Early risers have had an astronomical treat this month as Venus, Mars, Jupiter, and Saturn have lined up across the sky. The highlight of their dance will come this weekend when the two brightest planets will pass each other so close in the sky a casual observer may think they’re one object.
Venus and Jupiter are the brightest objects in the sky after the Sun and Moon – or were until the International Space Station’s (ISS) construction – so their appearance near each other is always quite a sight. This year, however, they will appear particularly close, a separation of just 0.2 degrees, and you don't need any special equipment to view it, just look up.
"They will appear to be so close that they'll look like one object, or appear as if they are kissing. Similar to what Jupiter and Saturn did at the end of 2020,” said Dr Brad Tucker of the Australian National University. Though you can see this celestial kissing with the naked eye, "If you have a telescope, a pair of binoculars or a decent camera, then you'll get an even better view."
What is more Mars and Saturn will be in attendance to add some extra incentive to get out of bed and view this cosmic sight. "Although Venus and Jupiter get close to one another every few years, this time there is also Mars and Saturn in the mix which is pretty rare, watching from afar like the creepy neighbour next door," Tucker added.
The exact closest conjunction will occur between 7:00 and 8:00 pm UTC on April 30. At that time the pair will be below the horizon from much of the world, but visible over eastern Asia and Australia, where it will be early Sunday morning. American and European readers needn’t fear, however, as this isn’t one of those blink-and-you’ll-miss-it astronomical events. From the UK, they’ll still be less than the width of the full Moon apart when they rise a few hours later. Parts of South America will have the added spectacle of a partial solar eclipse on Saturday.
Alternatively, you can experience the event via your computer and watch the live stream with the Virtual Telescope.
The best time to see the pair will be one to two hours before sunrise, whatever that is in your local time. They will be low in the sky, so a good view east is essential. Mars should be easy to spot some 15 degrees above them, and Saturn about the same distance higher still.
Jupiter’s brightness is fairly constant, based in large part on its size. Venus changes much more, since its distance from the Earth varies by a factor of three. Although Venus is not currently at its peak brightness, at -4.1 magnitudes it's somewhat above average, making the event even more spectacular.
Although never closer than 640 million kilometers apart in reality, Venus and Jupiter approach each other in the sky from our perspective up to three times a year. Many of these conjunctions, however, occur when the Sun is also aligned, making the event difficult or impossible, to see. Moreover, because the planets’ orbits are not exactly in a plane, on some passages Jupiter passes several degrees north or south of Venus – a gap of less than a degree is rare, let alone a mere 14 arcminutes.
Venus at its brightest can be so dazzling many people refuse to believe it’s natural, so close conjunctions of the two can spark UFO reports, or indeed a whole religion by some accounts. With this one only visible when most people are asleep, that’s not so likely this time.