Planet Earth appears to have entered a very prolific period for extremely close asteroid encounters. Just this week, Earth was buzzed by three tiny asteroids that skimmed the planet at high speed, creeping in almost as close as the moon. The series of close brushes will continue next week with another near-miss, as an even larger, 134-foot asteroid is due to fly by Earth at four times the distance to the moon.
The space rock in question is known as asteroid 2017 KP27 and has long been on NASA’s radar. As its name suggests, the asteroid was discovered two years ago – about 20 days after it performed a close flyby of Earth on May 4, 2017 – and has been closely monitored ever since. The asteroid orbits the sun once every 351 days and follows an orbital path that often brings it in Earth’s proximity. Its next flyby of Earth is due in just a few days and is expected to occur on September 26, scientists at NASA’s Jet Propulsion Laboratory (JPL) announced today.
The date will mark the asteroid’s closest-ever approach to Earth, bringing the rock within a little over 1 million miles from the planet’s surface. By comparison, the moon sits at an average distance of 238,900 miles from Earth. This means that, during Thursday’s flyby, asteroid 2017 KP27 will approach at exactly 4.22 times the lunar distance.
Due to its close proximity to our planet, the asteroid was classified as 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.
The rock’s orbit has earned it the designation of Aten-type asteroid. This specific classification refers to the fact that this particular NEO has the potential of being “Earth-crossing.” Aten asteroids circle the sun on an orbit that allows them to cross that of Earth. In fact, asteroids of this class spend most of their time inside Earth’s orbit, says NASA.
Traveling through space at a cruising speed of a little over 10,500 mph, the asteroid will be making its close approach to Earth on Thursday afternoon. The 134-foot rock is expected to safely fly past our planet at 3:36 p.m. ET and then swing by the moon an hour later at a distance of 902,100 miles from its cratered surface.
While any close brush with an asteroid can be unnerving, NASA assures that next week’s flyby will be a perfectly safe one. The asteroid is expected to harmlessly pass by Earth and the moon on its way out of the inner solar system and then continue its journey around the sun.
“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 2017 KP27, JPL scientists used a total of 59 observations to gauge out its orbital path and establish when and how close the rock will pass by Earth.
The asteroid is expected to return next September, and then again in 2036 and 2037.
Next week’s flyby comes hot on the heels of an even closer brush with an asteroid. Just yesterday, a 55.7-foot asteroid darted past Earth at 2.21 times the distance to the moon. Before that, an even smaller, 24-foot asteroid skimmed Earth at 1.1 times the lunar distance on Saturday.