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The argument that the moon is a dry, desolate place no longer holds water.

Secrets the moon has been holding, for perhaps billions of years, are now being revealed to the delight of scientists and space enthusiasts alike.

NASA today opened a new chapter in our understanding of the moon. Preliminary data from the Lunar CRater Observation and Sensing Satellite, or LCROSS, indicates that the mission successfully uncovered water during the Oct. 9, 2009 impacts into the permanently shadowed region of Cabeus cater near the moon’s south pole.

The impact created by the LCROSS Centaur upper stage rocket created a two-part plume of material from the bottom of the crater. The first part was a high angle plume of vapor and fine dust and the second a lower angle ejecta curtain of heavier material. This material has not seen sunlight in billions of years.

"We're unlocking the mysteries of our nearest neighbor and by extension the solar system. It turns out the moon harbors many secrets, and LCROSS has added a new layer to our understanding," said Michael Wargo, chief lunar scientist at NASA Headquarters in Washington.

Scientists have long speculated about the source of vast quantities of hydrogen that have been observed at the lunar poles. The LCROSS findings are shedding new light on the question of water, which could be more widespread and in greater quantity than previously suspected.

Permanently shadowed regions could hold a key to the history and evolution of the solar system, much as an ice core sample taken on Earth reveals ancient data. In addition, water, and other compounds represent potential resources that could sustain future lunar exploration.

Since the impacts, the LCROSS science team has been working almost nonstop analyzing the huge amount of data the spacecraft collected. The team concentrated on data from the satellite's spectrometers, which provide the most definitive information about the presence of water. A spectrometer examines light emitted or absorbed by materials that helps identify their composition.

"We are ecstatic," said Anthony Colaprete, LCROSS project scientist and principal investigator at NASA's Ames Research Center in Moffett Field, Calif. "Multiple lines of evidence show water was present in both the high angle vapor plume and the ejecta curtain created by the LCROSS Centaur impact. The concentration and distribution of water and other substances requires further analysis, but it is safe to say Cabeus holds water."

The team took the known near infrared spectral signatures of water and other materials and compared them to the spectra collected by the LCROSS near infrared spectrometer of the impact.

"We were only able to match the spectra from LCROSS data when we inserted the spectra for water," said Colaprete. "No other reasonable combination of other compounds that we tried matched the observations. The possibility of contamination from the Centaur also was ruled out."

Additional confirmation came from an emission in the ultraviolet spectrum that was attributed to hydroxyl, one product from the break-up of water by sunlight. When atoms and molecules are excited, they release energy at specific wavelengths that are detected by the spectrometers. A similar process is used in neon signs. When electrified, a specific gas will produce a distinct color. The ultraviolet visible spectrometer detected hydroxyl signatures just after impact that are consistent with a water vapor cloud in sunlight.

Data from the other LCROSS instruments are being analyzed for additional clues about the state and distribution of the material at the impact site. The LCROSS science team along with colleagues are poring over the data to understand the entire impact event, from flash to crater, with the final goal being the understanding of the distribution of materials, and in particular volatiles, within the soil at the impact site.

"The full understanding of the LCROSS data may take some time. The data is that rich," said Colaprete. "Along with the water in Cabeus, there are hints of other intriguing substances. The permanently shadowed regions of the moon are truly cold traps, collecting and preserving material over billions of years."

LCROSS was launched June 18, 2009 as a companion mission to the Lunar Reconnaissance Orbiter, or LRO, from NASA's Kennedy Space Center in Florida. After separating from LRO, the LCROSS spacecraft held onto the spent Centaur upper stage rocket of the launch vehicle, executed a lunar swingby and entered into a series of long looping orbits around the Earth.

After traveling approximately 113 days and nearly 5.6 million miles (9 million km), the Centaur and LCROSS separated on final approach to the moon. Traveling as fast as a speeding bullet, the Centaur impacted the lunar surface shortly after 4:31 a.m. PDT Oct. 9 with LCROSS watching with its onboard instruments. Approximately four minutes of data was collected before the LCROSS itself impacted the lunar surface.

