Wednesday, December 31, 2014

NASA New Horizon Mission 2015, the year of the Dwarf Planet

This “movie” of Pluto and its largest moon, Charon, by NASA’s New Horizons spacecraft taken in July 2014 clearly shows that the barycenter, the centre of mass of the two bodies, resides outside (between) both bodies. 

The 12 images that make up the movie were taken by the spacecraft’s best telescopic camera, the Long Range Reconnaissance Imager (LORRI), at distances ranging from about 267 million to 262 million miles (429 million to 422 million kilometers). 

Charon is orbiting approximately 11,200 miles (about 18,000 kilometers) above Pluto’s surface. 

Credit: NASA /Johns Hopkins University Applied Physics Laboratory /Southwest Research Institute

The New Horizons mission became the first mission of NASA's New Frontiers program, beginning development in 2001.

The probe was launched on January 19, 2006, atop an Atlas V 551 (5 solid rocket boosters plus a third stage).

Utilising more compact and lightweight electronics than its predecessors to the outer planets, Pioneer 10 & 11, and Voyager 1 & 2, the combination of reduced weight, a powerful launch vehicle, plus a gravity assist from Jupiter has lead to a nine year journey.

On December 6, 2014, New Horizons was taken out of hibernation for the last time and now remains powered on until the Pluto encounter.

The arrival date of New Horizon is July 14, 2015. A telescope called the Long Range Reconnaissance Imager (LORRI) has permitted the commencement of observations while still over 240 million kilometers (150 million miles) from Pluto.

The first stellar-like images were taken while still in the Asteroid belt in 2006.

Tuesday, December 30, 2014

The Healthy woman with no Cerebellum

A woman has reached the age of 24 without anyone realising she was missing a large part of her brain. The case highlights just how adaptable the organ is.

The discovery was made when the woman was admitted to the Chinese PLA General Hospital of Jinan Military Area Command in Shandong Province complaining of dizziness and nausea.

She told doctors she'd had problems walking steadily for most of her life, and her mother reported that she hadn't walked until she was 7 and that her speech only became intelligible at the age of 6.

Doctors did a CAT scan and immediately identified the source of the problem – her entire cerebellum was missing (see scan, below left).

The space where it should be was empty of tissue. Instead it was filled with cerebrospinal fluid, which cushions the brain and provides defence against disease.

The cerebellum – sometimes known as the "little brain" – is located underneath the two hemispheres.

It looks different from the rest of the brain because it consists of much smaller and more compact folds of tissue. It represents about 10 per cent of the brain's total volume but contains 50 per cent of its neurons.

Although it is not unheard of to have part of your brain missing, either congenitally or from surgery, the woman joins an elite club of just nine people who are known to have lived without their entire cerebellum.

A detailed description of how the disorder affects a living adult is almost non-existent, say doctors from the Chinese hospital, because most people with the condition die at a young age and the problem is only discovered on autopsy (Brain, doi.org/vh7)

The cerebellum's main job is to control voluntary movements and balance, and it is also thought to be involved in our ability to learn specific motor actions and speak. Problems in the cerebellum can lead to severe mental impairment, movement disorders, epilepsy or a potentially fatal build-up of fluid in the brain.

However, in this woman, the missing cerebellum resulted in only mild to moderate motor deficiency, and mild speech problems such as slightly slurred pronunciation.

Her doctors describe these effects as "less than would be expected", and say her case highlights the remarkable plasticity of the brain.

"These rare cases are interesting to understand how the brain circuitry works and compensates for missing parts," says Mario Manto, who researches cerebellar disorders at the Free University of Brussels in Belgium.

The patient's doctors suggest that normal cerebellar function may have been taken over by the cortex – brain scans should reveal the answer.

NASA Dawn Spacecraft Begins Approach to Ceres

NASA's Dawn spacecraft has entered an approach phase in which it will continue to close in on Ceres, a Texas-sized dwarf planet never before visited by a spacecraft. Dawn launched in 2007 and is scheduled to enter Ceres orbit in March 2015.

Dawn recently emerged from solar conjunction, in which the spacecraft is on the opposite side of the sun, limiting communication with antennas on Earth.

Now that Dawn can reliably communicate with Earth again, mission controllers have programmed the maneuvers necessary for the next stage of the rendezvous, which they label the Ceres approach phase.

Dawn is currently 400,000 miles (640,000 kilometers) from Ceres, approaching it at around 450 miles per hour (725 kilometers per hour).

The spacecraft's arrival at Ceres will mark the first time that a spacecraft has ever orbited two solar system targets.

Dawn previously explored the protoplanet Vesta for 14 months, from 2011 to 2012, capturing detailed images and data about that body.

"Ceres is almost a complete mystery to us," said Christopher Russell, principal investigator for the Dawn mission, based at the University of California, Los Angeles.

"Ceres, unlike Vesta, has no meteorites linked to it to help reveal its secrets. All we can predict with confidence is that we will be surprised."

The two planetary bodies are thought to be different in a few important ways. Ceres may have formed later than Vesta, and with a cooler interior.

Current evidence suggests that Vesta only retained a small amount of water because it formed earlier, when radioactive material was more abundant, which would have produced more heat.

Ceres, in contrast, has a thick ice mantle and may even have an ocean beneath its icy crust.

The two planetary bodies are thought to be very different. Ceres has an average diameter of 950 km (590 miles) while Vesta has an average diameter of 525 km (326 miles).

Ceres may have formed later than Vesta, and have a cooler interior. Vesta formed earlier, when radioactive material was more abundant, which produced more heat so Vesta retained little water, whereas Ceres has a thick ice mantle and may even have an ocean beneath its icy crust.

Dawn is currently 640,000 km (400,000 miles) from Ceres, approaching it at around 725 km per hour (450 miles per hour).

Ceres is also the largest body in the asteroid belt, the strip of solar system real estate between Mars and Jupiter.

By comparison, Vesta has an average diameter of 326 miles (525 kilometers), and is the second most massive body in the belt.

The spacecraft uses ion propulsion to traverse space far more efficiently than if it used chemical propulsion. In an ion propulsion engine, an electrical charge is applied to xenon gas, and charged metal grids accelerate the xenon particles out of the thruster.

These particles push back on the thruster as they exit, creating a reaction force that propels the spacecraft. Dawn has now completed five years of accumulated thrust time, far more than any other spacecraft.

"Orbiting both Vesta and Ceres would be truly impossible with conventional propulsion. Thanks to ion propulsion, we're about to make history as the first spaceship ever to orbit two unexplored alien worlds," said Marc Rayman, Dawn's chief engineer and mission director, based at NASA's Jet Propulsion Laboratory in Pasadena, California.

