It seems we have a major mystery facing us.

Thus far it is the major mystery, how he knew that the skeleton existed before the human race.

System Agents, violent and bizarre etherspace beings, are a major mystery.

Our interstellar visitor, meantime, even though it's no longer headed toward us, is still a major mystery.

What was about to happen would constitute one of the major mysteries of the animal world.

Half the time Percy's remarks were a major mystery.

One major mystery is why so many drinking women frequently have apparently normal babies.

One of the major mysteries remains how many Iraqi soldiers and civilians died.

Even today, the giant satellites of what was once Jupiter present us with major mysteries.

This book collects together what I consider to be some of the major unsolved mysteries of science.