Blogs / Bad Astronomy

While driving in Los Angeles recently, I was surprised to see this out my passenger window:

Wow. I know NASA’s budget is small, but this seems a bit unnecessary. I wonder if Harry Broderick was driving?

The Space Shuttle Atlantis is set to roar into space today, Monday November 16, at 19:28 GMT (14:28 Eastern time). Unlike the last time, weather looks pretty good for an on-time launch.

Unfortunately, I’ll be sitting on an airplane during the launch so I’ll miss it, but lots of people are covering it on Twitter. Just search on the hashtag #nasatweetup to get all the info you need.

Image courtesy NASA.

NASA has found a significant amount of water ice on the Moon!

Holy Haleakala!

On October 9, the LCROSS spacecraft watched as a Centaur rocket booster slammed into the south pole of the Moon, hoping to determine if any water ice exists under the lunar surface. The idea is that over millions of years, comet impacts and other events have brought water to the Moon. Most of it goes away over time, but if any water happens to accumulate at the bottoms of craters at the poles, where the Sun never shines, it can stay put, frozen forever in shadow. By impacting a spacecraft into the Moon, it can eject the ice where it gets hit by raw sunlight. The water breaks down into hydrogen and hydroxyl molecules (OH-), which can be directly detected.

The target crater, Cabeus, has a temperature on its floor of -230 Celsius, cold enough to store ice. The Centaur slammed into it at high speed, making a new crater about 20 meters across and splashing debris over an even bigger area. A plume went up and out of the crater, and it was that tower of ejected material that had the telltale signs of water. The infrared spectrometer on LCROSS definitely detected absorption lines from water, and the ultraviolet spectrometer saw it in emission. Not only that, the emission got stronger with time, which clinches the deal! That’s exactly what you expect by a plume containing water.

Wow.

The amount of water they found in the plume was a couple of hundred kilograms in total, but that indicates there is a lot more still lying on the surface. They don’t know how much exactly just yet; NASA wanted to release this news as soon as they were sure they had definite results, but there is still much to do. Where did this water come from? How long has it been there? How accessible is it to future astronauts? These questions and more will, hopefully, be answered in the coming weeks and months as the data are analyzed more thoroughly. So stay tuned. There’s lots more good news to come!

Last week I posted about Adam and Jamie on Craig Ferguson’s TV show. I also found this little gem, where he talks about Apollo deniers. The whole thing is funny, but the space stuff starts at 3:00.

I love that guy.

When Galileo first turned his telescope to the sky, almost exactly 400 years ago, he could not possibly have known what he was starting.

Today, four centuries later, we’ve come a long, long way. To celebrate the anniversary of Galileo’s telescopic revolution, NASA’s Great Observatories — Hubble, Spitzer, and Chandra — have released a jaw-dropping mosaic of the very heart of the Milky Way galaxy. Behold!

[Oh yes, you want to click to embiggen that-- what I show here is a very compressed version. Or you can go here for a massive copy. You can also get wallpaper versions here.]

This image is nothing less than a heroic effort of astronomical artistry. It’s a chunk of the sky 38 x 14 arcminutes across, or about half the size of the full Moon, and it’s aimed right into the core of our galaxy. See the bright spot just to the right of the center? Buried in there behind light years of dust and gas is the monster of the Milky Way, a black hole with four million times the mass of the Sun. But even that is dwarfed by the 400 billion solar mass heft of the entire galaxy.

There is so much going on in this image it’s hard to know where to start. But first… the Hubble images are in the near-infrared, with a wavelength a little more than twice what the eye can see (1.87 microns for those playing at home). That’s represented in the image as yellow. Spitzer contributed observations in four infrared wavelengths (3.6, 4.5, 5.8, and 8.0 microns), and those are depicted in red. Chandra sees X-rays which are normally written as units of energy, but to remain consistent with the other two images, they were at wavelengths of 0.0005, 0.00025, and 0.00016 microns, and are shown in blue.

What does all this mean? Different objects emit light at different characteristic wavelengths. Warm dust, for example, emits strongly in the infrared. Stars and warm gas emit visible and near-infrared light. Violently heated gas, affected by huge magnetic fields or shocked by colossal collisions glows in X-rays. So this image is a polychromatic view of the crowded downtown region of a bustling city: our galaxy.

You might want to look at an annotated version of this image so you can get your bearings. It’s worth it!

The huge arches of gas on the left are actually the edges of gigantic molecular clouds (dense nebulae where stars are born), lit up by the torrential blast of light from a clutch of massive stars nearby. This clot of stars, called the Arches Cluster due to the arcs it excites, can be seen as a small spot glowing blue just to the left of center in the picture. Don’t be deceived by its diminutive appearance: the Arches cluster has thousands of superstars in it, each dwarfing our Sun, and each capable of sleeting out vast amounts of radiation that lights up the gas surrounding it. Were this cluster much closer than its 25,000+ light year distance, it would blaze in our sky like a beacon. Replace the Sun in our solar system with just one of those stars, and the Earth would be fried beyond the capability of any life to survive. You might as well try living in the flame of an arc-welder.

