Hubble's WFPC-2, now on display at Air and Space
—Picture copyright Smithsonian Institution

"The difference between an artifact and an instrument is that, now that it's an artifact, you can't touch it anymore."

So General Jack Dailey told astronaut John Grunsfeld during the opening of a new gallery in the Smithsonian's National Air and Space Museum—now home to several significant artifacts from the Hubble Space Telescope.

Just a few short months ago, Grunsfeld was part of the shuttle mission sent to repair and upgrade the aging Hubble. The crew's tasks included removing the Wide-Field Planetary Camera 2 (WFPC-2) and the Corrective Optics Space Telescope Axial Replacement (COSTAR) so they could be replaced with more advanced instruments.

(See some of the first pictures from the upgraded Hubble.)

COSTAR, sometimes called Hubble's contact lenses
—Picture by Eric Long/NASM, copyright Smithsonian Institution

Air and Space made the phone booth-size COSTAR part of its new gallery, called Moving Beyond Earth, a high-tech setup full of interactives, computer feeds, and huge visual projections.

The gallery also houses the HST Power Control Unit Trainer, a life-size replica of Hubble's electrical nerve center. Grunsfeld was among the astronauts who used the trainer to practice replacing the unit during a 2002 servicing mission.

—Picture by Eric Long/NASM, copyright Smithsonian Institution

WFPC-2, meanwhile, gets a place of honor in the museum's Space Hall. The camera, about the size of a baby grand piano, "turned Hubble into the Great American comeback story," NASA's Edward J. Weiler told reporters during the gallery opening.

The now beloved space telescope had a few early setbacks, including the grim discovery shortly after launch that its primary mirror was deformed, making its science images pretty much useless.

WFPC-2 got installed during the first-ever Hubble servicing mission in December 1993, complete with its own built-in corrective optics that compensated for the faulty mirror.

(FYI, new instruments installed since then also carried their own corrective optics, eventually rendering COSTAR obsolete. It was removed to make room for a device called a spectrograph, designed to study the origins of the universe.)

The same mission added COSTAR, a bundle of tiny mirrors that sent corrected, focused light to the rest of Hubble's instruments. But WFPC-2 specifically went on to provide scientists with some of the most iconic Hubble pictures that both dazzled the public and offered new insights into the universe.

"Museums remind us of the choices we make as a culture." —David DeVorkin

(See WFPC-2's last "pretty picture" before the camera was removed in May 2009.)

"Hubble has more than fulfilled its promise," said senior curator of space history David DeVorkin.

But astronaut Grunsfeld, who joked about his title of "chief Hubble hugger," reminded the audience that it wasn't really the instruments that saved Hubble, it was the people.

"Museums remind us of the choices we make as a culture," DeVorkin added. During Hubble's development, people made the choice to build a space telescope that could see objects ten billion times fainter than the human eye.

People also made the choice to make that telescope something that could be regularly serviced rather than used until it broke and then abandoned.

And when Hubble suffered from its initial setback, people made the choice to find ways to fix what was quickly labeled as a national failure.

"It's a message of persistence," Dailey said. "Don't quit. Hubble is a perfect example of that."

For its part, Spirit has continued toiling away on Mars even after it broke a "foot," wore down one of its favorite tools, almost starved due to a strong dust storm blotting out sunlight, and suffered a series of memory glitches.

Then, this past May, the robust rover got stuck in the sand.

A screen shot from a computer simulation shows Spirit's current predicament.
—Picture courtesy NASA/JPL-Caltech

In the midst of a routine drive near Gusev crater, Spirit broke through a thin crust of soil over a filled-in crater. Its wheels became half buried in the soft sand, and the rover was struggling to gain traction on the slippery sulfates below.

So Spirit has stayed put for months while mission managers on Earth have raced to come up with an escape plan.

On Monday, NASA says, after working various tests, computer models, and presumably late nights, engineers will make the first attempt to free the venerable rover.