The next couple of months promise continually improving views of Ceres, prior to Dawn's arrival. By the end of January, the spacecraft's images and other data will be the best ever taken of the dwarf planet.

Sunday, December 28, 2014

NASA Messenger extends its mission life using Helium

Now orbiting the planet Mercury after over ten years in space, NASA's MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft is still functioning better than expected.

Its mission will soon come to an end though, it's running out of fuel and is scheduled to crash into the planet in March.

However, mission control have come up with a novel plan that will use the helium used to pressurize the unmanned probe's engine to give it another month of life.

According to the MESSENGER team, fuel is usually the last problem that a robotic exploration team worry about because there are so many other things that can go wrong long before it runs out.

That being said, the fuel is the single most important consumable aboard an orbiter mission because it not only allows the spacecraft to maintain the correct attitude and keep its antennae pointed at Earth, it also lets it use the main engine to boost its orbit against atmospheric drag, which decays the orbit.

The upshot is that when the propellant runs out, the spacecraft starts to tumble and spirals in to burn up in the atmosphere or, in MESSENGER's case, crash into the surface at hypersonic speed.



So normally when the fuel runs out, that's it, but NASA reasoned that MESSENGER's liquid-fuel rocket engine design meant there was still a bit of thrust left even after all the propellant was expended.

The MESSENGER's engine is pressure fed, which means that it uses helium from a separate tank to push the fuel and oxidizer into the engine's combustion chamber.

Since the helium needs to work against the force of the rocket's combustion, it's under considerable pressure, and when the fuel is gone, there will be some helium left in the pressure tank.

The idea is to use the helium as a cold propellant. In other word's where the rocket engine gets its thrust by burning fuel, the helium pushes the spacecraft by simple gas pressure like a toy balloon when the open neck is let go.

Unfortunately, this is the first time a pressurant has been as an improvised thruster and MESSENGER's engine is a bit more complicated than a balloon.

According to MESSENGER Mission Systems Engineer Dan O’Shaughnessy, of the Johns Hopkins University Applied Physics Laboratory (APL), the pressure in the helium tank isn't much compared to a firing engine.

In addition, the gas passes through a number of reduction valves and nozzles that have to be taken into account, and helium is the second lightest of gases, so it doesn't provide much in the way of thrust.

If these problems can be overcome, NASA estimates that it will give MESSENGER another month of active life before impact on Mercury. MESSENGER's current closest approach to Mercury is 25 km (15 mi).

If a scheduled course correction using the helium is successful, this will rise to 80 km (50 mi). This will allow the orbiter to carry out additional low altitude observations, including collecting a new set of high-resolution images.

"During the additional period of operations, up to four weeks, MESSENGER will measure variations in Mercury’s internal magnetic field at shorter horizontal scales than ever before, scales comparable to the anticipated periapsis altitude between 7 km (4 mi) and 15 km (9 mi) above the planetary surface," says APL’s Haje Korth, the instrument scientist for the spacecraft's magnetometer.

"Combining these observations with those obtained earlier in the mission at slightly higher altitudes will allow the depths of the sources of these variations to be determined. In addition, observations by MESSENGER’s Neutron Spectrometer at the lowest altitudes of the mission will allow water ice deposits to be spatially resolved within individual impact craters at high northern latitudes."

Built and operated by John Hopkins University for NASA, the MESSENGER spacecraft was launched from Cape Canaveral on August 3, 2004 as the first mission aimed to place an orbiter around the innermost planet Mercury. 

Saturday, December 27, 2014

From Dream to Discovery: Inside NASA Engineering - Video



Experience the challenges of the next generation of space exploration in this brand-new Planetarium show.

By using exciting real-life projects like NASA's James Webb Space Telescope (JWST) and the New Horizons mission to Pluto, the show highlights the extreme nature of spacecraft engineering and the life cycle of a space mission, from design and construction to the rigors of testing, launch, and operations.

Blast off and take the voyage with NASA!


Friday, December 26, 2014

Midwinter Festival celebrations on the Space Station

NASA astronaut Barry "Butch" Wilmore (left) floats with ESA astronaut Samantha Cristoforetti (center) and NASA's Terry Virts (right) are decked out for Christmas 2014.

Credit: Sam Cristoforetti Twitter/ESA

Astronauts in space have decked the halls of the International Space Station in honour of the holiday season.

The international crew members on the station have hung stockings, pulled out the orbiting outpost's Christmas tree, and they generally seem to be getting into the Christmas spirit.

European Space Agency astronaut Samantha Cristoforetti even sent out a picture of her with NASA astronauts Terry Virts and Barry "Butch" Wilmore with their decorations on the station.

"It's beginning to look like Christmas on the International Space Station," NASA officials wrote on a blog about the holiday.

"The stockings are out, the tree is up and the station residents continue advanced space research to benefit life on Earth and in space."

Space Station Christmas decorationsPin It ESA astronaut Samantha Cristoforetti decorates the International Space Station for Christmas 2014.

Credit: NASA

Although NASA astronauts usually get the day off for Christmas, they have still been taking part in a variety of experiments leading up to the holiday.

On Dec. 23, for example, the crewmembers participated in a neurology experiment to monitor how motor control, perception and other aspects of brain function change over time in space, according to NASA.

In addition to Wilmore, Virts and Cristoforetti, the station's cre includes Russian cosmonauts Elena Serova, Alexander Samokutyaev and Anton Shkaplerov.

People on Earth can also send holiday messages of cheer to astronauts in space this season. NASA has set up a special portal for Earthlings that want to send their greetings to Virts and Wilmore on the station.

Tuesday, December 23, 2014

ESA Rosetta Mission: ROSINA water vapour discovery


ESA announced the latest important discovery regarding comet 67P/Churyumov–Gerasimenko.

Rosetta spacecraft orbiting the comet has found the water vapour from its target to be significantly different to that found on Earth.

The discovery made by Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) fuels the debate on the origin of our planet's oceans.

That's not all, ESA's Rosetta project scientist, Matt Taylor, believes that ROSINA will make more key findings for our understanding of the origin of life. "ROSINA is continuing to take measurements and will for the rest of the mission," Taylor told reporters.

"It is making and will make invaluable detections of the composition of the comets atmosphere, as well as monitoring its density."

ROSINA is a combination of two mass spectrometers and a pressure sensor. The mass spectrometers determine the composition of the comet's atmosphere and ionosphere, measure the temperature and bulk velocity of the gas and ions, and investigate reactions in which they take part.

The ROSINA pressure sensor is capable of measuring both total and ram pressure, and will be used to determine the gas density and rate of radial gas flow.

