OrbitalHub

NASA dixit:

“Nate made landfall over the weekend along the northern Gulf Coast as a Category 1 hurricane with sustained winds reported at 85 mph (~140 kph) by the National Hurricane Center (NHC) first at 7:00pm CDT on Saturday October 7th in Louisiana near the mouth of the Mississippi River then again several hours later at 12:30 a.m. CDT on Sunday October 8th near Biloxi, Mississippi before moving quickly moving northward through northern Alabama and central Tennessee.

NASA’s GPM satellite helped track Nate’s progress through the Gulf of Mexico and also captured Nate’s landfall on the north central Gulf Coast. The following animation shows instantaneous rain rate estimates from NASA’s Integrated Multi-satellitE Retrievals for GPM or IMERG product over North America and the surrounding waters beginning on Thursday October 5th when Nate first became a tropical storm near the northeast coast of Nicaragua in the western Caribbean until its eventual landfall on the northern Gulf Coast on Sunday October 8th.

IMERG estimates precipitation from a combination of space-borne passive microwave sensors, including the GMI microwave sensor on board the GPM core satellite, and geostationary IR (infrared) data. The animation shows Nate moving rapidly northward through the Gulf of Mexico on the 7th. Nate’s rapid movement from 20 to as much as 26 mph to strengthen despite being over very warm waters and in a relatively low wind shear environment. Nate reached a peak intensity of 90 mph sustained winds, which it maintained while passing over the Gulf of Mexico, but it did not intensify any further before making landfall. The animation also shows two 3-D flyby’s of Nate captured by the GPM core satellite as it overflew the storm just before landfall at 22:58 UTC (5:58 CDT) on Saturday October 7th and again at 08:42 UTC (3:42 CDT) on Sunday October 8th soon after Nate’s second landfall.

The 3-D precipitation tops (shown in blue) are from GPM’s DPR as are the vertical cross sections of precipitation intensity. The first overpass shows that Nate is a very asymmetric storm with most of the rainbands associated with Nate located north and east of the center. With it’s rapid movement, Nate was unable to fully develop and lacks the classic ring of intense thunderstorms associated a fully developed eyewall. Although overall much the same, the second overpass shows an area of deep, intense convection producing heavy rains over southwest Alabama.

Because of its rapid movement, Nate did not produce the catastrophic flooding that Harvey did. However, Nate is being blamed for 2 storm-related fatalities in the U.S. and at least 38 across Central America, most in Nicaragua and Costa Rica.

GPM is a joint mission between NASA and the Japanese space agency JAXA.”

Video credit: NASA Goddard

NASA dixit:

“October 22, 2016. Shadows cast across Mimas’ defining feature, Herschel Crater, provide an indication of the size of the crater’s towering walls and central peak. Named after the icy moon’s discoverer, astronomer William Herschel, the crater stretches 86 miles (139 kilometers) wide, almost one-third of the diameter of Mimas (246 miles or 396 kilometers) itself. Large impact craters often have peaks in their center. Herschel’s peak stands nearly as tall as Mount Everest on Earth.

This view looks toward the anti-Saturn hemisphere of Mimas. North on Mimas is up and rotated 21 degrees to the left. The image was taken with the Cassini spacecraft narrow-angle camera using a combination of spectral filters which preferentially admits wavelengths of ultraviolet light centered at 338 nanometers. The view was acquired at a distance of approximately 115,000 miles (185,000 kilometers) from Mimas and at a Sun-Mimas-spacecraft, or phase, angle of 20 degrees. Image scale is 3,300 feet (1 kilometer) per pixel.”

Image credit: NASA/JPL-Caltech/Space Science Institute

NASA dixit:

“Occator Crater on Ceres is home to the brightest area on the entire dwarf planet. At 57 miles (92 kilometers) wide and 2.5 miles (4 kilometers) deep, Occator displays evidence of recent geologic activity. NASA’s Dawn mission found that the bright spots may have been produced by upwelling of salt-rich liquids after the impact that formed the crater. Pan and zoom as you fly over the crater with Dawn in this 360-degree animation made with observations from the spacecraft.”

Video credit: NASA

NASA dixit:

“August 22, 2016. The moon Hyperion tumbles as it orbits Saturn. Hyperion’s (168 miles or 270 kilometers across) spin axis has a chaotic orientation in time, meaning that it is essentially impossible to predict how the moon will be spinning in the future. So far, scientists only know of a few bodies with such chaotic spins. The image was taken in green light with the Cassini spacecraft narrow-angle camera.

The view was acquired at a distance of approximately 203,000 miles (326,000 kilometers) from Hyperion and at a Sun-Hyperion-spacecraft, or phase, angle of 10 degrees. Image scale is 1 mile (2 kilometers) per pixel.”

Image credit: NASA/JPL-Caltech/Space Science Institute

NASA dixit:

“August 12, 2016. Pandora is seen here, in isolation beside Saturn’s kinked and constantly changing F ring. Pandora (near upper right) is 50 miles (81 kilometers) wide. The moon has an elongated, potato-like shape. Two faint ringlets are visible within the Encke Gap, near lower left. The gap is about 202 miles (325 kilometers) wide. The much narrower Keeler Gap, which lies outside the Encke Gap, is maintained by the diminutive moon Daphnis (not seen here).

This view looks toward the sunlit side of the rings from about 23 degrees above the ring plane. The image was taken in visible light with the Cassini spacecraft narrow-angle camera. The view was acquired at a distance of approximately 907,000 miles (1.46 million kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 113 degrees. Image scale is 6 miles (9 kilometers) per pixel.”

Image credit: NASA/JPL-Caltech/Space Science Institute

NASA dixit:

“July 25, 2016. In the Shangri-La Sand Sea on Titan is shown in this image from the Synthetic Aperture radar (SAR) on NASA’s Cassini spacecraft. Hundreds of sand dunes are visible as dark lines snaking across the surface. These dunes display patterns of undulation and divergence around elevated mountains (which appear bright to the radar), thereby showing the direction of wind and sand transport on the surface. Sands being carried from left to right (west to east) cannot surmount the tallest obstacles; instead, they are directed through chutes and canyons between the tall features, evident in thin, blade-like, isolated dunes between bright some features. Once sands have passed around the obstacles, they resume their downwind course, at first collecting into small, patchy dunes and then organizing into larger, more pervasive linear forms, before being halted once again by obstacles.

These patterns reveal the effects not only of wind, perhaps even modern winds if the dunes are actively moving today, but also the effects of underlying bedrock and surrounding topography. Dunes across the solar system aid in our understanding of underlying topography, winds and climate, past and present. Similar patterns can be seen in dunes of the Great Sandy Desert in Australia, where dunes undulate broadly across the uneven terrain and are halted at the margins of sand-trapping lakes. The dune orientations correlate generally with the direction of current trade winds, and reveal that winds must have been similar back when the dunes formed, during the Pleistocene glacial and interglacial periods.

North on Titan is up in the image. Radar illuminates the scene from upper right at a 27-degree incidence angle. The image was obtained during the mission’s 122nd targeted Titan encounter.”

Image credit: NASA/JPL-Caltech/Space Science Institute