Here are some common sources of light pollution:

• Streetlights – Outdoor lighting used to illuminate streets, highways, and public areas can contribute significantly to light pollution if not properly designed and shielded.

• Commercial and residential lighting – Bright lights from businesses, homes, parking lots, and other buildings that are left on at night can create unwanted glare and sky glow.

• Vehicle headlights – The collective light emitted from cars, trucks, and other vehicles on roads at night adds to light pollution.

• Advertising and signage – Illuminated billboards, digital signs, and other bright advertisements can pollute the night sky.

• Sports stadiums and facilities – Floodlights used to illuminate large outdoor sports complexes and venues can scatter light into the atmosphere.

• Industrial facilities – Manufacturing plants, warehouses, and other industrial sites often have bright outdoor security and safety lighting that can contribute to light pollution.

• Improper lighting design – Poorly designed or improperly installed lighting fixtures that allow light to shine upwards or sideways rather than down towards the ground can exacerbate light pollution.

The key factors that contribute to light pollution are excessive, misdirected, or poorly shielded artificial outdoor lighting. Addressing these sources through better lighting practices can help reduce the impacts of light pollution.