On October 9, 2009, a piece of launch rocket still attached to an orbiting spacecraft will finally let go so it can take a dive into the moon.

The event is the end goal of NASA's LCROSS mission, which aims to study material kicked up by the impact to find out whether the lunar surface has water ice.

Today NASA announced that Cabeus A, a 25-mile-wide (40-kilometer-wide) crater on the moon's south pole, will be the site in the mission's crosshairs.

[LCROSS's Candidate Impact Craters -- That's Cabeus A Marked as "SP C"]
—Picture courtesy NASA/Ames Research Center

Not too much is known about this crater, which is part of the reason it was selected. Cabeus A sits on a region of the moon that's almost always in shadow, making it more likely that any water ice could exist there, since it wouldn't have been effectively vaporized by direct sunlight.

The crater is also among the sites on the moon known to have a mysterious quantity of hydrogen, which your grade-school chemistry teacher would remind you is a major component of good old H2O. Cabeus A in particular has a high concentration of hydrogen clustered in what NASA scientists call a "sweet spot" near its rim.

Finally, Cabeus A rests along an edge of the moon that is easily visible from Earth, making it an ideal place to send up a plume for people to see.

The plume will be bright but short lived, lasting only about 30 seconds before it starts to fade, LCROSS scientist Tony Colaprete said today at a news briefing.

To get the most out of this "flash in the pan," the LCROSS team has coordinated a vast army of stargazers on the ground and in space to watch the event and collect as much information as they can about the plume.

Top of the list will be the LCROSS craft itself, which will be speeding toward the impact site just after it sends the leftover rocket hurtling toward the moon.

Instruments aboard LCROSS will collect data about the plume and the newly minted impact crater until the probe looses contact with Earth about 15.5 miles (25 kilometers) above the lunar surface. Four minutes after the first impact, LCROSS itself will then slam into the moon.

The duty roster also includes massive telescopes in Hawaii and the U.S. Southwest as well as orbiters such as the Hubble Space Telescope and the GeoEye imaging satellite.

In addition, NASA has put out the call for amateur astronomers with backyard telescopes to train their instruments on Cabeus A and report back via a "citizen science" web site.

The data entry page isn't up and running just yet, but if you'd like to take part LCROSS does have a page full of tips for when and where to look, what equipment to use, and how to take pictures.

The impact will happen at 4:30 a.m. Pacific time, which should allow enough darkness for the plume to be visible to people in the Western Hemisphere. Us folks on the East Coast will have our view blocked by dawn skies, but we can watch live streaming video of the moon crash on NASA TV.

For an idea of what you might see, go out and look at the moon tonight, LCROSS experts suggest: The moon is in the same phase right now as it will be on impact day.

As for what we might find, water is the goal but it's not the only option. Hydrogen could also mean the moon's pockets are full of methane, hydrocarbons, or whatever else the body has collected over the last 3.5 billion years, Colaprete noted.

Water or no, the plume's contents, he said, will be "a window into the past of the entire inner solar system."

Of the more than 300 planets circling other stars we've found so far, only a handful have ever had their pictures taken directly.

Astronomers strongly suspect the vast majority of these so-called exoplanets exist based solely on indirect evidence, such as their gravitational effects on stars.

So the trick, then, is figuring out anything else about those planets beyond the fact that they're there.

Is a given exoplanet the size of Jupiter or Mars? What's it made of, and what's in its atmosphere? And perhaps the most exciting question, is there liquid water?

Enric Pallé, of Spain's Astrophysics Institute of the Canaries, and colleagues figured the best way to answer some of these questions would be to look no farther than home.

—Image courtesy Gabriel Perez Diaz/Nature

What's more, the researchers decided to advance the frontiers of 21st-century astronomy using one of the oldest known astrophysical tools: a lunar eclipse.

There's so many reasons Titan is just darn cool.

Discovered in 1655, the Saturn moon is the second biggest moon in our solar system (beat out only by Jupiter's Ganymede). It's also the only moon known to have a planet-like atmosphere, complete with clouds, a cool fact that unfortunately meant its surface long remained a big, chilly mystery wrapped in a hazy enigma.

Then came the Cassini-Huygens probe, which reached the Saturnian system in 2004 and began sending back detailed looks under the moon's veil.

In 2006 Cassini images revealed Titan to be the only body in our solar system other than Earth to have lakes—albeit lakes full of liquid methane.

Now comes more cool news from Cassini: Those lakes show distinct changes over time, supporting theories that Titan has a methane cycle similar to Earth's water cycle.

—Image courtesy NASA/CICLOPS

The implication of changing lakes is that they are being filled with methane rain, an idea previously suggested by ground-based observations.

NatGeo News contributor Rick Lovett will provide us with a full report tomorrow, so I won't go into any more detail here.

