Universe Today

September 30, 2009December 24, 2015 by Nancy Atkinson

LRO Provides Flashback to 1966

LROC image of Surveyor 1 on the Moon. NASA/GSFC/Arizona State University

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On June 2, 1966 the Surveyor 1 spacecraft soft landed on the Moon, the first US spacecraft to set down on another body. Now, 43 years later the Lunar Reconnaissance Orbiter Camera has spotted this historic spacecraft, sitting silently on the Moon’s surface. The scene shows the spacecraft (annotated with an arrow, and the shadow shows up very well) just south of a 40 m diameter crater and about 110 m northwest of a 190 m diameter crater lined with boulders. The landing site is in the northeast corner of the Flamsteed Ring, a 100 km diameter impact crater almost completely buried by mare lavas such that all that remains exposed is the upper part of the original crater rim.

Surveyor 1 took its own picture on the Moon back in 1966. Credit: NASA

Surveyor 1 collected over 11,000 images, most during the first lunar day between landing and July 7, 1966. The spacecraft continued to operate until January 7, 1967. The Surveyor images demonstrated that the lunar surface was strong enough to support a landed vehicle or a human. The detailed images also indicated that the surface was composed of a granular material interpreted to be produced by the impact of various size meteors over billions of years.

And 43 years later we figured out some H20 and OH were also part of the mix.

See the entire image swath at the LROC site.

Source: LROC

September 30, 2009December 24, 2015 by Nancy Atkinson

Where In The Universe #73

Ready for another Where In The Universe Challenge? Here’s #73! Take a look and see if you can name where in the Universe this image is from. Give yourself extra points if you can name the spacecraft responsible for the image. As usual, we’ll provide the image today, but won’t reveal the answer until tomorrow. This gives you a chance to mull over the image and provide your answer/guess in the comment section. Please, no links or extensive explanations of what you think this is — give everyone the chance to guess.

UPDATE: The answer has been posted below.

Doesn’t the Moon look good in pink? Yes, this is our Moon, as seen in gamma rays by the Compton Gamma Ray Observatory. If you could see gamma rays – photons with a million or more times the energy of visible light, the Moon would appear brighter than the Sun according to astronomers who worked with the Energetic Gamma Ray Experiment Telescope (EGRET), which toiled in orbit on board Compton from April 1991 to June 2000.

EGRET’s gamma-ray vision was not sharp enough to resolve a lunar disk or any surface features, but its sensitivity revealed the induced gamma-ray moonglow.

More info about Compton Gamma Ray Observatory.

Check back next week for another WITU challenge!

September 30, 2009December 24, 2015 by Nancy Atkinson

GOCE Satellite Begins Mapping Earth’s Gravity in Lower Orbit Than Expected

Anaglyph images created from an ESA video animation of global gravity gradients. A more accurate global map will be generated by ESA's GOCE craft. Credit: ESA and Nathaniel Burton Bradford.

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Is Earth’s gravity field as intriguing and misshapen as this image above? We’re about to find out. The sexy looking Gravity field and steady-state Ocean Circulation Explorer or GOCE satellite has completed its calibration and is now in its science orbit to map the tiny variations of Earth’s gravity in unprecedented detail. And it turns out the sun’s current period of low solar activity has a side benefit for the GOCE mission. Less solar activity means a calmer environment for GOCE in its low Earth orbit, so its current orbit of 255 km is a few kilometers lower than engineers had originally planned. This is good news – the gravity measurements being made at the moment will be even more accurate.

“The completion of the commissioning and first in-flight calibration marks an important milestone for the mission, ” said Rune Floberghagen, ESA’s GOCE Mission Manager. “We are now entering science operations and are looking forward to receiving and processing excellent three-dimensional information on the structure of Earth’s gravity field.”

Anaglyph created from an ESA GOCE craft animation. Credit: ESA and Nathanial Burton Bradford

Gravity is stronger closer to Earth, so GOCE was designed to orbit as low as possible while remaining stable as it flies through the fringes of our atmosphere. GOCE’s sleek aerodynamic design helps this the satellite to cut though the tenuous fringes of Earth’s atmosphere at this low altitude. Moreover, the electric ion thruster at the back continuously generates tiny forces to compensate for any drag that GOCE experiences along its orbit.