"It can detect many different kinds of molecules and get to the heart of the constituents of the ancient comet, giving us unprecedented insight into what the conditions were at the beginning of the solar system," Taylor revealed.

Add caption

No single instrument could have the capabilities required to accomplish the ROSINA science objectives, so a three-sensor approach has been adopted.

Each sensor is optimized for a part of the scientific objectives, while at the same time complementing the other sensors.

The latest results were the most anticipated, because the origin of Earth's water is still an open question.

Taylor noticed that those findings have put recent Herschel results into context and agree with results from the Giotto mission.

"It is a very important result and was of the most anticipated, if only that it was one of the first we would be able to make," he said.

In January 2014, ESA's Herschel mission discovered water vapor around dwarf planet Ceres, and in 1986, ESA's Giotto was the first spacecraft to make close up observations of a comet.

Comets in particular are unique tools for probing the early Solar System. They harbor material left over from the protoplanetary disc out of which the planets formed, and therefore should reflect the primordial composition of their places of origin.

Russia's First Angara 5 rocket blasts off

The Angara 5 rocket on the launch pad before Tuesday’s liftoff. Credit: Spetsstroy.ru

A new Russian rocket designed as a successor to the workhorse Proton booster lifted off Tuesday on a maiden test flight that could signify Russia’s shift away from launching satellites at the Baikonur Cosmodrome in Kazakhstan.

The 180-foot-tall Angara 5 rocket ignited five kerosene-fueled RD-191 booster engines and lifted off from the Plesetsk Cosmodrome, a military-run spaceport 500 miles north of Moscow, at 0557 GMT (12:57 a.m. EST) Tuesday, according to the Russian Federal Space Agency.

The RIA Novosti news agency reported the Angara 5 rocket’s lower stages, comprising the new technologies to be tested on Tuesday’s flight, performed as designed and released a Breeze M upper stage to begin a series of engine firings to put a dummy satellite into geostationary orbit 22,300 miles over the equator.

The Russian Ministry of Defence confirmed the Angara booster worked as expected before deploying the Breeze M stage 12 minutes after liftoff.

Russian President Vladimir Putin watched the launch via video conference, RIA Novosti reported. The launch was not broadcast live to the public.

Weighing 773 metric tons (852 tons) when filled with kerosene, liquid oxygen and hypergolic propellants, the Angara 5 is the biggest Russian launcher to debut since the Energia rocket for the Soviet Union’s Buran space shuttle flew in the late 1980s.

The rocket’s kerosene-fueled RD-191 engines, made by NPO Energomash of Khimki, Russia, generated roughly 2 million pounds of thrust at maximum throttle to drive the launcher into the sky. Engineers derived the single-chamber RD-191 engine from the four-nozzle RD-171 and dual-chamber RD-180 engines flying on the Zenit and Atlas 5 launchers.

Russia tested a smaller version of the Angara rocket in July on a suborbital flight powered by a single RD-191 engine. Engineers designed the Angara 5 booster to use five RD-191 engine cores bolted together to put Russia’s heaviest satellites into orbit.

The five engines were supposed to fire in unison for more than three minutes, when four of the outboard boosters were expected to shut down and fall away from the launcher.

The core RD-191 engine, operated at a partial thrust throttle setting in the first phase of the flight, was programmed to ramp up to full power and continue burning until it consumed all of its kerosene and liquid oxygen propellant supply.

A second stage RD-0124A engine and a Breeze M upper stage, borrowed from Russia’s Soyuz 2-1b and Proton rockets, were to finish the job.

The Angara 5’s five-meter (16-foot) diameter payload shroud was also armed to jettison once the rocket flew out of the dense lower layers of the atmosphere.

The flight’s Breeze M main engine was expected to ignite four times over several hours to reach the mission’s targeted orbit.

Russia’s Itar-Tass news agency reported the test launch was aiming for a geostationary orbit 22,300 miles over the equator with a dummy satellite weighing about two tons.

The end of the test flight was scheduled for 1457 GMT (9:57 a.m. EST) with a simulated separation of the mock-up payload, according to RIA Novosti.

NASA Cassini: Europa's atmosphere is thinner than previously thought

Data collected by NASA's Cassini spacecraft during its 2001 flyby of Jupiter shows that Europa's tenuous atmosphere is thinner than had been thought.

Europa is considered one of the most exciting destinations in the Solar System for future exploration because it shows strong indications of having an ocean beneath its icy crust.

Long, linear cracks and ridges crisscross Europa's surface, interrupted by regions of disrupted terrain where the surface ice crust has been broken up and re-frozen into new patterns.

Colour variations across the surface are associated with differences in geologic feature type and location.

The polar regions are bluer than the more equatorial latitudes, which appear more white. This colour variation is thought to be due to differences in ice grain size in the two locations.

Europa has a crust made up of blocks, which are thought to have broken apart and 'rafted' into new positions, as shown in the image on the left. 

Image Credit: NASA /JPL /University of Arizona

Europa is surrounded by very tenuous hot, excited gas. Indications of possible plume activity were reported in 2013 by researchers using NASA's Hubble Space Telescope.

Data collected by Cassini's ultraviolet imaging spectrograph (UVIS) as Cassini sped through the Jupiter system en route to Saturn, shows that most of the plasma around Europa originates not from the moon itself, but from volcanoes on the nearby moon Io.

Cassini's ultraviolet imaging spectrograph (UVIS)
The researchers calculate that Europa contributes 40 times less oxygen than previously thought to its surrounding environment, making it less likely that the moon is regularly venting plumes of water vapour high into orbit.

"Our work shows that researchers have been overestimating the density of Europa's atmosphere by quite a bit," said Don Shemansky, a Cassini UVIS team member with Space Environment Technologies, who led the study.

The moon's tenuous atmosphere, which was already thought to be millions of times thinner than Earth's atmosphere, is actually about 100 times less dense than those previous estimates.

The data shows no evidence of plume activity occurring at the time of the flyby, so if there is plume activity, it is likely intermittent.

Ongoing plume activity at Europa, as Cassini has observed at Saturn's moon Enceladus, would inject large amounts of water vapour into the area around Europa's orbit if the plumes were large enough, but that is not what UVIS observed.

"It is certainly still possible that plume activity occurs, but that it is infrequent or the plumes are smaller than we see at Enceladus," said Amanda Hendrix, a Cassini UVIS team member with the Planetary Science Institute, who co-authored the new study.

Missions that visited Jupiter prior to Cassini provided strong indications that Io is the major contributor of material to the environment around Jupiter, and indicated a hot, low density plasma surrounding Europa. The new results confirm that. "Io is the real monster here," Shemansky said.

