Seven planets will align in the sky next month—here's what it signifies.

On February 28, stargazers will witness a rare celestial event as Mercury aligns with six other planets already visible in the night sky. Here's why this phenomenon is significant to scientists.

On clear nights this January and February, the night sky offers a captivating spectacle: six planets—Venus, Mars, Jupiter, Saturn, Uranus, and Neptune—are visible. In late February, Mercury will join them, creating a rare seven-planet alignment.

Such alignments aren't just stunning for stargazers; they also hold significance for understanding our Solar System. The eight major planets orbit the Sun in a flat plane, each at a unique speed. Mercury, the closest planet, completes an orbit in just 88 days, while Neptune, the farthest, takes 165 Earth years.

Occasionally, the varying orbital speeds cause multiple planets to align on one side of the Sun. From Earth, this alignment appears as planets arcing across the sky along the ecliptic, the Sun's apparent path. Bright planets like Mercury, Venus, Mars, Jupiter, and Saturn are visible to the naked eye, while Uranus and Neptune require binoculars or a telescope.

In January and February, a “planetary parade” is taking place, with all the planets (except Mercury) visible in an arc across the sky. On February 28, weather permitting, all seven planets will align in the night sky—a rare treat for observers.

"There’s something magical about seeing the planets with your own eyes," says Jenifer Millard, an astronomer at Fifth Star Labs in the UK. "These photons have traveled millions or billions of miles to reach your retinas."

But do planetary alignments have any tangible effects on Earth or provide new insights into our Solar System? According to Millard, these alignments are mere coincidences in the planets’ orbits. While some theories suggest planetary alignments might influence Earth, such claims lack robust scientific evidence.

In 2019, researchers proposed that alignments could affect solar activity. Physicist Frank Stefani suggested that the combined tidal forces of Venus, Earth, and Jupiter might create small rotations inside the Sun, known as Rossby waves, potentially influencing the Sun’s 11-year activity cycle. However, not all scientists agree with this theory, noting that solar activity is likely driven by internal solar processes.

Beyond potential solar effects, planetary alignments have practical applications in space exploration. For example, such alignments have been used to reduce spacecraft travel times. In 1966, NASA scientist Gary Flandro identified an alignment of Jupiter, Saturn, Uranus, and Neptune that allowed the Voyager missions to explore all four planets within 12 years—a feat that would otherwise have taken three decades.

Planetary alignments also play a crucial role in exoplanet research. Astronomers use the transit method to study distant worlds, measuring the dimming of a star’s light when a planet passes in front of it. This method has revealed planetary atmospheres and compositions, enabling discoveries like the seven Earth-sized planets of the TRAPPIST-1 system.

On a grander scale, galaxy alignments help us study the distant universe through gravitational lensing. When a galaxy or cluster magnifies light from a more distant object, telescopes like the James Webb Space Telescope can observe early galaxies and stars from the Universe's first billion years.

Even extraterrestrial life research benefits from alignments. In 2024, Nick Tusay of Pennsylvania State University studied potential interplanetary communications in the TRAPPIST-1 system during planetary alignments. While the search yielded no results, it highlights the potential of alignments as tools for exploring alien civilizations.

As we marvel at the planetary parade this month, it’s worth imagining other civilizations watching similar alignments from their vantage points, perhaps conducting their own investigations into the mysteries of the cosmos.