Venus inferior conjunction, 23 March 2025

Venus has been an evening beacon in early 2025, but that’s about to change as the planet heads towards inferior conjunction on 23 March, the position in its orbit closest to Earth.

Thereafter, it will begin to emerge as a morning object in the sky.

In recent weeks, Venus has been approaching us, moving along part of its orbit closest to Earth.

Its apparent sunward crawl accelerates as it moves towards inferior conjunction.

Lined up with the Sun in the sky, at inferior conjunction Venus is also closest to Earth.

A diagram showing Venus's orbit and its positions at conjunction and greatest elongation. Credit: Pete Lawrence

Venus phases

Like the Moon, Venus shows phases and over recent weeks has appeared as a shrinking crescent through the eyepiece.

All the while, its apparent diameter has been expanding, reaching around 1 arcsecond across at inferior conjunction.

At this time, Venus will be at its slimmest phase.

Unlike the airless Moon, which essentially disappears when new, Venus’s atmosphere can illuminate all the way around to form what’s known as an atmospheric ring.

Unfortunately, this won’t be seen in March 2025, as this inferior conjunction takes Venus too wide of the Sun’s centre, at 8.4° separation.

Phases of Venus. Credit: Pete Lawrence

Observing Venus at inferior conjunction

With care and attention to safety, it is possible to locate and image Venus in this position, but it’s not safe to look at it through the eyepiece of a telescope.

This should only be attempted if you know what you’re doing and have experience with finding Venus close to the Sun.