To help avoid drag and ensure that the gravity measurements are of true gravity, the satellite has to be kept stable in ‘free fall’. Any buffeting from residual air at this low altitude could potentially drown out the gravity data.

Space gradiometry and the use of the sophisticated electric propulsion are both ‘firsts’ in satellite technology, so the commissioning and calibration were particularly important for the success of the mission. This phase was completed in the summer, ready for the tricky task of bringing GOCE down to its operational altitude, which took a couple of months.

Worldwide gravity gradients from simulations. GOCE is now gathering data such as shown here to map Earth's gravity with unprecedented accuracy and spatial resolution. Credit: ESA

Over two six-month uninterrupted periods, GOCE will map these subtle variations with extreme detail and accuracy. This will result in a unique model of the ‘geoid’ – the surface of an ideal global ocean at rest.

A precise knowledge of the geoid is crucial for accurate measurement of ocean circulation and sea-level change, both of which are influenced by climate. The data from GOCE are also much-needed to understand the processes occurring inside Earth. In addition, by providing a global reference to compare heights anywhere in the world, the GOCE-derived geoid will be used for practical applications in areas such as surveying and leveling.

Stay tuned for some unique data about our home planet from GOCE.

Thanks to Nathanial Burton-Bradford for the terrific anaglyphs he created from a GOCE animation. See more of Nathanial’s images on his Flickr page.

Source: ESA

September 30, 2009December 24, 2015 by Nancy Atkinson

Soyuz Launch Video

Soyuz launch on Sept. 30. Credit: NASA/Bill Ingalls.

The Soyuz TMA-16 spacecraft launched today at 07:14 GMT (2:14 CDT) from the Baikonur Cosmodrome in Kazakhstan. On board were Soyuz Commander Max Suraev, NASA Flight Engineer Jeff Williams and spaceflight participant Guy Laliberte, founder of Cirque du Soleil . They will arrive at the International Space Station on Friday.

If you’ve ever wondered about some of the unusual rituals the Russians partake in before a launch, an article on Discovery Space outlined the following traditions witnessed over the years by reporters for The Associated Press, or reported in the Russian media:

CARNATIONS FOR YURI: Before leaving for Baikonur, crew members lay red carnations at the monuments of the first Soviet cosmonauts in Star City outside Moscow and visit the office of Yuri Gagarin, the first human in space, and write their names in the visitors’ book.

ARRIVAL: Cosmonauts arrive in Baikonur on different planes and without their spouses. They check into the Kosmonaut hotel and walk down the alley where every tree was planted by cosmonauts who successfully returned from space.

MOVIE NIGHT: On the night before the launch, the cosmonauts watch “The White Sun of the Desert,” a 1969 comedy about a Russian soldier fighting in Central Asia.

MUSIC: Before leaving for the launch, the cosmonauts sip champagne and leave their signatures on the doors of their hotel rooms. Then they ride aboard a minibus to the launch pad listening to “Grass Near Home,” a 1983 hit of Soviet rock band The Earthlings.

BLESSING: After the Soviet era, black-robed Orthodox priests began to bless each rocket before launch.

SOAKING THE STAND-INS: 30 minutes before the launch, when the main crew is sealed in the spaceship, the cosmonaut’s stand-ins, who act as backup for the regular crew, are “soaked” by gulping vodka shots with journalists at a shabby cafeteria near the launch pad.

SOILING THE WHEEL: The cosmonauts get out of the bus near the rocket and urinate on its right rear wheel. The rite dates back to Gagarin himself, who reportedly did not want to soil his space suit during the takeoff.

MASCOT: A mascot, usually a stuffed animal named “Boris,” hangs in front of the crew. When the toy begins to float, the cosmonauts know they are approaching near zero gravity.

LANDING: After the landing in Kazakh steppe, the cosmonauts sign their capsule, which is charred by the heat of re-entry, and drink a bottle of vodka stashed before the launch. After a helicopter ride to Baikonur, they plant a tree near the Kosmonaut hotel.

RETURN TO MOSCOW: Upon their return to Star City outside Moscow, they pay a final visit to Gagarin’s monument and go to the church of St. Prince Daniil of Moscow, where they kiss the saint’s relics.

