LCROSS – astroengine.com

First Images of LCROSS Centaur Impact Plume Released

The lunar dust plume as seen 15 seconds after Centaur impact. The size of the plume was approximately 6-8 km wide at this time (NASA)

Rising a mile high and up to 5 miles wide, the impact plume of the spent Centaur rocket was observed by the NASA LCROSS shepherding probe before it travelled through the cloud of dust and crashed 4 minutes later.

The lack of an observed dust plume has been the cause of much confusion to people who watched the events unfold in the early hours of October 9th. NASA publicised the impact event as if it was going to be an explosion of dust (and possibly ice), observable from telescopes on Earth. To say the mission finale was a disappointment is an understatement.

Following the impact, NASA responded by saying that although infrared images proved the Centaur crashed on target (and a 20 meter-wide crater was created), the lack of an accompanying plume could mean that the mass hit the side of a crater (therefore blasting debris at an angle), or it hit a region devoid of dust and water ice, or the plume was simply less obvious than expected. Now that NASA has released new images of the impact, it would appear the latter may be the case; the plume was just less spectacular than the promo videos depicted.

Nine instruments on board LCROSS captured impact sequence, but until now it was unknown whether an impact plume occurred. Now NASA has confirmed that an impact flash, plume and crater were all generated.

“There is a clear indication of a plume of vapor and fine debris,” said Anthony Colaprete, LCROSS principal investigator. “Within the range of model predictions we made, the ejecta brightness appears to be at the low end of our predictions and this may be a clue to the properties of the material the Centaur impacted.”

So the number-crunching continues as we wait to find out whether water was contained within that plume. However, judging by the faint cloud of ejecta, I’m thinking dreams of a H₂O reservoir in Cabeus crater might be short lived.

Source: NASA, LA Times. A special thanks to @jamerz3294 for the tip!

Did NASA “Bomb” the Moon? Kinda

NASA possesses Weapons of Moon Destruction, obviously.

There’s been a lot of criticism concerning the media’s ability to report science recently. After all, what is “good” science reporting? The tabloid press is well known for hyping up scientific endeavour, and although some news outlets deliberately fill their columns with hyperbole, it doesn’t necessarily mean the science is being misrepresented, it just means the column in question is making a mountain out of a molehill.

Take Friday morning’s NASA LCROSS impact with the Moon. Those of us that were following the action on the various news outlets and online feeds were astonished by the sheer amount of fear, misinformation, disinformation and general weirdness that was being banded about. To be honest, I was shocked.

[I actually have a theory about one of the reasons why LCROSS was a particular target for many conspiracy wingnuts and doomsday woo, but I’ll save that for another article I’ll be writing shortly.]

Although a lot of the stuff was total silliness (i.e. the Moon feels pain, LCROSS might knock the Moon off it’s axis, many moonpeople might die etc. etc.), many worried individuals were concerned by the reports from the mainstream press. Let’s have a look at one of the claims being disseminated by a wide variety of news outlets in the run-up to, and the days following, LCROSS: The Moon was being “bombed” by NASA.

Did NASA “bomb” the Moon or not?

A huge number of people have a problem with the word “bomb” when connected with the LCROSS mission (I’m not fond of the description either). Could this one word be indicative of bad journalism? For the scientifically-minded, “bomb” doesn’t sound very scientific and would rather use “impactor.” For the non-specialist, “bomb” conjures thoughts of war, violence and Al Qaeda.

Is it just creative writing? Is it an inaccurate term? Is it wrong? First off, let’s look at the definition of “a bomb.”

bomb. n. An explosive weapon detonated by impact, proximity to an object, a timing mechanism, or other means.

The LCROSS Centaur was certainly not manufactured as a conventional weapon (as in, it didn’t carry explosives and couldn’t “detonate”), but just by its mass, could it cause an explosion like a bomb? In the case of the above definition, I’m referring to the “or other means” part.

Energy is energy

The Centaur was empty of propellent when it was sent careening toward the lunar south pole, but it still had a mass of 2366 kg (the size of an SUV). At the time of impact, it was travelling at a velocity of 2.5 km/s (2500 m/s). From this information alone, we can calculate the kinetic energy of Centaur at the moment it slammed into the lunar surface.

E_kinetic = 1/2 mv² = 1/2 × 2366 (kg) × 2500² (m/s) = 7.4×10⁹ Joules

This is the total energy the Centaur had when it was speeding toward the Moon, and according to basic physics energy is always conserved. So, when the Centaur ate Moon dust, where did this energy go?

We know energy wasn’t lost through the production of sound waves, as there’s no atmosphere on the Moon — In space, no one can hear your rocket go *bang* (although seismic waves would have been generated, propagating through the Moon’s surface). Also, lots of chunks of rock (from the surface) and shards of metal (from the Centaur) would have been ejected from the crater, each piece carrying a little piece of that kinetic energy away from the impact (much like very high-energy shrapnel). A lot of rock was displaced too, creating a crater 20 meters in diameter and 3 meters deep. Much of the kinetic energy will have also been converted to heat and light (the “flash” of the impact was captured by the LCROSS infrared camera).

