A large near-Earth asteroid, measuring about 4 to 8 meters in diameter is set to fly past the Earth today (Wednesday). According to NASA, the asteroid will fly past the Earth at 3 PM today and the phenomenon will provide astronomers a chance to study the 1.5-mile-wide (2-kilometer-wide) object in great detail. The asteroid, called 1998 OR2, will make its closest approach, but will still be more than 16 times farther away than the Moon.
“Small asteroids like 2020 HS7 safely pass by Earth a few times per month,” said Lindley Johnson, Planetary Defense Officer and Program Executive for the Planetary Defense Coordination Office at NASA Headquarters in Washington, DC.
Asteroid 1998 OR2 was discovered by the Near-Earth Asteroid Tracking program at NASA's Jet Propulsion Laboratory in July 1998, and for the past two decades, astronomers have tracked it.
According to NASA, this asteroid poses no possibility of impact for at least the next 200 years. Its next close approach to Earth will occur in 2079 when it will pass by closer — only about four times the lunar distance.
Despite this, 1998 OR2 is still categorized as a large "potentially hazardous asteroid" because, over the course of millennia, very slight changes in the asteroid's orbit may cause it to present more of a hazard to Earth than it does now.
What is a near-Earth object?
Near-Earth objects (NEOs) are asteroids and comets that orbit the Sun, but their orbits bring them into Earth’s neighborhood – within 30 million miles of Earth’s orbit.
These objects are relatively unchanged remnant debris from the solar system’s formation some 4.6 billion years ago. Most of the rocky asteroids originally formed in the warmer inner solar system between the orbits of Mars and Jupiter, while comets, composed mostly of water ice with embedded dust particles, formed in the cold outer solar system.
Who searches for near-Earth objects?
NASA’s Near-Earth Object (NEO) Observations Program finds, tracks and monitors near-Earth asteroids and comets. Astronomers supported by the program use telescopes to follow up the discoveries to make additional measurements, as do many observatories all over the world. The Center for Near-Earth Object Studies, based at NASA’s Jet Propulsion Laboratory, also uses these data to calculate high-precision orbits for all known near-Earth objects and predict future close approaches by them to Earth, as well as the potential for any future impacts.
How do we calculate the orbit of a near-Earth object?
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. 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.
How many near-Earth objects have been discovered so far?
At the start of 2019, the number of discovered NEOs totaled more than 19,000, and it has increased to22,776 at the time of this writing. An average of 30 new discoveries are added each week. More than 95 percent of these objects were discovered by NASA-funded surveys since 1998 when NASA initially established its NEO Observations Program and began tracking and cataloging them.
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