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New Ceres Views

New Ceres Views
The brightest area on Ceres stands out amid shadowy, cratered terrain in a dramatic new view from NASA’s Dawn spacecraft, taken as it looked off to the side of the dwarf planet. Dawn snapped this image on Oct. 16, from its fifth science orbit, in which the angle of the sun was different from that in previous orbits. Dawn was about 920 miles (1,480 kilometers) above Ceres when this image was taken — an altitude the spacecraft had reached in early October.Occator Crater, with its central bright region and secondary, less-reflective areas, appears quite prominent near the limb, or edge, of Ceres. At 57 miles (92 kilometers) wide and 2.5 miles (4 kilometers) deep, Occator displays evidence of recent geologic activity. The latest research suggests that the bright material in this crater is comprised of salts left behind after a briny liquid emerged from below, froze and then sublimated, meaning it turned from ice into vapor.

The impact that formed the crater millions of years ago unearthed material that blanketed the area outside the crater, and may have triggered the upwelling of salty liquid.

“This image captures the wonder of soaring above this fascinating, unique world that Dawn is the first to explore,” said Marc Rayman, Dawn’s chief engineer and mission director, based at NASA’s Jet Propulsion Laboratory, Pasadena, California.

Dawn scientists also have released an image of Ceres that approximates how the dwarf planet’s colors would appear to the human eye. This view, produced by the German Aerospace Center in Berlin, combines images taken from Dawn’s first science orbit in 2015, using the framing camera’s red, green and blue filters. The color was calculated based on the way Ceres reflects different wavelengths of light.

New Ceres Views

The spacecraft has gathered tens of thousands of images and other information from Ceres since arriving in orbit on March 6, 2015. After spending more than eight months studying Ceres at an altitude of about 240 miles (385 kilometers), closer than the International Space Station is to Earth, Dawn headed for a higher vantage point in August. In October, while the spacecraft was at its 920-mile altitude, it returned images and other valuable insights about Ceres.

On Nov. 4, Dawn began making its way to a sixth science orbit, which will be over 4,500 miles (7,200 kilometers) from Ceres. While Dawn needed to make several changes in its direction while spiraling between most previous orbits at Ceres, engineers have figured out a way for the spacecraft to arrive at this next orbit while the ion engine thrusts in the same direction that Dawn is already going. This uses less hydrazine and xenon fuel than Dawn’s normal spiral maneuvers. Dawn should reach this next orbit in early December.

One goal of Dawn’s sixth science orbit is to refine previously collected measurements. The spacecraft’s gamma ray and neutron spectrometer, which has been investigating the composition of Ceres’ surface, will characterize the radiation from cosmic rays unrelated to Ceres. This will allow scientists to subtract “noise” from measurements of Ceres, making the information more precise.

The spacecraft is healthy as it continues to operate in its extended mission phase, which began in July. During the primary mission, Dawn orbited and accomplished all of its original objectives at Ceres and protoplanet Vesta, which the spacecraft visited from July 2011 to September 2012.

Dawn’s mission is managed by NASA’s Jet Propulsion Laboratory for NASA’s Science Mission Directorate in Washington. Dawn is a project of the directorate’s Discovery Program, managed by NASA’s Marshall Space Flight Center in Huntsville, Alabama. UCLA is responsible for overall Dawn mission science. Orbital ATK Inc., in Dulles, Virginia, designed and built the spacecraft. The German Aerospace Center, Max Planck Institute for Solar System Research, Italian Space Agency and Italian National Astrophysical Institute are international partners on the mission team. For a complete list of mission participants

source: world press news

Matthew’s Total Rainfall

Matthew's Total Rainfall

NASA Adds Up Deadly Hurricane Matthew’s Total Rainfall  

A NASA rainfall analysis estimated the amount of rainfall generated by Hurricane Matthew when it moved over the Carolinas.

Hurricane Matthew dropped a lot of rain, caused flooding and deaths in the state of North Carolina. Flooding is still widespread in North Carolina.  Some rivers in North Carolina such as the Tar and the Neuse Rivers were still rising on Oct. 12.

At NASA’s Goddard Space Flight Center in Greenbelt, Maryland a rainfall analysis was accomplished using data from NASA’s Integrated Multi-satellitE Retrievals for GPM (IMERG). The GPM or Global Precipitation Measurement mission is a joint mission between NASA and the Japanese space agency JAXA.

Matthew's Total Rainfall

The Integrated Multi-satellitE Retrievals for GPM (IMERG) is a unified U.S. algorithm that provides a multi-satellite precipitation product. IMERG is run twice in near-real time with the “Early” multi-satellite product being created at about 4 hours after observation time and a “Late” multi-satellite product provided at about 12 hours after observation time.

This rainfall analysis was created using IMERG real time data covering the period from Sept. 28 through Oct. 10, 2016. The totals included some rain from a low pressure area that moved through the area near the end of September.