What with all this heat, light and shrapnel, the Centaur impact sure is sounding like an exploding bomb. If you convert the 7.4×10⁹ Joules into units more synonymous with weaponry, we find that the energy released during the Centaur impact was the equivalent of 1.8 tonnes of TNT exploding. That’s the size of a small bunker-busting bomb.

What’s more, kinetic weapons are a well-known method to take out orbiting satellites, so this concept isn’t a new one.

As much as it pains me, using an inflammatory statement like “NASA Bombed The Moon” is a correct analysis of the effects of the Centaur dead-weight hitting the Moon. However, the press milked “the Moon bombing” way beyond what I’d consider to be reasonable, taking full advantage of the violent connotations associated with this incredible NASA mission to probe for water on the Moon.

“I think that people are apprehensive about it because it seems violent or crude, but it’s very economical.” –Tony Colaprete, principal investigator for LCROSS (Feb. 2008)

What REALLY Happened to the LCROSS Centaur?

In the early hours of Friday morning at 4:31am, the spent Centaur rocket from the NASA LCROSS mission slammed into the surface of the south pole of the moon. What was the point in that?

Well, NASA was hoping that the tumbling chunk of metal the size of a small bus would kick up a huge plume of dust. Following 4 minutes behind was the shepherding LCROSS spacecraft, also on a kamikaze dive, hoping to drop through the plume, sensitive instruments ready to analyse the dust for water.

I know what you’re thinking: what right does NASA have to BOMB the Moon? They have NO RIGHT AT ALL!!

It turns out that they are actually waging a top secret war against the population of peaceful extraterrestrials that live on the far side of the Moon. This “experiment” was in fact a reckless attack against a superior alien civilization, intended to strike fear into the hearts of the aliens.

If you were to believe the NASA promo video of the event, this should have been spectacular, vast quantities of lunar regolith blasting into space… it should have been akin to the biggest Fourth of July firework detonating. This “shock and awe” tactic is typical of the US space agency. The huge mass of the Centaur (a little under 2400kg), combined with its break-neck speed (1.5 miles per second) should have unleashed the equivalent energy of a tonne of TNT exploding. However, what NASA didn’t tell us was that Centaur was also carrying plutonium, so the explosion should have been a LOT bigger, easily visible to the naked eye.

But what did we see? Nothing. What did NASA see? Nothing. So what happened? Well, the answer to that is a little more compelling than what NASA is telling us.

Yes, they can show us images of a meagre “flash” as the Centaur hit inside a lunar crater, but I don’t think Centaur hit the Moon at all… the Centaur rocket was swallowed by the Moon.

Don’t believe me? Moments before impact, NASA’s lunar satellite — the Lunar Reconnaissance Orbiter (LRO) — was approaching the location and it took this photo. What you see here will shock you. It will astound you. And what’s more, it’s REAL.

Aliens DO live on the Moon, and they were prepared for the NASA bombing…

lcross-conspiracy

</conspiracy mode>

I’m sorry, I couldn’t resist. In the run-up to the LCROSS impact, the sheer amount of crazy conspiracy theories hit fever-pitch (I blogged about it on Space Disco 2 hours before impact). Some of my favourite theories involved alien civilizations on the lunar surface, plutonium on LCROSS (to destroy the Moon), the “fact” that it was all just a publicity stunt and the LCROSS mission didn’t exist at all… and the strange theory that the Moon feels pain.

Yawn.

A polite message to the conspiracy theorists: Come on people, stop making stuff up and understand the real science. You might find reality more interesting than your twisted fantasies.

Image: The Sarlacc pit monster from Star Wars, Copernicus lunar crater and the LCROSS Centaur rocket. Photoshopping: Me.

Oops… I really geeked out this time, didn’t I.

@Astroengine Got CNN’d (and other epic things)

I’ve been pondering a word that could describe today.

I drew a blank.

It’s a very hard day to sum up in one word. In fact, this entire week has been something of a unique one. From a space point of view, it’s been busy, largely due to the endless supply of space science research spewing from the American Astronomical Society’s Division of Planetary Sciences meeting in Puerto Rico.

However, last night (and early this morning) is what topped it all off. The NASA LCROSS mission slammed into the lunar south pole at 4:31am (PDT) and I was there tweeting away, keeping abreast of all the juicy LCROSS news. That was until Time Warner Cable decided to pull the plug on my internet connection 10 minutes before the main event (I’m certain they did it deliberately, it’s the only explanation). Panic-stricken — and really peeved that I’d spent the whole night excited to see the glorious end to this Moon mission, only to be foiled by my ISP — I checked the TV, and it was working, plus a local channel was covering the event. Phew.

