NASA Engineer



In September 2015, a new study provided an important missing piece to the intriguing puzzle of how our Moon came to be the lovely object that we see today. Vast regions of dark dunes also extend across Titan's exotic landscape, especially around its equatorial regions. Unlike Earth's sand, the "sand" that creates Titan's dunes is composed of dark grains of hydrocarbon that resemble coffee grounds. The tall linear dunes of this misty moisty moon-world appear to be quite similar to those seen in the desert of Namibia in Africa. Because Titan's surface is pockmarked by relatively few impact craters, its surface is considered to be quite young. Older surfaces display heavier cratering than more youthful surfaces, whose craters have been "erased" by resurfacing. This resurfacing is caused by processes that cover the scars left by old impacts as time goes by. Our own planet is similar to Titan in this respect. The craters of Earth are erased by the ongoing processes of flowing liquid (water on Earth), powerful winds, and the recycling of Earth's crust as a result of plate-tectonics. These processes also occur on Titan, but in modified forms. In particular, the shifting of the ground resulting from pressures coming from beneath (plate tectonics), also appear to be at work on this veiled moon-world. However, planetary scientists have not seen signs of plates on Titan that are analogous to those of our own planet. Discovered on March 31, 2005, by a team of planetary scientists led by Dr. Michael E. Brown of the California Institute of Technology (Caltech) in Pasadena, Makemake was initially dubbed 2005 FY 9, when Dr. Brown and his colleagues, announced its discovery on July 29, 2005. The team of astronomers had used Caltech's Palomar Observatory near San Diego to make their discovery of this icy dwarf planet, that was later given the minor-planet number of 136472. Makemake was classified as a dwarf planet by the International Astronomical Union (IAU) in July 2008. Dr. Brown's team of astronomers had originally planned to delay announcing their discoveries of the bright, icy denizens of the Kuiper Belt--Makemake and its sister world Eris--until additional calculations and observations were complete. However, they went on to announce them both on July 29, 2005, when the discovery of Haumea--another large icy denizen of the outer limits of our Solar System that they had been watching--was announced amidst considerable controversy on July 27, 2005, by a different team of planetary scientists from Spain.