Kilometer-Wide Asteroid Passes Earth on June 27

Asteroid 1997 NC1, estimated to be about a kilometer across, passes Earth on Friday, June 27, 2026, at a closest distance of roughly 2.4 million kilometers. That is nearly seven times the distance that separates us from the Moon, so according to NASA there is no risk of collision. The flyby falls on the day a heat wave begins over the region, but the two have nothing to do with one another, beyond the coincidence that both the sky and the ground demand attention on the same date.

The object also carries the formal designation 152637 and belongs to the Aten group of asteroids, bodies whose orbits lie mostly inside Earth’s orbit around the Sun. It is one of the larger near-Earth objects approaching us this year. For comparison, this asteroid is 50 to 60 times wider than the meteor that exploded over Chelyabinsk, Russia, in 2013 and shattered windows across six cities. Precisely because it is large and passes relatively close, scientists are using it as a natural target for precise measurement.

How does NASA image an asteroid we cannot see with the naked eye?

A team at the Jet Propulsion Laboratory plans to observe 1997 NC1 with planetary radar at Goldstone, in California. The principle is simple in essence and demanding in practice. The DSS-26 antenna sends a beam of radio waves toward the asteroid, and a second antenna, DSS-13, receives the faint echo that returns. From that echo, scientists can reconstruct the body’s shape, measure its rotation rate and estimate the roughness of its surface. JPL radar astronomer Marina Brozovic describes it vividly: they bring their own flashlight, because they do not wait for the body to be lit, they illuminate it themselves.

The observations are planned for June 24, 25 and 27. The goal is to pin down the asteroid’s true diameter and to map its surface structure, since earlier size estimates left room for error. Radar measurements also sharply narrow the uncertainty in the orbital calculation, which matters for the long-term tracking of objects classified as potentially hazardous, even though this particular pass poses no current threat.

Can I observe it from my own telescope?

The asteroid is not visible to the naked eye. It requires a telescope with an aperture of at least 15 centimeters, and even then it appears only as a very faint star, near magnitude 10. The best windows for observing are the nights of June 26 to 28, when the body is closest and moves visibly against the background of fixed stars. For those without equipment, several observatories have announced live online broadcasts of the flyby.

It is worth separating two things that often get blurred in stories like this. The label potentially hazardous asteroid is a technical category assigned on the basis of size and orbital geometry, not on the basis of an actual risk at a given moment. For June 27 the calculations are clear and leave a wide safety margin. What remains open is not the question of impact, but how precisely the radar will manage to measure this object during the short window. Which interests you more, the flyby itself, or the fact that we still know less about a kilometer-wide rock than we would like?