I know I said that NASA’s LCROSS impactor was going to smack into the crater Cabeus-A on October 9th, but NASA changed their minds: the new target is the crater Cabeus proper. New analysis of data from other probes indicates that Cabeus has more hydrogen locked up in the regolith than Cabeus-A, and in fact has the highest hydrogen concentration in the south polar region. As an added bonus, the topography of the crater is such that a valley will let sunlight hit the plume of ejected dust sooner than it would have had they stayed with Cabeus-A as a target. That gives scientists more time to look at the ejecta, and earlier is better because the plume will be denser too.
I hope this is the right choice for NASA, but I have to say I’m impressed they can change their plans this late in the game. Let’s hope they see some water!
September 29th, 2009 at 7:52 am
& I thought I left things till the last minute to decide!
T-minus ten days and counting to LCROSS impact…
I guess those craters are pretty close together anyhow and not too much needs to be changed right?
Also – MESSENGER’s third & final fly past of Mercury is happening today isn’t it?
Couple of things to look forward to.
September 29th, 2009 at 7:58 am
New analysis of data from other probes indicates that Cabeus has more hydrogen locked up in the regolith than Cabeus-A, and in fact has the highest hydrogen concentration in the south polar region. As an added bonus, the topography of the crater is such that a valley will let sunlight hit the plume of ejected dust sooner than it would have had they stayed with Cabeus-A as a target.
So this is watery dust we’re talking about here – or dusty water?
Or is it ice underneath the dust hidden in shadow?
Is this steam or hydroxl chemically present as an amalgam of other compounds and elements?
Also did anyone ever answer – could this same dusty water* /watery dust be the case for Mercury?
—
* Dusty Water – now is that a Blues band name or singer’s stage name or what?
September 29th, 2009 at 8:02 am
So Oct 9th is still the date? Do we have a time estimate with that date, so we know about what time to start looking up?
September 29th, 2009 at 8:05 am
Wouldn’t the crater be on the limb of the moon from our perspective? So might we be looking for a flash along the “bottom” edge of the moon? Also, is the LCROSS impactor projected to hit with a higher level of energy, ejecting more material and making it go higher? It seems that these factors could make the telescopic view more impressive and less split-second than the Smart-1 impact.
September 29th, 2009 at 9:38 am
@dhtroy
Impact time right now is at4:30 AM PDT. There’s a countdown clock here:
http://www.nasa.gov/mission_pages/LCROSS/main/index.html
If you’re interested in making amateur observations, this seems like a good guide:
http://lcross.arc.nasa.gov/observation/amateur.htm
BTW, this may not end up being the last change. NASA going to keep on looking at data from LRO and other spacecraft so there is a chance it could change its mind again.
September 29th, 2009 at 9:42 am
dhtroy Said:
“Do we have a time estimate with that date, so we know about what time to start looking up?”
According to Jack Horkheimer, it’s always time to Keep Looking Up.
September 29th, 2009 at 9:50 am
I always wanted to know if the impact woould be visible from Brazil…. more precisely from Ceara state…its almost at the eastern edge of the south american continent
September 29th, 2009 at 9:55 am
Here’s an LCROSS website that has links to info on LCROSS event viewing.
http://www.nasa.gov/mission_pages/LCROSS/impact/index.html
It includes a link to participating observatories as well as info regarding amateur viewing.
September 29th, 2009 at 10:16 am
I think the amount of water in the moon due to comet impacts is proof that god is a really bad homeopath.
September 29th, 2009 at 10:34 am
Phil (and others), the following is off topic but it bugs me.
Recent calculations showed that we could theoretically reach the edge of the visible universe within 30 years or something like that at a steady acceleration of 9,8m/s. 30 years would pass by for the astronauts, 70 billion years would pass by on earth, at the destination and anywhere in between. Of course there are major problems to build a suitable spaceship since its mass would grow and grow and would need more and more energy to keep accelerating. You’d be fried with high energy radiation and bump into interstellar mass as if it was a concrete wall. Even if we could surpass these problems, 70 billion years would deliver the astronaut in a quite different universe. I wouldn’t volunteer.