Working closely with scientists from LRO and other observatories that viewed the impact, the LCROSS team is working to understand the full scope of the LCROSS data. LRO continues to make passes over the impact site to give the LCROSS team additional insight into the mechanics of the impact and its resulting craters.

What other secrets will the moon reveal? The analysis continues!
 

Jupiter's moon Europa is flowing with a buried liquid water ocean that contains much more oxygen than previously thought – enough to possibly support life, scientists say.

There is no solid evidence of life for anywhere besides Earth, but Europa has long been considered a good place to look for biological activity.

Europa's ocean lies beneath several miles of ice, so scientists wondered whether it has much oxygen, which is thought to be created at the surface by interaction with energetic charged particles from the sun. Scientists think oxygen is probably necessary for life's metabolic processes, unless some creatures use exotic chemistry involving sulfur or methane.

The global ocean on Europa contains about twice the liquid water of all the Earth's oceans combined. The new research suggests that there may be a hundred times more oxygen than previously estimated.

To probe how much oxygen might lie in the ocean, Richard Greenberg of the University of Arizona studied Europa's surface, which appears to be only about 50 million years old - roughly 1 percent of the age of the solar system - and continually reforming.

He considered three possible resurfacing processes: gradually laying fresh material on the surface, opening cracks which fill with fresh ice from below, and disrupting patches of surface in place and replacing them with fresh material. Using estimates for the production of oxygen at the surface, Greenberg found that the delivery rate into the ocean is likely so fast that the oxygen concentration could exceed that of the Earth's oceans in only a few million years.

These concentrations of oxygen could be great enough to support not only microorganisms, but also larger animals that have greater oxygen demands, Greenberg said.

The good news for the question of the origin of life is that there would be a delay of a couple of billion years before the first surface oxygen reached the ocean. Without that delay, the first pre-biotic chemistry and the first primitive organic structures would be disrupted by oxidation, or rusting. Oxidation is a hazard unless organisms have evolved protection from its damaging effects. A similar delay in the production of oxygen on Earth was probably essential for allowing life to get started here.

Greenberg will present his findings Friday at the 41st meeting of the American Astronomical Society's Division for Planetary Sciences in Fajardo, Puerto Rico.

An amino acid has been found on a comet for the first time, a new analysis of samples from NASA's Stardust mission reveals. The discovery confirms that some of the building blocks of life were delivered to the early Earth from space.

Amino acids are crucial to life because they form the basis of proteins, the molecules that run cells. The acids form when organic, carbon-containing compounds and water are zapped with a source of energy, such as photons – a process that can take place on Earth or in space.

Previously, researchers have found amino acids in space rocks that fell to Earth as meteorites, and tentative evidence for the compounds has been detected in interstellar space. Now, an amino acid called glycine has been definitively traced to an icy comet for the first time.

"It's not necessarily surprising, but it's very satisfying to find it there because it hasn't been observed before," says Jamie Elsila of NASA's Goddard Space Flight Center, lead author of the new study. "It's been looked for [on comets] spectroscopically with telescopes but the content seems so low you can't see it that way."

Life in Venus' clouds may be the best way to explain some curious anomalies in the composition of its atmosphere, claimed University of Texas astrobiologists in 2002. They scoured data from NASA's Pioneer and Magellan space probes and from Russia's Venera Venus-lander missions of the 1970s.

Solar radiation and lightning should be generating masses of carbon monoxide on Venus, yet it is rare, as though something is removing it. Hydrogen sulphide and sulphur dioxide are both present too. These readily react together, and are not usually found co-existing, unless some process constantly is churning them out. Most mysterious is the presence of carbonyl sulphide. This is only produced by microbes or catalysts on Earth, and not by any other known inorganic process.

