THE MARTIAN BULGE

FROM: NASA

Thermal Tides at Mars

This diagram illustrates Mars' "thermal tides," a weather phenomenon responsible for large, daily variations in pressure at the Martian surface. Sunlight heats the surface and atmosphere on the day side of the planet, causing air to expand upwards. At higher levels in the atmosphere, this bulge of air then expands outward, to the sides, in order to equalize the pressure around it, as shown by the red arrows. Air flows out of the bulge, lowering the pressure of air felt at the surface below the bulge. The result is a deeper atmosphere, but one that is less dense and has a lower pressure at the surface, than that on the night side of the planet. As Mars rotates beneath the sun, this bulge moves across the planet each day, from east to west. A fixed observer, such as NASA's Curiosity rover, measures a decrease in pressure during the day, followed by an increase in pressure at night. The precise timing of the increase and decrease are affected by the time it takes the atmosphere to respond to the sunlight, as well as a number of other factors including the shape of the planet's surface and the amount of dust in the atmosphere.

Image credit: NASA/JPL-Caltech/Ashima Research/SWRI

TITAN'S LAKE DISTRICT AND CHANGES IN LAKE LEVELS

FROM: NASA
Titan's Lake District, One Season Later

These images obtained by NASA's Cassini spacecraft show Titan's stable northern lake district. Cassini's radar instrument obtained the recent images on May 22, 2012. It observed some previously unseen regions but also some regions containing lakes that were last observed about six years-nearly one Titan season--ago. This marks the longest time interval between lake observations in the northern hemisphere.

The top image here shows part of the radar swath from May 22, 2012, centered near 79 degrees north latitude, 58 degrees west longitude, and about 220 by 47 miles (350 by 75 kilometers) in dimension. At the bottom, parts of this image are compared with those obtained in 2006. (The images appear slightly different from previous releases because they use a new filtering technique). In 2006, it was winter in the northern hemisphere and the lakes were in the dark. Although Titan spring began in 2009 and the sun has now risen over the lakes, there is no apparent change in lake levels since the 2006 flybys, consistent with climate models that predict stability of liquid lakes over several years. This shows that the northern lakes are not transient weather events, in contrast to the temporary darkening of parts of the equator after a rainstorm in 2010 (PIA 12819).

Changes in lake levels may still be detected later in the mission as Cassini continues to observe these high northern latitudes into the beginning of summer in 2017. At that point, the sun may cause evaporation. However, the lack of significant change over six years sets important constraints for climate models and the stability of liquids on Titan. Illumination is coming from the bottom.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, DC. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the Italian Space Agency, working with team members from the United States and several European countries. Image Credit: NASA/JPL-Caltech/ASI

NEW ADDITION TO SPACE STATION TO BE DISCUSSED

FROM: NASA

NASA, BIGELOW OFFICIALS TO DISCUSS SPACE STATION EXPANDABLE MODULE WASHINGTON


-- NASA has awarded a $17.8 million contract to Bigelow Aerospace to provide a new addition to the International Space Station. The Bigelow Expandable Activity Module will demonstrate the benefits of this space habitat technology for future exploration and commercial space endeavors. "The International Space Station is a unique laboratory that enables important discoveries that benefit humanity and vastly increase understanding of how humans can live and work in space for long periods," NASA Deputy Administrator Lori Garver said. "This partnership agreement for the use of expandable habitats represents a step forward in cutting-edge technology that can allow humans to thrive in space safely and affordably, and heralds important progress in U.S. commercial space innovation." Garver and Bigelow Aerospace Founder and President Robert Bigelow will discuss the Bigelow Expandable Activity Module program at a media availability at 1:30 p.m. EST (10:30 a.m. PST) Wednesday, Jan. 16, at Bigelow Aerospace facilities located at 1899 W. Brooks Ave. in North Las Vegas.

PHOTOS FROM MARS

FROM: NASA

Opportunity at 'Copper Cliff,' Sol 3153, Stereo View

This 180-degree, stereo mosaic of images from the navigation camera on the NASA Mars Exploration Rover Opportunity shows terrain near the rover during the 3,153rd Martian day, or sol, of the rover's work on Mars (Dec. 6, 2012). West is at the center, south at the left edge, north at the right edge. The view appears in three dimensions when viewed through red-blue glasses with the red lens on the left.