Source: Discovery Space

September 30, 2009December 24, 2015 by Nancy Atkinson

MESSENGER Went Into Safe Mode Approaching Mercury

This unnamed basin was imaged as MESSENGER approached Mercury. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

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The MESSENGER spacecraft went into safe mode just before its closest approach of Mercury on Sept. 29. Although the instruments were taking data as the spacecraft came near the planet during this third flyby of the mission, after going into safe mode, no further data or pictures were obtained. This means the expected science investigations from the flyby were not executed. However, as Emily Lakdawalla pointed on in the Planetary Blog, the most important purpose of this flyby was the last gravity assist that will allow MESSENGER to enter orbit in 2011, and to that end, the flyby was a complete success. Additionally, the images taken during the approach are of the 5% of Mercury that was previously unseen, as in the image above of this unnamed basin. See more images from the approach below.

A High-resolution Look over Mercury's Northern Horizon. Credit: MESSENGER team

MESSENGER skimmed just 142 miles (228 km) above Mercury at closest approach, and then whipped behind the planet for the gravity assist. During the operation, five MESSENGER “fellows” or master teachers were reporting the flyby live via Twitter. Gene Gordon (Porchdragon on Twitter) reported that unexpectedly, the signal dropped from MESSENGER before the expected signal blackout while flying on the other side of Mercury: “Suddenly room got quiet and people hovering near computers. Unexpected signal drop just occurred. Sense of nervousness seems to have happened.”

Read Gene Gordon’s blog post about his experiences.

The MESSENGER team had to wait over 50 minutes until the spacecraft emerged from behind Mercury, and were relieved to be able to resume contact. As of Wednesday morning, the spacecraft was operating normally, and the reason for the signal drop was unclear. At a briefing, MESSENGER team members said the spacecraft went into safe mode when it entered Mercury’s shadow and tried to switch to battery power. The team is still looking into why this anomaly occurred.

A little less than half of the”extra” science goals for the flyby were accomplished. See our previous article on the science goals for the flyby. Following this flyby. only the polar regions of Mercury have never been seen.

Previously unseen side of Mercury. Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

MESSENGER made its closest approach on Tuesday at about 5:55 p.m. EDT (2155 GMT), zooming at speeds of about 12,000 mph (19,312 kph). Mercury’s gravity was expected to slow MESSENGER by about 6,000 mph (9,656 kph) during the flyby and place it on track to enter orbit of Mercury in March 2011.

See all the images acquired by the third flyby here.

Learn more about MESSENGER and the two previous flybys which occured in 2008 here.

Lead image caption: his unnamed impact basin was seen for the first time yesterday during MESSENGER’s third flyby of Mercury. The outer diameter of the basin is approximately 260 kilometers (160 miles). This basin has a double-ring structure common to basins with diameters larger than 200 kilometers (about 125 miles).

Additional information from Jeff Goldstein on Twitter (doctorjeff) was also used in this article

September 30, 2009December 24, 2015 by Nancy Atkinson

Hubble Sees Galaxies Stripped by Ram Pressure

This composite shows the two ram pressure stripping galaxies NGC 4522 and NGC 4402. Credit: NASA & ESA

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Strange forces of nature are stripping away gas from galaxies in the Virgo cluster. An extremely hot X-ray emitting gas known as the intra-cluster medium permeates the regions between galaxies inside clusters and, as fast moving galaxies whip through this medium, strong winds tear through galaxies distorting their shape and even halting star formation with a process known as “ram pressure stripping.” Hubble spied two galaxies “losing it” to these forces.

Ram pressure is the drag force that results when something moves through a fluid — much like the wind you feel in your face when bicycling, even on a still day — and occurs in this context as galaxies orbiting about the centre of the cluster move through the intra-cluster medium, which then sweeps out gas from within the galaxies.

The two galaxies — NGC 4522 and NGC 4402 – were imaged by the old Advanced Camera for Surveys on Hubble before it suffered from a power failure in 2007. Astronauts on Servicing Mission 4 in May 2009 were able to restore ACS during their 13-day mission.

