hubble_deep_filed doc string changes.

skimage/data/__init__.py

@@ -206,7 +206,7 @@ def coffee():
 def hubble_deep_field():
     """Hubble eXtreme Deep Field
 
-    This photograph contains the Hubble Telescopes farthest ever view of
+    This photograph contains the Hubble Telescope's farthest ever view of
     the universe. Originally intended to be used as an example of blob
     detection.
 
@@ -216,8 +216,7 @@ def hubble_deep_field():
     `HubbleSite
     <http://hubblesite.org/newscenter/archive/releases/2012/37/image/a/>`__.
 
-    The image was captured by NASA and may be freely used in the public domain
-    according to NASA's contract (NAS5-26555).
+    The image was captured by NASA and `may be freely used in the public domain <http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html>`_.
 
     """
     return load("hubble_deep_field.jpg")