So an astronaut on the flight of Gemini Four, Ed White,took that first frightening step into the unknown.

VOA: special.2009.07.01

And the strong man, still holding the small child, drifted away on the shadowy river that flows forever to the unknown sea.

VOA: special.2009.06.06

The exact cause is unknown. But in a recent study, an experimental drug showed signs of halting the disorder in laboratory mice.

VOA: special.2010.05.19

Ed White would leave the protection of the spacecraft and move out into the unknown emptiness of space.

VOA: special.2009.06.24

Not only did the always interesting Lady Gaga show up inside a large egg-like structure, but unknown artists also won top prizes.

VOA: special.2011.02.18

It has some grammar structure and words from several other languages that are unknown or that have disappeared.

VOA: special.2009.12.02

The expression probably began because the jungle is filled with wild animals and unknown dangers that threaten people.

VOA: special.2010.05.16

Then on April thirtieth, two thousand seven,a huge fire of unknown cause almost completely destroyed South Hall.

VOA: special.2009.08.21

Their ancient languages contain a great deal of information about environmental systems and species of plants and animals that are unknown to scientists.

VOA: special.2009.12.02

If hoarseness continues or the cause is unknown, doctors should perform an examination called a laryngoscopy.

VOA: special.2009.09.02

And they feel that unknown dangers in the business world threaten the survival of their business.

VOA: special.2010.05.16

They gave a name to this mysterious continent: Terra Australis Incognita, or the "Unknown Southern Land."

VOA: special.2009.06.03

She died in eighteen eighty-six, at the age of fifty-five, completely unknown to the world.

VOA: special.2010.07.18

The song is about driving by yourself at night into the unknown and feeling free.

VOA: special.2010.05.28