Scorpius, the Scorpion, is a recognizable constellation known for its distinctive hook or J-shape. Its most famous feature is the star Antares, a massive red supergiant that pulses with a fiery hue, earning it the ancient Greek name meaning “rival of Mars.” While this prominent stellar figure is a summer favorite, it vanishes completely from view during the winter months, particularly in January. This seasonal disappearance is a direct consequence of Earth’s constant journey through space.
Earth’s Orbital Dance and Seasonal Stars
The visibility of constellations is determined by Earth’s 365-day orbit around the Sun. The stars are so distant that they form a fixed backdrop, known as the celestial sphere. As Earth travels along its path, our nighttime view constantly shifts to face a different sector of this stellar background.
During the summer, Earth is positioned so that at night, we face outward toward the “summer constellations.” Six months later, in the winter, Earth has moved to the opposite side of the Sun. Our nighttime view is now directed at a different set of stars, the “winter constellations,” such as Orion. The summer stars are still present, but they are now positioned in the same general direction as the Sun.
Why Scorpius is Hidden by Daylight
Scorpius is one of the constellations of the Zodiac, a belt of twelve constellations that lie along the Sun’s apparent annual path across the sky. This path is called the Ecliptic, which is the plane of Earth’s orbit projected onto the celestial sphere. Because Scorpius is situated on the Ecliptic, the Sun passes through or near it at a specific time each year.
From Earth’s perspective, the Sun appears to transit through Scorpius in late November, placing the constellation directly behind the Sun. By January, Earth has continued its orbit, but Scorpius remains in the same general quadrant of the sky as the Sun. When the Sun is above the horizon, Scorpius is also above the horizon.
This alignment causes the constellation to rise and set almost simultaneously with the Sun. The light from Scorpius’s stars is entirely overwhelmed by the immense brightness of the Sun. Although the constellation is technically present in the daytime sky, it is impossible to see its stars. Observers must wait until Earth moves further along its orbit, allowing the Sun to appear to move out of the Scorpius region and making the constellation visible in the dark night hours once again.
Finding Scorpius The Rest of the Year
For most Northern Hemisphere observers, the optimal time to view Scorpius is during the summer months, from late May through early September. The constellation is best seen when it reaches its highest point in the sky, which occurs around 9:00 p.m. in mid-July. It is found low above the southern horizon, particularly for those at mid-to-high northern latitudes.
The constellation is easy to identify due to its distinctive shape, which resembles a scorpion or a celestial fishhook. Begin by spotting the bright, reddish star Antares, which marks the heart. From there, trace the line of stars that curves downward and back up. This line culminates in the distinct pair of stars, Shaula and Lesath, which form the stinger asterism at the end of the tail.