Asteroid (152637) 1997 NC1 will pass Earth on June 27, 2026 at about 2.566 million kilometers, or 1.594 million miles, from our planet.
That is safely far away. It is also close enough in astronomical terms for NASA and ESA to watch it closely. The flyby gives scientists a chance to improve measurements of a large near-Earth asteroid without any impact risk.
The Asteroid Is 1997 NC1, and It Is Not a Threat
What NASA and JPL say about the closest approach
NASA/JPL’s Goldstone radar planning page for 1997 NC1 says the asteroid will approach within about 0.017 au, or 6.8 lunar distances, on June 27, 2026. One astronomical unit, or au, is the average distance from Earth to the Sun.
The more exact NASA/JPL Close Approach Data API gives the closest approach as 2026-Jun-27 11:16 UTC. It lists a nominal geocentric distance of 0.0171515837165736 au and a relative velocity of 8.8866894322877 kilometers per second.
ESA’s NEO Coordination Centre lists the same pass at 2026-06-27 11:15 UTC, with a miss distance of 2,565,839 kilometers, 0.017152 au and 6.675440 lunar distances. The one-minute difference is just a display or rounding difference between source tables.
Why “potentially hazardous” is a technical label, not a warning
NASA/JPL’s Small-Body Database marks 1997 NC1 as a near-Earth object and a potentially hazardous asteroid. The Goldstone page also says the Minor Planet Center has given it that label.
That wording can sound alarming. In this case, it is not an impact warning. It tells astronomers that the object is large and passes close enough to Earth’s orbit to deserve careful tracking. It does not mean the asteroid is on a collision path.
NASA/JPL’s Sentry API returned “specified object not found” for both 152637 and 1997 NC1. Sentry is NASA/JPL’s impact-monitoring system. The useful plain-English takeaway is simple: this object is not listed there as an active impact-risk object.
For context on everyday risk, ScienceFeature has also covered the real odds of space rocks reaching people.
How Close Will It Come?
The closest approach time and distance in plain English
The closest approach happens at about 11:16 UTC on June 27, 2026. At that moment, 1997 NC1 will be about 2.566 million kilometers from Earth’s center.
That distance is about 6.7 times the average Earth-Moon distance. ESA defines one lunar distance as 384,399 kilometers on its close-approaches page. By that scale, the ESA value of 6.675440 lunar distances fits the NASA/JPL distance.
The asteroid will not pass between Earth and the Moon. It will pass far outside the Moon’s orbit.
Why 6.7 lunar distances is close for astronomy but safe for Earth
Astronomers call this a close approach because space is large and near-Earth asteroids usually travel far from Earth. A few million kilometers is close enough for useful tracking, but it is far from an impact.
The difference between “close” and “dangerous” depends on the orbit. NASA/JPL lists a time uncertainty of less than one minute for the close approach. That is why scientists can say the object will miss Earth.
Close tracking also helps observers notice when object positions change. That is the same general reason how tracked orbital objects can change risk calculations after new measurements arrive.
Related: more from our astronomy and space coverage.
How Big Is 1997 NC1?
Why the best size estimate is about 0.9 km, with uncertainty
The Goldstone page gives the asteroid’s absolute magnitude as 17.9. It says that brightness suggests a diameter within a factor of two of 900 meters.
That does not mean scientists know the size perfectly. The same NASA/JPL page says the diameter, optical albedo and spectral class measurements conflict. Optical albedo means how much sunlight the surface reflects.
The page lists a diameter of about 0.9 kilometer if the asteroid has an S-type optical albedo. It also says the diameter could be close to 1.5 kilometers if the object is an optically dark B-type asteroid.
What radar observations may help scientists learn
NASA/JPL says 1997 NC1 has not been observed with radar before. That makes the 2026 pass useful.
Radar observations can help scientists narrow down the asteroid’s diameter, spectral class and albedo. The Goldstone page says those observations may also help calibrate earlier Spitzer Space Telescope and NEOWISE measurements.
The asteroid is not interesting because it threatens Earth. It is interesting because this safe pass gives scientists a better chance to measure a large near-Earth object.
