Hot on the heels of a multi-asteroid flyby that brought four rather sizeable space rocks through our neck of the cosmic woods on Friday morning, three other asteroids are set to cruise by Earth on Saturday. Similar to the asteroid clusters that have wandered close to our planet over the past two weeks, tomorrow’s celestial visitors will approach Earth one at a time rather than as a group, performing three separate flybys between early morning and late evening. While two of these space rocks will pass relatively far from the planet’s surface, quietly shooting past Earth from a few million miles away, one asteroid will skim Earth from very close by, creeping in at under three times the distance to the moon.
According to NASA’s Center for Near-Earth Object Studies (CNEOS), the three asteroids were all recently discovered and vary in size and velocity, each traveling at a different speed as they make their way toward Earth. The first two rocks to swing by our planet on Saturday were first detected only last week, on October 8 and October 10. Meanwhile, the third asteroid in the group was first spotted about three weeks ago, being picked up by NASA asteroid trackers on September 29.
Although the three asteroids couldn’t be more different from one another, they all share one common trait. Based on their orbit around the sun, all three objects were labeled as potentially “Earth-crossing” and classified as Apollo-type asteroids. As NASA explains, asteroids of this class get their name from asteroid 1862 Apollo and zip through the solar system on an orbital path that allows them not only to approach Earth, but also to cross the planet’s orbit.
The first asteroid due to fly by Earth on October 19 is also the closest and the smallest of the bunch. Known as 2019 TK5, the rock is estimated to measure no more than 62 feet in diameter, per CNEOS. This particular Apollo asteroid circles the sun once every 381 days, or 1.04 years, often passing through our corner of space as it treks the inner solar system. In fact, the wayfaring space rock is a frequent traveler through our cosmic neighborhood, having performed 15 flybys of Earth during the past 50 years. The rock is slated to pass by our planet 16 more times over the next four decades, according to a report released yesterday by NASA.
Interestingly enough, tomorrow’s flyby will be the closest one so far for asteroid 2019 TK5. The rock is expected to approach Earth in the pre-dawn hours of Saturday morning, safely passing past our planet at 3:25 a.m. ET. As it cruises by at nearly 13,000 mph, the asteroid will come as close as 595,200 miles from Earth — marking the closest asteroid encounter of the day. To put that into perspective, that’s almost 2.5 times the distance between Earth and the moon.
The asteroid will return for another visit next year, coming around on an annual basis up until 2025. After that, the rock will disappear for 25 years, only to resume its yearly flybys of Earth in 2050. However, it will be a long time before asteroid 2019 TK5 passes so close to Earth again. The space rock won’t have another close brush with Earth until 2056, when it will scrape past our planet from a measly 130,200 miles away, passing even closer than the moon.
The second asteroid to swing by Earth tomorrow is a 124-foot space rock known as 2019 TG7. CNEOS records show that this is the fastest and the farthest of the trio. The asteroid zips around the sun once every 1,070 days, or nearly three years, and is currently embarked on its first-ever trip through our corner of the solar system. The rock will pass by Earth about three hours after its predecessor, swooping in for its close encounter with our planet at 6:40 a.m. ET. Hurtling past us at nearly 17,000 mph, the asteroid will only come within 3.9 million miles of our planet, or nearly 17 times the distance to the moon. The rock is not expected to return for the foreseeable future.
The third and final celestial visitor of the day is an Apollo asteroid dubbed 2019 SJ8. Estimated to be around 252 feet wide, asteroid 2019 SJ8 is the largest of the group. The rock orbits the sun once every 714 days, or 1.96 years, occasionally passing by Earth on its journey around the giant star. The asteroid will buzz Earth late in the afternoon, reaching its closest point to our planet at 7:44 p.m. ET. As it barrels past us at a little over 16,600 mph, the space rock will approach within 2.7 million miles from the Earth’s surface, or about 11.5 times the lunar distance.
As it happens, this will be the closest-ever flyby of Earth for asteroid 2019 SJ8. The rock previously visited our planet two other times, in 2016 and 2017, only coming as close as 18.7 million miles from Earth. The asteroid will double back for another visit in 2021 and 2022, and then again in 2050. However, its future flybys of Earth will only bring it as close as 27.1 million miles from the planet’s surface.