Source: NASA News
YouTube Video: NASA Science Casts
Back in 2008, the solar cycle plunged into the deepest minimum in nearly a century. Sunspots all but vanished, solar flares subsided, and the sun was eerily quiet.
With a burst of solar flares and Northern Lights, the sun is waking up from a three-year slumber.(read more)
Source: NASA News
The first six of 18 segments that will form NASA's James Webb Space Telescope's primary mirror for space observations will begin final round-the-clock cryogenic testing this week. These tests will confirm the mirrors will respond as expected to the extreme temperatures of space prior to integration into the telescope's permanent housing structure.
The X-ray and Cryogenic Facility at NASA's Marshall Space Flight Center in Huntsville, Ala. will provide the space-like environment to help engineers measure how well the telescope will image infrared sources once in orbit.
Each mirror segment measures approximately 4.3 feet (1.3 meters) in diameter to form the 21.3 foot (6.5 meters), hexagonal telescope mirror assembly critical for infrared observations. Each of the 18 hexagonal-shaped mirror assemblies weighs approximately 88 pounds (40 kilograms). The mirrors are made of a light and strong metal called beryllium, and coated with a microscopically thin coat of gold to enable the mirror to efficiently collect light. (read more)
Source: ESA
Dense filaments of gas in the IC5146 interstellar cloud.
Image credits: ESA/Herschel/SPIRE/PACS/D. Arzoumanian (CEA Saclay).
ESAs Herschel space observatory has revealed that nearby interstellar clouds contain networks of tangled gaseous filaments. Intriguingly, each filament is approximately the same width, hinting that they may result from interstellar sonic booms throughout our Galaxy. (read more)
Source: ESO Photo Release eso1113
Image credit: ESO, Digitized Sky Survey 2 and Joe DePasquale
This image of the nebula NGC 3582, which was captured by the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile, shows giant loops of gas bearing a striking resemblance to solar prominences. These loops are thought to have been ejected by dying stars, but new stars are also being born within this stellar nursery. These energetic youngsters emit intense ultraviolet radiation that makes the gas in the nebula glow, producing the fiery display shown here.(read more)
Source: ESA/Hubble Science Release heic1106
Image credit: NASA, ESA, J. Richard (CRAL) and J.-P. Kneib (LAM). Acknowledgement: Marc Postman (STScI)
Using the amplifying power of a cosmic gravitational lens, astronomers have discovered a distant galaxy whose stars were born unexpectedly early in cosmic history. This result sheds new light on the formation of the first galaxies, as well as on the early evolution of the Universe. (read more)
Fifty years ago, on April 12, 1961 Yuri Alekseyevich Gagarin became the first human to journey into outer space when his Vostok spacecraft completed an orbit around Earth . Gagarin was transformed into an international celebrity, and was awarded many medals and honours, including Hero of the Soviet Union.
Vostok 1 marked his only spaceflight, but he served as backup to the Soyuz 1 mission, which ended in a fatal crash. Gagarin later became deputy training director of the Cosmonaut Training Center outside Moscow, which was later named after him. Gagarin died in an accident in 1968 while piloting a training jet.
View ESA's Euronews video about the event:
Source: Chandra X-Ray Observatory
GRB 110328A. Image credit:NASA/CXC/Warwick/A.Levan et al.
An extraordinary gamma-ray burst, known as GRB110328A, has been observed by a team of NASA telescopes (Chandra, Hubble, and Swift). The source of GRB110328A appears to be a galaxy about 3.8 billion light years from Earth. arly analysis of the data suggests the burst may have been caused by a star torn apart by a supermassive black hole in the galaxy's center.(read source)
Source: NASA News
Merger of two neutron stars recently simulated using a new supercomputer model.
Image credit: NASA/AEI/ZIB/M. Koppitz and L. Rezzolla
A new supercomputer simulation shows the collision of two neutron stars can naturally produce the magnetic structures thought to power the high-speed particle jets associated with short gamma-ray bursts (GRBs). The study provides the most detailed glimpse of the forces driving some of the universe's most energetic explosions.
The state-of-the-art simulation ran for nearly seven weeks on the Damiana computer cluster at the Albert Einstein Institute (AEI) in Potsdam, Germany. It traces events that unfold over 35 milliseconds - about three times faster than the blink of an eye.
GRBs are among the brightest events known, emitting as much energy in a few seconds as our entire galaxy does in a year. Most of this emission comes in the form of gamma rays, the highest-energy form of light. (read more)
Source: NASA News
GREAT collected its first THz photons from the M173W star.
Image credit: GREAT Team/ NASA/DLR/USRA/DSI
The Stratospheric Observatory for Infrared Astronomy, or SOFIA, completed its first science flight Wednesday, April 6, using the German Receiver for Astronomy at Terahertz Frequencies (GREAT) scientific instrument. GREAT is a high-resolution far-infrared spectrometer that finely divides and sorts light into component colors for detailed analysis.
