During hot summer evenings, sleeping early was often challenging for children. A small stool would be moved outside the house to make someone relax from the heat.

Surrounded by the sounds of frogs and insects, evenings are spent gazing at the starry sky, occasionally catching a glimpse of the Milky Way, which is remarkably beautiful but not entirely understood in those early years.

As time passed, the frequency of witnessing the dazzling Milky Way decreased.

Questions arose about the change — was it due to Earth's orientation or simply a shift in observation?

Understanding this involves delving into celestial mechanics.

The cosmos is in constant motion. Earth's rotation completes a full cycle every 24 hours. From our vantage point on this spinning planet, our view of the sky naturally alters.

Additionally, Earth orbits the sun, marking a year-long journey that modifies our perspective of the stars.

However, Earth is dynamic in the grand scheme of the cosmos. We exist within the Milky Way, a colossal galaxy spanning 200,000 light-years in diameter.

Our solar system resides on one of its spiral arms, about 26,000 light-years from the galaxy's center. Hurtling through space at a speed of approximately 250 kilometers per second, it takes around 250 million years to complete a single orbit around the Milky Way.

What we perceive as the Milky Way is essentially a collection of stars toward the galaxy's center. Its orientation in the sky varies across the seasons—spring, summer, fall, and winter. But why has it become less visible recently, with fewer stars dotting the night sky?

Two significant factors contribute to this shift: light pollution and atmospheric pollution. Advancements in technology and urban living have illuminated and prolonged nights, making it increasingly challenging to catch sight of the Milky Way.

Photography enthusiasts seek remote locales to capture the pristine beauty of the starry sky, recognizing the profound impact of reduced light and air pollution.

Yet, the Earth is enveloped in an atmosphere that absorbs and weakens light, posing challenges for astronomers and stargazers.

In remote areas with clear skies and minimal light pollution, the Milky Way can be viewed all through the year. Its appearance changes with the seasons, with winter usually offering the most spectacular views.

The reason lies in our position within the Orion Arm of the Milky Way during winter, facing towards its edge where stars densely cluster, illuminating the night sky.

Conversely, in spring and summer, our orientation changes, resulting in a fainter view due to fewer visible stars.

On Earth, about 6,000 stars are visible to the human eye. These stars vary in proximity, ranging from a dozen light-years to almost a thousand light-years away.

The brightness of a star depends on its nuclear fusion, where larger stars with more mass exhibit more luminosity due to their stronger gravitational collapse effect and higher efficiency of nuclear fusion.

Humanity's enduring fascination with the stars persists, even when the night sky appears less adorned. The ultimate goal remains the exploration of space, venturing beyond Earth, the solar system, and even the Milky Way—a lofty ambition.