As NASA's Dawn spacecraft gets closer to Ceres, the space agency noted, the dwarf planet's strange bright spot is not going away.

According to BBC News, Dawn is about to start orbiting Ceres to become the first spacecraft to do so with a dwarf planet. But before Dawn's primary mission gets underway, it is beaming back clearer and clearer images of Ceres.

When Dawn was still on its way to Ceres, it took low-resolution images of Ceres that showed two mysterious bright spots that have not dimmed or vanished as the spacecraft got closer. Dawn mission managers do not have a concrete explanation for them at this point.

"It may be a surface composition situation in that the different material at that particular spot conducts heat differently than in the other area," Chris Russell, Dawn's principal investigator, told BBC News. "So, the first thing you go to when you see different temperatures is the different thermal conductivity of the surface material."

Dawn recently took photos of Ceres with only its North Pole in sufficient light, but has taken more when the sun was catching more the dwarf planet's surface. In the past week, NASA also released the first ever color image of Ceres.