Opportunity had driven about 7 feet (2.2 meters) westward earlier on Sol 3153 to get close to the outcrop called "Copper Cliff," which is in the center of this scene. The location is on the east-central portion of "Matijevic Hill" on the "Cape York" segment of the western rim of Endeavour Crater.

The view is presented as a cylindrical-perspective projection.
Credit-NASA-JPL-Caltech

Panoramic View From Near 'Point Lake' in Gale Crater, Sol 106

This panorama is a mosaic of images taken by the Mast Camera (Mastcam) on the NASA Mars rover Curiosity during the 106th Martian day, or sol, of the mission (Nov. 22, 2012). The rover was near a location called "Point Lake" for an overlook of a shallow depression called "Yellowknife Bay" which is in the left third of this scene, in the middle distance.

The image spans 360 degrees, with south at the center. It has been white-balanced to show what the rocks and soils in it would look like if they were on Earth.

Image Credit-NASA-JPL-Caltech-Malin Space Science Systems

THE IION THRUSTER

FROM: U.S. DEPARTMENT OF DEFENSE

by jtozer

Saturday Space Sight: Ion Thruster Sets World Record

While the Dawn spacecraftis visiting the asteroids Vesta and Ceres, NASA Glenn has been developing the next generation of ion thrusters for future missions. NASA's Evolutionar Xeon Thruster (NEXT) Project has developed a 7-kilowatt ion thruster that can provide the capabilities needed in the future.

An ion thruster produces small levels of thrust relative to chemical thrusters, but does so at higher specific impulse (or higher exhaust velocities), which means that an ion thruster has a fuel efficiency of 10-12 times greater than a chemical thruster.

The higher the rocket’s specific impulse (fuel efficiency), the farther the spacecraft can go with a given amount of fuel.

Given that an ion thruster produces small levels of thrust relative to chemical thrusters, it needs to operate in excess of 10,000 hours to slowly accelerate the spacecraft to speeds necessary to reach the asteroid belt or beyond.

The NEXT ion thruster has been operated for over 43,000 hours, which for rocket scientists means that the thruster has processed over 770 kilograms of xenon propellant and can provide 30 million-newton-seconds of total impulse to the spacecraft. This demonstrated performance permits future science spacecraft to travel to varied destinations, such as extended tours of multi-asteroids, comets, and outer planets and their moons.

Photo Credit:  NASA

ISS WEEKLY RECAP FOR JANUARY 11, 2013

FROM: NASA

THE MARTIAN MOUNTAIN WINDS

FROM: NASA

Mountain Winds at Gale Crater
This graphic shows the pattern of winds predicted to be swirling around and inside Gale Crater, which is where NASA's Curiosity rover landed on Mars. Modeling the winds gives scientists a context for the data from Curiosity's Rover Environmental Monitoring Station (REMS).

Curiosity's current location is marked with an "X." The rover's setting within a broad depression between the mountain dubbed "Mount Sharp" to the southeast and the rim of Gale Crater to the northwest strongly affects wind measurements collected by REMS.

This snapshot shows midday conditions. In the daytime, winds rise out of the crater, shown by the red arrows, and up the mountain, shown by the yellow arrows. Blue arrows indicate winds that flow along the depression and seem, to Curiosity, to be coming up out of the depression since Curiosity is near the bottom. At its current location, Curiosity may be seeing a mixture of these winds, making it challenging to understand its weather readings.

The patterns reverse in the evening and overnight, when winds flow in the downhill direction.

The background image is an oblique view of Gale Crater, looking toward the southeast. It is an artist's impression using two-fold vertical exaggeration to emphasize the area's topography. The crater's diameter is 96 miles (154 kilometers).

The image combines elevation data from the High Resolution Stereo Camera on the European Space Agency's Mars Express orbiter, image data from the Context Camera on NASA's Mars Reconnaissance Orbiter, and color information from Viking Orbiter imagery.