This image shows NGC 4522 within the context of the Virgo Cluster. Credit: NASA, ESA and the Digitized Sky Survey 2. Acknowledgment: Davide De Martin (ESA/Hubble)

The spiral galaxy NGC 4522 is located some 60 million light-years away from Earth and it is a spectacular example of a spiral galaxy currently being stripped of its gas content. Astronomers estimate the galaxy is moving at more than 10 million kilometers per hour, and its rapid motion within the cluster results in strong winds across the galaxy as the gas within is left behind. A number of newly formed star clusters that developed in the stripped gas can be seen in the Hubble image.

The image provides a vivid view of the ghostly gas being forced out of it. Bright blue pockets of new star formation can be seen to the right and left of centre. The image is sufficiently deep to show distant background galaxies.

The image of NGC 4402 also highlights some telltale signs of ram pressure stripping such as the curved, or convex, appearance of the disc of gas and dust, a result of the forces exerted by the heated gas. Light being emitted by the disc backlights the swirling dust that is being swept out by the gas. Studying ram pressure stripping helps astronomers better understand the mechanisms that drive the evolution of galaxies, and how the rate of star formation is suppressed in very dense regions of the Universe like clusters.

Source: Hubble Science Center

September 29, 2009December 24, 2015 by Nancy Atkinson

LRO Takes Second, Closer Look at Apollo 11 Landing Site

LROC's second look at the Apollo 11 Landing Site [NASA/GSFC/Arizona State University]. Click for larger version.

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The Lunar Reconnaissance Orbiter Camera has taken a second look at the Apollo 11 landing site. These images were taken before LRO reached its science orbit of 50 km (31 miles) above the Moon, but the lighting is different from the previous images it took of this region, providing more detail and a whole new look at this historic site. This time the Sun was 28 degrees higher in the sky, making for smaller shadows and bringing out subtle brightness differences on the surface. The look and feel of the site has changed dramatically. See below for a close-up view.

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The astronaut path to the TV camera is visible, and you may even be able to see the camera stand (arrow). You can identify two parts of the Early Apollo Science Experiments Package (EASEP) – the Lunar Ranging Retro Reflector (LRRR) and the Passive Seismic Experiment (PSE). Neil Armstrong’s tracks to Little West crater (33 m diameter) are also discernable (unlabeled arrow). His quick jaunt provided scientists with their first view into a lunar crater.

Nice going LROC!

This article was edited on Sept. 30 to correct a mistake about LRO’s orbit at the time these images were taken.
See our previous article on the first round of LROC’s images of various Apollo landing sites.

Source: LROC

September 29, 2009December 24, 2015 by Brian Ventrudo

Cosmic-Ray Intensity Hits 50-Year High

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Planning a trip to Mars? Take plenty of shielding. According to sensors on NASA’s ACE (Advanced Composition Explorer) spacecraft, galactic cosmic rays have just hit a space-age high.

“In 2009, cosmic ray intensities have increased 19% beyond anything we’ve seen in the past 50 years,” says Richard Mewaldt of Caltech. “The increase is significant, and it could mean we need to re-think how much radiation shielding astronauts take with them on deep-space missions.”

The cause of the surge is solar minimum, a deep lull in solar activity that began around 2007 and continues today. Researchers have long known that cosmic rays go up when solar activity goes down. Right now solar activity is as weak as it has been in modern times, setting the stage for what Mewaldt calls “a perfect storm of cosmic rays.”

“We’re experiencing the deepest solar minimum in nearly a century,” says Dean Pesnell of the Goddard Space Flight Center, “so it is no surprise that cosmic rays are at record levels for the Space Age.”

Galactic cosmic rays come from outside the solar system. They are subatomic particles–mainly protons but also some heavy nuclei–accelerated to almost light speed by distant supernova explosions. Cosmic rays cause “air showers” of secondary particles when they hit Earth’s atmosphere. They pose a health hazard to astronauts. And a single cosmic ray can disable a satellite if it hits an unlucky integrated circuit.

The sun’s magnetic field is our first line of defense against these highly-charged, energetic particles. The entire solar system from Mercury to Pluto and beyond is surrounded by a bubble of solar magnetism called “the heliosphere.” It springs from the sun’s inner magnetic dynamo and is inflated to gargantuan proportions by the solar wind. When a cosmic ray tries to enter the solar system, it must fight through the heliosphere’s outer layers; and if it makes it inside, there is a thicket of magnetic fields waiting to scatter and deflect the intruder.