But if we wanted to go to Alpha Centauri in this way, what would be the figures? Let’s presume we have a spaceship that keeps all the nasty radiation outside, it wouldn’t take damage by collisions with space debris and it would have enough energy to accelerate and decelerate to sustain 9,8m/s. A quick calculation indicates that at 9,8m/s the speed of light is met within a year or so, so what maximum speed is reasonable to be possible and how long would it take to reach this speed? How many years would pass for the astronaut and how many years would pass on earth? An interstellar SMS would take about 5 years. Could we send a probe and see some pictures 20 years later? Or would it still be something like 520 years? Or 505020 years?
Interstellar travel seems to be possible, although the speed of light is theoretically reached within a year, which makes further acceleration impossible for the greatest part of any serious trip. Correct me if I’m wrong.
This is also an interesting thought experiment: if we do go out to other star systems we would be living in our own bubbles of local time where most other colonies are history++. And while the universe is expanding at an accelerating rate, the further you go out, the closer you’d be to universal annihilation.
Thank you for sharing your opinion on this.
PS, could the answer to the Fermi Paradox be something like ‘they’re here but not quite yet’?
September 29th, 2009 at 11:51 am
I’m sure the San Francisco astrology known as Satya (http://www.examiner.com/x-12038-SF-Astrology-Examiner~y2009m6d10-Orbiter-crashing-into-the-moon) will have something to say about THIS!
September 29th, 2009 at 1:13 pm
EK0r031,
Disregarding drag from the interstellar medium, the ship could accelerate continuously the whole trip. As reckoned within the ship’s reference frame the ship would maintain a constant acceleration and the Universe outside would become progressively more squashed, making distances shorter. Reckoned from Earth’s frame the ship would accelerate continuously, but the magnitude of the acceleration would be progressively smaller in step with its clock transformation.
But for a trip to Alpha Centauri (or anyplace else) it’s simple to put a cap on the amount of time measured from Earth: it can’t be longer than the time for light to travel that distance. No matter the ship’s acceleration, no matter what its time dilation factor is, not more than about 4.3 years will have passed on Earth.
September 29th, 2009 at 8:08 pm
@EK0r031
Don’t forget you’d have to be decelerating for at least a year too. Assuming you want to stop at Alpha Centauri and not go whizzing by.
If you want a very cool novel that deals with interstellar travel kinda realistically check out Stephen Baxter’s new book Ark. Not to mention world ending floods and what not. Very cool book.
September 30th, 2009 at 1:44 am
Just imagine if that big impact happens and we see gold particles and rare earths spew forth from just under the dusty lunar surface on the spectrometer…
THEN we would have some space program funding.
September 30th, 2009 at 6:17 am
Shane writes: “If you want a very cool novel that deals with interstellar travel kinda realistically check out Stephen Baxter’s new book Ark.”
I recently finished Baxter’s “Flood” and thought it was pretty good sci-fi, especially at a time when the so-called sci-fi sections in libraries and bookstores are becoming increasingly dominated by sword & sorcery fantasies and (ICK!) “alternate histories.” I mean, YEAH, I know science fiction is by definition FICTION, but I prefer that it has at least some basis in reality.
I’m waiting for my local library to get “Ark.” I can’t wait to read it.
September 30th, 2009 at 8:04 am
MarkD Said:
“THEN we would have some space program funding.”
The irony is that, really, we wouldn’t. There’s a classic argument which is used to illustrate just how expensive it is to lift a lump of matter to orbit, it being that the cost per pound of space flight is greater than the price of gold per pound. The punchline then is that it would cost more to mine gold on other planets than it could be sold for on the Market.
September 30th, 2009 at 7:19 pm
@Chuck
I didn’t realise Ark was the sequel to Flood until after I read it (haven’t read Flood yet). So it can be read as as a standalone but I still feel like a dill considering I’ve had Flood sitting on my pile-to-read for some time. Must read it now though.