Some witnesses managed to grab a photo of the light, which prompted all sorts of theories on social media, with either UFOs or NASA looking for diesel on Mars seeming among the favourites.
However, it may not have been alien in origin, but it certainly was a spacecraft.
It was in fact NASA's most powerful Earth-imaging satellite leaving the earth's atmosphere last night on an Atlas rocket.
The Landsat-9, dubbed the world's most important satellite, launched to orbit from Vandenberg Space Force BaseCalifornia on Monday evening.
It is the continuation of a series of Earth-observing spacecraft stretching back almost 50 years.
Once all onboard systems are commissioned, it will start acquiring images that can be compared carefully with those of the still-flying Landsat-8, which was launched in 2013.