[Dude, it's even cooler than I thought! Rick found out the pictures show methane rains actually created a new lake on Titan that's four times the size of Yellowstone.]

Instead, I will add the rather amusing note that so far the only comment on the Cassini page announcing this news is from a poster who thinks intense interest in methane on Titan is being driven by political and economic aims to find new sources of fuel.

Wha?

From the comment:

"Most carbon was removed from the terrestrial environment circulating in ancient times during the Carboniferous when fossil fuels were laid down. As a result, the digging of coal and pumping of oil out of the ground should be viewed as a good thing, a part of what is called Reclamation here in the United States."

I sit blinking in astonishment.

Given the vast distance between us and Saturn (~820 million miles away) and the difficulties and expense of even getting humans to the moon (~230,000 miles away), I can't see Titan becoming the next Arctic National Wildlife Refuge anytime soon.

—Image courtesy NASA/CICLOPS

Of course, since my entire existence seems tied to Futurama, I'd hope that future space miners would build tankers for transporting all that methane off Titan with enough hulls, and thus not endanger the penguin preserve on Pluto...

Building on the Hubble-Slipher smackdown from last week, a group of historians at the Royal Astronomical Society in the U.K. is aiming to give credit where it's due to the man who drew the first maps of the moon using a telescope.

Popular thought pegs Italian scientist Galileo Galilei with this feat—in fact, the International Year of Astronomy is built around Galileo's first use of a telescope to peer into the heavens 400 years ago.

Galileo produced and published a series of drawings based on his observations, including maps of mountains and craters on the moon, the phases of Venus, and the four large moons he could see orbiting Jupiter [the gas giant actually has more than 60 moons, but only four were visible using 1600s technology].

The key part of the above statement is the word "published." Historically, if you get your work on the record first, you get the glory.

The trouble is that an English mathematician named Thomas Harriot also made detailed maps of the moon using a telescope several months *before* Galileo.

—Image copyright Lord Egremont/RAS

Tip 'o the backyard telescope to the folks over at EarthSky, who have a skywatcher alert that this Friday, December 12, the full moon will be closer to Earth than it has been for the past 15 years.

If the weather cooperates, viewers will see the whole round, shining face of the moon at its closest approach around 9:45 p.m. UT.

In astro-speak, the moon will be in perigee—the closest the body gets to Earth during its elliptical orbit around our planet. At it's farthest, the moon is considered to be at apogee.

—Illustration courtesy Pearson Scott Foresman

[And now fans of ancient Disney films will know where Angela Lansbury got the words to her spell for turning poor David Tomlinson into a fluffy white rabbit ... ]

Back in September I had a chance to get inside the Chariot, a prototype of the next-gen lunar rover being designed at the Johnson Space Center in Houston, Texas.

It's a pretty wacky concept: Instead of just making a frame with wheels a la the original Apollo moon buggies, NASA is giving the lunar voyagers of 2020 a tricked-out RV.

This puppy comes equipped with six-wheel drive and an active suspension system, plus a full cabin with comfy seats, benches that double as beds, a pantry, a toilet, and enough juice to ride for 62 miles (100 kilometers) before heading home to recharge.

The idea is that a pair of astronauts could live in the rover wearing NASA-approved street clothes for up to two weeks. Their space suits ride on the back, attached so that moon walkers can slip in and out as needed to collect samples and snapshots from various lunar sites.

The current version of the Chariot is being field tested this weekend in Arizona, and while I couldn't make the trip to the desert, I was able to use information collected on my Houston trip to whip up a preview piece on the craft.

NASA's lead engineer for mobility, Robert Ambrose, gave me a ton of details on the vehicle and how it's being designed, including some interesting tidbits that I didn't have room for in the article.

There's always a twinkle in a science writer's eye when real life imitates art.

In 2005 we had a snapshot of gases and dust around a star that seemed to be auditioning for the next Lord of the Rings film.

Then in 2007 there came the news that the universe could be packed with double-sunned planets like Star Wars' Tatooine.

Earlier this year a Mars orbiter sent in high-resolution shots of a body called Phobos, highlighting its massive Stickney Crater and its uncanny resemblance to the Empire's ultimate weapon.

With apologies to Sir Alec Guinness, this time that is a moon—Phobos is the larger of the two known natural satellites orbiting Mars.

—Image courtesy NASA/JPL-Caltech/University of Arizona

Although it was discovered way back in 1877, Phobos has remained fairly enigmatic.

In the late 1950s, its odd orbit inspired Russian astronomers to suggest that the moon is a hollow shell, and an artificial one at that.

It took almost a decade to silence that offbeat theory, based on better calculations of the moon's orbit combined with new density measurements and eventually images from the Viking mission.

But Phobos still boasts some unusual characteristics, prompting much speculation about what the moon is made of and how it took up residence around Mars.