July 30, 2014

22.03.10- On the Trail of Lunar Water.

The Moon as imaged during the 1999 Cassini flyby. (Credit: CASA/JPL/USGS).

The Moon as imaged during the 1999 Cassini flyby. (Credit: CASA/JPL/USGS).

 

    Last year’s big news story was the announcement of water on the Moon. This evidence came from five separate sources, and spanned over a decades’ worth of data. This climaxed with the October 9th impact of the LCROSS spacecraft in the quest for a moisture laden plume. Now, a reanalysis of lunar samples returned by Apollo astronauts have turned up evidence of microscopic water beads imbedded in volcanic glass. This leads scientist Alberto Saal to suggest that the lunar interior may contain water in the order of 745 parts per million, a tiny but measureable amount.

The first whiff of water in the form of clay hydroxyls came from the Clementine and Lunar Prospector orbiters in the mid 90’s. Cassini imaged the Moon in the infrared on its way out to Saturn, but the water signature detected at the time was suspected to be due to spacecraft contamination. More recently, lunar water got a boost from NASA’s spectrometer aboard the Indian orbiter Chandrayaan 1 and observations by the Deep Impact spacecraft in its role of simulated exoplanet hunter… keep in mind, the amount of water being discussed is tiny; were talking maybe a liter per ton of lunar regolith near the poles, and half that amount at the equator! With the cancellation of Constellation, it’s to be seen if any of the proposed unmanned rovers will take up the hunt for lunar water over the next few years.

Hailing Phoenix.

The receding ice in the region of the Phoenix Lander as seen from HiRise. (Credit:NASA/JPL/Caltech/Texas A&M University.

The receding ice in the region of the Phoenix Lander as seen from HiRise. (Credit:NASA/JPL/Caltech/Texas A&M University.

This week, engineers at NASA’s Jet Propulsion Laboratory will begin listening for a very special phone call; that of the Phoenix Lander on the northern polar region of Mars. Spring is in the air on the northern hemisphere of Mars, and bets are on as to whether the Lander survived the bleak Martian winter. Already, the outlook isn’t stellar; Phoenix has more than likely been encased in CO2 ice for several months; and don’t forget, the Martian year and seasons are roughly twice as long as here on Earth! Add to the fact the Mars is close to aphelion in its relatively eccentric orbit, and the odds don’t look good.  To phone home, Phoenix will need to recharge its spent batteries to a point where its automated broadcasting can kick in; the solar angle is currently about the same as when scientists lost contact last year. If it does start transmitting, Mars Odyssey currently in orbit will be listening. Odyssey passes over the landing site about 10 times a day, and will listen in over the next few months.  The sixth successful landing on the Red Planet and only the third successful soft landing, Phoenix returned some first rate science, and gave us concrete evidence of water ice lurking just below the Martian soil. Now approaching opposition, Mars is rising low in the east just after dusk; more on that next week! For now, Let’s hope that Phoenix lives up to its namesake and rises from the dead!

04.11.09:Did Ancient Comets give Earth its Seas?

Comet McNaught gave us a dusk show in 2007. (Credit: Paul Salzgeber under a Creative Commons license).

Comet McNaught gave us a good dusk show in 2007. (Credit: Paul Salzgeber under a Creative Commons license).

