Blogs / Bad Astronomy

When NASA slammed the 700 kg (1500 pound) 2400 kg (5200 pound) Centaur rocket booster into the Moon on October 9, the hope was that it would make a plume visible from Earth. Terrestrials were disappointed, however, when none was seen.

However, a better view was to be had by LCROSS, the Lunar Crater Sensing and Observation spacecraft, which shepherded and closely followed the rocket booster, impacting itself just minutes later. From its much closer (and doomed) location it spotted both the plume and the flash of impact! Here’s the plume:

I’ll be honest with you, it’s not much to see. For some reason, the plume was not several kilometers high as hoped, but instead more like only one or maybe two (and, it seems, blocked from our Earthly view by the rim of a crater). In the above image, taken 15 seconds after the booster impact, the plume was 6-8 kilometers wide. The fact that it was not as bright as hoped is itself interesting, however! The actual plume brightness was at the low end of what was expected, which may be due to the nature of the material it slammed into.

There was never really a chance to see the flash from Earth, since it was at the bottom of a crater blocked from our view. But LCROSS was directly above the crater when the Centaur hit, and took several images, including the one shown here right at the moment of impact. This image shows the flash in the mid-infrared, beyond what our eyes can see but where a lot of the energy of the impact went. Other images can be found on the NASA site.

The crater carved out by the Centaur was less than 30 meters across. That’s far too small to be seen from Earth (our limit, even with Hubble, is more than 100 meters in size), but the orbiting Lunar Reconnaissance Orbiter should be able to see it easily, and in fact did take observations of the impact just a minute or so after it happened.

All of these data are being analyzed right now. Did any of those instruments see the signature of water in the plume? Did the much larger LCROSS impact (it had a mass of 2000 kg) dig up any water? No one’s telling right now, but I suspect we’ll know soon enough. You can read more about this at Universe Today.

Update: Somehow, in my head, I got the masses of LCROSS and the Centaur reversed. Apologies, and thanks to IVAN3MAN for correcting me!

The Mars Global Surveyor was in operation around the Red Planet for over nine years. From 1997 to 2006 it snapped away with its Mars Orbiter Camera, taking more than 240,000 images. One of these pictures from the MOC is circulating the web right now; but no one is giving the supplemental info on what it is or linked to where it’s from! So I’m chiming in.

The picture was taken in May 2003, but its impact has not lessened with time. It shows Earth and Jupiter in one shot as seen from Mars! The whole image can be found here, but it’s huge (basically a long strip) so I’ve extracted the two planets here:

Whoa. You can clearly see the Earth and Moon, and even the continent of South America! On Jupiter, the banding of the clouds of obvious, as are three of the Galilean moons.

But I think you really need to click through and see the whole image (as well as the accompanying explanation on the MOC site). In this case, context is important. It’s critical! It’s images like this that remind us that we live on a planet, a world like any other and yet unique in that it’s our home. I get people asking me if space exploration is worth it, and then I see images like this, and I know the answer is yes. We need this perspective. It’s said that the Apollo 8 shot of the Earth rising over the Moon launched the modern environmental movement, because it showed all of us eggs sitting in our one, lone basket. We should be reminded of this idea as often as possible, and images like this one from the MOC need to be spread far and wide.

The 124th Carnival of Space is up and breathing at the blog We’re All In The Gutter. They’ve collected this week’s best astronomy and space blog posts and put them in one spot for your easy perusal. The blog itself is done by a collection of young astronomy researchers, and is pretty good! Looks like I have another entry to drop into my RSS feed reader.

In October of 1957, the Soviet Union started the Space Age with the launch of Sputnik. Since then, a lot of spacecraft have wended their way through the solar system and beyond. Trying to visualize all those trips can be mind-bending, so what better way to do so then to make a mind-bending graphic?

The good folks at National Geographic have done just that. Check this out:

This clever image displays all the space missions to various bodies. If an object (like the Moon) has a thicker spiral wound around it, then that means it’s been visited more times. Here’s some detail:

This shows a stylized view of the 73 missions that went to the Moon in the past 5 decades, and has some info on each. The original map is zoomable and pannable, so you can spend some time fooling around there. Take a look at the bottom, too, and you’ll find a scaled view of the solar system with spacecraft positions. Look how far away Voyager 1 is! There’s also a static version of the image online, but I’m not sure how legal that copy is. The original artwork is by Sean McNaughton on the National Geographic staff and Samuel Velasco of 5W Infographics.

And may I add, holy cow! 73 missions to the Moon! And more to come. We’re a cool species.

Tip o’ the spacesuit visor to Fark.

[Update 11:45 UTC): IMPACT! LCROSS and the Centaur rocket have both impacted the Moon, apparently right on target. Ground-based reports are that no plume has been detected, but the observations from the Lunar Reconnaissance Orbiter itself, still orbiting the Moon, will be downlinked in a couple of hours. Keep your eyes on the NASA TV and the LCROSS sites (linked below) for more info.]

The Lunar Crater Observation and Sensing Satellite (LCROSS) is about to hit the Moon! The impact time is 11:31:20 UTC. NASA TV is covering the impact live.

The LCROSS site is getting slammed so you may have a hard time getting in. Wired.com has a bunch of links to places covering the event live too, so try there and see if you an watch this very cool event as it happens!

The 123rd Space Carnival is now live at Weird Warp. Lots of bloggy goodness there, as usual. Go take a peek!

Last week, the MESSENGER spacecraft passed the solar system’s smallest planet for the third and final time; when they next meet it won’t be some quick fling, it’ll be for a long term relationship.

Several gorgeous images were returned from the spacecraft, but this one is my favorite so far:

This is a large impact basin about 260 km (160 miles) across. It’s never been seen before! Only one other spacecraft has visited Mercury before — Mariner 10 in 1974 — and its orbit was such that it never did see many parts of the planet. MESSENGER was in the right place at the right time to snap this picture.

Note that it’s a double ringed crater. It’s not quite clear why these features form. It may be due to the forces generated upon impact, when a shock wave travels through the rock and rebounds inside the crater, or it may be from subsequent volcanic flows. Double rings are only seen in large impact events, so that must have something to do with it. You can also see concentric troughs or cracks in the crater middle. Those are due to the stretching of the crater floor after the impact.

Other images of Mercury from this third pass are just as cool: a bright splash around a double crater (seen here; most likely lighter material under the surface blasted out on impact), a crater with an elongated pit in its floor that makes it a pretty good smiley face, and a lovely shot of the northern limb of the planet spattered with craters.

I imagine they’ll release a handful more images over the next few days, but that’ll be it for the most part until March 2011, when MESSENGER meets up with Mercury one last time, settling into orbit… and then we’ll see lots more images. Lots and lots more… and they’ll be even higher resolution than these. What wonders will we see then?