This week, skywatchers around the globe are treated to a rare celestial event — a planetary parade where all seven planets are visible in the night sky at once. While these planetary parades occur periodically, a full seven-planet alignment is an uncommon spectacle. Enthusiasts are catching a glimpse of this extraordinary event from diverse locations, including Australia and the United States.
Dr. Greg Brown, an expert in planetary observation, describes a planetary parade as a time "when multiple planets are visible in the sky at the same time." This week, the dim planet Mercury joins the celestial ensemble, making seven planets visible. While Venus, Mars, and Jupiter can be easily seen with the naked eye, Uranus and Neptune require binoculars or telescopes due to their faintness.
“Venus, Jupiter and Mars, however, are all very easy to see with the unaided eye.” – Dr Greg Brown
In the United States, experts recommend venturing out about 30 minutes after sunset to witness the celestial show. Meanwhile, in Australia, stargazers are advised to look north after sunset. The alignment offers a unique opportunity for both amateur and seasoned astronomers to observe these distant worlds.
Dr. Brown notes that "Mercury, Neptune and Saturn are all very close to the horizon in the early evening" and may struggle to be seen in the twilight. Despite these challenges, those equipped with a telescope can identify the planets by looking for moon shapes.
“Mercury, Neptune and Saturn are all very close to the horizon in the early evening and, particularly in the case of Neptune and Saturn, will struggle to be seen in the twilight.” – Dr Greg Brown
“In addition, Uranus, like Neptune, is very faint, making it almost impossible to find without a pair of binoculars or a telescope.” – Dr Greg Brown
Interestingly, four planets were visible at the beginning of the year. However, it is Mercury's recent appearance that completes this week's line-up. According to NASA, alignments of four or five planets visible to the naked eye occur every few years. A similar parade last June only offered visibility of two planets without special equipment.
“Groups of three, four or even five planets being visible aren’t uncommon, regularly appearing throughout each year.” – Dr Greg Brown
The current parade will slowly disperse as spring progresses. The next opportunity to witness such a seven-planet spectacle will not occur until 2040. Dr. Shyam Balaji explains that these alignments happen because "the planets in our solar system orbit the Sun within roughly the same plane, known as the ecliptic plane."