“At times of low solar activity, this natural shielding is weakened, and more cosmic rays are able to reach the inner solar system,” explains Pesnell.

Mewaldt lists three aspects of the current solar minimum that are combining to create the perfect storm:

(1) The sun’s magnetic field is weak. “There has been a sharp decline in the sun’s interplanetary magnetic field (IMF) down to only 4 nanoTesla (nT) from typical values of 6 to 8 nT,” he says. “This record-low IMF undoubtedly contributes to the record-high cosmic ray fluxes.”

(2) The solar wind is flagging. “Measurements by the Ulysses spacecraft show that solar wind pressure is at a 50-year low,” he continues, “so the magnetic bubble that protects the solar system is not being inflated as much as usual.” A smaller bubble gives cosmic rays a shorter-shot into the solar system. Once a cosmic ray enters the solar system, it must “swim upstream” against the solar wind. Solar wind speeds have dropped to very low levels in 2008 and 2009, making it easier than usual for a cosmic ray to proceed.

(3) The current sheet is flattening. Imagine the sun wearing a ballerina’s skirt as wide as the entire solar system with an electrical current flowing along the wavy folds. That is the “heliospheric current sheet,” a vast transition zone where the polarity of the sun’s magnetic field changes from plus (north) to minus (south). The current sheet is important because cosmic rays tend to be guided by its folds. Lately, the current sheet has been flattening itself out, allowing cosmic rays more direct access to the inner solar system.

“If the flattening continues as it has in previous solar minima, we could see cosmic ray fluxes jump all the way to 30% above previous Space Age highs,” predicts Mewaldt.

Earth is in no great peril from the extra cosmic rays. The planet’s atmosphere and magnetic field combine to form a formidable shield against space radiation, protecting humans on the surface. Indeed, we’ve weathered storms much worse than this. Hundreds of years ago, cosmic ray fluxes were at least 200% higher than they are now. Researchers know this because when cosmic rays hit the atmosphere, they produce the isotope beryllium-10, which is preserved in polar ice. By examining ice cores, it is possible to estimate cosmic ray fluxes more than a thousand years into the past. Even with the recent surge, cosmic rays today are much weaker than they have been at times in the past millennium.

“The space era has so far experienced a time of relatively low cosmic ray activity,” says Mewaldt. “We may now be returning to levels typical of past centuries.”

NASA spacecraft will continue to monitor the situation as solar minimum unfolds. Stay tuned for updates.

September 29, 2009December 24, 2015 by Nancy Atkinson

NASA’s Version of Star Trek Replicator Ready for On Orbit Test

The Star Trek replicator. Credit: Computer Weekly

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It’s not quite like requesting “Tea, Earl Grey, hot” and having a steaming drink appear, but almost. The Electron Beam Freeform Fabrication, developed at NASA’s Langley Research Center, is an engineer’s version of the science fiction replicator on Star Trek. “You start with a drawing of the part you want to build, you push a button, and out comes the part,” said Karen Taminger, the technology lead for NASA’s Fundamental Aeronautics Program.

Electron beam freeform fabrication process. Image credit: NASA

Electron Beam Freeform Fabrication or EBF3150 creates parts for airplanes — not food and drink — and uses an environmentally-friendly construction process to manufacture layered metal objects. This technique could revolutionize the aviation industry and may have applications for the future spacecraft and the medical community as well. It can be used to make small, detailed parts or large structural pieces of airplanes.

EBF3150 works in a vacuum chamber, where an electron beam is focused on a constantly feeding source of metal, which is melted and then applied layer by layer on top of a rotating surface until the part is complete. A detailed 3-dimensional cross-sectional drawing of the part is fed into the device’s computer, providing information of how the the part should be built from the inside out. This guides the electron beam and and the inflow of metal to produce the object, building it up layer by layer.

Commercial applications for EBF3150 are already known and its potential already tested, Taminger said, noting it’s possible that, within a few years, some aircraft will be flying with parts made by this process.