SOFIA is the only operational airborne observatory. It is a joint program between NASA and the German Aerospace Center (DLR). The observatory is a heavily modified Boeing 747SP aircraft carrying a reflecting telescope with an effective diameter of 100 inches. Flying at altitudes between 39,000 and 45,000 feet, above the water vapor in Earth's lower atmosphere that blocks most infrared radiation from celestial sources, SOFIA conducts astronomy research not possible with ground-based telescopes. (read more)
Source: NASA News
NASA's Swift, Hubble Space Telescope and Chandra X-ray Observatory have teamed up to study one of the most puzzling cosmic blasts yet observed. More than a week later, high-energy radiation continues to brighten and fade from its location.
Astronomers say they have never seen anything this bright, long-lasting and variable before. Usually, gamma-ray bursts mark the destruction of a massive star, but flaring emission from these events never lasts more than a few hours.
Although research is ongoing, astronomers say that the unusual blast likely arose when a star wandered too close to its galaxy's central black hole. Intense tidal forces tore the star apart, and the infalling gas continues to stream toward the hole. According to this model, the spinning black hole formed an outflowing jet along its rotational axis. A powerful blast of X- and gamma rays is seen if this jet is pointed in our direction. (read more)
Source: NASA Science
NASA's Dawn spacecraft has entered the asteroid belt and it is closing in on giant asteroid Vesta. (read more)
Source: NASA
NASA and co-researchers from the United States, South Korea and Japan have found a new mineral named "Wassonite" in one of the most historically significant meteorites recovered in Antarctica in December 1969.
Image credit: NASA
The new mineral was discovered within the meteorite officially designated Yamato 691 enstatite chondrite. The meteorite was discovered the same year as other landmark meteorites Allende and Murchison and the return of the first Apollo lunar samples. The study of meteorites helps define our understanding of the formation and history of the solar system. (read more)
Source: Messenger Press Release
On April 4th, MESSENGER began its yearlong science campaign to understand the innermost planet. The spacecraft will fly around Mercury 700 times over the next 12 months, and its instruments will perform the first complete reconnaissance of the cratered planet’s geochemistry, geophysics, geological history, atmosphere, magnetosphere, and plasma environment.
“MESSENGER’s orbital commissioning phase, which we just completed, demonstrated that the spacecraft and payload are all operating nominally, notwithstanding Mercury’s challenging environment,” says Principal Investigator Sean Solomon, of the Carnegie Institution of Washington. “With the beginning today of the primary science phase of the mission, we will be making nearly continuous observations that will allow us to gain the first global perspective on the innermost planet. Moreover, as solar activity steadily increases, we will have a front-row seat on the most dynamic magnetosphere–atmosphere system in the Solar System.”
MESSENGER’s 12-month orbital phase covers two Mercury solar days (one Mercury solar day, from sunrise to sunrise, is equal to 176 Earth days). This means that the spacecraft can view a given spot on the surface under given lighting conditions only twice during the mission, six months apart, making available observation time a precious resource. “So the surface mapping observations had to be planned for the entire year far in advance to ensure coverage of the entire planet under acceptable illumination and viewing geometries,” says MESSENGER Deputy Project Scientist Brian Anderson, who oversaw the planning for orbital operations.
SciBox – a suite of software tools for science observation simulation– was developed to help the team choreograph the complicated process of maximizing the scientific return from the mission and minimizing conflicts between instrument observations, while at the same time meeting all spacecraft constraints on pointing, data downlink rates, and onboard data storage capacity. The SciBox tool simulates the entire year of science observations and identifies the best times to take each type of observation. The commands for each week of observations are derived from this full mission analysis.
For instance, Anderson explains, “The remote sensing instruments to measure topography and determine surface and atmospheric composition are fixed on the spacecraft and share the same view direction. Because the ideal viewing directions for these instruments are not the same, we assigned altitude ranges for which the spacecraft pointing is optimized for the science from each instrument. The camera has its own pivot, so it has much greater freedom in viewing the surface and it takes pictures at all altitudes,” he continues. “Several other instruments make measurements of local properties, magnetic field, or charged particles and acquire excellent data regardless of the spacecraft pointing.”
SciBox works by finding the best opportunities for each of the instruments to make their measurements and then analyzing how those measurements contribute toward the science goals of the entire mission. “The SciBox tool allows us to plan thousands of science observation activities every week that have to be precisely timed with customized spacecraft pointing,” Anderson says.
The observations depend critically on where the spacecraft is in its orbit around Mercury, so the final science observation plan was not generated until the MESSENGER spacecraft completed Mercury orbit insertion. The software commands for this week’s instrument operations were sent to MESSENGER only last week.
