Pluto hasn’t been the only source of startling new discoveries in space this week, but it has delivered the the biggest surprises.
The latest images of the broad and bright heart shaped region on the dwarf planet have found more icy mountains and hints that whatever its surface is made of is also condensing or infiltrating or pooling within and filling older adjacent craters.
One of those photos from NASA’s New Horizons probe (above) shows the abrupt boundary between the apparently new material that makes up Pluto’s heart shaped region and the older dark crater pitted terrain that it is invading and covering its features by a mechanism yet to be determined.
NASA scientists are cautiously discussing some of the early images being gradually downloaded from the spacecraft which flew through the Pluto-Charon system on 14 July. However downloading the official source material is proving difficult as NASA’s servers struggle to keep up with public demand.
The most recent release from New Horizons includes tantalizing glimpses of two of its moon, Nix and Hydra.
However NASA’s Dawn spacecraft, which is in orbit around Ceres, the largest object in the main asteroid belt, has sprung its own surprise. It has now taken images of a fog or haze coming off the most prominent of many mysterious bright spots seen on its surface.
This may support the theory that a liquid is escaping from the interior of the micro-planet and then turning to ice, to form the highly reflective patches rather than an accumulation of salts, although solving that riddle should become easier in coming months as Dawn lowers its mapping orbit to reveal these and other bright spots in much clearer detail.
Closer to Earth, comet 67P/Churyumov-Gerasimenko is within weeks of perihelion, or its closest approach to the sun, with the orbiting European probe Rosetta detecting lumps of cometary material up to several metres in diameter being ejected from sink holes or pits on its complex double lobed surface.
Unfortunately the comet lander Philae which was deployed by Rosetta last November, has again fallen silent, frustrating hopes that its cameras might capture close ups of the violent surface processes that shed the material that forms the comet’s dust and gas tails during the period of maximum solar heating.
The Rosetta mother ship has been forced to retreat to a more distant viewpoint because of the risk of damage from material ejected from the comet. However the European Space Agency is drawing up plans to attempt to land Rosetta on the comet later this year as 67P recedes away from the sun and the surface activity diminishes.