Her death was later determined to be by blunt force trauma to the head with an unknown heavy object.

Therefore, the unknown object was, when looking back to the right of their track.

The unknown object is still on a course for the sun.

"We do have the right to find out about this unknown object and what it may mean to us."

Around her waist was a shining belt from which hung unknown dark objects.

If objects like this are visible in the image, it is possible to determine the size of the unknown object by simply comparing the two.

Certain facts might be immediately presumed with reference to the unknown object.

A good classification system must have the ability to differentiate between known and unknown objects during testing.

She had been struck on the head several times with an unknown object, they said.

She liked scraping the dirt away from unknown objects, trying to guess what they would be.