Dr. Porco further believes that Enceladus's orbit could have been much more eccentric in the past. The greater the eccentricity, the greater the tidal squeezing, and the resulting structural variations produce heat. In this case, the heat would have been saved inside the icy moon, melting some of the ice to replenish the liquid water sea. Dr. Porco continued to explain that "(T)he tidal flexing occurring now is not enough to account for all the heat presently coming out of Enceladus. One way out of this dilemma is to assume that some of the heat observed today was generated and stored internally in the past... (N)ow that the orbit's eccentricity has lessened, the heat emanating from the interior is a combination of heat produced today and in the past."
Makemake is a classical KBO. This means that its orbit is situated far enough away from Neptune to remain in a stable stage over the entire age of our more than 4 billion year old Solar System. Classical KBOs have perihelia that carry them far from the Sun, and they are also peacefully free from Neptune's perturbing influence. Such objects show relatively low eccentricities and circle our Star in a way that is similar to that of the major planets. However, Makemake is a member of what is referred to as a "dynamically hot" class of classical KBOs, which instead display a high inclination when compared to other classical KBOs.
The scientists also ruled out the possibility that the mysterious features actually exist on Titan's surface in the form of frozen methane rain or icy lava erupted from cryovolcanoes. Such surface features would show a different chemical signature and would be visible for much longer periods of time than the bright features observed in this study. The bright features were visible from time spans of only 11 hours to five weeks.