Can People See It Through a Telescope?
Why magnitude 10 is telescope territory, not naked-eye viewing
NASA/JPL says 1997 NC1 will brighten to 10th magnitude in late June and will be visible in small telescopes. ESA’s close-approaches table lists a maximum brightness of magnitude 10.0.
Magnitude works backward. Smaller numbers are brighter. A magnitude 10 object is much too faint for the unaided eye.
That puts 1997 NC1 in telescope territory. It is not a bright sky show like Venus or the International Space Station. Readers who enjoy tracking bright objects across the night sky should expect a much harder target here.
Why location, timing, sky conditions and equipment matter
A small telescope can help, but it does not guarantee an easy view. The observer needs the right sky position, a dark enough sky, good timing and enough experience to identify a moving faint point.
The asteroid will also move across the sky quickly near closest approach. Finder charts or astronomy software will matter more than casual scanning.
NASA’s Eyes on Asteroids app can help people see asteroid orbits in a visual way, but actual viewing still depends on local conditions and equipment.
Why Scientists Care About a Safe Flyby
Close approaches improve orbit and physical measurements
A safe flyby gives scientists two kinds of help. First, it gives them more position measurements for the orbit. Second, it gives them a chance to study the asteroid’s physical traits.
NASA/JPL says the orbital uncertainties are small because observers have an optical arc from 1997 to 2026. That long record helps scientists point radar instruments accurately.
Radar work depends on faint radio returns from distant objects. That is one reason why radio quiet matters for faint space signals in astronomy.
What NASA Goldstone radar is scheduled to do
NASA/JPL says observing time is scheduled on June 24, 25 and 27. The plan uses the 34-meter DSS-26 antenna as a transmitter at 7190 MHz and the 34-meter DSS-13 antenna as a receiver.
The page says this setup should produce continuous-wave detections on each day. It may also produce coarse-resolution imaging if the asteroid rotates slowly enough.
The larger DSS-14 antenna at Goldstone would have produced stronger imaging data, but NASA/JPL says that antenna is offline until 2028 for modernization and new equipment.
How We Know It Will Miss Earth
The observation arc from 1997 to 2026
1997 NC1 was discovered by NEAT at Haleakala, Hawaii on July 5, 1997. NASA/JPL’s Small-Body Database lists the first observation as 1997-07-05 and the last observation in the API result as 2026-06-24. It also lists 981 observations used in the orbit solution.
That long observation arc is a major reason the orbit is well known. Each observation gives orbit calculators another point to fit.
This is not very different from how astronomers confirm small objects in distant orbits. More observations over time turn a moving point into a stronger orbit.
Why small orbital uncertainties help planetary defense
Planetary defense depends on small uncertainties. Scientists do not need to know only where an asteroid is today. They need to know where it will be when it passes near Earth.
For 1997 NC1, the official sources point in the same direction. NASA/JPL and ESA list a safe pass at about 6.7 lunar distances. NASA/JPL lists a time uncertainty of less than one minute. Sentry does not list it as an active impact-risk object.
That is the answer behind the technical labels. 1997 NC1 is large, close and useful to study. It is not headed for Earth.
References
European Space Agency NEO Coordination Centre. (2026). Close approaches list. https://neo.ssa.esa.int/close-approaches
European Space Agency NEO Coordination Centre. (2026). News details. https://neo.ssa.esa.int/news-details
NASA Jet Propulsion Laboratory. (2026, June 23). Goldstone radar observations planning: (152637) 1997 NC1. https://echo.jpl.nasa.gov/asteroids/1997nc1.2026.goldstone.planning.html
NASA Jet Propulsion Laboratory. (n.d.). Eyes on asteroids. https://eyes.nasa.gov/apps/asteroids/
NASA/JPL Solar System Dynamics. (2026). SBDB close-approach data API query for 152637. https://ssd-api.jpl.nasa.gov/sbdb.api?sstr=152637
NASA/JPL Solar System Dynamics. (2026). Sentry data API query for 152637. https://ssd-api.jpl.nasa.gov/sentry.api?des=152637