"Europa is a complex, amazing world, and understanding it is challenging given the limited observations we have," said Curt Niebur, Outer Planets program scientist at NASA Headquarters.

"Studies like this make the most of the data we have and help guide the kinds of science investigations NASA should pursue in the future."

The Hubble Space Telescope is currently conducting an extensive six-month long survey looking for plume activity, and NASA is studying various possible Europa missions for future exploration.

Monday, December 22, 2014

Multicoloured view of supernova remnant RCW 86


Credit: ESA/XMM-Newton & NASA/Chandra (X-ray); NASA/WISE/Spitzer (Infrared)

Most celestial events unfold over thousands of years or more, making it impossible to follow their evolution on human timescales.

Supernovas are notable exceptions, the powerful stellar explosions that make stars as bright as an entire galaxy for several days.

Although they are very rare, only a few such explosions take place every century in a typical galaxy, supernovas can be seen with the naked eye if they are reasonably nearby.

In fact, when supernovas were discovered they were thought to be new stars appearing in the sky, 'nova' means new in Latin.

Astronomers have recorded supernovas long before a theoretical understanding of these events as stellar explosions was developed in the 20th century.

The most ancient documented record dates back to 185 AD, when Chinese astronomers saw a 'guest star' that remained visible for several months, in the vicinity of the two stars Alpha and Beta Centauri.

The material ejected during these explosions sweeps up gas and dust from the surroundings, creating picturesque supernova remnants that can be observed long after the explosion.

Modern astronomers believe that the object shown in this image, the supernova remnant RCW 86, is what remains of the supernova that was discovered in 185 AD.

The blue and green glow at the edges of the bubble represents X-ray emission from hot gas, heated to millions of degrees by shock waves generated after the explosion.

The diffuse red glow marks infrared emission from warm dust in the interstellar medium around RCW 86.

Sprinkled across the image, in yellow, are young stars that shine brightly at infrared wavelengths.

This image combines X-ray data from ESA's XMM-Newton and NASA's Chandra X-ray Observatory (combined to form the blue and green colours) with infrared observations from NASA's Spitzer Space Telescope and Wide-Field Infrared Survey Explorer - WISE (yellow and red).

The supernova remnant RCW 86 is some 8000 light-years away.

Saturday, December 20, 2014

ESA Mars Express: Flying over Becquerel Crater - Video


This latest release from the camera on ESA’s Mars Express is a simulated flight over the Becquerel crater, showing large-scale deposits of sedimentary material.

Becquerel crater is 167 km in diameter and lies in the Arabia Terra region on Mars, on the boundary between the southern highlands and northern lowlands.

This movie shows the location of Becquerel crater on Mars and then provides a flyover of a mound of layered, sulphate-bearing deposits on the crater floor, thought to have formed under the influence of water.

The darker material surrounding the mound is wind-blown dust from a source to the north, and provides evidence for effects of wind in eroding the sedimentary deposits.

The movie was made from a mosaic of four individual images acquired by the High Resolution Stereo Camera on ESA’s Mars Express during orbits 3253/1, 5332, 5350 and 5368.

The image is centred at about 22ºN / 352ºE. The average ground resolution is about 17 m per pixel.

ESA's Planck Satellite: The magnetic field along the galactic plane

Credit: ESA/Planck Collaboration. 

Acknowledgment: M.-A. Miville-Deschênes, CNRS – Institut d’Astrophysique Spatiale, Université Paris-XI, Orsay, France

While the pastel tones and fine texture of this image may bring to mind brush strokes on an artist's canvas, they are in fact a visualisation of data from ESA's Planck satellite.

The image portrays the interaction between interstellar dust in the Milky Way and the structure of our Galaxy's magnetic field.

Between 2009 and 2013, Planck scanned the sky to detect the most ancient light in the history of the Universe, the cosmic microwave background.

It also detected significant foreground emission from diffuse material in our Galaxy which, although a nuisance for cosmological studies, is extremely important for studying the birth of stars and other phenomena in the Milky Way.

Among the foreground sources at the wavelengths probed by Planck is cosmic dust, a minor but crucial component of the interstellar medium that pervades the Galaxy. Mainly gas, it is the raw material for stars to form.

Interstellar clouds of gas and dust are also threaded by the Galaxy's magnetic field, and dust grains tend to align their longest axis at right angles to the direction of the field.

As a result, the light emitted by dust grains is partly 'polarised', it vibrates in a preferred direction, and, as such, could be caught by the polarisation-sensitive detectors on Planck.

Scientists in the Planck collaboration are using the polarised emission of interstellar dust to reconstruct the Galaxy's magnetic field and study its role in the build-up of structure in the Milky Way, leading to star formation.

In this image, the colour scale represents the total intensity of dust emission, revealing the structure of interstellar clouds in the Milky Way.

The texture is based on measurements of the direction of the polarised light emitted by the dust, which in turn indicates the orientation of the magnetic field.

This image shows the intricate link between the magnetic field and the structure of the interstellar medium along the plane of the Milky Way.

In particular, the arrangement of the magnetic field is more ordered along the Galactic plane, where it follows the spiral structure of the Milky Way. Small clouds are seen just above and below the plane, where the magnetic field structure becomes less regular.

From these and other similar observations, Planck scientists found that filamentary interstellar clouds are preferentially aligned with the direction of the ambient magnetic field, highlighting the strong role played by magnetism in galaxy evolution.

The emission from dust is computed from a combination of Planck observations at 353, 545 and 857 GHz, whereas the direction of the magnetic field is based on Planck polarisation data at 353 GHz.

NASA's Curiosity Mars Rover: Organics Possibly Present

This image illustrates possible ways methane might be added to Mars' atmosphere (sources) and removed from the atmosphere (sinks). 

NASA's Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur on modern Mars. 

Credit: NASA/JPL-Caltech/SAM-GSFC/Univ. of Michigan

NASA's Curiosity Mars rover has measured a tenfold spike in methane, an organic chemical, in the atmosphere around it and detected other organic molecules in a rock-powder sample collected by the robotic laboratory's drill.

"This temporary increase in methane, sharply up and then back down, tells us there must be some relatively localized source," said Sushil Atreya of the University of Michigan, Ann Arbor, and Curiosity rover science team.

"There are many possible sources, biological or non-biological, such as interaction of water and rock."

Researchers used Curiosity's onboard Sample Analysis at Mars (SAM) laboratory a dozen times in a 20-month period to sniff methane in the atmosphere.

During two of those months, in late 2013 and early 2014, four measurements averaged seven parts per billion.

Before and after that, readings averaged only one-tenth that level.

