Tomorrow is shaping up to be a busy day for close asteroid encounters. Three space rocks are due to pass by Earth on Sunday, two of which will be flying very close to the terrestrial surface -- at just a few times the distance to the moon. The three asteroids vary in size and speed, but do have one thing in common -- except for their shared flyby date, that is. All three objects are recently discovered and are classified as Apollo-type asteroids. The rocks won't swing by Earth as a group, but rather approach the planet at different times throughout the day. As such, planet Earth will see three individual flybys unfolding on December 1, each of them unique in its own way.
The first rock to traipse through our cosmic neighborhood tomorrow is also the smallest and the fastest of the bunch. According to a report released today by NASA's Jet Propulsion Laboratory (JPL), this first celestial visitor of the day is known as asteroid 2019 WH2 and only measures 82 feet in diameter at the most. The rock was first spotted just five days ago, on November 25, and is cruising through space at speeds of nearly 22,800 mph. That's almost 30 times the speed of sound.
The asteroid orbits the sun once every 810 days, or 2.22 years, and is currently embarked on its first-ever trip through our corner of the solar system. The rock will swing by Earth in the pre-dawn of Sunday morning, reaching its closest point to our planet at 4:15 a.m. ET. As it does so, the object will creep in as close as 818,400 miles from Earth's surface, marking the closest asteroid approach of the day. To put that into perspective, that's nearly 3.5 times the distance between Earth and the moon. The rock is not likely to return any time soon.
Less than five hours after the close brush with 2019 WH2, Earth will be visited by a significantly larger asteroid dubbed 2019 WD3. The rock was discovered nearly a month ago, on October 31, and is estimated to be up to 180 feet wide -- it boasts the most impressive proportions among the three. However, at 18,500 mph, it is also the most sluggish of the group. Asteroid 2019 WD3 is expected to approach Earth at 9:01 a.m. ET and will harmlessly shoot past our planet from a little over 3 million miles away -- or 12.6 times the distance to the moon.
Unlike its predecessor, the wayfaring space rock is a frequent traveler through our neck of the cosmic woods. The asteroid circles the sun once every 502 days, or about 1.4 years, and regularly pops by for a visit as it orbits the sun, per JPL. Interestingly enough, tomorrow's flyby will be its closest encounter with Earth in half a century. The last time that asteroid 2019 WD3 passed at a comparable distance to our planet was in 1969, when it buzzed Earth from 4.3 million miles away. Its previous flyby of Earth occurred six years ago, in 2013, and brought the asteroid only some 27.5 million miles from the planet's surface. The rock will be back for another visit next year, and then again in 2024, 2030, and 2031.
The last flyby of the day will get Earth closely acquainted with a 98-foot asteroid called 2019 WN1. According to JPL, the object was first picked up by NASA asteroid trackers nearly two weeks ago, on November 19. The asteroid completes a full orbit around the sun in about 696 days or just under two years.
The space rock will cruise by our planet in the afternoon, swooping in for its close flyby of Earth at 4:14 p.m. ET. Traveling at a speed of 22,660 mph, the asteroid will come within 1.01 million miles of our planet -- or just under 4.3 times the lunar distance. Just like in the case of asteroid 2019 WH2, this will be the rock's first and only approach of Earth.
While NASA has reported plenty of close asteroid approaches over the last few weeks, it's been a while since we've seen a multi-asteroid flyby. The last time that our planet was visited by a swarm of asteroids was on November 1, when Earth was buzzed by six space rocks in a single day. Space enthusiasts might find it fitting that the month of December should begin in a similar fashion as November did, with a cluster of asteroids elegantly whizzing by in a quiet, cosmic ballet.