Image credit: NASA/JPL-Caltech/ESA/DLR/FU Berlin/MSSS

ROVER SELF-PORTRAIT

 

FROM:  NASA
Curiosity Self-Portrait, Wide View
On the 84th and 85th Martian days of the NASA Mars rover Curiosity's mission on Mars (Oct. 31 and Nov. 1, 2012), NASA's Curiosity rover used the Mars Hand Lens Imager (MAHLI) to capture dozens of high-resolution images to be combined into self-portrait images of the rover.

The mosaic shows the rover at "Rocknest," the spot in Gale Crater where the mission's first scoop sampling took place. Four scoop scars can be seen in the regolith in front of the rover. A fifth scoop was collected later.

Self-portraits like this one document the state of the rover and allow mission engineers to track changes over time, such as dust accumulation and wheel wear. Due to its location on the end of the robotic arm, only MAHLI (among the rover's 17 cameras) is able to image some parts of the craft, including the port-side wheels.

Image Credit: NASA/JPL-Caltech/MSSS

THE DIRT ON MARS

FROM: NASA

A Sampling of Martian Soils
This collage shows the variety of soils found at landing sites on Mars. The elemental composition of the typical, reddish soils were investigated by NASA's Viking, Pathfinder and Mars Exploration Rover missions, and now with the Curiosity rover, using X-ray spectroscopy. The investigations found similar soil at all landing sites. In addition, the soil was usually unchanged over the traverse across the Martian terrain made by both Mars Exploration Rovers.

The Mars Exploration Rover Spirit's landing region in Gusev Crater is seen in both pictures at top; Viking's landing site is shown at lower left; and a close-up of Curiosity's Gale Crater soil target called "Portage" is at lower right.

In Gusev Crater, several white subsurface deposits were excavated with Spirit’s wheels and found to be either silica-rich or hydrated ferric sulfates.

Image credit-NASA-JPL-Caltech

EARTH AT NIGHT

FROM:  NASA
This view of Earth at night is a cloud-free view from space as acquired by the Suomi National Polar-orbiting Partnership Satellite. A joint program by NASA and NOAA, Suomi NPP captured this nighttime image by the day-night band of the satellite's Visible Infrared Imaging Radiometer Suite VIIRS. It combines the Earth at night view created by NASA's Earth Observatory with data processed by NOAA's National Geophysical Data Center with the EO Blue Marble: Next Generation.

Credit-NASA Goddard-NASA's Earth Observatory-NOAA-DOD

NEW ION THRUSTERS MAY TAKE US TO THE EDGE OF THE SOLAR SYSTEM

FROM: NASA
While the Dawn spacecraft is visiting the asteroids Vesta and Ceres, NASA Glenn has been developing the next generation of ion thrusters for future missions. NASA's Evolutionary Xenon Thruster (NEXT) Project has developed a 7-kilowatt ion thruster that can provide the capabilities needed in the future. An ion thruster produces small levels of thrust relative to chemical thrusters, but does so at higher specific impulse (or higher exhaust velocities), which means that an ion thruster has a fuel efficiency of 10-12 times greater than a chemical thruster. The higher the rocket's specific impulse (fuel efficiency), the farther the spacecraft can go with a given amount of fuel. Given that an ion thruster produces small levels of thrust relative to chemical thrusters, it needs to operate in excess of 10,000 hours to slowly accelerate the spacecraft to speeds necessary to reach the asteroid belt or beyond. The NEXT ion thruster has been operated for over 43,000 hours, which for rocket scientists means that the thruster has processed over 770 kilograms of xenon propellant and can provide 30 million-newton-seconds of total impulse to the spacecraft. This demonstrated performance permits future science spacecraft to travel to varied destinations, such as extended tours of multi-asteroids, comets, and outer planets and their moons. Image Credit: NASA

A REALLY BIG BLACK HOLE

FROM:  NASA, BLACK HOLE

The black hole at the center of this galaxy is part of a survey of 18 of the biggest black holes in the universe. This large elliptical galaxy is in the center of the galaxy cluster PKS 0745-19, which is located about 1.3 billion light years from Earth.. X-ray data from NASA's Chandra X-ray Observatory are shown in purple and optical data from the Hubble Space Telescope are in yellow.

The researchers found that these black holes may be about ten times more massive than previously thought, with at least ten of them weighing between 10 and 40 billion times the mass of the sun.

