The planet Venus is switching sides today – sides of the Sun. It’s crossing behind the Sun as seen from Earth, so it’s moving from the morning sky to the evening sky. But we won’t be able to see it for several weeks.

Venus is the second planet from the Sun, while Earth is third. So Venus crosses both behind the Sun and between Earth and the Sun. It switches between Morning Star and Evening Star appearances each time.

Each of these crossings happens every 584 days – about 19 and a half months. The planet spends about eight months in both the morning and evening sky, and disappears from view during the crossings.

When Venus passes between Earth and the Sun, it’s closest to us, so it moves across the sky quickly – it’s hidden in the Sun’s glare for only a few days.

When it’s behind the Sun, it’s farthest – about 160 million miles. Because of the relative motions of Earth and Venus, it moves across the sky quite slowly. So it remains hidden in the light for three months or so.

Depending on your location, Venus could emerge as the Evening Star as early as mid- to late February. It’ll be quite low in the twilight, so it won’t be easy to find. The planet will climb into better view in early March. Venus will reign over the evening sky until October, when it will vanish in the sunlight as it once again switches sides.

Tomorrow: slowing down the stellar birth rate.

Script by Damond Benningfield