the predictions of a computer model of its orbit around the sun,” explains NASA.
“The more observations that are used and the longer the period over which those observations are made, the more accurate the calculated orbit and the predictions that can be made from it.”
In the case of asteroid 2019 SE5, JPL scientists used a total of 47 observations to determine its orbit. The rock is expected to swoop in for its close approach to Earth at 3:35 a.m. ET on September 29. At its closest point to Earth, the asteroid will fly at 1.34 million miles from the planet’s surface. To put that into perspective, that’s 5.6 times the distance between Earth and the moon.
Interestingly enough, tomorrow’s flyby comes just four days after another, significantly larger 324-foot Apollo asteroid swung by our planet at roughly the same distance.
While 1.34 million miles may sound like a vast distance in terrestrial terms, by cosmic standards it’s just a stone’s throw away. In fact, tomorrow’s brush with Earth will be the closest that asteroid 2019 SE5 has ever gotten to our planet — and the closest it should get for the foreseeable future.
The last time the rock visited Earth was in 2017, when it came within 7.8 million miles of the planet’s surface. Before that, the asteroid buzzed by Earth in 2015 from a staggering distance of 17.7 million miles away.
The asteroid will return for its next close approach in 2021, when it’s expected to miss Earth by 4.1 million miles. Its subsequent flybys will carry the space rock increasingly farther away from the planet’s surface.