Ceres grabbed special attention of earthlings last year when NASA’s Dawn spacecraft beamed back images showing its strange, bright spots. These planetoid freckles gave rise to debate in scientific community while astronomers and general public started predicted what these weird things are.

Now, a study has found that the mysterious dots on the largest object in the asteroid belt are changing. It supports the idea that light coming from the sun is turning ice into vapor in the region where these dots are located. The new observations are based on data collected from earth-bound telescopes.

The study also stated that the rate of Ceres’ ice changing into vapor may not be regular and doesn’t match up with the dwarf planet’s day-night cycle. It also cleared that a final report on the findings can be made only when the Dawn probe completes its mission as Ceres is too far to be studied effectively with earth-based telescopes.

NASA’s Hubble Space Telescope has been studying Ceres that lies in the belt between the orbits of Mars and Jupiter before Dawn probe reached there is 2015. The dwarf planet is too distant that even the Hubble cannot study it the Dawn does.

The study cannot be considered as final verdict as it is using a ground-based telescope and following a basic principle of physics, called Doppler shift. The new observations are based on data collected from the HARPS instrument at the European Southern Observatory's (ESO) La Silla Observatory in Chile. The researchers claimed they have accurately measured Doppler shifts.

“We did find the expected changes to the spectrum from the rotation of Ceres, but with considerable other variations from night to night”, said Antonino Lanza, an astronomer and co-author of the study.