At 4.06pm on Wednesday, the sun’s centre crosses the celestial equator heading north. This is the exact instant of the southern hemisphere autumn equinox, which marks the day when the length of day and night is equal, wherever you live on Earth. It is well worth watching for the southern lights after dark over the next few weeks. That’s because auroras are more common at this time of year, due to a lining up of both the sun and Earth’s magnetic fields, which astronomers call the Russell-McPherron effect. Fingers crossed for some auroral action.
On Friday morning, the planets will be separated by less than the full moon’s diameter, which should be an absolutely splendid sight. Venus will be, by far, the brighter of the two planets. This week, Venus is exactly one hundred times brighter than its planetary sibling. Venus’s blue-white colour will contrast nicely with Saturn’s yellow hue.
The best time to view the close approach is about an hour before sunrise, when both planets will be roughly seven degrees above the eastern horizon.