Below and just to the left of the Arches is a clumpier, more twisted arc of gas called the Sickle. That’s a giant cavity being carved out of dense gas by the Quintuplet cluster, the pinkish glow in its center. It’s another nursery of stars like the Arches cluster, which is also blasting out light and stellar winds which eat away at the gas enveloping it. The Pistol Star resides there, perhaps one of the most massive stars in the Milky Way.

And there’s more! The blue glow on the left is from an X-ray binary called 1E1743.1-2834, what is probably a massive star being orbited by either a neutron star or a black hole. Matter is being stripped from the star and piling up outside the collapsed companion, where it gets heated up to millions of degrees and emits X-rays.

Supernovae remnants dot the image, as do stars, filaments of gas, clouds of dust, and more. This picture is an astronomer’s dream, a map of everything someone might want to visit with a starship — as long as the shields are at full strength. This image is also a map of violence, turbulence, and unrest… a typical scene, so we think, of any normal spiral galaxy like ours. And our Galaxy’s center is considered quiet by astronomers! Some are far worse.

But this is home for us. It’s a place of unimaginable fury but also astonishing beauty… and we see it now as we do because we have dared to examine the world around us, to use tools we invent to peer closer, to magnify the tiny, to extend our eyes into realms we once didn’t even know existed. And every time we do — every single time — we find more questions, more puzzles, more things to examine.

And we find art. Galileo wasn’t the first to turn his telescope to the sky, nor was he the first to record what he saw. But he was the one who made everyone see what he did, and for that, all these years later, he is owed a debt of gratitude.

Let me show you something. And when I say "something", I mean something.

See the red arrow, and where it’s pointing? That arrow is pointing to a place that changed humanity forever. You can divide all of history between the time before and the time after what happened where that arrow points.

You see, that arrow is pointing to the spot, the very spot, where Neil Armstrong became the first human to step on another world.

Yeah.

This image is from the Lunar Reconnaissance Orbiter, and it shows the Apollo 11 landing site. We’ve seen it before, but this time LRO is in its 50 km mapping orbit, so the resolution on this image is far higher — about 50 or so centimeters (20 inches). In this image, the tracks made by Armstrong and Buzz Aldrin as they scampered on the Moon for 2 hours and 31 minutes are obvious. You can even see the lander footpads, each just less than a meter (a bit over a yard) across.

The bright spots south of (below) the lander are various scientific packages they installed, including the Lunar Ranging Retro Reflector and the Passive Seismic Experiment. If I’ve got the scale right, the faint dark trail going to the upper left is where they put the TV camera. Somewhere between that and the lander is the flag. The Sun was shining straight down in this image, so the flag isn’t visible.

The image above is only one part of a bigger shot:

That big feature to the right is West crater. As the astronauts rode the lunar lander down to the surface, Armstrong saw that the computer was going to put them down right in the rubble field west (left) of the crater. He took control, and with literally seconds of fuel left, put the lander safely down where you see it in this image. His cool hand saved the mission; had they landed among the rubble the lander could have hit a boulder, or landed so lopsided they would not have been able to take off again.

Note the picture’s scalebar. If this were the Earth, you could stroll across this image in maybe 10 minutes. Encumbered as they were in their spacesuits, and lacking time, Armstrong and Aldrin never got very far, and certainly not to West crater. Pity; it’s interesting. Look at the rubble around it! Those boulders which almost wiped out our first attempt to land on the Moon must have been excavated by the impact, and would have provided instant insight into the Moon’s deeper layers.

Of course, we went back five more times. There was plenty of interplanetary booty to be nabbed.

I love these pictures from LRO! I’ve waited for years to be able to see images like this, and they are just as I imagined them. And they come at a propitious time, when the fate of our exploration of space is changing rapidly, and decisions on its future are to be made. It’s at just this time we most need to be reminded of what we can do when we strive for what seems to be impossible, and when we set our sights, quite literally, beyond the horizon.

Credit: NASA/GSFC/Arizona State University

If you’re jonesing for some spacey stuff and maybe some critical thinking too, then check out these three links:

1) Starts with a Bang has a diary of the Ares I-X launch a couple of weeks ago.

2) The 127th Carnival of Space is lying in wait at Next Big Future.

3) The 123rd Skeptics Circle is at Blue Genes Science News, where things have become decidedly Galilean.

So go waste your Thursday afternoon learning stuff.