Ceres bright spots still a mystery despite new close-ups

12 May 2015

Dawn got its closest look yet at Ceres' bright spots

It’s the mystery that keeps on giving, and while the Ceres bright spots are now shown clearer than ever, NASA’s Dawn spacecraft still can’t tell what exactly they are.

The new images taken on 3 and 4 May by the spacecraft were taken from a distance of just 13,600km from Ceres’ surface — it having first snapped the dwarf planet back in January this year when it appeared as a blurry sphere 383,000km away.

Now, according to NASA, they can reveal that the mysterious bright spots that have filled astronomers and conspiracy theorists alike with intense interest are actually a collection of smaller spots but, despite strong guesses, they say their exact nature remains unknown.

“Dawn scientists can now conclude that the intense brightness of these spots is due to the reflection of sunlight by highly reflective material on the surface, possibly ice,” said Christopher Russell, principal investigator for the Dawn Mission from the University of California, Los Angeles.

Ceres bright spot gif

Ceres gif via NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

The spacecraft was sent to space to analyse the dwarf planets Ceres and Vesta; it completed its analysis of Vesta back in 2012 after 14 months and entered Ceres’ orbit in March this year.

On 9 May, Dawn and its powerful ion engine will begin the next part of its journey toward its second mapping orbit, which it will enter on 6 June.

In this phase, the spacecraft will circle Ceres approximately every three days at an altitude of 4,400km and will map the dwarf planet’s entire geology.

Colm Gorey was a senior journalist with Silicon Republic