When looking up at the night sky, people frequently notice a brilliant, non-twinkling point of light positioned remarkably close to the Moon. This common observation is a recurring astronomical event. The object is so prominent it often leads people to wonder if they are seeing a particularly bright star or something else entirely. The simple, scientific explanation for this phenomenon nearly always involves one of our solar system’s planetary neighbors.
The Most Likely Candidates: Bright Planets
The bright object seen near the Moon is typically not a star, but one of the solar system’s inner or outer planets. Venus and Jupiter are the most frequent and dazzling companions, though Mars and Saturn also make appearances. These planets appear so bright primarily because of their proximity to Earth compared to distant stars.
Venus is often the brightest object in the night sky after the Sun and Moon, aided by its dense, highly reflective cloud cover. Jupiter is also bright due to its sheer size, reflecting a significant amount of sunlight back toward Earth. Unlike stars, which generate their own light, planets only reflect the Sun’s light. Their relative closeness makes that reflected light appear intense, though their apparent brightness changes depending on their orbital position relative to Earth and the Sun.
Why Objects Appear Close to the Moon
The appearance of two celestial bodies being close together is a matter of perspective, caused by specific orbital alignment. All major planets, along with the Moon and the Sun, appear to travel along a narrow, imaginary path across our sky called the ecliptic. This path is a projection of Earth’s orbital plane around the Sun, as all the planets orbit the Sun in roughly the same flat disk.
Because their orbits are situated close to the ecliptic plane, the Moon and the planets constantly appear to chase each other along this predictable celestial highway. When the Moon and a planet appear to have the smallest separation as seen from Earth, the event is called a conjunction. Despite appearing side-by-side, the planet remains vast distances away, with the Moon merely passing in front of or behind it from our viewpoint.
How to Identify the Object You Are Seeing
The most straightforward way to distinguish a planet from a star is to observe whether the light twinkles. Stars are so distant that their light reaches Earth as a near-perfect point source, which atmospheric turbulence easily distorts, causing the familiar twinkling effect. Conversely, planets are much closer and appear as tiny disks rather than points of light. Therefore, their light is less susceptible to atmospheric scattering and shines with a steady glow.
Planets also tend to have distinct colors, which aids identification; for instance, Venus shines pale yellow, Jupiter is often golden-orange, and Mars has a noticeable reddish hue. For immediate and precise identification, modern astronomy applications are highly effective tools. These apps allow a user to point their phone at the sky, instantly overlaying a map that identifies all visible stars, planets, and constellations based on the user’s location and time.