Are the planets as bright as we see them from here?

Certainly…

We all see the planets glowing like large light bulbs or giant garlands hanging from the ceiling of the world in the distant sky.

But are they really as bright and luminous as we see them down here on earth?

If the well-known proverb which says: all that glitters is not gold is true, here for our subject we will say that all that glitters is not light!

And that Unlike the stars which illuminate the spaces in the vast night sky, the planets are only gigantic mirrors which reflect the solar light from their surface towards our gaze on earth, thanks to their proximity to the Earth and which allows us to observe them in the night sky.

The planet Venus, which is often the most visible in the night sky, reflects 90% of the light it receives from the sun back into space and towards the earth.

And this is due to the composition of its atmospheric layer which operates like an extraordinary mirror, compared to our living room mirrors which only reflect 60% of the light received.

And at sunset when we observe these bright spots in the sky, it is likely that we are looking at planets rather than stars.

But to properly contemplate the skies and enjoy the beauty of the celestial vault while navigating with only one's eyes and to enjoy this human pleasure of all times, without any optical instrument, one must become aware of the ecological conditions of modern times and atmospheric conditions of recent decades.

We are of course still able to clearly see the Milky Way, although the night and the night sky continue to disappear more and more as scientists predict, due to light pollution from the abundant public lighting in our cities, and which deprives us of the quality of the sky.

Light pollution and its economic, ecological and astronomical effects are today a serious problem of which certain cities around the world have become aware and are beginning to combat this phenomenon by applying new solutions, such as the installation of street lights that are triggered by detection of motion or downward-facing street lights.

And this is how it is in the darkest areas that we can spot stars of great magnitude with the naked eye, and that we cannot see in the lit areas, because they are stars which shine the least. For example, we can see the star Sirius, which is almost always visible, but not the Orion Nebula which requires a much darker sky at night.

Light pollution refers to the excessive or misdirected artificial light produced by human activities, which disrupts the natural darkness of the night sky and negatively impacts the environment, wildlife, and human health. It is caused by various sources, including streetlights, outdoor advertising, commercial buildings, and residential properties.

One of the most visible effects of light pollution is the obscuring of the night sky, making it difficult to observe stars, planets, and other celestial objects. This not only diminishes the aesthetic beauty of the night but also interferes with astronomical research and observation. In areas heavily affected by light pollution, only a fraction of the stars visible to the naked eye can be seen, limiting opportunities for stargazing and astronomical education.

Moreover, light pollution disrupts natural ecosystems and wildlife behavior. Nocturnal animals rely on darkness for navigation, foraging, and reproduction. Excessive artificial light confuses their internal clocks and disrupts natural rhythms, leading to changes in behavior, migration patterns, and reproductive cycles. For example, sea turtles may become disoriented by coastal lighting, causing them to stray from their nesting sites or hatchlings to move inland instead of towards the ocean.

In addition to its ecological impacts, light pollution has adverse effects on human health. Exposure to artificial light at night can disrupt the body's circadian rhythm, leading to sleep disorders, fatigue, and increased risk of chronic diseases such as obesity, diabetes, and certain cancers. Furthermore, excessive nighttime lighting has been linked to increased levels of stress, anxiety, and depression in urban populations.

Efforts to mitigate light pollution include the implementation of outdoor lighting regulations and the use of energy-efficient lighting technologies. These measures aim to minimize light trespass, glare, and skyglow while ensuring adequate illumination for safety and security. Additionally, public awareness campaigns and community initiatives promote the importance of preserving natural darkness and reducing unnecessary nighttime lighting.

By addressing light pollution, we can protect the integrity of the night sky, safeguard biodiversity, and promote human health and well-being. It requires a concerted effort from individuals, communities, governments, and industries to prioritize sustainable lighting practices and minimize the impacts of artificial light on the environment and society.