Sky & Telescope

The Vera Rubin Observatory's telescope has begun work in the search for dark matter, the invisible substance thought to make up most of the universe's mass. By surveying the sky in unprecedented detail, it aims to detect subtle gravitational effects that could reveal dark matter's pull. Astronomers hope the mission will transform cosmology.

Stargazers are looking to the October night sky, with attention on the month's meteor shower alongside other astronomical events. Sky & Telescope is highlighting Saturn at opposition the night of October 3–4, when the planet's rings are at their brightest, adding to a busy period for skywatchers this October.

An amateur astronomer pointed a large telescope at NGC 456, a faint nebula in the Small Magellanic Cloud, during last weekend's full Moon. He called the attempt ill-advised, because even narrowband filters struggle when the Moon brightens the sky background. The resulting images are being shared with other space enthusiasts, who appreciate the difficulty of deep-sky imaging in poor lunar conditions.

Periodic comet 161P/Hartley-IRAS is being tracked as it approaches the inner solar system. Latest figures put its barycentric speed at 32.91 km/s, with perihelion due in about 56 days, in late November 2026. The comet currently sits at magnitude 14.33, observable from both hemispheres with a small telescope under dark skies, in the constellation Aquarius. Amateur astronomers are sharing observations and brightness updates as the comet slowly brightens on its way to perihelion.

Comet 161P/Hartley-IRAS is being monitored as it moves toward the inner solar system. Its barycentric speed has ticked up to 32.82 km/s, with perihelion about 57 days away. Current brightness sits around magnitude 14.2, meaning it remains a small-telescope target from dark-sky sites, currently in the constellation Aquarius and visible from both hemispheres. Amateur astronomers are following its gradual brightening as the approach continues.

Astronomers use powerful lasers to create artificial 'guide stars' in the night sky, helping telescopes correct for the blurring caused by Earth's atmosphere. By shining a laser into the upper atmosphere, observatories can measure atmospheric distortion in real time and sharpen images of distant stars and galaxies. The technique, used at major observatories worldwide, has drawn renewed attention as part of wider coverage of modern telescope technology.