Curiosity also detected different Martian organic chemicals in powder drilled from a rock dubbed 'Cumberland', the first definitive detection of organics in surface materials of Mars.

These Martian organics could either have formed on Mars or been delivered to Mars by meteorites.

Organic molecules, which contain carbon and usually hydrogen, are chemical building blocks of life, although they can exist without the presence of life.

Curiosity's findings from analyzing samples of atmosphere and rock powder do not reveal whether Mars has ever harboured living microbes, but the findings do shed light on a chemically active modern Mars and on favorable conditions for life on ancient Mars.

"We will keep working on the puzzles these findings present," said John Grotzinger, Curiosity project scientist of the California Institute of Technology in Pasadena (Caltech).

"Can we learn more about the active chemistry causing such fluctuations in the amount of methane in the atmosphere? Can we choose rock targets where identifiable organics have been preserved?"

Researchers worked many months to determine whether any of the organic material detected in the Cumberland sample was truly Martian.

Curiosity's SAM lab detected in several samples some organic carbon compounds that were, in fact, transported from Earth inside the rover.

However, extensive testing and analysis yielded confidence in the detection of Martian organics.

NASA HAVOC: Manned mission to Venus Possible

HAVOC. Credit: NASA Langley Research Center

NASA's Systems Analysis and Concepts Directorate has issued a report outlining a possible way for humans to visit Venus, rather than Mars, by hovering in the atmosphere instead of landing on the surface.

The hovering vehicle, which they call a High Altitude Venus Operational Concept (HAVOC), would resemble a blimp with solar panels on top, and would allow people to do research just 50 kilometers above the surface of the planet.

Most everyone knows that NASA wants to send people to Mars, that planet also gets most of the press. Mars is attractive because it looks more like Earth and is relatively close to us.

The surface of Venus on the other hand, though slightly closer, is not so attractive, with temperatures that can melt lead and atmospheric pressure 92 times that of Earth.

There's also that thick carbon dioxide atmosphere with sulphuric acid clouds, lots of earthquakes, volcanoes going off and terrifying lightning bolts.

Perhaps humans could ride through the upper atmosphere of Venus in a solar-powered airship. Dale Arney and Chris Jones, from Nasa's Space Analysis Branch, propose that it may make sense to go to Venus before we ever send humans to Mars.

So, why would anyone rather go to Venus than Mars? Because of far lower radiation and much better solar energy.

No one wants to go the surface of Venus, at least not anytime soon, instead, researchers at NASA are looking into the possibility of sending people to hover in the sky above the planet, conducting research in a far less dangerous place than even on the surface of Mars.

At 50 kilometers up, an HAVOC would experience just one atmosphere of atmospheric pressure and temperatures averaging just 75 degrees Celsius, with radiation levels equivalent to those in Canada.

Astronauts on Mars, on the other hand would experience 40 times the amount of radiation typically faced back here on Earth, which suggests they'd have to live deep underground to survive, a problem that scientists have not yet solved.

Read the full article here

Wednesday, December 17, 2014

30,000 Diamonds in one rock - Alrosa 's Udachnaya diamond mine

Strange rock containing 30,000 diamonds baffles science and the geologists.

Credit: Getty Images

When Russian miners pulled a strange red and green stone out of the ground, they immediately knew it was different to the thousands of tons of ore they process every day.

In fact, what workers at Alrosa 's Udachnaya diamond mine had unearthed was a 30mm rock that contained 30,000 diamonds, a concentration 1M times higher than normal.

However, despite the rare find the company donated the rock to the Russian Academy of Sciences, as the diamonds are so small that they cannot be used as gems.

After scanning the rock with X-rays, scientists found that the diamonds inside measure just 1mm and are octahedral in shape - similar to two pyramids stuck together at the base.

The red and green colouring comes from larger crystals of garnet, olivine and pyroxene.

"The exciting thing for me is there are 30,000 itty-bitty, perfect octahedrons, and not one big diamond," said Larry Taylor, a geologist at the University of Tennessee, who presented the findings at the American Geophysical Union 's annual meeting.

"It's like they formed instantaneously. This rock is a strange one indeed."

Scientists are excited at the finding as they hope it will shed further light on how diamonds are made.

They know diamonds are crystals of pure carbon that form under crushing pressures and intense heat, mostly formed in the Earth's mantle, the layer beneath the crust or surface layer, at a depth of about 150km. However, certain processes in their creation remain a mystery.

"The [chemical] reactions in which diamonds occur still remain an enigma," Mr Taylor told Live Science, which first reported the story.

Mr Taylor works with researchers at the Russian Academy of Sciences to study Udachnaya diamonds.

Russia is the largest diamond-producing country in the world, and produced more than 33m carats last year.

State-controlled Alrosa is the world's leading diamond miner, accounting for 99pc of Russia’s output and 27pc of global production. Its sees rough diamond revenues of more than $4bn a year.

Last week Alrosa signed a dozen deals with Indian buyers to increase direct deliveries to Asia's third-largest economy.

The firm earns half of its revenue, or around $2.5bn, from Indian-funded clients, and the deal could help Russia reduce risks linked to Western sanctions imposed over its role in the Ukraine crisis.

Last month Alrosa revealed a 10.5bn rouble (£110m) loss for its third quarter despite sales rising 7.6pc.

The Udachnaya mine, in the Sakha Republic, just outside the Arctic circle, is more than 600 metres deep, making it the third deepest open-pit mine in the world.

ESA Rosetta Mission: Philae Landing on Comet 67/P 'all a blur'

The CIVA image from ESA Rosetta's Philae Lander is all blurred because the lander is bouncing away from the surface of the comet.

Credit: ESA

An image has been released that shows the hairy moment that the Philae comet lander bounced back into space.

The little robot touched down on 4km-wide 67P in November - but not before rebounding twice.

The new picture is a big blur, which is not surprising given that the lander was far from static.

It was acquired by Philae's CIVA camera system, which was primed to start shooting the moment the robot settled on to the surface.

Sharp images of the comet's terrain were eventually taken, but by then the robot had shot 1km across the surface and into a dark "ditch".

The shadowed hole limited the amount of sunlight reaching Philae's power generator, restricting its ability to charge its batteries.

The probe now lies dormant, waiting for better lighting conditions, which could arrive in the next few weeks as the comet moves into the inner-Solar System.

An update on the mission was given here at the American Geophysical Union's Fall Meeting in San Francisco.

Philae co-principal investigator Jean-Pierre Bibring also showed some reprocessed imagery taken by CIVA camera when Philae had finally come to a stop.

These pictures have been shown before, but the manipulation undertaken by scientists has revealed some new details.

