Some scientists have conjectured that the distant planet could sustain life.
“[Kim Kardashian's] changing wardrobe, everyone conjectured, must be Kanye's influence—he's a bona fide designer these days with affinity for top models like Chanel Iman and Anja Rubik and top labels like Givenchy, Celine and Hermes.” —From an article in the Style section of The Huffington Post, August 24, 2012
When the noun “conjecture” entered English in the 14th century, it referred to the act of interpreting signs or omens (as for making prognostications). That sense is now obsolete, but by the 16th century both the noun and verb “conjecture” had acquired the meanings of speculation and inference that we use today. “Conjecture” derived via Middle English and Middle French from the Latin verb “conicere” (“to throw together”), a combination of “com-” (“together”) and “jacere” (“to throw”).
From Merriam-Webster Online at www.Merriam-Webster.com.