"This is going to be a lengthy process, and there's a high probability attempts to free Spirit will not be successful" Doug McCuistion, director of the Mars Exploration Program at NASA Headquarters, said in a statement.

"Mobility on Mars is challenging, and whatever the outcome, lessons from the work to free Spirit will enhance our knowledge about how to analyze Martian terrain and drive future Mars rovers," McCuistion said.

The drive to freedom will start with a forward march up a mild slope, which mission managers hope will steer Spirit past a rock lying underneath. Data collected from the first drive attempt will help NASA figure out its next move, and it's anticipated that efforts to edge Spirit out of the crater will continue into early 2010.

But even if the rover can't be budged, Spirit has been learning a lot from its unexpected surroundings.

"The soft materials churned up by Spirit's wheels have the highest sulfur content measured on Mars," said Ray Arvidson, deputy principal investigator for the science payloads on Spirit and Opportunity.

"We're taking advantage of its fixed location to conduct detailed measurements of these interesting materials."

The 17th-century Italian was on hand today to witness the official opening of the National Air and Space Museum's Public Observatory, a new 22-foot (6.7-meter) dome housing a more than 40-year-old telescope.

"Galileo" and David DeVorkin stargaze in front of the observatory's dome.
—Photograph by Eric Long/NASM, National Air and Space Museum, Smithsonian Institution

The 16-inch (40-centimeter) Boller and Chivens telescope is an artifact on loan from the Smithsonian Astrophysical Observatory, once a feature of the National Mall in Washington, D.C., but now based in Cambridge, Massachusetts.

The telescope had been purchased in 1966 and used for research at Harvard's Oak Ridge Observatory, about 30 to 40 miles (48 to 64 kilometers) from Cambridge.

When Oak Ridge closed in 2005, the museum's senior space historian, David DeVorkin, had an idea: Bring the historic telescope to the Mall, but don't put it in a display case. Instead, make it available for public use.

Starting today, museum visitors can head over to the East Terrace Tuesdays through Sundays from 10 a.m. to 2 p.m. and see like an astronomer. And yes, it is entirely possible to closely examine the sun (with special filters), the moon, and several of the brighter stars, planets, and nebulae during broad daylight.

—Photograph by Eric Long/NASM, National Air and Space Museum, Smithsonian Institution

Like a Mauna Kea dome in miniature, the new facility has a rotating top and a sliding door in the ceiling to protect the telescope from the elements. FYI, if you're there on a cloudy or rainy day, you won't be able to use the observatory.

Overall, the project makes for a nice complement to the museum's collections, since it should help the museum's seven million annual visitors gain first-hand understandings of the science presented inside the building, noted museum director General John R. "Jack" Dailey.

"The observatory will enable us to share our mission in an interactive way," Dailey told reporters at this morning's unveiling ceremony.

And Wayne Clough, secretary of the Smithsonian Institution, called the telescope a "key element" in the museum's education mission, "since it is so physical, so dramatic."

Speaking of drama, one of the highlights of the ceremony was DeVorkin's speech, which was interrupted by an unnamed actor portraying Galileo.

In a re-enactment of many an astronomer's dream interview, DeVorkin plied Galileo for information about his famous first glimpses of the heavens 400 years ago and how he came to his now celebrated conclusions about what revolves around what.

Contrary to the then-beloved teachings of Greek philosopher Aristotle, "the heavens are not perfect," Galileo told the crowd. Just look at the orb of the moon. Its seemingly smooth face is actually littered with valleys and mountains [really impact craters, later astronomers figured out].

The moon's pockmarked surface is clearly visible in a picture taken August 3 with a Meade Lunar and Planetary Imager mounted on the Public Observatory's telescope.
—Photograph courtesy Smithsonian Public Observatory Project

"And have you looked at the little ears on Saturn?" Galileo asked. Or at Jupiter, which has four distinct spheres in its orbit? If something is rotating around Jupiter, that means not all things in the heavens revolve around Earth!

