Complete the passage: pick from possible candidates.

For the the last few decades Nasa has spent billions of dollars on a variety of missions to Mars to find out if the planet might once have been habitable. But has a YouTube blogger found evidence for past life on Mars in the form of a human face-like rock hidden in an old Nasa photo? The answer, of course, is an emphatic 'no', but that hasn't stopped the UFO enthusiast from suggesting that the rock may be a sign the planet was once inhabited. Scroll down for video Scott Waring claims he has found signs of life in an old Nasa photo (Mr Waring has highlighted the 'facial' features to the right). The image comes from the Washington-based agency's first rover on Mars, called Sojourner, which landed on Mars on 4 July 1997. In the image the rock seems to have a human-like appearance

The image was taken by Nasa's

OPTIONS:
- Jesus on 22 July 1997.
- Mars on 22 July 1997.
- Nasa on 22 July 1997.
- Scott Waring on 22 July 1997.
- Sojourner on 22 July 1997.
- UFO on 22 July 1997.
- Waring on 22 July 1997.
- Washington on 22 July 1997.
- YouTube on 22 July 1997.


Sojourner on 22 July 1997.