AstroTalk Episode November 17, 2016

Mercury, Arctic Ice and Saturn's Watercolours

2:57pm - 3:31pm

Mercury is shrinking. A newly discovered valley on Mercury, close to the Rembrandt Basin, is being studied by NASA scientists. The valley, which is 620 miles long, (longer than the Grand Canyon) is caused by the global contraction of the planet. On Earth, similar valleys are often formed by the pulling apart of lithospheric plates due to plate tectonics. On Mercury, the great valley is thought to have formed from long-wavelength buckling of the planet's outermost shell in response to the global contraction of the planet. Valley formation on Earth is well-known process, but this may the first evidence of similar processes occurring on Mercury.
NASA is also monitoring conditions on Earth from satellites orbiting our planet. The Goddard Institute for Spaces Studies in New York has presented data that suggest the past three Octobers, 2014, 2015 & 2016, have seen the highest global temperatures on record for that month. Global temperatures have been monitored for 136 years, and October 2016 was the second warmest October on our planet for the past 136 years, the warmest October happening in October 2015. The 10 warmest Octobers on record have also been recorded after the year 2,000. Goddard scientists also suggest that the study of trends are more important than just year-to-year data. Data after 2,000 therefore suggest that our planet is, indeed, warming up.
Perhaps tied in with these findings are other findings relating to a cyclone in the Arctic. In their monitoring of our planet, NASA scientists have detected the damage done to the ice pack in the Arctic by a cyclone that passed through that region in late December 2015. The cyclone brought a lot of humidity and an increase in air temperature of 10 degrees F to the air over the Arctic. The warm air thinned and shrunk the sea ice cover in the Arctic, at a time when ice there should have been growing stronger and thicker. The warm air from the storm, and the storm itself, compacted the ice pack, pushing it further North. More evidence seems to floating in that our planet is warming up, leading to more loss of ice in the polar regions.
NASA also released more images from Saturn, showing a kaleidoscope of water swirl colours painted on the northern pole of Saturn. The hexagon shape is again noted in the images provided, but the main highlight is the colorful representation of the latitudinal bands, which come about from air flowing at different speeds, and at different heights, in Saturn's atmosphere. Many eddies and swirls are also noted where the separate bands meet. Just another fascinating, gorgeous breathtaking image from the planet Saturn.