All of the potential "ultramassive" black holes found in this study lie in galaxies at the centers of galaxy clusters containing huge amounts of hot gas. This hot gas produces the diffuse X-ray emission seen in the image. Outbursts powered by the central black holes create cavities in the gas preventing it from cooling and forming enormous numbers of stars. To generate the outbursts, the black holes must swallow large amounts of mass. Because the largest black holes can swallow the most mass and power the biggest outbursts, ultramassive black holes had already been predicted to exist to explain some of the most powerful outbursts seen. Credits: X-ray: NASA/CXC/Stanford/Hlavacek-Larrondo, J. et al; Optical: NASA/STScI

 

HAPPY HOLIDAYS

A Cosmic Holiday Ornament, Hubble-Style

'Tis the season for holiday decorating and tree-trimming. Not to be left out, astronomers using NASA's Hubble Space Telescope have photographed a festive-looking nearby planetary nebula called NGC 5189. The intricate structure of this bright gaseous nebula resembles a glass-blown holiday ornament with a glowing ribbon entwined.

Planetary nebulae represent the final brief stage in the life of a medium-sized star like our sun. While consuming the last of the fuel in its core, the dying star expels a large portion of its outer envelope. This material then becomes heated by the radiation from the stellar remnant and radiates, producing glowing clouds of gas that can show complex structures, as the ejection of mass from the star is uneven in both time and direction.

A spectacular example of this beautiful complexity is seen in the bluish lobes of NGC 5189. Most of the nebula is knotty and filamentary in its structure. As a result of the mass-loss process, the planetary nebula has been created with two nested structures, tilted with respect to each other, that expand away from the center in different directions.

Image Credit: NASA/Hubble

GROUND SYSTEMS DEVELOPMENT AND OPERATIONS PROGRAM

FROM: NASA
GSDO: Exploration Begins Here

NASA's Ground Systems Development and Operations Program is developing the technologies and innovations to launch the next generation of rockets and spacecraft.

A NEW TRIO HEAD FOR THE INTERNATIONAL SPACE STATION

FROM:  NASA

New Trio Launches to Join Expedition 34
The Soyuz TMA-07M spacecraft launched from the Baikonur Cosmodrome in Kazakhstan to the International Space Station at 7:12 a.m. EST on Wednesday, Dec. 19.

ISS WEEKLY UPDATE FOR DECEMBER 14, 2012

FROM:  NASA

LAUNCH DAY FOR EXPEDITION 29

 

FROM:  NASA
Soyuz on the Launch Pad
The is seen on the launch pad during a snow storm the morning of the launch of Expedition 29 to the International Space Station at the Baikonur Cosmodrome in Kazakhstan, Monday, Nov. 14, 2011.

SPHERES USE IN HUMAN EXPLORATION TELEROBOTICS TEST

NASA

ISS Update: SPHERES with Telerobotics Project Manager Terry Fong

NASA Public Affairs Officer Brandi Dean talks with Terry Fong, Telerobotics Project Manager, about how the Synchronized Position, Hold, Engage and Reorient Experimental Satellites, or SPHERES, are being used for a Human Exploration Telerobotics test.

IS THERE WATER ON MERCURY?

The First Solar DayAfter its first Mercury solar day (176 Earth days) in orbit, MESSENGER has nearly completed two of its main global imaging campaigns: a monochrome map at 250 m/pixel and an eight-color, 1-km/pixel color map. Apart from small gaps, which will be filled in during the next solar day, these global maps now provide uniform lighting conditions ideal for assessing the form of Mercury’s surface features as well as the color and compositional variations across the planet. The orthographic views seen here, centered at 75° E longitude, are each mosaics of thousands of individual images. At right, images taken through the wide-angle camera filters at 1000, 750, and 430 nm wavelength are displayed in red, green, and blue, respectively.
Release Date: October 5, 2011
Image Credit-NASA-Johns Hopkins University Applied Physics Laboratory-Carnegie Institution of Washington

FROM: NASA
NASA Spacecraft Finds New Evidence for Water Ice on Mercury

WASHINGTON -- A NASA spacecraft studying Mercury has provided compelling support for the long-held hypothesis the planet harbors abundant water ice and other frozen volatile materials within its permanently shadowed polar craters.