“We had to wait until after MESSENGER was in orbit before we could start building the actual science sequences that start today, because we needed the actual in-orbit ephemeris as calculated by our navigation team to ensure that images and other pointed observations were taken where planned,” explains MESSENGER Payload Operations Manager Alice Berman.
On March 21, her team received the first ephemeris following Mercury orbit insertion, a delivery that provided less than two weeks for each instrument payload lead to generate inputs, test them, and deliver them to the mission operations team. That team then had to merge those science observation commands with the spacecraft operating commands and fully test the entire package.
For example, the command load for this week’s observations provides for the acquisition of 4,196 images by the Mercury Dual Imaging System (MDIS). The MDIS team had to check the commands governing each of those images; and the guidance and control team next had to run detailed software simulations on all the science guidance and control commands for the entire week and then add the non-science commands, such as those directing solar panel motions and star trackers. Finally the team re-simulated the full sequence again.
“It’s a tremendous amount of work and analysis that has to be done every week,” Berman notes. “From our experience with the In-the-Life exercises over the last two years, we determined that we would need three weeks for that process. But our entire team did an outstanding job getting it all done on the accelerated schedule.”
Imaging during the MESSENGER flybys provided important reconnaissance for the observations from orbit. During MESSENGER’s first six months in orbit, MDIS will create new, higher resolution, global maps of the planet in color and monochrome, acquired under near-ideal viewing conditions.
Emphasis during the second six months will shift to targeted, high-resolution imaging with the MDIS narrow-angle camera and acquisition of a second monochrome map but from a different viewing direction to allow stereoscopic analysis of topography. Additionally,
· The Mercury Laser Altimeter will measure the topography of the northern hemisphere over four Mercury years.
· The Gamma-Ray and Neutron Spectrometer and the X-Ray Spectrometer will yield global maps of elemental composition.
· The Magnetometer will measure the vector magnetic field under a range of solar distances and conditions.
· The Visible and Infrared Spectrograph will produce global maps of surface reflectance from which surface mineralogy can be inferred, and the Ultraviolet and Visible Spectrometer will produce time-dependent global maps of exospheric species abundances versus altitude.
· The Energetic Particle and Plasma Spectrometer will sample the plasma and energetic particle population in the solar wind, at major magnetospheric boundaries, and throughout the environment of Mercury at a range of solar distances and levels of solar activity.
· The radio science experiment will extend topographic information to the southern hemisphere by making occultation measurements of planet radius, and the planet’s obliquity and the amplitude of the physical libration will be determined independently from the topography and gravity field.
MESSENGER orbits Mercury twice every Earth day. Once a day, the spacecraft will stop making measurements and turn its antenna toward Earth for eight hours to send data back – via the Deep Space Network – to the MESSENGER Mission Operations Center at the Johns Hopkins University Applied Physics Laboratory in Laurel, Md.
“The engineering teams accomplished an astonishing achievement by developing, launching, and guiding MESSENGER through the inner solar system and safely placing the spacecraft in orbit about Mercury” says Anderson. “Now the science planning teams are working hard to take full advantage of this unprecedented opportunity to learn everything we can about Earth’s heretofore enigmatic sibling planet. With thousands of science observation commands to plan, test, and verify every week, not to mention the need to verify that the observations are successful, we certainly have our work cut out for us,” Anderson says. “But we have the tools, the people, and the processes in place to do the job. So far, everything is going just the way we planned.”
Source: ESA
ESA’s Envisat satellite has measured record low levels of ozone over the Euro-Atlantic sector of the northern hemisphere during March.
This record low was caused by unusually strong winds, known as the polar vortex, which isolated the atmospheric mass over the North Pole and prevented it from mixing with air in the mid-latitudes.
This led to very low temperatures and created conditions similar to those that occur every southern hemisphere winter over the Antarctic. (read more)
Source: ESA/Hubble
Image Credit:ESA/Victor R. Ruiz
Access a universe of knowledge about the Universe with three new free iPad apps from ESO’s education and Public Outreach Department (ePOD), available just in time for the iPad 2.
Together with the European Space Agency (ESA), ePOD has launched the free ESA/Hubble Top 100 Images app, which brings users the best Hubble pictures from ESA, as NASA’s partner in this international project.(read more)
Related links:
ESO ann11012 - Announcement
Source: ESA
Neibouring volcanoes on Mars. Credits: ESA/DLR/FU Berlin (G. Neukum)
ESA’s Mars Express has returned images of mist-capped volcanoes located in the northern hemisphere of the red planet. Long after volcanic activity ceased, the area was transformed by meteor impacts that deposited ejected material over the lower flanks of the volcanoes. (read more)
Source: ESA
GOCE's new geoid. Credits: ESA/HPF/DLR
After just two years in orbit, ESA's GOCE satellite has gathered enough data to map Earth's gravity with unrivalled precision. Scientists now have access to the most accurate model of the 'geoid' ever produced to further our understanding of how Earth works.(read more)