Hurricane Matthew’s interaction with a frontal boundary caused extreme rainfall in North Carolina resulting in over 20 inches (508 mm) of rain being reported in North Carolina. The area was already saturated before Hurricane Matthew arrived. Heavy rainfall from a slow moving low and frontal system moved through during the last week of September. Maximum rainfall total estimates for the real-time IMERG product have been adjusted to reflect observed values.

On Wednesday, Oct. 12 the National Weather Service (NWS) in Wilmington, North Carolina (NC) reported “All major area rivers will remain above flood stage throughout this upcoming week. At 10:59 a.m. EDT on Oct. 12, the North Carolina Department of Transportation reported numerous flooded roads persisting across much the coastal plain of North Carolina. This being the result of heavy rainfall totaling 5 to 12 inches across the region in the last 36 hours. Many roads are impassable, barricaded or washed away. Some neighborhoods are cut off. Swamps, creeks and rivers are still rising flooding even more areas and slowing the recession of high water. People in the warned area should not travel and be prepared for widespread flooding of a magnitude not seen in many years. If asked to evacuate please do so.”

Further south, a Flood Warning has been extended for the following rivers: Cape Fear at Elizabethtown affecting Bladen County NC; Cape Fear at Lock and Dam 1 affecting Bladen County NC; Black Creek at Quinby affecting Darlington and Florence Counties South Carolina (SC); Lynches at Effingham affecting Florence County SC.

In addition, a Flood Warning continues for the following rivers: Cape Fear at William O. Huske Lock and Dam 3 affecting Bladen County NC; Northeast Cape Fear near Burgaw affecting Pender County NC; Lumber Near Lumberton affecting Robeson County NC;  Little Pee Dee at Galivants Ferry affecting Dillon, Horry and Marion Counties,  SC;  Waccamaw at Conway affecting Horry County SC;  Great Pee Dee at Pee Dee affecting Marion and Florence Counties SC; and Black at Kingstree affecting Williamsburg County SC.

source:world press news

NASA Analyzes Heavy Rainfall

NASA Analyzes Heavy Rainfall

Slow moving frontal systems draped over Hispaniola and a tropical wave recently caused heavy rainfall that led to wide spread flooding over the northern Dominican Republic. NASA analyzed that heavy rainfall using data from satellites.

Scattered to numerous showers and scattered thunderstorms have occurred over Hispaniola during the week of Nov. 14. Hispaniola includes the Dominican Republic and Haiti.

The Global Precipitation Measurement mission or GPM core satellite can analyze rainfall rates from space. GPM is a joint mission between NASA and the Japanese space agency JAXA.

NASA’s Integrated Multi-satellite Retrievals for GPM (IMERG) were used to estimate totals for rainfall that fell over the Dominican Republic during the period from Nov. 8 to 15, 2016. IMERG data indicates that rainfall totals of greater than 230 mm (9 inches) fell over the northeastern Dominican Republic during this period. Estimates of real-time IMERG rainfall totals have been adjusted to reflect observed values in similar extreme events.

NASA Analyzes Heavy Rainfall

The Integrated Multi-satellitE Retrievals for GPM (IMERG) creates a merged precipitation product from the GPM constellation of satellites. These satellites include DMSPs from the U.S. Department of Defense, GCOM-W from the Japan Aerospace Exploration Agency (JAXA), Megha-Tropiques from the Centre National D’etudies Spatiales (CNES) and Indian Space Research Organization (ISRO), NOAA series from the National Oceanic and Atmospheric Administration (NOAA), Suomi-NPP from NOAA-NASA, and MetOps from the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT).  All of the instruments (radiometers) onboard the constellation partners are inter-calibrated with information from the GPM Core Observatory’s GPM Microwave Imager (GMI) and Dual-frequency Precipitation Radar (DPR).
On Nov. 18, the National Hurricane Center discussion noted “A stationary front extends from the west-central Atlantic near 20 degrees north latitude and 70 degrees west longitude, then along the north coast of the island to the Windward Passage continuing over the west Caribbean. A surface trough (elongated area of low pressure) is just south of the Mona Passage and coupled with the frontal boundary are generating scattered showers possible isolated thunderstorms over the Dominican Republic this morning. This front will lie across the north portion of the island through Saturday, and coupled with the surface trough moving through the central Caribbean will give the island scattered showers and possible isolated thunderstorms spreading west across the island today and will persist through Saturday.”

For information from the National Weather Service of Puerto Rico on how that system is affecting the region, go to: http://www.weather.gov/sju/

In addition to that system, a broad area of low pressure designated as System 90L in the southwestern Caribbean is also being monitored for possible tropical cyclone development by the National Hurricane Center. Very warm sea surface temperatures and upper level winds are expected to provide favorable conditions for tropical cyclone development in that area.

source: world news,press news