sentence1: The 2 1/2 -ton probe will plunge into the thick Jovian atmosphere today at 3:49 p.m. Eastern time, disintegrating moments later from the friction generated by its 108,000-mph free-fall.
sentence2: The 2 1/2-ton probe will plunge into the thick Jovian atmosphere today at 1:49 p.m. MDT, disintegrating moments later from the friction generated by its 108,000 mph free-fall.