of the Thunder Bolt

GREAT FIREBALL: A remarkable midnight fireball that "turned night into day" over parts of the western United States last night was not a Leonid. Infrasound measurements suggest a sporadic asteroid not associated with the Leonid debris stream. The space rock exploded in the atmosphere with an energy equivalent to 0.5 - 1 kilotons of TNT. Approximately 6 hours later, observers in Utah and Colorado witnessed a twisting iridescent-blue cloud in the dawn sky. Debris from the fireball should have dissipated by that time, but the cloud remains unexplained; we cannot yet rule out a connection to the fireball event. Stay tuned for further analysis.

Meteor the size of oven lights up the night sky, alarms Utahns

Meteor lit up night sky, caught on video

Great Fireball over Utah and surrounding area

Approximately 6 hours after the fireball, people in Utah and Colorado got another surprise. As the sun rose over those states, a twisting electric-blue cloud appeared in the dawn sky: "These curious clouds on the horizon caught my attention just before sunrise," says photographer Don Brown of Park City, Utah. "They were strangely bright relative to the rest of the sky."

The cloud strongly resembles artificial noctilucent clouds formed at high altitudes by rocket and shuttle launches. Yet there was no (officially reported) rocket launch at dawn on Nov. 18th. Could the cloud be associated with the fireball? The geographical coincidence is certainly striking. Debris from the fireball should have dissipated by sunrise, but the cloud remains unexplained and a connection to the fireball cannot yet be dismissed. Readers, if you have more information about this event,