A relatively small asteroid, one thought to be no bigger than 128 feet across, is expected to fly very close to Earth tomorrow, NASA has announced. While the rock may not be a particularly hefty one, it will, however, creep in extremely close to the planet's surface, buzzing Earth from just 771,900 miles away. By comparison, the moon sits at an average distance of 238,900 miles from our planet. To put that into perspective, the asteroid will pass at 3.2 times the distance to the moon when it comes swinging by on Wednesday.
According to a report released yesterday by NASA's Jet Propulsion Laboratory (JPL), tomorrow's celestial visitor is known as asteroid 2019 XO3. The object was very recently discovered and nearly slipped past NASA's radar, being spotted a mere two days ago. Although NASA scientists had only a short interval at their disposal to calculate the asteroid's orbit and plot its course through the inner solar system, it was more than enough to determine that its flyby of Earth will be a perfectly safe one.
"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 XO3, JPL scientists performed a total of 13 observations over the course of one day to trace its orbital path around the sun. NASA assures that the rock poses no threat of veering off course and potentially slamming into Earth; it will harmlessly pass by us as it circles the giant star.
NASA predicts that the wayfaring space rock will approach Earth in the afternoon. The asteroid will be traveling at speeds of around 21,300 mph and will reach its closest point to our planet at 3:33 p.m. ET.
About five hours after its close brush with Earth, 2019 XO3 will swing by the moon. The asteroid will fly a lot closer to Earth's natural satellite, coming within 576,600 miles of the lunar surface.
Interestingly enough, tomorrow's flyby will be the asteroid's first trip through the Earth-moon system. The rock orbits the sun once every 1,075 days, or nearly three years, and has never ventured to our corner of space before. The asteroid is unlikely to return, making tomorrow's encounter a unique event.
Based on its orbital path, 2019 XO3 has been classified as an Apollo-type asteroid. As NASA explains, asteroids of this class are known as "Earth-crossing" because they follow orbits that allow them not only to approach Earth but also to cross our planet's orbit.
Its upcoming flyby follows the close encounter with a significantly larger Apollo asteroid due to shoot past Earth later tonight.