Comet C/2024 J3 (ATLAS) makes its closest approach to the Earth.

Comet C/2024 J3 (ATLAS) will make its closest approach to the Earth on Sunday 26 July 2026, when it will reach a distance of 3.45 AU (i.e 3.45 times the average distance between the Earth and the Sun), or 515 426 942 km from us. At this time it will be in the constellation of Lyra, which is above the horizon permanently in much of the Northern Hemisphere at this time of year, but invisible from most of the Southern Hemisphere. The comet will have an apparent optical magnitude of 13.9, meaning it will be hard to spot without a fairly good telescope to observe it. Furthermore, the closest approach comes three days before the Full Moon on Wednesday 29 July, so there is likely to be considerable light interference.

The approximate positions and orbits of the C/2024 J3 (ATLAS), the Earth, and selected planets of the Solar System on 26 July 2026. JPL Small Body Database.

Comet C/2024 J3 (ATLAS) was discovered on 3 May 2024 by scientists at the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope in Río Hurtado, Chile. The name C/2024 J3 (ATLAS) implies that it is a Comet (C/), that it was the 3rd comet (3) discovered in the first half of May 2024 (period 2024 J), and that it was discovered by the ATLAS sky survey.

An image of C/2024 J3 (ATLAS) taken on 10 July 2026, when it was a Magnitude 18.7 object in the constellation of Cygnus, taken from Gahberg in Austria. Günter Kerschhuber.

Comet C/2024 J3 (ATLAS) is a Parabolic Comet, which is to say a comet that was disrupted from an orbit in the Oort Cloud, and is passing through the Inner Solar System on a parabolic orbit that will probably not bring it back again. This parabolic trajectory is tilted at an angle of 75.6° to the plain of the Solar System, and will bring it at its closest to 3.87 AU from the Sun, on 25 November this year. C/2024 J3 (ATLAS) is not expected to pass close to any planets.

See also...