The metals used must be compatible with the electron beam so that it can be heated by the stream of energy and briefly turned into liquid form. Aluminum is an ideal material to be used, but other metals can be used as well. In fact, the EBF3150 can handle two different sources of the feed stock metal at the same time, either by mixing them together into a unique alloy or embedding one material inside another, such as inserting a strand of fiber optic glass inside an aluminum part, enabling the placement of sensors in areas that were impossible before, Taminger said.

structural metal part fabricated from EBF3. Image credit: NASA

While the EBF3 equipment tested on the ground is fairly large and heavy, a smaller version was created and successfully test flown on a NASA jet that is used to provide researchers with brief periods of weightlessness. The next step is to fly a demonstration of the hardware on the International Space Station, Taminger said.

Future lunar base crews could use EBF3 to manufacture spare parts as needed, rather than rely on a supply of parts launched from Earth. Astronauts might be able to mine feed stock from the lunar soil, or even recycle used landing craft stages by melting them.

But the immediate and greatest potential for the process is in the aviation industry where major structural segments of an airliner, or casings for a jet engine, could be manufactured for about $1,000 per pound less than conventional means, Taminger said.

The device is environmentally friendly because its unique manufacturing technique cuts down on the amount of waste. Normally an aircraft builder might start with a 6,000-pound block of titanium and machine it down to a 300-pound part, leaving 5,700 pounds of material that needs to be recycled and using several thousand gallons of cutting fluid used in the process.

“With EBF3 you can build up the same part using only 350 pounds of titanium and machine away just 50 pounds to get the part into its final configuration,” Taminger said. “And the EBF3 process uses much less electricity to create the same part.”

While initial parts for the aviation industry will be simple shapes, replacing parts already designed, future parts designed from scratch with the EBF3150 process in mind could lead to improvements in jet engine efficiency, fuel burn rate and component lifetime.

“There’s a lot of power in being able to build up your part layer by layer because you can get internal cavities and complexities that are not possible with machining from a solid block of material,” Taminger said.

For more information, watch Karen Taminger’s presentation on the EBF3150.

Source: NASA

September 28, 2009December 24, 2015 by Nancy Atkinson

LCROSS Team Changes Target Crater for Impact

LCROSS Mission — Artist impression of LCROSS approaching the Moon. Credit: NASA

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Based on new analysis of the latest lunar data, the science team for NASA’s Lunar Crater Observation and Sensing Satellite mission (LCROSS) decided to change the target crater for impact from Cabeus A to Cabeus (proper). The decision was based on a consensus that Cabeus shows, with the greatest level of certainty, the highest hydrogen concentrations at the south pole. The most current terrain models provided by JAXA’s Kaguya spacecraft and the LRO Lunar Orbiter Laser Altimeter (LOLA) was important in the decision process, as the latest models show a small valley in an otherwise tall Cabeus perimeter ridge, which will allow for sunlight to illuminate the ejecta cloud, making it easier to see from Earth.

The decisison was based on continued evaluation of all available data and consultation/input from members of the LCROSS Science Team and the scientific community, including impact experts, ground and space based observers, and observations from (LRO), Lunar Prospector (LP), Chandrayaan-1 and JAXA’s Kaguya spacecraft. This decision was prompted by the current best understanding of hydrogen concentrations in the Cabeus region, including cross-correlation between the latest LRO results and LP data sets.

As for the sunlight illuminating the ejecta cloud on Oct. 9, it should show up much better than previously estimated for Cabeus. While the ejecta does have to fly to higher elevations to be observed by Earth telescopes and observers, a shadow cast by a large hill along the Cabeus ridge, provides an excellent, high-contrast, back drop for ejecta and vapor measurements.

See this link for how to observe the impact from Earth. Eastern and central north America has the best chance of seeing the impact.

The LCROSS team concluded that Cabeus provided the best chance for meeting its mission goals. The team critically assessed and successfully advocated for the change with the Lunar Precursor Robotic Program (LPRP) office. The change in impact crater was factored into LCROSS’ most recent Trajectory Correction Maneuver, TCM7.

During the last days of the mission, the LCROSS team will continue to refine the exact point of impact within Cabeus crater to avoid rough spots, and to maximize solar illumination of the debris plume and Earth observations.

Source: LCROSS