Hunting Massive Stars with Herschel

In this new view of a vast star-forming cloud called W3, the Herschel space observatory tells the story of how massive stars are born. Herschel is a European Space Agency mission with important NASA contributions. W3 is a giant gas cloud containing an enormous stellar nursery, some 6,200 light-years away in the Perseus Arm, one of our Milky Way galaxy's main spiral arms.

By studying regions of massive star formation in W3, scientists have made progress in solving one of the major conundrums in the birth of massive stars. That is, even during their formation, the radiation blasting away from these stars is so powerful that they should push away the very material from which they feed. If this is the case, how can massive stars form at all?

Observations of W3 point toward a possible solution: in these very dense regions, there appears to be a continuous process by which the raw material is moved around, compressed and confined, under the influence of clusters of young, massive stars called protostars.

Through their strong radiation and powerful winds, populations of young, high-mass stars may well be able to build and maintain localized clumps of material from which they can continue to feed during their earliest and most chaotic years, despite their incredible energy output.

The W3 star-formation complex is one of the largest in the outer Milky Way, hosting the formation of both low- and high-mass stars. The distinction between low- and high-mass stars is drawn at eight times the mass of our own sun: above this limit, stars end their lives as supernovas.

Dense, bright blue knots of hot dust marking massive star formation dominate the upper left of the image. Intense radiation streaming away from the stellar infants heats up the surrounding dust and gas, making it shine brightly in Herschel's infrared-sensitive eyes.

Older high-mass stars are also seen to be heating up dust in their environments, appearing as the blue regions, for example, lower down and to the left.
Extensive networks of much colder gas and dust weave through the scene in the form of red filaments and pillar-like structures. Several of these cold cores conceal low-mass star formation, hinted at by tiny yellow knots of emission.

Herschel is a European Space Agency mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community

Mimas Peeks Over Saturn

Saturn and its north polar hexagon dwarf Mimas as the moon peeks over the planet's limb. Saturn's A ring also makes an appearance on the far right. Mimas is 246 miles (396 kilometers) across.

This view looks toward the sunlit side of the rings from about 21 degrees above the ringplane. The image was taken with the Cassini spacecraft wide-angle camera on Nov. 28, 2012 using a spectral filter sensitive to wavelengths of near-infrared light centered at 752 nanometers.

The view was obtained at a distance of approximately 495,000 miles (797,000 kilometers) from Saturn and at a Sun-Saturn-spacecraft, or phase, angle of 4 degrees. Image scale is 27 miles (44 kilometers) per pixel.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C. The Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo. 

Supercomputer Helps Planck Mission Expose Ancient Light

Like archeologists carefully digging for fossils, scientists with the Planck mission are sifting through cosmic clutter to find the most ancient light in the universe.

The Planck space telescope has created the most precise sky map ever made of the oldest light known, harking back to the dawn of time. This light, called the cosmic microwave background, has traveled 13.8 billion years to reach us. It is so faint that Planck observes every point on the sky an average of 1,000 times to pick up its glow.

The task is even more complex than excavating fossils because just about everything in our universe lies between us and the ancient light. Complicating matters further is "noise" from the Planck detectors that must be taken into account.

That's where a supercomputer helps out. Supercomputers are the fastest computers in the world, performing massive amounts of calculations in a short amount of time.
"So far, Planck has made about a trillion observations of a billion points on the sky," said Julian Borrill of the Lawrence Berkeley National Laboratory, Berkeley, Calif. "Understanding this sheer volume of data requires a state-of-the-art supercomputer."

Planck is a European Space Agency mission, with significant contributions from NASA. Under a unique agreement between NASA and the Department of Energy, Planck scientists have been guaranteed access to the supercomputers at the Department of Energy's National Energy Research Scientific Computing Center at the Lawrence Berkeley National Laboratory. The bulk of the computations for this data release were performed on the Cray XE6 system, called the Hopper. This computer makes more than a quintillion calculations per second, placing it among the fastest in the world.

One of the most complex aspects of analyzing the Planck data involves the noise from its detectors. To detect the incredibly faint cosmic microwave background, these detectors are made of extremely sensitive materials. When the detectors pick up light from one part of the sky, they don't reset afterwards to a neutral state, but instead, they sort of buzz for a bit like the ringing of a bell. This buzzing affects observations made at the next part of the sky.

This noise must be understood, and corrected for, at each of the billion points observed repeatedly by Planck as it continuously sweeps across the sky. The supercomputer accomplishes this by running simulations of how Planck would observe the entire sky under different conditions, allowing the team to identify and isolate the noise.

