The European Space Agency (ESA) revealed that asteroid (152637) 1997 NC1 will approach Earth at its nearest point in 400 years this weekend. While there is no risk of it hitting Earth, it can be viewed through commercial telescopes and astronomical binoculars globally.

On Saturday, June 27, the asteroid will come within 2.56 million kilometers (1.59 million miles) of Earth—6.6 times the distance between Earth and the moon. Its size is estimated to range from 700 meters to 1.6 kilometers in diameter. It will not approach this closely again until 2133, according to the ESA.

The closest encounter will occur on June 27 at 11:14 UTC. Viewing times depend on the region:

– Europe: Night of June 26-27, particularly early morning
– Mexico: Night of June 26-27
– US: Night of June 26-27, prime before sunrise
– Argentina and Southern Cone: Night of June 27-28, as it moves south

The asteroid will be observable for several days afterward, although its luminosity will decrease and its position will shift. Chances to view it extend for a few days following the approach but become less favorable in the northern hemisphere.

Even though it is larger than a skyscraper, the asteroid will not be visible without assistance. It will exhibit a brightness comparable to Neptune, about magnitude 10, according to the ESA.

Through a telescope or binoculars, the asteroid will show as a small light point moving at 40 arc seconds per minute against the backdrop of stars—easy to detect movement over a few minutes.

Your eyesight alone will not suffice, as the asteroid’s dimness exceeds naked-eye visibility by 40 times, and the brightness of the moon reduces sky contrast.

As it approaches closest, the asteroid will be positioned in the constellations Ophiuchus and Serpens Cauda, below the star Vega. Astronomy applications such as Stellarium and SkySafari can assist in finding it by searching for “1997 NC1.”

Astronomers recommend using a commercial telescope with at least a 100mm aperture, though models in the 150 to 200mm range offer improved viewing. It is also visible with 15 x 70 or 20 x 80 binoculars mounted on a tripod, away from light pollution.

For those who cannot observe in person, the Virtual Telescope Project will broadcast the event on June 26 and 27.

Originally published on WIRED en Español, translated from Spanish.