In one, which Prof Bibring dubbed "Perihelion Cliff", it is possible to see glare marks. The Frenchman said these were reflections from the lander.

The glare is probably the reflection of the Philae lander itself.

Credit: ESA

Philae managed to despatch a good deal of science data from the surface before going into hibernation.

This information was successfully passed by the orbiting mothership, Rosetta, to Earth - and scientists continue to make their interpretations.

Meanwhile, the hunt goes on for Philae. Its precise location on the surface of 67P is unknown.

Rosetta took a series of pictures of the comet's surface on 12, 13 and 14 December. When these pictures are downlinked to Earth, researchers are hopeful they will find their lost probe.

Understanding precisely where Philae is on the comet will help engineers understand its predicament and the likely time of an awakening.

Part of this work is already under way using the limited number of pictures sent back from CIVA.

A preliminary model of the final landing location and its difficult terrain has been constructed.

Philae Lander's CIVA camera images have been used to construct a model of the final landing location.

Credit: ESA

MARS HiRise Map: Signs of Ancient Mars Lakes and Quakes

Long ago, in the largest canyon system in our solar system, vibrations from "marsquakes" shook soft sediments that had accumulated in Martian lakes.

The shaken sediments formed features that now appear as a series of low hills apparent in a geological map based on NASA images.

The map was released by the U.S. Geological Survey (USGS).

This map of the western Candor Chasma canyon within Mars' Valles Marineris is the highest-resolution Martian geological map ever relased by USGS.

It is derived from images taken by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter (MRO), which reveal details smaller than a desk.

"This new map shows that at the time these sediments were deposited, a part of west Candor Chasma, specifically Condor Colles, contained numerous shallow, spring-fed lakes," said map author Chris Okubo of the USGS Astrogeology Science Center, Flagstaff, Arizona.


"These lakes helped to trap wind-blown sand and dust, which accumulated over time and formed the extensive sedimentary deposits we see today."

The wet sediments experienced seismic shaking in "marsquakes" related to movement along several large geological faults in the area. A series of low hills resulted.

Valles Marineris is more than 2,500 miles (4,000 kilometers) long. The conditions under which sedimentary deposits in it formed have been an open issue for decades.

Possibilities proposed have included accumulation in lakebeds, volcanic eruptions under glaciers within the canyons, and acculation of wind-blown sand and dust.

The map is available for download here. Additional information about the map is available here.

Tuesday, December 16, 2014

NASA Mars Opportunity Rover: Changes to non-Flash Memory usage

Persistent computer resets and "amnesia" events on NASA's Mars Exploration rover Opportunity that have occurred after reformatting the robot's flash memory have prompted a shift to a working mode that avoids use of the flash data-storage system.

The most recent reformatting of Opportunity's flash memory was last week.

Following that, performance of the flash memory remained intermittent, and difficulty in placing data into the memory led to computer resets during the weekend.

Flash memory retains information even when power is shut off during the rover's overnight power-conserving "sleep" time.

In the no-flash mode, the rover can continue normal operations of science observations and driving, though it cannot store data during the overnight sleep.

Data gathered each Martian day is stored in volatile memory, which on Opportunity is random-access memory (RAM). That data stored in volatile memory is relayed Earthward before sleep because it is lost when power goes off.

The team is developing a set of commands to restore usability of the flash memory through an overhaul more extensive than the reformatting that has been used so far.

The incidents of Opportunity's flash memory not accepting data for storage have occurred in only one of the seven banks of flash microchip circuitry on board. The team plans to send commands for the rover to avoid that entire bank.

"The mission can continue without storing data to flash memory, and instead store data in volatile RAM," said Mars Exploration Rover Project Manager John Callas of NASA's Jet Propulsion Laboratory, Pasadena, California.

"While we're operating Opportunity in that mode, we are also working on an approach to make the flash memory usable again."

"We will be sure to give this approach exhaustive reviews before implementing those changes on the rover."

Opportunity is examining outcrops on the western rim of Endeavour Crater while traversing southward toward "Marathon Valley," where clay minerals have been detected in observations by NASA's Mars Reconnaissance Orbiter.

ESA Radar Scans: Ground displacement in Bucharest, Romania

Satellite radar scans show various points on and around the Palace of Parliament in Romania’s capital, Bucharest,  that are rising (blue) and sinking (red/orange) from 2011–14.

The radar data were processed using Persistent Scatterer Interferometry (PSI), a technique that can help detect and monitor movements over wide areas with high sensitivity.

It typically works best with hard structures such as buildings, roads or railways, and can trace weak spots in such structures.

This image was produced by the Advanced Studies and Research Center, a Romanian company that processes and interprets optical and radar satellite date for public and private clients across the globe.

The company has recently been validated by ESA’s Terrafirma project as a PSI service provider.

Monday, December 15, 2014

NASA MAVEN: Links in Chain Leading to Atmospheric Loss Identified

NASA’s MAVEN mission is observing the upper atmosphere of Mars to help understand climate change on the planet. 

MAVEN entered its science phase on Nov. 16, 2014.

Image Credit: NASA's Goddard Space Flight Center

Early discoveries by NASA’s newest Mars orbiter are starting to reveal key features about the loss of the planet’s atmosphere to space over time.

The findings are among the first returns from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission, which entered its science phase on Nov. 16.

The observations reveal a new process by which the solar wind can penetrate deep into a planetary atmosphere.

They include the first comprehensive measurements of the composition of Mars’ upper atmosphere and electrically charged ionosphere.

The results also offer an unprecedented view of ions as they gain the energy that will lead to their to escape from the atmosphere.

“We are beginning to see the links in a chain that begins with solar-driven processes acting on gas in the upper atmosphere and leads to atmospheric loss,” said Bruce JakoskyMAVEN principal investigator with the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder.

“Over the course of the full mission, we’ll be able to fill in this picture and really understand the processes by which the atmosphere changed over time.”

On each orbit around Mars, MAVEN dips into the ionosphere, the layer of ions and electrons extending from about 75 to 300 miles above the surface.

This layer serves as a kind of shield around the planet, deflecting the solar wind, an intense stream of hot, high-energy particles from the sun.

Scientists have long thought that measurements of the solar wind could be made only before these particles hit the invisible boundary of the ionosphere.

The SWIA instrument will measure the solar wind and ion density and velocity in the magnetosheath of Mars. 

Credit: UCB/SSL

MAVEN’s Solar Wind Ion Analyzer (SWIA), however, has discovered a stream of solar-wind particles that are not deflected but penetrate deep into Mars’ upper atmosphere and ionosphere.

Interactions in the upper atmosphere appear to transform this stream of ions into a neutral form that can penetrate to surprisingly low altitudes.