Another challenge is carefully teasing apart the signal of the relic radiation from the material lying in the foreground. It's a big mess, as some astronomers might say, but one that a supercomputer can handle.
"It's like more than just bugs on a windshield that we want to remove to see the light, but a storm of bugs all around us in every direction," said Charles Lawrence, the U.S. project scientist for the Planck mission. "Without the exemplary interagency cooperation between NASA and the Department of Energy, Planck would not be doing the science it's doing today."

The computations needed for Planck's current data release required more than 10 million processor-hours on the Hopper computer. Fortunately, the Planck analysis codes run on tens of thousands of processors in the supercomputer at once, so this only took a few weeks.

Planck is a European Space Agency mission, with significant participation from NASA. NASA's Planck Project Office is based at JPL. JPL, a division of the California Institute of Technology, Pasadena, contributed mission-enabling technology for both of Planck's science instruments. European, Canadian and U.S. Planck scientists work together to analyze the Planck data.

Hubble Digs Up Galactic Glow Worm

This charming and bright galaxy, known as IRAS 23436+5257, was captured by the NASA/ESA Hubble Space Telescope. It is located in the northern constellation of Cassiopeia, which is named after an arrogant, vain, and yet beautiful mythical queen.

The twisted, wormlike structure of this galaxy is most likely the result of a collision and subsequent merger of two galaxies. Such interactions are quite common in the universe, and they can range from minor interactions involving a satellite galaxy being caught by a spiral arm, to major galactic crashes. Friction between the gas and dust during a collision can have a major effect on the galaxies involved, morphing the shape of the original galaxies and creating interesting new structures.

When you look up at the calm and quiet night sky it is not always easy to picture it as a dynamic and vibrant environment with entire galaxies in motion, spinning like children’s toys and crashing into whatever crosses their path. The motions are, of course, extremely slow, and occur over millions or even billions of years.

The aftermath of these galactic collisions helps scientists to understand how these movements occur and what may be in store for our own Milky Way, which is on a collision course with a neighboring galaxy, Messier 31.

Hubble Gazes on One Ring to Rule Them All

Galaxies can take many forms — elliptical blobs, swirling spiral arms, bulges, and disks are all known components of the wide range of galaxies we have observed using telescopes like the NASA/ESA Hubble Space Telescope.

Ring galaxies are mysterious objects. They are thought to form when one galaxy slices through the disk of another, larger, one — as galaxies are mostly empty space, this collision is not as aggressive or as destructive as one might imagine. The likelihood of two stars physically colliding is minimal, and it is instead the gravitational effects of the two galaxies that cause the disruption.

This disruption upsets the material in both galaxies, and redistributes it forming a dense central core, encircled by bright stars. All this commotion causes clouds of gas and dust to collapse and triggers new periods of intense star formation in the outer ring, which is full of hot, young, blue stars and regions that are actively giving rise to new stars.

The sparkling pink and purple loop of Zw II 28 is not a typical ring galaxy due to its lack of a visible central companion. For many years it was thought to be a lone circle on the sky, but observations using Hubble have shown that there may be a possible companion lurking just inside the ring, where the loop appears to double back on itself. The galaxy has a knot-like, swirling ring structure, with some areas appearing much brighter than others.

Landforms on Mars

This image was taken by the High Resolution Imaging Science Experiment (HiRISE) flying onboard the Mars Reconnaissance Orbiter mission.

Gully landforms like those in this image are found in many craters in the mid-latitudes of Mars. Changes in gullies were first seen in images from the Mars Orbiter Camera in 2006, and studying such activity has been a high priority for HiRISE. Many examples of new deposits in gullies are now known.

This image shows a new deposit in Gasa Crater, in the Southern mid-latitudes. The deposit is distinctively blue in enhanced-color images. This image was acquired in southern spring, but the flow that formed the deposit occurred in the preceding winter.

Current gully activity appears to be concentrated in winter and early spring, and may be caused by the seasonal carbon dioxide frost that is visible in gully alcoves in the winter. 

Guinness World Record for Largest Astronomy Lesson at SXSW

Looking up through hundreds of colored filters and spectral glasses, 526 people shattered the record for the Largest Astronomy Lesson. Under the Texas night sky, students were instructed on the lawn of the Long Center for the Performing Arts at the South by Southwest (SXSW) festival in Austin on Sunday, March 10, 2013.

