Dozens of Americans have said they saw a fireball streak across the sky above southern Rocky Mountains over the weekend.
The American Meteor Society, a non-profit supporting the amateur astronomers' community, has received 28 reports about the sighting over Colorado, New Mexico, South Dakota and Wyoming on Sunday.
"The feeling of having witnessed this was incredible," one spotter mused.
Another said: "This event was SPECTACULAR for the two of us who witnessed."
Most skygazers who saw the fireball described it as having a light yellow, green, or white colour.
One woman's security camera captured the glowing greenish object beaming across the night sky.
Fireballs like this one are normally meteors that appear brighter than normal. Space rocks larger than one millimetre in diameter are capable of giving off a flash of light when they enter the Earth's upper atmosphere and heat up.
The International Meteor Organisation advises that the easiest method to determine whether a meteor was a fireball or not, is to estimate its brightness: "If the object you witnessed is brighter than any object in the sky except for the Sun and the Moon, then it is a fireball. Another important factor is the duration of a fireball. While larger than most all other meteors entering the atmosphere, they still are travelling at tremendous velocities."
"Like ordinary meteors, they will suffer disintegration and will slow down to the point where they no longer produce light. This usually takes only a few seconds. Rarely a very large fireball will last 5-10 seconds before it is extinguished. If your object lasts in excess of 10 seconds it is most likely a satellite or some sort of aircraft and not a fireball."