Astronauts working on the International Space Station spot something unexpected: a flying object under the space station. But... was it all a mistake?

Moments after Apollo 12 launched from the Kennedy Space Center in November 1969, lighting struck the spacecraft...and then the craft was struck a second time. Things only got stranger once the crew was in space.

After the Apollo 16 astronauts return to Earth, photos taken in space appear to show an unidentified flying object floating near their craft. It takes decades for experts to determine what was hovering near the American astronauts.

Were "moon pigeons" spotted on Apollo 10 mission a warning for humans to stay away? Some people think so. This is the moon mission mystery you may not know about.

It looked like a massive spacecraft launching from the sun. What was the mysterious dark object?

Space Shuttle Atlantis commander sees something strange outside the space shuttle and reports his sighting to mission control. What did he see?

A space shuttle's camera captured several white blinking dots on film near planet Earth. What are these objects and why were they blinking?

Countless mysterious objects have been caught by NASA's cameras. Many astronauts have even reported seeing unidentified flying objects. Has NASA recorded the first traces of extraterrestrial life?

The U.S. Air Force created the Condon Report in 1968 to address supposed UFO sightings. The report stated that "further extensive study of UFO's probably cannot be justified" and is seen by some as an attempted government cover up.

James McDivitt, a NASA astronaut and engineer in the 1960's, reported he saw and filmed a strange object in space. Is there a logical explanation or was there really something out there?

Residents of Utah see a strange fireball in the sky officially explained as a meteor – though it leaves no trace of landing. Is it evidence of a secret project - a space weapon named “Thor?” What does it do?

The Lunar Reconnaissance Orbiter captures images of footprints left by the Apollo 17 crew forty years earlier. It also captures another feature that looks just like footprints but on a huge scale and scientists look for explanations. Could something have

On a routine space walk, Astronaut Luca Parmitano starts to feel water building up in his helmet. Mission Control aborts the walk but Parmitano struggles to get back to the ISS as the water still rises.

In 2003, astronomers spot a new dark spot on Jupiter. Could it be another raging storm? A trail left from an asteroid strike? Or something we caused?

Russians analyze soil from the moon’s Sea of Crises, and realize something has disturbed the surface. Experts agree Nazi technology was advanced enough; could they have reached the moon first?

After spotting a mysterious star with two rings around it, scientists struggle to explain the anomaly. Could it be a "Ringworld" created by a highly superior race as suggested in a sci-fi novel?