Landslides on Ceres

NASA's Dawn spacecraft has revealed many landslides on Ceres, which researchers interpret to have been shaped by a significant amount of water ice. A 2017 study in the journal Nature Geoscience classifies three types of these debris flows.

Image 1 shows an example of "Type I" flow features, which are relatively round and large, have thick "toes" at their ends. They look similar to rock glaciers and icy landslides on Earth. Type I landslides are mostly found at high latitudes, which is also where the most ice is thought to reside near Ceres' surface.

Image 2 shows an example of a "Type II" flow feature. Type II features are often thinner and longer than Type I, and are the most common type of landslide on Ceres. They appear more like the avalanches seen on Earth.

Image 3 shows an example of a "Type III" flow feature at Datan Crater. The study authors interpret Ceres' Type III landslides to involve melted ice, although scientists do not know if they actually contain liquid water. The authors think Type III landslides are related to impact craters, and may have formed during impact events into the ice on Ceres. The features resemble fluid material ejected from craters in the icy regions of Mars and Jupiter's moon Ganymede.

Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Explanation from: https://photojournal.jpl.nasa.gov/catalog/PIA21471

Exoplanet HD 80606b

The turbulent atmosphere of a hot, gaseous planet known as HD 80606b is shown in this simulation based on data from NASA's Spitzer Space Telescope. The planet spends most of its time far away from its star, but every 111 days, it swings extremely close to the star, experiencing a massive burst of heat. Spitzer measured the whole heating cycle of this planet, determining its coolest (less than 400 degrees Fahrenheit) and hottest (2,000 degrees Fahrenheit) temperatures.

Image Credit: NASA/JPL-CalTech
Explanation from: https://www.nasa.gov/image-feature/jpl/simulated-atmosphere-of-a-hot-gas-giant

Protoplanetary Disk HH 212

This intriguing image may look like a collection of coloured blobs, but it is actually a high-resolution snapshot of a newborn star enshrouded in dust. Just 1300 light-years away in the Orion Nebula, the star, named HH 212, is remarkably young. The average lifespan of such a low-mass star is around 100 billion years, but this star is only 40 000 years old — truly an infant in stellar terms.

In the cores of the vast molecular clouds in star formation regions, an ongoing battle rages; gravity versus the pressure of gas and dust. If gravity wins, it forces the gas and dust to collapse into a hot dense core that eventually ignites — forming a protostar. All the leftover gas and dust form a spinning disc around this baby star, and in many star systems they eventually coalesce to make planets. Such very young protostellar discs have been hard to image because of their relatively small size, but now the exceedingly high resolution of the Atacama Large Millimeter/submillimeter Array (ALMA) makes it possible to understand the intricate details of star and planet formation.

A closer look at HH 212 reveals a prominent, cool, dark dust lane running through the disc, sandwiched between two brighter regions that are heated by the protostar. The result resembles a cosmic “hamburger”. This is the very first time astronomers have spotted such a dust lane in the earliest phases of star formation, and so it may provide clues as to how planetary systems are born.

Image Credit: ALMA (ESO/NAOJ/NRAO)/ Lee et al.
Explanation from: https://www.eso.org/public/images/potw1720a/