The new information comes from NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. Its onboard instruments have been studying Mercury in unprecedented detail since its historic arrival there in March 2011. Scientists are seeing clearly for the first time a chapter in the story of how the inner planets, including Earth, acquired their water and some of the chemical building blocks for life.

"The new data indicate the water ice in Mercury's polar regions, if spread over an area the size of Washington, D.C., would be more than 2 miles thick," said David Lawrence, a MESSENGER participating scientist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., and lead author of one of three papers describing the findings. The papers were published online in Thursday's edition of Science Express.

Spacecraft instruments completed the first measurements of excess hydrogen at Mercury's north pole, made the first measurements of the reflectivity of Mercury's polar deposits at near-infrared wavelengths, and enabled the first detailed models of the surface and near-surface temperatures of Mercury's north polar regions.

Given its proximity to the sun, Mercury would seem to be an unlikely place to find ice. However, the tilt of Mercury's rotational axis is less than 1 degree, and as a result, there are pockets at the planet's poles that never see sunlight.

Scientists suggested decades ago there might be water ice and other frozen volatiles trapped at Mercury's poles. The idea received a boost in 1991 when the Arecibo radio telescope in Puerto Rico detected radar-bright patches at Mercury's poles. Many of these patches corresponded to the locations of large impact craters mapped by NASA's Mariner 10 spacecraft in the 1970s. However, because Mariner saw less than 50 percent of the planet, planetary scientists lacked a complete diagram of the poles to compare with the radar images.

Images from the spacecraft taken in 2011 and earlier this year confirmed all radar-bright features at Mercury's north and south poles lie within shadowed regions on the planet's surface. These findings are consistent with the water ice hypothesis.

The new observations from MESSENGER support the idea that ice is the major constituent of Mercury's north polar deposits. These measurements also reveal ice is exposed at the surface in the coldest of those deposits, but buried beneath unusually dark material across most of the deposits. In the areas where ice is buried, temperatures at the surface are slightly too warm for ice to be stable.

MESSENGER's neutron spectrometer provides a measure of average hydrogen concentrations within Mercury's radar-bright regions. Water ice concentrations are derived from the hydrogen measurements.

"We estimate from our neutron measurements the water ice lies beneath a layer that has much less hydrogen. The surface layer is between 10 and 20 centimeters [4-8 inches] thick," Lawrence said.

Additional data from detailed topography maps compiled by the spacecraft corroborate the radar results and neutron measurements of Mercury's polar region. In a second paper by Gregory Neumann of NASA's Goddard Flight Center in Greenbelt, Md., measurements of the shadowed north polar regions reveal irregular dark and bright deposits at near-infrared wavelength near Mercury's north pole.
"Nobody had seen these dark regions on Mercury before, so they were mysterious at first," Neumann said.

The spacecraft recorded dark patches with diminished reflectance, consistent with the theory that ice in those areas is covered by a thermally insulating layer. Neumann suggests impacts of comets or volatile-rich asteroids could have provided both the dark and bright deposits, a finding corroborated in a third paper led by David Paige of the University of California at Los Angeles.

"The dark material is likely a mix of complex organic compounds delivered to Mercury by the impacts of comets and volatile-rich asteroids, the same objects that likely delivered water to the innermost planet," Paige said.

This dark insulating material is a new wrinkle to the story, according to MESSENGER principal investigator Sean Solomon of Columbia University's Lamont-Doherty Earth Observatory in Palisades, N.Y.

"For more than 20 years, the jury has been deliberating whether the planet closest to the sun hosts abundant water ice in its permanently shadowed polar regions," Solomon said. "MESSENGER now has supplied a unanimous affirmative verdict."

MESSENGER was designed and built by APL. The lab manages and operates the mission for NASA's Science Mission Directorate in Washington. The mission is part of NASA's Discovery Program, managed for the directorate by the agency's Marshall Space Flight Center in Huntsville, Ala.

THE MOON PHASE AND LIBRATION FOR 2013

FROM: NASA

Moon Phase & Libration 2013: Additional Graphics

This visualization shows the phase and libration of the Moon throughout the year 2013, at hourly intervals. Each frame represents one hour. In addition, this version of the visualization shows additional relevant information, including the Moon's orbit position, subsolar and subearth points, distance from the Earth, and more.