Galileo published some of these initial findings in 1610 in Sidereus Nuncius, the first scientific "paper" based on telescopic astronomy.

A first edition of this publication is also on display for the next three months at Air and Space, safely ensconced inside the museum's "Explore the Universe" gallery.

Mercury, as seen from MESSENGER on September 28, 2009
—Image courtesy NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

When images from the flyby start pouring in around midnight, scientists hope the snapshots will reveal even more about the tiny world's rocky surface.

The flybys are part of maneuvers to bring MESSENGER safely into Mercury's orbit in 2011, making it the first probe to take off its proverbial coat and stay for a while in the planet's embrace.

Until 2008, only the Mariner 10 spacecraft had been anywhere close to Mercury, and that was just a drive-by back in 1974 and '75. What's more, Mariner was only able to take pictures of less than half the planet, leaving the bulk of Mercury shrouded in mystery for more than 30 years.

The first MESSENGER flyby in January 2008 showed the world a whole new side of Mercury—literally. Cameras snapped more than 1,200 pictures, imaging an additional 30 percent of the planet.

A second flyby in October 2008 added to the bounty, and now we have a pretty good idea of what 90 percent of the planet's surface looks like.

The latest flyby will take a few more shots of never-before-seen features, but it's mostly geared toward what the mission managers are calling targeted observations. In other words, this is a chance to take a closer look at interesting features spying during the previous flybys.

From the MESSENGER Web site:

The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) will gather high-quality spectral data by "staring" at the chosen surface targets for ~30 seconds per target. Simultaneously, the Mercury Dual Imaging System (MDIS) will obtain many sets of high-resolution color images of the targeted regions using all 11 of its color filters. Together, the data from these targeted observations will provide a wealth of new information and insights into the nature and history of Mercury's surface.

For me, MESSENGER's results serve as an example of the information arms race between science and fiction.

I'm about halfway through the English translation of a Japanese science fiction novel called Usurper of the Sun by Housuke Nojiri. The book is all about a high school student who spots a tower being built on Mercury during a planetary transit—when Mercury passes in front of the sun as seen from Earth.

The tower, it seems, is made of nanobots that are using materials from Mercury to build a ring encircling the sun (you'll have to read the book to find out why). But the ring is in just the right spot that its shadow engulfs Earth, triggering environmental catastrophe and spurring a desperate race to make contact with the mysterious alien Builders.

Ultimately this book is not about Mercury—it's meant to be a philosophical take on the nature of aliens and what a first-contact scenario might be like [and about a beautiful, brilliant female student who is humanity's last hope for salvation, a fact that won't even faze anime fans the world over].

Trick is, the whole story hinges on us not knowing a darn thing about Mercury's backside. The book was published in 2002, two years before MESSENGER even launched. At that point, for all anyone knew, it was entirely plausible that aliens might have set up a nanobot workshop right under our noses.

Science fiction has a long history of building imaginative stories on plausible science that later turns out to be bunk. What, for example, would the Martian Chronicles have been about if Ray Bradbury had seen data from the Mars Mariner missions?

And poor Venus, once celebrated in fiction as the most likely planet to house non-Earthly life, was exposed by science in the 1960s as too hot and too under pressure for anything resembling humans to exist on its surface.

Thank goodness science in the '90s delivered unto us the first confirmed extrasolar planets, ushering in a whole new class of possible targets for the fictional (and literal) search for extraterrestrial intelligence.

On the flip side, science fiction is most frequently touted as the source of some of our modern technological advances. Star Trek tech gets closer to reality every day, it seems, and early SF masters like Verne and Wells are credited with practically inventing commonplace gadgets such as sliding doors and cell phones.

Heck, even the recent announcement that there is, in fact, water on the lunar surface just made Robert A. Heinlein's The Moon is a Harsh Mistress a touch more plausible.

Give astronomers a few decades, and I wonder what soon-to-be-published icons of SF will become either outdated whimsy or remarkable prescience?