As it turned out, there wasn’t much to see. Oh well.

Anyway, on waking up this morning, I was shocked to find my inbox was stuffed full of Twitter follow messages and notes of congratulations from my team at Discovery News. CNN had picked me, with four heavy-hitters on Twitter as their #FollowFriday. But it wasn’t an ordinary #FollowFriday, the guys at CNN Technology posted this #FollowFriday on their site!

Editor’s note: In this new weekly feature, we highlight five recommended Twitter feeds about a hot topic in the news. Today’s list focuses on space-related tweets and NASA’s plan to crash two spacecraft on the moon Friday in a search for water in lunar soil. —CNN Tech

So despite my internet woes, CNN had chosen me (@astroengine) with @BadAstronomer, @Astro_Mike, @LCROSS_NASA and @NASA_AMES. So I was in the company of an entire NASA facility (Ames), a NASA mission that had just hours before slammed into the Moon (LCROSS), the first astronaut to tweet from space (Mike Massimino) and the one, and only, Phil “The Bad Astronomer” Plait.

Wow.

They also added this very flattering description of @astroengine:

4. astroengine — Astroengine is the Twitter name of Ian O’Neill, a British-born physicist with a long resume and a healthy sense of humor. It’s also the name of his blog, which gathers articles and posts on such light-reading topics as quantum mechanics, solar physics, relativity, cosmology, space flight science and “some of the more bizarre theories that drive our universe.”

Number of followers: more than 1,700

Sample tweet: “Europa, Jupiter’s Moon, Could Support Complex Life http://bit.ly/3n6iKL (I, for one, welcome our alien Jellyfish Overlords)”

So, I’d like to take this opportunity to say “hello” to my hundreds of new followers!

And did I think of a word that describes today? Actually, I think I just did:

Epic.

Moon Water, Confirmed

moon-water

The biggest factor hanging over human settlement of other worlds is the question of water. We need it to drink, we need it to cultivate food, we need it for fuel (indeed, we need it for the first lunar microbrewery); pretty much every human activity requires water. Supplies of water could be ferried from Earth to the Moon, but that would be prohibitively expensive and ultimately futile. For us to live on the Moon or further afield, H₂O needs to already be there.

Ever since the Apollo lunar landings when samples of rock were transported to Earth we’ve been searching for the mere hint of this life-giving molecule. There have been indications that the lunar regolith may indeed contain trace amounts of the stuff, but on the whole, scientific endeavour has yet to return evidence of any large supply of water that could sustain a colony.

Until today.

Up until now, scientists haven’t been able to seriously entertain the thought of water on or near the surface of the Moon, apart from in the depths of the darkest impact craters. However, data from the recently deceased Indian Chandrayaan-1 mission has supported data taken by the Cassini probe (when it flew past the Moon in 1999 on its way to Saturn) and NASA’s Deep Impact probe (which made several infrared observations of the lunar surface during Earth-Moon flybys on its way to the 2010 rendezvous with Comet 103P/Hartley 2). Both Cassini and Deep Impact found the signature of water and hydroxyl, and now, a NASA instrument on board Chandrayaan-1 reinforces these earlier findings.

The NASA-built Moon Mineralogy Mapper (M3) on board the Indian satellite detected wavelengths of light reflected off the surface that indicated hydrogen and oxygen molecules. This is convincing evidence that water is either at, or near, the lunar surface. As with the previous measurements, the water signal gets stronger nearer the lunar poles.

So what does this mean for the future of manned space exploration? Although water has been detected, this doesn’t mean there are huge icy lakes for us to pitch a Moon base and pump out the water. In actuality, the signal indicates water, but there is less water than what is found in the sand of the Earth’s deserts (you can pack away the drinking straws now).

“It’s still pretty damn dry, drier than anything we have here. But we’ve found this dynamic, ongoing process and the moon was supposedly dead,” University of Maryland senior research scientist Jessica Sunshine told Discovery News. “This is a real paradigm shift.”

If there are widespread water deposits (despite the low concentrations), even in regions constantly bathed in sunlight, there is huge potential for water deposits in those mysterious, frozen craters. Interestingly, these measurements indicate that the water may not have just been deposited there by comets; the interaction between the solar wind and the existing lunar mineralogy could be a mechanism by which lunar ice is constantly being formed.

“Every place on the moon, at some point during the lunar day, though not necessarily at all times, has water and OH [hydroxyl],” Sunshine said.

We may see self-sufficient lunar colonies yet. But the saying “getting blood out of a stone” should probably be replaced with “getting water out of the lunar regolith”…

Next up is NASA’s LCROSS mission that is scheduled to impact a crater in the south pole on October 9th. Analysis from the impact plume will supplement this positive Chandrayaan-1 result, hopefully revealing yet more water in this frozen region.

Sources: Discovery News, Space.com, Times.co.uk