Ground-based measurements also provide data that can be used to investigate changes in Titan… At this temperature, ... 2004, and took the highest-resolution images ever of Titan's surface, at only 1,200 kilometers (750 mi), discerning patches of light and dark that would be invisible to the human eye. Although Titan's lower atmosphere is relatively inert to seasonal temperature variations, sunlight in the visible and near-infrared reaches the surface and the resultant heating drives temperature gradients at the base of the atmosphere. Titan’s nitrogen atmosphere is so dense that a human wouldn’t need a pressure suit to walk around on the surface. The surface temperature on Titan is a frigid –290 degrees Fahrenheit (–179 degrees Celsius). Astronomers on Earth had previously studied Titan’s temperature, and calculated its mass, and Pioneer 11 confirmed those characteristics. Of the flux incident at the top of Titan's atmosphere, only 10% reaches the surface (compared to 57% for Earth) [see, e.g., Griffith et al., 2012a; Read et al., 2015]. Titan's surface temperature is about 94 K (−179.2 °C). This information and ground-based instrumental capabilities can predict observations ultimately made by close flyby spacecraft. Titan receives about 1% of the solar flux that reaches Earth. 2011). “The ironic thing on Titan is that although it’s much colder than Earth, it actually acts like a super-hot Earth rather than a snowball Earth, because at Titan temperatures, methane is more volatile than water vapor is at Earth temperatures,” Pierrehumbert said. Surface features, particularly at the edges of seas at high southern latitudes, have changed in response to temperature changes (Hayes et al. Titan is therefore much colder than Earth, with an effective temperature of ∼82 K. He or she would, however, need an oxygen mask and protection against the cold—temperatures at Titan’s surface are around minus 290 degrees Fahrenheit (minus 179 Celsius). Because of Titan’s extended and opaque atmosphere, scientists at the time thought (incorrectly, it turns out) that Titan might be the largest moon in the solar system. Ten years ago, the Huygens probe took these images of Saturn's moon Titan at four different altitudes as it descended to the surface. High spectral resolution studies of Titan’s atmosphere provide information on dynamics temperature, and composition prior to and during the Cassini Huygens mission.