A large near-Earth asteroid will pass within 2.6 million kilometres of the planet on Saturday, its closest approach in more than four centuries. The object, designated 1997 NC1, measures between 750 metres and 1.65 kilometres across and will reach its minimum distance at 11:14 UTC, roughly 6.6 times the Earth–Moon separation. The European Space Agency (ESA) and NASA confirm the trajectory poses no impact risk, and the asteroid will not return to a comparable distance until 2133.

The flyby offers a brief observational window for amateur astronomers. With binoculars or small telescopes, the asteroid will appear as a faint point of light moving slowly against the background stars near the constellations Ophiuchus and Serpens Cauda. Visibility is favoured in the northern hemisphere during the approach, shifting to southern skies after closest passage. The object’s brightness, around magnitude 10, makes it invisible to the naked eye but detectable with modest equipment under dark skies.

The event unfolds amid broader planetary-defence monitoring. A separate analysis by the Pluto Project, cited by NASA, forecasts that a spent Falcon 9 upper stage from a January 2025 launch will strike the Moon near the Einstein crater on 5 August 2026, an impact that may be observable from Earth and is being treated as a rare chance to study lunar surface dynamics. Meanwhile, the asteroid 2024 YR4, estimated at 40–90 metres in diameter, has triggered international notification protocols after its impact probability for 22 December 2032 briefly exceeded 1%. That probability has since declined as orbital data improved, and NASA’s Sentry system continues to refine the trajectory. Scientists note that an object of that size would likely produce an airburst rather than a ground impact, with damage potential dependent on composition and location.

Agencies in Europe and North America characterise the 1997 NC1 flyby as a recurring scientific opportunity. “A close flyby of an object this size happens only every few years,” said Juan Luis Cano of ESA’s Planetary Defence Office. The last comparable event was the 2022 passage of 1994 PC1. Observers seeking to locate the asteroid can use planetarium applications by searching the designation 1997 NC1; the object will remain visible for several nights, fading gradually as it recedes.