In the spirit of Science, Technology, Engineering and Mathematics (STEM) Education Coalition outreach at SXSW, NASA, the Space Telescope Science Institute (STScI) and Northrop Grumman organized the record breaking event which was arbitrated by the Guinness World Records organization. In breaking this record, instructors aimed to shine light on the importance of astronomy with the full-scale model of the James Webb Space Telescope as their backdrop.

During the lesson, Frank Summers, an astrophysicist, and Dan McCallister, an education specialist, both from STScI, Baltimore, Md., demonstrated how astronomers use light and color to uncover the secrets of the cosmos. The lesson, prepared by STScI’s Office of Public Outreach, explained how astronomers use light and color to gain information about objects nearby like the moon and asteroids to young galaxies that are billions and billions of light-years away, and the importance of observing in wavelengths across the electromagnetic spectrum (the full range of light waves possible).

For more info, visit: http://www.nasa.gov

Tropical Cyclone Sandra

Sandra formed as a tropical storm over the southern Pacific Ocean on March 7, 2013, and strengthened into a cyclone two days later. On March 11, the U.S. Navy’s Joint Typhoon Warning Center (JTWC) reported that Sandra was located roughly 350 nautical miles (650 kilometers) northwest of Nouméa, New Caledonia. The storm had maximum sustained winds of 90 knots (165 kilometers per hour) and gusts up to 110 knots (205 kilometers per hour).

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this natural-color image of Sandra on March 10. The eye of the cyclone was located northwest of New Caledonia and west of Vanuatu, and storm clouds spanned hundreds of kilometers.

Sandra had been moving toward the southeast, and the JTWC forecast that the storm would continue in that direction for the next few days, although it was expected to weaken considerably over the next day or so.

Hubble Finds Birth Certificate of Oldest Known Star

A team of astronomers using NASA's Hubble Space Telescope has taken an important step closer to finding the birth certificate of a star that’s been around for a very long time.

"We have found that this is the oldest known star with a well-determined age," said Howard Bond of Pennsylvania State University in University Park, Pa., and the Space Telescope Science Institute in Baltimore, Md.

The star could be as old as 14.5 billion years (plus or minus 0.8 billion years), which at first glance would make it older than the universe's calculated age of about 13.8 billion years, an obvious dilemma.

But earlier estimates from observations dating back to 2000 placed the star as old as 16 billion years. And this age range presented a potential dilemma for cosmologists. "Maybe the cosmology is wrong, stellar physics is wrong, or the star's distance is wrong," Bond said. "So we set out to refine the distance."

The new Hubble age estimates reduce the range of measurement uncertainty, so that the star's age overlaps with the universe's age — as independently determined by the rate of expansion of space, an analysis of the microwave background from the big bang, and measurements of radioactive decay.

This "Methuselah star," cataloged as HD 140283, has been known about for more than a century because of its fast motion across the sky. The high rate of motion is evidence that the star is simply a visitor to our stellar neighborhood. Its orbit carries it down through the plane of our galaxy from the ancient halo of stars that encircle the Milky Way, and will eventually slingshot back to the galactic halo.

This conclusion was bolstered by the 1950s astronomers who were able to measure a deficiency of heavier elements in the star as compared to other stars in our galactic neighborhood. The halo stars are among the first inhabitants of our galaxy and collectively represent an older population from the stars, like our sun, that formed later in the disk. This means that the star formed at a very early time before the universe was largely "polluted" with heavier elements forged inside stars through nucleosynthesis. (The Methuselah star has an anemic 1/250th as much of the heavy element content of our sun and other stars in our solar neighborhood.)

The star, which is at the very first stages of expanding into a red giant, can be seen with binoculars as a 7th-magnitude object in the constellation Libra.

Hubble's observational prowess was used to refine the distance to the star, which comes out to be 190.1 light-years. Bond and his team performed this measurement by using trigonometric parallax, where an apparent shift in the position of a star is caused by a change in the observer's position. The results are published in the February 13 issue of the Astrophysical Journal Letters.
The parallax of nearby stars can be measured by observing them from opposite points in Earth's orbit around the sun. The star's true distance from Earth can then be precisely calculated through straightforward triangulation.

Once the true distance is known, an exact value for the star's intrinsic brightness can be calculated. Knowing a star's intrinsic brightness is a fundamental prerequisite to estimating its age.