Deep in the ionosphere, the stream emerges, almost Houdini-like, in ion form again.

The reappearance of these ions, which retain characteristics of the pristine solar wind, provides a new way to track the properties of the solar wind and may make it easier to link drivers of atmospheric loss directly to activity in the upper atmosphere and ionosphere.

The NGIMS instrument will measure the composition and isotopes of thermal neutrals and ions in the Martian atmosphere. 

Credit: NASA/GSFC

MAVEN’s Neutral Gas and Ion Mass Spectrometer (NGIMS) is exploring the nature of the reservoir from which gases are escaping by conducting the first comprehensive analysis of the composition of the upper atmosphere and ionosphere.

These studies will help researchers make connections between the lower atmosphere, which controls climate, and the upper atmosphere, where the loss is occurring.

The instrument has measured the abundances of many gases in ion and neutral forms, revealing well-defined structure in the upper atmosphere and ionosphere, in contrast to the lower atmosphere, where gases are well-mixed.

The variations in these abundances over time will provide new insights into the physics and chemistry of this region and have already provided evidence of significant upper-atmospheric “weather” that has not been measured in detail before.

The STATIC instrument will enable measurement of energetic particles in the Martian atmosphere. Credit: NASA/SSL

New insight into how gases leave the atmosphere is being provided by the spacecraft’s Suprathermal and Thermal Ion Composition (STATIC) instrument.

Within hours after being turned on at Mars, STATIC detected the “polar plume” of ions escaping from Mars.

This measurement is important in determining the rate of atmospheric loss.

Friday, December 12, 2014

ESA Rosetta: First colour image of Comet 67/P

Scientists superimposed images taken with three different filters.

Credit: ESA

The first colour image from the ESA Rosetta spacecraft shows that Comet 67P is even more dark and monochrome than expected.

Despite being carefully assembled from three images taken with red, green and blue filters, the shot still looks effectively black-and-white.

It comes from the Osiris camera, which is on board the orbiting craft that last month made history by dropping a lander onto the comet's surface.

The Osiris team says 67P is "as black as coal" and surprisingly uniform.

The image was released by the Max Planck Institute for Solar System Research, which leads the consortium behind the camera.

"We like to refer to Osiris as the eyes of Rosetta," said the instrument's principal investigator Dr Holger Sierks.

But the camera is unlike human eyes, and so the colour image had to be produced by combining three separate shots.

This was no easy task. Rosetta is constantly moving and the comet beneath is spinning, so various changes in angle had to be accounted for.

The result is an image that looks remarkably similar to previous, greyscale views of 67P.

"As it turns out, 67P looks dark grey, in reality almost as black as coal," Dr Sierks said.

By the time the image is brightened enough for us to see the comet's features, it looks much lighter grey - but not what anyone would call colourful.

Using observations from the ground, scientists had already observed that Comet 67P, like many other small bodies in our Solar System, appeared to be grey "on average".

But the new results reveal that it seems to be this dark, coal colour all over - with little variation.

That suggests that its surface composition is fairly uniform and shows no sign of ice patches, which would appear bluish.

The comet's ice is presumably hidden below its dusty, boulder-strewn surface.

“All About That Space” NASA volunteer outreach video


“All About That Space” is a volunteer outreach video project created by the Pathways Interns of NASA's Johnson Space Center. It was created as a parody (to raise interest and excitement for Orion's first flight) of Meghan Trainor’s “All About That Bass”.

The lyrics and scenes in the video have been re-imagined in order to inform the public about the amazing work going on at NASA and the Johnson Space Center.

NASA’s Orion spacecraft is built to take humans farther than they’ve ever gone before. Orion will serve as the exploration vehicle that will carry the crew to space, provide emergency abort capability, sustain the crew during the space travel, and provide safe re-entry from deep space return velocities.

Thursday, December 11, 2014

Boeing short film: The Path to Mars



Can the recently flown and tested, Orion spacecraft truly get us to Mars?

NASA has been portraying the mission as part of the roadmap to the Red Planet, but there are observers who say a human landing mission is an unrealistic goal given the budget just isn't there right now in Congress.

That doesn't stop Boeing from dreaming, though. In this new video, the prime contractor for the future Space Launch System rocket suggests that going to Mars will take six spacecraft elements.

Two are in the works right now, Orion and SLS, while a Mars lander and other bits are just ideas right now, but shown in the video.

According to Boeing, the missing elements include a deep-space tug, a habitat, a lander and a rocket designed to get up out of the Mars gravity well.

They also suggest it will take several SLS launches to assemble all the pieces to bring humans to the Red Planet.

"I think we'll be able to colonize Mars someday," said Mike Raftery, director of Boeing Space Exploration Systems, in the video. "It'll take time."

"It may take hundreds of years. But that's not unusual for humans. It's really about establishing a human foothold on the planet. It's a natural evolution of humanity to take this challenge on."

That said, the video does hold to the old joke that a Mars landing is always 20 years in the future; the opening sequence suggests that the landing would take place in the 2030s and that those first astronauts are between the ages of 10 to 20 right now.

Severe North Atlantic cyclone strikes Ireland and UK

A very deep area of low pressure resulted in a North Atlantic cyclone (named Alexandra) which caused massive ocean surges and brought strong winds to parts of Ireland and the UK.

Met-10/Metop-B, 09 December 2014, 12:00 UTC 

Airmass RGB, with surface pressure and ASCAT winds 

Credit: EUMeTrain

Gale force gusts of more than 129 km/h (80 mph) were recorded at Tiree in Scotland and ocean waves over 15 m (50 ft) high were recorded by the K5 buoy off the north west coast of Scotland (59.10N, 11.40W)

The strong winds caused transport chaos and power outtages across the Northern parts of the UK.

The gales and ocean surges were caused by rapid or explosive cyclogenesis — an intense low pressure system with a central pressure that falls 24 hPa in a 24-hour period, referred to colloquially as a 'weather bomb'.

In EUMETSAT weather blog, ITV weather forecaster Liam Dutton explained how the jet stream caused the cyclogenesis.

The Airmass RGB image from 9 December 12:00 UTC (left side) shows the system had a central pressure of less than 950 hPa.

Met-10, 10 December 2014, 06:00 UTC.

Airmass RGB with 10 m ECMWF model winds 

Credit: EUMeTrain

The ASCAT instrument on Metop measured 60 knots (111 km/h), but the real winds were probably higher as ASCAT winds saturate at around 60 knots (higher winds than 60 knots do not produce a higher ASCAT signal).

Also striking in this image are the strong winds over the Western Mediterranean caused by Mistral winds (two storms caught in one image).

