A waxing gibbous cometary nucleus…(Credit: NASA/JPL/CalTech).
An artists’ impression of Stardust NExT at comet Temple 1.
NASA engineers directed the Stardust spacecraft to fire its rockets briefly on the of 17th of February, putting it on course for a new mission; a flyby of comet Tempel 1 February 14th of next year. If that comet sounds familiar, it should be; Tempel 1 was smacked by an impactor released from the Deep Impact space probe in 2005. The pass will allow scientists to see how the impact crater has evolved, as well as mark the first mission to re-visit a comet. Launched on February 7th, 1999, Stardust also returned a first ever sample of a comet. This sample has been the subject of much scrutiny by Earth-bound scientists, including that favorite obsessive/compulsive-creating crowd-sourcing project, Stardust@home. Hey, I’m still in the top 100, last time I checked… NASA has also rechristened the spacecraft as Stardust NExT, or the New Exploration of Tempel. Not only will next years’ passage provide close-ups of the nucleus, but expect to see high resolution images of the coma and key insight into just how these Jupiter-class family of comets formed and evolved.
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.
I was recently at a waiting room the other day, when the secretary noticed that I had brought a copy of Death From the Skies! to “kill” time. “Is that stuff true?” she asked. I mentioned that yes, sooner or later, a killer space rock may well have our species collective name on it. I knew what was coming next. “I mean, I like saw this documentary on the Discovery channel about how the world is supposed to end in 2012…”
Every generation enjoys its own Apocalypse, and for better or worse, 2012 is ours. [Read more...]
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!
- The LRO Photographs the Apollo landing sites: Fans of this space may have noticed the racy lunar pics we ran a week back as part of our From Earth to the Moon review. The Lunar Reconnaissance Orbiter did indeed snap pics of the famous Apollo landing sites last month. These clearly show the hardware left at multiple sites, as well as the base(s) of the Lunar Lander ascent stages, complete with shadow. You can even see the astronaut’s foot trails in the lunar dust! And the LRO hasn’t even entered its cruising orbit yet… expect more great pics to come! [Read more...]