Since modern humans have been around for only about 60,000 years of that time, it's hard for us to even guess at how exactly the planet was born.

Luckily we have a variety of tools at our disposal to make sure we're making highly educated guesses, including orbiting observatories like the Spitzer Space Telescope.

Using its infrared vision to peer through dust and thick gases, Spitzer has seen plenty of evidence for young star systems taking shape since it was launched in 2003. But most of that evidence has been fairly static, considering that it takes planets millions of years to develop.

Now, in a rare catch, astronomers using Spitzer think they've witnessed an early stage of planet formation in real time.

—Image courtesy NASA/JPL-Caltech/R. Hurt (SSC)

The team watched one young star, LRLL 31, for five months, recording changes in its infrared light. The star had previously been called out for having a type of debris ring known as a transitional disk.

According to a popular theory of planet formation, some stars are surrounded by thick disks of dust and gases. Over time, larger grains within these disks start to collect material, and, like rolling snowballs, they grow larger as they pull more material unto themselves.

At some point, objects get so large that they carve gaps in the original disk, creating what's known as a transitional disk.

Spitzer showed that LRLL 31 has such a disk with both an inner and outer gap. What's more, the infrared light from the inner disk changes its brightness and wavelength every few weeks.

The team thinks the changes are due to a "companion"—some body circling the star inside the inner gap. As it orbits the star, this body pushes the disk's material around like a cornering boat pushes water, creating a "wave" that periodically changes the disk's height.

Higher waves facing Earth mean more and hotter material reflecting the host's starlight, so more infrared radiation and at shorter wavelengths. The wave also casts its shadow on the outer disk, blocking its longer-wavelength light.

The opposite scenario is true when the wave crests between Earth and the star.

Astronomers aren't 100 percent sure if the body creating the wave is really a developing planet or some other companion, maybe even another star.

But lead study author James Muzerolle, of the Space Telescope Science Institute in Baltimore, notes in a statement: "For astronomers, watching anything in real-time is exciting. It's like we're biologists getting to watch cells grow in a petri dish, only our specimen is light-years away."

The event is the end goal of NASA's LCROSS mission, which aims to study material kicked up by the impact to find out whether the lunar surface has water ice.

Today NASA announced that Cabeus A, a 25-mile-wide (40-kilometer-wide) crater on the moon's south pole, will be the site in the mission's crosshairs.

[LCROSS's Candidate Impact Craters -- That's Cabeus A Marked as "SP C"]
—Picture courtesy NASA/Ames Research Center

Not too much is known about this crater, which is part of the reason it was selected. Cabeus A sits on a region of the moon that's almost always in shadow, making it more likely that any water ice could exist there, since it wouldn't have been effectively vaporized by direct sunlight.

The crater is also among the sites on the moon known to have a mysterious quantity of hydrogen, which your grade-school chemistry teacher would remind you is a major component of good old H2O. Cabeus A in particular has a high concentration of hydrogen clustered in what NASA scientists call a "sweet spot" near its rim.

Finally, Cabeus A rests along an edge of the moon that is easily visible from Earth, making it an ideal place to send up a plume for people to see.

The plume will be bright but short lived, lasting only about 30 seconds before it starts to fade, LCROSS scientist Tony Colaprete said today at a news briefing.

To get the most out of this "flash in the pan," the LCROSS team has coordinated a vast army of stargazers on the ground and in space to watch the event and collect as much information as they can about the plume.

Top of the list will be the LCROSS craft itself, which will be speeding toward the impact site just after it sends the leftover rocket hurtling toward the moon.

Instruments aboard LCROSS will collect data about the plume and the newly minted impact crater until the probe looses contact with Earth about 15.5 miles (25 kilometers) above the lunar surface. Four minutes after the first impact, LCROSS itself will then slam into the moon.

The duty roster also includes massive telescopes in Hawaii and the U.S. Southwest as well as orbiters such as the Hubble Space Telescope and the GeoEye imaging satellite.