Comets continue to be at the center of controversy concerning the early Earth and life. If you’ve been following our recent reports as of late, you know that opinions run the gamut, from ancient cometary impacts being relatively rare, to comets being crucial to life as we known it. Now, researchers at the Niels Bohr Institute in Denmark have scored one for the comet camp. Recent studies of ancient rocks in Greenland suggest that the primordial Earth may have undergone a massive cometary bombardment early in its history, about 3.85 billion years ago. Were talking waaaaay back in the Archean period, before life had even taken hold. The conclusion is based on our friendly elemental smoking gun, Iridium. Rare on Earth, what little iridium is found in the Earth’s crust is almost certainly of extraterrestrial origin. Asteroid impacts generally distribute about 18,000 parts per trillion, while comets, due to a higher impact velocity and icy rock composition, produce amounts much lower, about 130 parts per trillion. The team found a ratio of 150 ppt, strongly suggesting that comets were the primary constituents of the Late Heavy Bombardment. This is a tantalizing clue in two enduring mysteries concerning the early Earth; how did we our get our large oceans, and how did life start? Looking out into the solar system, we are the only planet with a large surface covering of liquid water. Could it have been deposited by comets? That’s a lot of dirty snowballs… there is some thought that life itself, or at least amino acids, known as the chemical building blocks of life, might have been deposited in the same fashion by a method known as panspermia. Not all scientists remain convinced, however, and for now, spinning cometary hypotheses remains a sure way to generate scientific controversy. Are we all “comet-stuff?”

21.10.09:IBEX: The Unsung Hero.

Our passage thru the instellar medium as seen by IBEX. (Credit: Adler Planetarium/Southwest Research Institute).

Our passage thru the instellar medium as seen by IBEX. (Credit: Adler Planetarium/Southwest Research Institute).

Amidst the recent water on the Moon hoopla, one key player was largely missed by the media; IBEX, NASA’s Interstellar Boundary Explorer. Launched in October 19th, 2008, IBEX travels in a highly eccentric Earth orbit that takes it from a perigee of 4,000 miles to an apogee of 150,000 miles in 3 days. This enables IBEX to dip in and out of Earth’s magnetosphere and bow shock, panning its 7 degree field of view camera in an all sky survey to map the heliopause, the boundary of our solar system with interstellar space. The cameras, dubbed IBEX Hi & Lo respectively, are the most sensitive neutron detectors ever flown, and span the sky looking for particles moving in access of 161,000 miles per hour. When it was first turned on & checked out earlier this year, engineers got a start; a nearby, large source of neutral atoms nearly filling the field of view. That was none other than our own Moon, reflecting the solar wind off of the lunar soil. The Earth’s magnetic field protects us from this onslaught, which hits the daytime side of the Moon unimpeded. The signature and percentage of particles seen lends credence to the water mixed in with the lunar soil theory, embedded mostly as hydroxyl compounds. In fact, the heliopause itself has shown signs of shrinking as of late due to the ongoing solar minimum… the just released image above released by the IBEX team sheds light on the overall structure of the heliopause as our solar system moves through the interstellar medium. Most interestingly, it shows that a large ribbon of Energetic Neutral Atoms (ENA’s) flowing between Voyager 1 & 2, our farthest soon-to-be intergalactic outposts. Just what would life in the interstellar medium be like, should it be pressed down or swept back interior to Earth’s orbit, as has been hypothesized in the distant past? Watch for more news on IBEX to come!

09.10.09: An LCROSS Update.

Impact! (Credit: NASA/LCROSS).

Impact! (Credit: NASA/LCROSS).

NASA’s LCROSS spacecraft performed its promised “moon crash” early this AM at 0731 AM EDT… all eyes, electronic and otherwise were on Cabeus crater. Unfortunately, no impact was detected here at Astroguyz HQ in Hudson, Florida, although we did have a rising Sun and a brightening sky to contend with. The 10 AM news conference at the Ames research center revealed that the secondary control module of LCROSS did detect the impact in both UV and IR signatures as well as a visual fix on the crater created by the Centaur booster. The controller itself met its fiery end four minutes later. Ground based observatories from Apache Point, New Mexico to the Keck telescopes in Hawaii to observatories in South Korea as well as Hubble, LRO, and Sweden’s ODIN in orbit all gathered data. Its to be seen if any amateur ‘scopes recorded this event. Kitt Peak did record a sodium flash during the event. Of course, the data itself will need to be compiled and analyzed before any meaningful scientific conclusions can be done…I smell a follow up post! Kudos to all that woke up early to look at our nearest neighbor in space, as well as NASA scientists that are no doubt now getting some much needed sleep!

