Image credits: NASA/JHUAPL/SwRI.NASA’s New Horizons spacecraft spied several features on Pluto that offer evidence of a time millions or billions of years ago when — thanks to much higher pressure in Pluto’s atmosphere and warmer conditions on the surface — liquids might have flowed across and pooled on the surface of the distant world. “In addition to this possible former lake, we also see evidence of channels that may also have carried liquids in Pluto’s past,” said Alan Stern, Southwest Research Institute, Boulder, Colorado—principal investigator of New Horizons and lead author of the scientific paper.
This feature appears to be a frozen, former lake of liquid nitrogen, located in a mountain range just north of Pluto’s informally named Sputnik Planum. Captured by the New Horizons’ Long Range Reconnaissance Imager (LORRI) as the spacecraft flew past Pluto on 14 July 2015, the image shows details as small as about 430 feet (130 metres). At its widest point the possible lake appears to be about 20 miles (30 kilometres) across.
We can’t see the wind, but we can learn about it by observing things that are being blown about. And by studying changes in a comet’s bright tail of gas and ions, scientists are on the trail to solving two big mysteries about the solar wind — the supersonic outflow of electrically charged gas from the Sun’s million-degree upper atmosphere, or corona.
The Moon was formed by a violent, head-on collision between the early Earth and a “planetary embryo” called Theia (pronounced THAY-eh) approximately 100 million years after the Earth formed, UCLA scientists reveal. This new research also refutes the work of a team of German scientists who, in 2014, reported that the Moon also has its own unique ratio of oxygen isotopes, different from Earth’s.
New research from North Carolina State University finds that major volcanic activity on the innermost planet most likely ended about 3.5 billion years ago — in stark contrast to the volcanic ages found for Venus, Mars and Earth. These findings add insight into the geological evolution of Mercury and what happens when rocky planets cool and contract.