In addition, NASA has put out the call for amateur astronomers with backyard telescopes to train their instruments on Cabeus A and report back via a "citizen science" web site.

The data entry page isn't up and running just yet, but if you'd like to take part LCROSS does have a page full of tips for when and where to look, what equipment to use, and how to take pictures.

The impact will happen at 4:30 a.m. Pacific time, which should allow enough darkness for the plume to be visible to people in the Western Hemisphere. Us folks on the East Coast will have our view blocked by dawn skies, but we can watch live streaming video of the moon crash on NASA TV.

For an idea of what you might see, go out and look at the moon tonight, LCROSS experts suggest: The moon is in the same phase right now as it will be on impact day.

As for what we might find, water is the goal but it's not the only option. Hydrogen could also mean the moon's pockets are full of methane, hydrocarbons, or whatever else the body has collected over the last 3.5 billion years, Colaprete noted.

Water or no, the plume's contents, he said, will be "a window into the past of the entire inner solar system."

A team of Japanese scientists has found that microgravity significantly lowers the birth rate in mammals, based on their study of mice embryos subjected to space-like conditions in the lab.

In previous studies in rats, scientists had seen that microgravity during space flight lowered sperm counts and even caused the poor rodents' testicles to weigh less. [Rat-testicle weigher sounds like a job for Mike Rowe to me!]

Meanwhile, mouse-embryo cells flown aboard the space shuttle Columbia in 1996 failed to yield any mousey babies.

Reporting in the open-access journal PLoS ONE, Sayaka Wakayama, of the Laboratory for Genomic Reprogramming in Kobe, and colleagues note that the issue warrants further study, but sending actual mice into space and seeing if they breed presents a few challenges.

"If mice were to be taken into space, they would be exposed to strong vibrations and hypergravity during the launch, and then suddenly exposed to the additional stress of µG conditions. In these situations, it is highly unlikely that the mice would copulate during the flight period," the study authors write.

The solution? Mouse in vitro fertilization, or IVF.

Using a device that kinda looks like a robot's rotissomat to simulate microgravity, the scientists fertilized mouse embryos and allowed them to develop in conditions like what they would experience in space.

The eggs were then taken out and transferred to waiting mouse moms. The fertilization part worked as expected, and the mice gave birth to 75 healthy space babies.

"All these offspring appeared normal, and randomly selected animals were later proven fertile by natural mating," the authors note.

But that's just a 35 percent birth rate, compared to the 63 percent of successfully born IVF mice that got to develop under normal Earth gravity.

Next steps, the authors say, will be to see how well embryo implantation works in space.

If a colony ever does get built on the moon or Mars, I suppose eventually we'll want to extend such studies to humans, although I'm guessing much more work will be done between now and then on whether we can make babies in space the old-fashioned way.

Any volunteers for this important medical research?

—Image courtesy NASA/JPL/University of Arizona

Those of you who think it's cool to drill into Google Maps and find, for example, your car sitting in your driveway, probably know that it's all about coming to a resolution.

The higher a camera's resolution, the more details you can capture in a single image, and the deeper you can zoom in.

Google gets many of its images from Earth-orbiting probes that have eyes sharp enough to see 19.7 inches (50 centimeters) per pixel.

Such satellites have a counterpart orbiting Mars: the High Resolution Imaging Science Experiment, or HiRISE, camera aboard the Mars Reconnaissance Orbiter.

HiRISE can see in resolutions of 9.8 to 19.7 inches (25 to 50 centimeters) per pixel, enough to take snapshots of features as small as an office desk from about 186 miles (300 kilometers) above the planet's surface.

And like Earthlings scanning web maps for their tricked-out Hondas, Mars mission managers can peer into the more detailed shots of the Martian terrain to pick out their vehicles in action.

Case in point: Last week HiRISE treated us to a glorious new shot of Victoria Crater, which the Mars rover Opportunity had risked life and limb to explore in 2007.