The researchers' suggested solution to this conundrum is that microbes live in the Venusian atmosphere. Venus's searing hot, acidic surface may be prohibitive to life, but conditions 50 kilometres up in the atmosphere are more hospitable and moist, with a temperature of 70°C and a pressure similar to Earth.

In 2003, Italian scientists hypothesised that sulphur traces on Europa might be a sign of alien life. The compounds were first detected by the Galileo space probe, along with evidence for a volcanically-warmed ocean beneath the moon's icy crust. The sulphur signatures look similar to the waste-products of bacteria, which get locked into the surface ice of lakes in Antarctica on Earth. The bacteria survive in the water below, and similar bacteria might also thrive below Europa's surface, the researchers suggest. Others experts rejected the idea, suggesting that the sulphur somehow originates from the neighbouring moon Io, where it is found in abundance.

In 2004 three groups - using telescopes on Earth and the European Space Agency's Mars Express orbiting space probe - independently turned up evidence of methane in the atmosphere. Nearly all methane in our own atmosphere is produced by bacteria and other life.

Methane could also be generated by volcanism, the thawing of frozen underground deposits, or delivered by comet impacts. However, the source has to be recent, as the gas is rapidly destroyed on Mars or escapes into space.

In January 2005, an ESA scientist controversially announced that he had also found evidence of formaldehyde, produced by the oxidation of methane. If this is proved it will strengthen the case for microbes, as a whopping 2.5 million tonnes of methane per year would be required to create the quantity of formaldehyde postulated to exist.

There are ways to confirm the presence of the gas, but scientists will need to get the equipment to Mars first.

Tests performed on Martian soil samples by NASA's Viking landers hinted at chemical evidence of life. One experiment mixed soil with radioactive-carbon-labelled nutrients and then tested for the production of radioactive methane gas.

The test reported a positive result. The production of radioactive methane suggested that something in the soil was metabolising the nutrients and producing radioactive gas. But other experiments on board failed to find any evidence of life, so NASA declared the result a false positive.

Despite that, one of the original scientists - and others who have since re-analysed the data - still stand by the finding. They argue that the other experiments on board were ill-equipped to search for evidence of the organic molecules - a key indicator of life.

Astronomers have found one of the oldest stars known to date. The star, HE 1523-0901, is in the Milky Way and is estimated to be 13.2 billion years old. With such an age, it would have formed just 500 million years after the Big Bang and must have formed very early in the life of our very own galaxy.

To measure the age of the star, astronomers used a technique similar to the carbon-14 dating method used to measure the age of archaeological finds here on Earth. In this case, however, they measured the abundance of radioactive isotopes of Uranium and Thorium. Such a feat can only be performed by the largest telescopes. So the astronomers used ESO's VLT (Very Large Telescope) to observe the star for a total of 7.5 hours with an ultraviolet spectrograph - allowing the spectral lines from the radioactive elements to be observed. This is the first time that more than a single cosmic clock has been measured for a star. In all, a total of six measurements were made and the results suggested that HE 1523-0901 was 13.2 billion years old. This is quite an amazing find considering that the Universe is believed to have existed for only 13.7 billion years!

The HiRISE (High Resolution Imaging Science Experiment) camera on the Mars Reconnaissance Orbiter has detected a very dark spot on the surface of Mars that appears to be the entrance to a cavern or cave.

The entrance to the cave measures approximately 100 m across and was found on a dusty lava plain to the northeast of Arsia Mons. Even though the HiRISE camera is extremely sensitive and can see details in almost any shadow on Mars, it was unable to see any details in the dark region suggesting that it must be very deep. It was also unable to see any walls, suggesting that the walls of the cave must be either perfectly vertical, extremely dark, or overhanging.

Archive observations by the Hubble Space Telescope have been used to identify the progenitor of a supernova seen in an external galaxy in 2005.  This highly luminous star, of around 100 solar masses, appears not to have evolved to the iron core stage required for collapse to initiate a supernova.  The observations may require modifications to theories of supernovare explosions, as occurred after the only other firm identification of a progenitor – that of SN 1987a.