LCROSS Strikes Back!

The Earth as seen from LCROSS at the time of impact...see your house? Then look up on Friday morning! (Credit: NASA).

The Earth as seen from LCROSS at the time of impact...see your house? Then look up on Friday morning! (Credit: NASA).

The Moon won’t know what hit it Friday. On October 9th at 11:30 Universal Time, the LCROSS twin impactors will slam into the Moon’s south pole region. The quarry; permanently shaded water ice. LCROSS consists of a upper stage Centaur rocket weighing in at 5,200 lbs and a controlling “shepherd” spacecraft weighing in at 1,900 lbs. The stage section will separate shortly before impact, enabling the control package to fly through the resulting debris plume, which is expected to be 6 miles high at eject 350 tons of material from the surface. Both will successively slam into the surface at 5,600 mph. Recently, the candidate impact crater was shifted from Cabeus A to Cabeus proper. [Read more...]

LCROSS target crater announced.

A map of potential LCROSS canidate targets. (Credit: NASA/LCROSS).

A map of potential LCROSS canidate targets. (Credit: NASA/LCROSS).

Scientists at NASA have announced the candidate target crater for the LCROSS impactor on October 9th; Cabeus A, a 11km wide polar crater thought to contain the ever- elusive water ice. The Centaur upper stage will slam into the carter floor at 7:30 AM EDT, at which time the Moon will be waning gibbous, and about 70% illuminated, and favoring viewers in the Americas (including Astroguyz HQ!). Contrary to earlier fears, LCROSS has enough fuel to make final maneuvers for impact. Both Keck observatories and LCROSS’s twin, the Lunar Reconnaissance Orbiter, as well as a multitude of eager amateur observers will be on hand to witness this rare event!

25.9.9: Water Confirmed on the Moon!

Erlanger crater, a permenantly shadowed polar crater. (Credit: NASA/LRO).

Erlanger crater, a permenantly shadowed polar crater. (Credit: NASA/LRO).

In a stunning press conference on Thursday, NASA revealed conclusive proof for what has been suspected for decades; evidence for water-ice mixed into the lunar surface! The evidence comes from multiple sources over the past decade;

  • Lunar Prospector, which measured a “flux drop” with its neutron spectrometer during its operational phase of 1998-9.

  • The “M-cubed” instrument NASA sent aboard India’s Chandrayaan-1 measured tell tale infrared signatures during its recent lunar mission;

  • Cassini (yes, that Cassini!) and Deep Impact both measured signatures highly suggestive of water during their respective outbound passes. Cassini with the VIMS (the Visible Mapping Infrared Spectrometer) and Deep Impact in its extended EPOXY (Extrasolar Planet Observation and Deep Impact Extended Investigation) role.

  • Clementine, which operated in 1994 produced data that also backed up these findings.

Perhaps what was most astounding was the fact that water signatures were found not only at the poles, which has been long suspected, but in the lunar equatorial regions as well! Apparently, water exists in some degree at all latitudes… quantities quoted were of the magnitude of one quart per ton near the poles to a tablespoon per ton of lunar material at the equator. Keep in mind, much of this is mixed in as hydroxyl compound as well as lunar ice. Think a clay-like material. Scientists also pointed out that this is still “drier than the driest terrestrial desert…” clearly, future settlers will have to move tons of lunar regolith to exact a useable amount of H2O… another stunning mechanism discussed for the existence of equatorial water was the possibility of a pseudo “hydrological cycle” on the Moon! This would be driven by gravity, heating, and hydrogen ions from the solar winds bombarding the surface throughout the lunar day. The layer is perhaps a few millimeters thick. Three separate papers were published formalizing these findings yesterday. This will undoubtedly spur on lunar exploration, as well as put all eyes on the Moon for the LCROSS impact on October 9th!