Before the Hubble observation, the European Space Agency's Hipparcos satellite made a precise measurement of the star's parallax, but with an age measurement uncertainty of 2 billion years. One of Hubble's three Fine Guidance Sensors measured the position of the Methuselah star. It turns out that the star's parallax came out to be virtually identical to the Hipparcos measurements. But Hubble's precision is five times better that than of Hipparcos. Bond's team managed to shrink the uncertainty so that the age estimate was five times more precise.

With a better handle on the star's brightness Bond's team refined the star's age by applying contemporary theories about the star's burn rate, chemical abundances, and internal structure. New ideas are that leftover helium diffuses deeper into the core and so the star has less hydrogen to burn via nuclear fusion. This means it uses fuel faster and that correspondingly lowers the age.

Also, the star has a higher than predicted oxygen-to-iron ratio, and this too lowers the age. Bond thinks that further oxygen measurement could reduce the star's age even more, because the star would have formed at a slightly later time when the universe was richer in oxygen abundance. Lowering the upper age limit would make the star unequivocally younger than the universe.

"Put all of those ingredients together and you get an age of 14.5 billion years, with a residual uncertainty that makes the star's age compatible with the age of the universe," said Bond. "This is the best star in the sky to do precision age calculations by virtue of its closeness and brightness."

This Methuselah star has seen many changes over its long life. It was likely born in a primeval dwarf galaxy. The dwarf galaxy eventually was gravitationally shredded and sucked in by the emerging Milky Way over 12 billion years ago.

The star retains its elongated orbit from that cannibalism event. Therefore, it's just passing through the solar neighborhood at a rocket-like speed of 800,000 miles per hour. It takes just 1,500 years to traverse a piece of sky with the angular width of the full Moon. The star's proper motion angular rate is so fast (0.13 milliarcseconds an hour) that Hubble could actually photograph its movement in literally a few hours.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington.

NASA Is With You When You Fly

Traveling by air this holiday season, or any time of year? If so then you'll be in the company of millions who are directly benefiting from the ongoing research performed by NASA's aeronautical innovators now, and in the future.

During 2012, NASA's Aeronautics Research Mission Directorate continued a wide range of research projects aimed at advancing the science of flight. Among the goals: enhancing safety, designing more fuel efficient jet engines, enabling quieter airplanes and improving air traffic management while also seeking to educate and inspire future generations of aviation experts.

NASA's "aeronauts" even had a hand in helping scientists learn about the Martian atmosphere during Curiosity's nail-biting descent toward the Red Planet in August.

Here are some highlights from 2012.

Developing Technology

NASA worked closely with Boeing in 2012 to fly the X-48C Blended Wing Body research aircraft, a sub-scale, remotely piloted vehicle intended to test new aircraft designs that forgo the conventional tube-and-wing airplane look in favor of one that blends the vehicle's wing and body into a smoothly contoured shape. Researchers believe this design could someday reduce fuel consumption by nearly 60 percent, noise by 70 percent, and emissions by 80 percent.

For more info, visit: http://www.nasa.gov/

NASA Transfers Operational Control of Environmental Satellite

The Suomi National Polar-orbiting Partnership (NPP) satellite, a partnership between NASA and the National Oceanic and Atmospheric Administration (NOAA), was transitioned to NOAA operational organization control Feb. 22, 2013. The transition marks the next step of the mission that supports NASA's Earth science research and NOAA's weather forecasting missions.

Suomi NPP continues the observations of Earth from space that were pioneered by NASA's Earth Observing System. The satellite's five instruments are providing scientists with data to extend more than 30 key long-term datasets. These records, which include observations of the ozone layer, land cover, atmospheric temperatures and ice cover, provide critical data for global change science.

"Suomi NPP is an important asset for NASA, NOAA, and the nation," said Michael Freilich, director of the Earth Science Division in NASA's Science Mission Directorate in Washington. "As a true collaboration in which all partners benefit, Suomi NPP measurements are supporting researchers and weather forecasters alike."

Suomi NPP also collects critical data for our understanding of long-term climate change while increasing our ability to improve weather forecasts in the short term. NOAA meteorologists are incorporating Suomi NPP information into their weather prediction models to produce forecasts and warnings that already are helping emergency responders anticipate, monitor, and react to many types of natural events.

"Satellites like Suomi NPP are critical to the National Weather Service's mission and improved decision support services," said Louis Uccellini, director of NOAA's National Weather Service. "These polar satellites provide an important dataset for the global Earth-observing system and will lead to improved forecasts out to three days in the future and beyond."

