Image Credit: Palomar Observatory / Caltech
No. At least, not yet, and I don't think it will.
For a few months now, NASA has been hyping this morning's impact of the LCROSS spacecraft with a shadowed crater on the Moon. Many websites (including this blog yesterday) passed on information on how people with 10-inch or larger telescopes could watch the event, yet professional observatories with 200-inch diameter telescopes didn't see anything obvious. Because of this, many websites, bloggers, and news casts have painted the LCROSS mission as a fizzle and a failure. This is as unfair and exaggerated as the predictions of spectacular fireworks were.
I do believe now that NASA overhyped the LCROSS impact, at least in terms of what we might be able to see from the Earth. But I do not believe the mission has failed. And that's because science is not about getting the answer we want, it's about getting the answer right.
The LCROSS spacecraft's main mission was to look for water on the Moon, specifically water frozen as ice in the permanently-shadowed craters at the Moon's poles. The methodology that the scientists who lead the mission chose was to impact a spent rocket engine into a crater, and then fly a spacecraft through the plume of debris tossed into space. The LCROSS spacecraft would analyze the content and structure of the plume before crashing into the Moon itself, sending up a second plume of debris. With luck, these plumes would also have risen high enough for Earth-based telescopes to see; these telescopes could then provide even more data.
All of this worked except some of the last part. The spent rocket engine collided with the Moon, LCROSS flew through the debris plume, made measurements, and sent those to Earth before colliding with the Moon itself. LCROSS saw a flash from the first crash and did indeed detect debris. Some satellites, including LCROSS's sister spacecraft, the Lunar Reconnaissance Orbiter (LRO), did detect the debris plume. But, at first glance, many telescopes did not. Palomar did not, Hubble did not.
What does this mean? It means the debris plume (which we know was created, because both LCROSS and LRO saw it) was not as big or substantial as mission scientists thought they might see. This means the Moon is different than we thought, at least in these polar craters. This means we're learning something unexpected. That's science! In fact, it's more interesting than if we'd seen a big plume of water like we hoped, because it means we scientists were wrong and that there's something we still need to learn. That's not failure, it's success.
Now, it still may be possible to snatch failure from the jaws of victory. Maybe we'll learn that some human error was responsible for the lack of plumes. Maybe some computer made a mistake on the size of the debris plume. Maybe the trajectory of the impactors was miscalculated. Maybe the wrong model of lunar ice and soil was used. Maybe the Hubble was pointing just the tiniest fraction of a degree in the wrong direction. As the scientists involved in the LCROSS team analyze their data, they'll be checking all of these things, even as they look for signatures of water and the other components of the debris plumes. But my gut feeling is that everything went right.
So, what happened? Where was the towering pillar of water rising from craters that haven't seen the sun in two billion years? I'm just guessing, but I suspect that big plume we were all expecting to see was one of the best-case scenarios. NASA probably felt comfortable predicting the best-case scenario after the spectacular fireworks of the Deep Impact mission, which used the same basic idea to probe the comet Temple 1. Certainly the claims of fireworks got the mission a lot of attention, but when the best-case scenario failed to materialize, it led to a lot of disappointment. I wonder what would have happened if NASA said, "You probably won't see anything, but there's a small chance you'll see fireworks on the moon." Perhaps fewer people would have been watching, but at least NASA wouldn't be the butt of jokes this evening.
Whatever problems they've been handed in public outreach, the LCROSS team has put together an ambitious mission that has, so far, worked. Time will tell how much we'll learn from the mission. How much time? Having worked with tons of data myself, we're talking months. The team will look at the data, study it, poke it, prod it, and push the data to its limits. Once they are sure of what they've found, they'll tell us. So, we just need to wait. I hate waiting.
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