The oldest stars in our galaxy are characterised by very low ‘metal’ (i.e. elements other than hydrogen and helium) content since they formed over 10 Myr ago when the interstellar medium contained far fewer heavy elements released from previous stars.  The object had been identified as a possible member of the old ‘halo’ population by its proper motion.  Measurements of its distance using trigonometric parallax imply that one of these halo stars is so intrinsically faint it must be a brown dwarf.

Observations using the Very Long Baseline Array (VLBA) radio telescope to make parallax measurements of star formation regions in the Milky Way, have revealed that our galaxy is rotating faster than previously thought. The measurements indicate that the Sun is orbiting at a speed of about 265 km s-1 rather than the 220 km s-1 previously believed . This implies that the galaxy has a mass 50% greater than previously thought, meaning it rivals the Andromeda galaxy (the other large spiral galaxy in our Local Group .

The parallax measurements of masers (objects which naturally amplify radio waves in a similar way to optical lasers) in spiral arms provide a direct determination of distance and motion that is more precise than previously used indirect methods.  The data also imply that the Milky Way has four, rather than two spiral arms.

n February 2003, astronomers with the search for extraterrestrial intelligence (SETI) project, used a massive telescope in Puerto Rico to re-examine 200 sections of the sky which had all previously yielded unexplained radio signals. These signals had all disappeared, except for one which had become stronger.

The signal - widely thought to be the best candidate yet for an alien contact - comes from a spot between the constellations Pisces and Aries, where there are no obvious stars or planets. Curiously, the signal is at one of the frequencies that hydrogen, the most common element, absorbs and emits energy. Some astronomers believe that this is a very likely frequency at which aliens wishing to be noticed would transmit.

Nevertheless, there is also a good chance the signal is from a never-seen-before natural phenomenon. For example, an unexplained pulsed radio signal, thought to be artificial in 1967, turned out to be the first ever sighting of a pulsar.

In August 1977 an Ohio State University radio telescope detected an unusual pulse of radiation from somewhere near the constellation Sagittarius. The 37-second-long signal was so startling that an astronomer monitoring the data scrawled "Wow!" on the telescope's printout.

The signal was within the band of radio frequencies where transmissions are internationally banned on Earth. Furthermore, natural sources of radiation from space usually cover a wider range of frequencies.

As the nearest star in that direction is 220 million light years away, either a massive astronomical event - or intelligent aliens with a very powerful transmitter would have had to have created it. The signal remains unexplained.

The Sumerians were one of the earliest urban societies to emerge in the world, in Southern Mesopotamia more than 5000 years ago. They developed a writing system whose wedge-shaped strokes would influence the style of scripts in the same geographical area for the next 3000 years. Eventually, all of these diverse writing systems, which encompass both logophonetic, consonantal alphabetic, and syllabic systems, became known as cuneiform.

The Sumerian writing system during the early periods was constantly in flux. The original direction of writing was from top to bottom, but for reasons unknown, it changed to left-to-right very early on (perhaps around 3000 BCE). This also affected the orientation of the signs by rotating all of them 90° counterclockwise. Another change in this early system involved the "style" of the signs. The early signs were more "linear" in that the strokes making up the signs were lines and curves.

Later Mesopotamian people (Babylonians, Assyrians, Persians, etc) adopted this system but modified it so that it became positional (like ours). This reduced the system to only two symbols (the "1" and "10" signs) and the position a sign occur within a number changes its quanity, just like "1" in the number "100" is different from the "1" in the number "10,000" in our modern system.

The Sumerian writing system was adopted and modified by other contemporaneous Mesopotamian people such as the Akkadians and the Babylonians. As a spoken language, Sumerian died out around the 18th century BCE, but continued as a "learned" written language (much like Latin was during the Middle Ages in Europe). In this way, Sumerian was used continually until the 1st century CE, making it one of the longest used writing system in history.