yestersol adverb 1noun 1forms 1 adverb1 •On the sol (Martian day) before the present one.But yestersol he took Mother into the old middle-pressure greenhouse (the little one they built when they first arrived here) and got her involved in a long discussion. — 2001 noun1 •The sol (Martian day) before the present one."We'll basically be waking up in the Mars morning, which will be 47 minutes later each day, and uploading our commands from 'yestersol,'" he said. — 2003 formsyestersols
