Natural Phenomenon:

* Starlink Satellites: The most likely explanation is a string of Starlink satellites. SpaceX's Starlink project involves launching thousands of satellites to provide internet access globally. They often appear as a line of bright lights moving across the sky.

* Meteors: While less likely, a meteor shower could produce multiple streaks of light.

* Aircraft: A line of aircraft flying in formation, particularly at night, could appear as a series of lights.

Unnatural Phenomenon:

* UFOs: While this is the most intriguing possibility, it's highly unlikely. There's no credible evidence to support the existence of extraterrestrial craft visiting Earth.

Important Considerations:

* Location and Time: Where and when you observed the lights are crucial to understanding the phenomenon.

* Speed and Movement: Did the lights move quickly, slowly, or remain stationary? Were they in a straight line, or did they change direction?

* Brightness and Color: How bright were the lights? Did they have a distinct color?

How to Find Out More:

* Check online resources: Websites like "Find Starlink" or "Heavens Above" can help track satellite movement.

* Join astronomy forums: Discuss your observations with other skywatchers.

* Contact local astronomers: They might be able to offer expert advice based on your specific location and observations.

It's important to note that without more information about your specific observations, it's impossible to definitively determine what you saw. However, Starlink satellites are the most probable explanation for seeing a line of lights in the sky.