The Suomi NPP mission is a bridge between NASA's legacy Earth-observing missions and NOAA's next-generation Joint Polar Satellite System (JPSS). Suomi NPP carries groundbreaking new Earth-observing instruments that JPSS will use operationally. The first satellite in the JPSS series, JPSS-1, is targeted for launch in early 2017.

NASA launched Suomi NPP Oct. 28, 2011, from California. Since then, the JPSS program based at NASA's Goddard Space Flight Center in Greenbelt., Md., has been helping maintain the Suomi NPP instruments in addition to providing the ground system, with NOAA institutional organizations providing operational mission support. The NOAA operations group now assumes responsibility for Suomi NPP.

Suomi NPP instruments observe key attributes of the Earth, including measurements of cloud and vegetation cover, ice cover, ocean color, and sea and land surface temperatures. The suite includes the Visible/Infrared Imaging Radiometer Suite (VIIRS); the Cross-track Infrared Sounder (CrIS); the Clouds and Earth Radiant Energy System (CERES); the Advanced Technology Microwave Sounder (ATMS); and the Ozone Mapping and Profiler Suite (OMPS).

"Observations from Suomi NPP are helping to advance science and to increase the accuracy of short-term meteorological predictions," said James Gleason, Suomi NPP project scientist at NASA Goddard. "ATMS data are being used by the National Weather Service in their forecast models. And OMPS data continued over 30 years of ozone hole measurements helping the community put this year's smaller ozone hole in perspective."

Suomi NPP observes Earth's surface twice a day, once in daylight and once at night, flying 512 miles (824 kilometers) high in a polar orbit. The satellite sends its data once an orbit to a ground station in Svalbard, Norway. The information is transferred via fiber optic cable for processing at NOAA's Satellite Operations Facility in Suitland, Md. Data products are archived at the NOAA National Climatic Data Center in Ashville, N.C.

Suomi NPP is named in honor of the late Verner E. Suomi, a meteorologist at the University of Wisconsin who is recognized widely as the father of satellite meteorology.

Cyclone Rusty's Rains Stirred Up Sediment

In the wake of Cyclone Rusty's heavy rains from the week of Feb. 25 when it made landfall near Port Hedland on the Pilbara coast of Western Australia, sediment filled many rivers and tributaries that flowed northwest into the Southern Indian Ocean. In addition to sediment that was swept into the ocean, Rusty stirred up sediment from the ocean bottom. The sediment appears as swirls in this true-color satellite image from the Moderate Resolution Imaging Spectroradiometer instrument that flies aboard NASA's Aqua satellite on March 3, 2013 at 0600 UTC 1 a.m. EST).

NASA's SDO Observes Fast-Growing Sunspot

As magnetic fields on the sun rearrange and realign, dark spots known as sunspots can appear on its surface. Over the course of Feb. 19-20, 2013, scientists watched a giant sunspot form in under 48 hours. It has grown to over six Earth diameters across but its full extent is hard to judge since the spot lies on a sphere not a flat disk.

The spot quickly evolved into what's called a delta region, in which the lighter areas around the sunspot, the penumbra, exhibit magnetic fields that point in the opposite direction of those fields in the center, dark area. This is a fairly unstable configuration that scientists know can lead to eruptions of radiation on the sun called solar flares.

Hubble Observes Glowing, Fiery Shells of Gas

It may look like something from "The Lord of the Rings," but this fiery swirl is actually a planetary nebula known as ESO 456-67. Set against a backdrop of bright stars, the rust-colored object lies in the constellation of Sagittarius (The Archer), in the southern sky.

Despite the name, these ethereal objects have nothing at all to do with planets; this misnomer came about over a century ago, when the first astronomers to observe them only had small, poor-quality telescopes. Through these, the nebulae looked small, compact, and planet-like — and so were labeled as such.

When a star like the sun approaches the end of its life, it flings material out into space. Planetary nebulae are the intricate, glowing shells of dust and gas pushed outwards from such a star. At their centers lie the remnants of the original stars themselves — small, dense white dwarf stars.

In this image of ESO 456-67, it is possible to see the various layers of material expelled by the central star. Each appears in a different hue — red, orange, yellow, and green-tinted bands of gas are visible, with clear patches of space at the heart of the nebula. It is not fully understood how planetary nebulae form such a wide variety of shapes and structures; some appear to be spherical, some elliptical, others shoot material in waves from their polar regions, some look like hourglasses or figures of eight, and others resemble large, messy stellar explosions — to name but a few.