The Airmass RGB image from 10 December 06:00 UTC (right side) shows the very large fetch zone of the storm, which is ideal (conditions) for forming high (monster) waves and very large ocean surge.


ESA Rosetta: First measurements of Comet 67/P’s water ratio

ESA Rosetta’s measurement of the deuterium-to-hydrogen ratio (D/H) measured in the water vapour around Comet 67P/Churyumov–Gerasimenko. 

The measurements were made using ROSINA’s DFMS double focusing mass spectrometer between 8 August and 5 September 2014.

Credit: ESA, DLR.

Deuterium is an isotope of hydrogen with an added neutron.

The ratio of deuterium to hydrogen in water is a key diagnostic to determining where in the Solar System an object originated and in what proportion asteroids and/or comets contributed to Earth’s oceans.

The graph displays the different values of D/H in water observed in various bodies in the Solar System.

The data points are grouped by colour as planets and moons (blue), chondritic meteorites from the Asteroid Belt (grey), comets originating from the Oort cloud (purple) and Jupiter family comets (pink). Rosetta’s Jupiter-family comet is highlighted in yellow.

Diamonds represent data obtained in situ; circles represent data obtained by astronomical methods.

The lower part of the graph shows the value of D/H measured in molecular hydrogen in the atmosphere of the giant planets of the Solar System (Jupiter, Saturn, Uranus, Neptune) and an estimate of the typical value in molecular hydrogen for the protosolar nebula, from which all objects in our Solar System formed.

The ratio for Earth’s oceans is 1.56 ×10–4 (shown as the blue horizontal line in the upper part of the graph).

The value for Comet 67P/Churyumov–Gerasimenko is found to be 5.3 x 10–4, more than three times greater than for Earth’s oceans.

The discovery fuels the debate on the origin of Earth’s oceans and whether asteroids or comets played the bigger role in delivering water.

Wednesday, December 10, 2014

SpaceX to attempt Falcon 9 Rocket landing on Floating Ocean Platform

The SpaceX Falcon 9 rocket, complete with "hypersonic grid fins," that SpaceX will attempt to land on a floating platform in the Atlantic Ocean as part of a Dec. 16, 2014 launch.

Credit: Elon Musk/SpaceX

SpaceX will apparently attempt something truly epic during next week's cargo launch to the International Space Station.

During the Dec. 16 launch from Florida's Cape Canaveral Air Force Station, which will send SpaceX's robotic Dragon capsule toward the orbiting lab, the California-based company will try to bring the first stage of its Falcon 9 rocket back to Earth for a controlled landing on a floating platform in the Atlantic Ocean.

The bold maneuver marks a big step forward in SpaceX's development of reusable-rocket technology, which the company's billionaire founder, Elon Musk, says could eventually cut the cost of spaceflight by a factor of 100 and perhaps make Mars colonization economically feasible.

A photo of the "autonomous spaceport drone ship" on which SpaceX will attempt to land the Falcon 9 rocket.

Credit: Elon Musk/SpaceX

Musk shared photos of the Falcon 9 and landing platform via Twitter late last month, ratcheting up interest in the cargo mission, the fifth of 12 unmanned resupply flights SpaceX will make to the space station for NASA under a $1.6 billion contract.

"Autonomous spaceport drone ship. Thrusters repurposed from deep sea oil rigs hold position within 3m even in a storm," Musk tweeted about the platform on Nov. 22.

"Base is 300 ft by 100 ft, with wings that extend width to 170 ft. Will allow refuel & rocket flyback in future," he added in another tweet.


The Falcon 9 photo revealed that the rocket is outfitted with "hypersonic grid fins" to increase stability during a return to Earth.

"Grid fins are stowed on ascent and then deploy on reentry for 'x-wing' style control," Musk tweeted on Nov. 22. "Each fin moves independently for pitch/yaw/roll."

At a conference at MIT in October, Musk said that SpaceX would attempt to land the Falcon 9 first stage on the floating platform during the rocket's next flight.

The next liftoff on the rocket's schedule is the Dec. 16 Dragon launch.

ESA Rosetta: Earth's Water Came from Asteroids, Not Comets

ESA Rosetta’s navigation camera obtained the four images in this mosaic on Dec. 7, 2014, from a distance of 12.2 miles (19.7 km) from the center of Comet 67P/Churyumov-Gerasimenko.

Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0

Asteroids, not comets, may have delivered most of Earth's water to the planet when the solar system was young, new data from the ESA Rosetta probe orbiting comet 67/P suggests.

Comets are some of the solar system's most primitive building blocks, with many dating to soon after its formation.

Scientists think that these dirty snowballs probably helped seed Earth with key ingredients for life, such as organic compounds.

The European Space Agency's (ESA) Rosetta spacecraft is helping scientists learn more about the role these icy nomads have played in the evolution of the solar system and life on Earth by analyzing the composition of Comet 67P/Churyumov–Gerasimenko.

In August, Rosetta became the first spacecraft to orbit a comet, and in November, its Philae lander became the first probe to make a soft touchdown on a comet's surface.

Rosetta is also the first mission to escort a comet as it travels around the sun.

Now, Rosetta has helped solve a mystery about how Earth became the watery world it is today.

Before Rosetta began orbiting Comet 67P/C-G in August, it was using an instrument known as ROSINA (short for Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) to analyze the chemical fingerprint of gases in the comet's fuzzy envelope.

Scientists focused on data from the instrument regarding water to help uncover whether asteroids or comets delivered the water in Earth's oceans.

Rosetta has provided data from Comet 67P/C-G, another Kuiper Belt comet.

However, Rosetta has discovered that this comet possesses an even higher deuterium-to-hydrogen ratio than seen in Oort Cloud comets, three times the amount of heavy water compared to normal water as Earth has.

If Earth's water had come from Kuiper Belt objects, even if most of them were like comet 103P/Hartley 2, and if only a small fraction were like Comet 67P/C-G, Earth's deuterium-to-hydrogen ratio would be significantly higher than it is today.

"This probably rules out Kuiper Belt comets from bringing water to Earth," Altwegg said. Instead, most of Earth's water was probably delivered by asteroids, Altwegg said.

"Today's asteroids have very little water, that's clear," Altwegg added. "But that was probably not always the case. During the Late Heavy Bombardment 3.8 billion years ago, at that time, asteroids could have had much more water than they could now."

The asteroids seen now "have stayed in the vicinity of the sun for 4.6 billion years," Altwegg said.

"They've lost water due to the sun, due to heat. But to start with, they might have had much more water than they have now."

Future analysis of ice-rich bodies in the asteroid belt could shed light on whether Earth's water really did come from there, Altwegg said.