Solomon Aran was the brother of Samus Aran. Mentioned only in Blood of the Chozo alongside Chief Engineer Avram Aran and Captain Thea Aran, he was said to be four years old, two years younger than the six-year old Samus, and was missing and presumed dead in the attack on the "human settlement". Since many of the elements of Samus' past have been changed since in the 2002 Metroid Manga, such as the naming of the parents as Chief Rodney and Virginia Aran (though the Blood of the Chozo characters are never explicitly stated to be her parents), as well as naming the "human settlement" K-2L, and finally Samus' age at the time being changed to three, Solomon may have been retconned and has not been mentioned since.
Blood of the ChozoEdit
"When Samus was just six years old, pirates attacked and destroyed the human settlement. Captain Thea Aran and Chief Engineer Avram Aran were both killed in the raid. Solomon Aran, Samus's four year old brother, was missing and presumed dead."