Editor’s note, June 5, 2020: Asteroid 2002 NN4 will safely pass by the Earth on June 6 at a distance of approximately 3.2 million miles (5.1 milliion kilometers), about 13 times further away from the Earth than the Moon is. There is no danger the asteroid will hit the Earth. The frequently asked questions below answer some basic questions about how asteroids are observed and tracked.
Original story, April 28, 2020: A relatively small asteroid, about 4 to 8 meters in diameter, will fly safely past Earth just before 3 p.m. EDT April 28. NASA is tracking the object, but orbit calculations ruled out any chance that the near-Earth object could pose a threat to our planet.
“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. “At its closest approach 2020 HS7 will pass Earth by a distance of about 23,000 miles/36,400 km. It poses no threat to our planet, and even if it were on a collision path with Earth it is small enough that it would be disintegrated by our Earth’s atmosphere.”
Near-Earth asteroid 2020 HS7, estimated to be 13 to 24 feet (4 to 8 meters) in size, will safely pass Earth at 2:51 p.m. EDT on Apr. 28 (6:51 UTC).
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.
Video: “NASA Science Live: Asteroid Close Approach”
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 cataloguing them.
Video: “All Known Asteroids in the Solar System (1999-2018)”
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NASA Center for Near-Earth Object Studies
International Astronomical Union (IAU) Minor Planet Center
