What Is a Planetary Alignment and When Will the Planets Align Again
A planetary alignment occurs when multiple planets appear close together in the sky from Earth’s perspective, based on their orbital positions. The next major alignment involving several planets is expected in the mid-2020s to early 2030s, with exact dates depending on how many planets are included. NASA and JPL track these events using precise orbital mechanics and ephemeris data.
According to current JPL Horizons data, a loosely grouped alignment of Mercury, Venus, Mars, Jupiter, and Saturn can occur roughly every few decades, while tighter groupings are rarer. The last notable multi-planet alignment happened in June 2022, and the next similar event is projected around 2040. These predictions use the latest published orbital elements from NASA's Jet Propulsion Laboratory.
How Often Do the Planets Align and What Determines the Timing
Orbital Periods and Synodic Cycles
Each planet orbits the Sun at a different speed, so alignments depend on synodic periods, which are the time it takes for planets to return to the same relative position. For example, Jupiter takes about 11.86 years to orbit the Sun, while Saturn takes 29.46 years, making a Jupiter-Saturn conjunction roughly every 19.6 years. These cycles are calculated using high-precision data from NASA's Horizons system.
The frequency of alignments involving more planets decreases exponentially because their orbital periods must coincide closely. A five-planet alignment like the one visible in 2022 occurs on average once every few decades, while a six-planet alignment is much rarer. Current models from JPL and the Minor Planet Center provide the most accurate forecasts for these events.
Where and How to See the Next Planetary Alignment
Best Viewing Conditions and Tools
The next visible planetary alignment will depend on the planets' positions relative to the Sun and Earth, with some events best seen just before sunrise or after sunset. Sky observers can use tools like Stellarium or apps from Sky & Telescope to track real-time positions. For precise timing, NASA's SkyCal and JPL's Horizons tools provide updated coordinates and visibility windows.
Professional observatories and citizen science projects often publish alerts for major alignments, and some events coincide with meteor showers or conjunctions with the Moon. The next notable alignment window is expected in the early 2030s, with exact dates refined as orbital data is updated. For ongoing tracking, refer to NASA's official planetary ephemeris and Sky & Telescope's event calendar.