Now peer closely at those scalloped edges, and you can just see where it looks like someone was playing connect the dots up near the crater's left-hand rim.

Those are Opportunity's tacks, preserved in the Martian dust after all this time!

—Image courtesy NASA/JPL/University of Arizona

After about a year in the crater, the rover clambered back out and headed south, and NASA's been using its orbiters to follow the rover's path since then.

Using such "traverse maps," like the one featured above, Emily Lakdawalla over at the Planetary Society did some heavy lifting and tracked down the rover itself in the full version of the new crater picture.

She's zoomed in so you can clearly see Opportunity ambling across the red planet's dunes after it had stopped to investigate a Martian meteorite.

—Image courtesy NASA/JPL/University of Arizona

Now is that freakin' sweet or what?

The extension, dubbed the Equinox Mission, is primarily focused on changes wrought on Saturn by the onset of equinox, when the sun shines directly on the gas giant's equator, which happens just once every 15 years.

In the past Saturn, its rings, and its moons were all illuminated from the south. But tomorrow the equinox comes, and afterward the sunlight will glide over to Saturn's northern face.

Over the long term, Cassini will be able to watch the planet's seasonal changes—at least until the currently funded mission ends in September 2010.

But the time immediately around the equinox is especially exciting, because changes in the planet's position combined with light coming in at different angles are exposing all sorts of 3-D effects in the normally "two-dimensional" rings.

Last week, for example, Cassini images revealed a new itteh bitteh moon hovering just outside Saturn's B ring.

—Image courtesy NASA/JPL/Space Science Institute, little white arrow courtesy moi

The small, light-colored object is so close to the dense rings—the scientists guess it's a mere 660 feet (200 meters) above—that it was effectively hidden until now.

The unique interplay of light brought on by the upcoming equinox caused the little moon to cast a long shadow on the rings. In general, Saturn's moons cast shadows on the rings only before and after an equinox, so pictures like this are incredibly rare.

That means it's a treat even when bigger, known moons decorate the rings with their own shadowy dances, since the shadows allow Cassini scientists to create unprecedented images with scientific punch.

Here, the moon Tethys casts its spiky shadow across the A and B rings in a mosaic of 17 pictures taken about 2 minutes, 17 seconds apart.

—Image courtesy NASA/JPL/Space Science Institute

The changing degrees of light and dark in the same parts of each shadow can tell scientists just how dense the planet's rings are in certain regions.

Saturn's moons also sometimes interact directly with the rings, as seen in this picture of the moon Prometheus creating dark "steamers" through the thin outer F ring.

—Image courtesy NASA/JPL/Space Science Institute

The 53-mile-wide (86-kilometer-wide) moon dips into the F ring when its orbit takes it farthest from the planet. The moon's gravity then pulls material out of the rings as it moves closer to Saturn. (Watch a movie of Prometheus "bouncing" off the F ring.)

So far we've only seen this phenomenon lit from the south, but it's due to happen again late this fall, after the equinox. Scientists hope light coming in from the north will, pardon the cliché, literally shed new light on the moon's effects on the F ring.

As for the equinox itself, Cassini will likely have its eye trained on Saturn to see the gas giant make its roughly 170,000-mile-wide (273,000-kilometer-wide) rings ... disappear!

As wide as the rings are, they're just 30 feet (9 meters) thick. As the planet turns on its axis during the equinox, the edge of the rings will line up with the light from the sun.

It's like turning a piece of white paper edge-on against a mostly white wall and then shining a light directly at it. For all you can see, the paper will seem to vanish.

—Image courtesy NASA/Hubble Heritage

Astronomer Galileo Galilei saw this happen in December 1612 (although through his low-power 'scope, he thought the rings were actually two moons on either side of the planet!).

He was appropriately baffled at the vanishing act, writing in a letter: "I do not know what to say in a case so surprising, so unlooked for and so novel."

Sadly the folks at home won't be able to witness the spectacle this year, as Saturn is also in solar conjunction—basically behind the sun as seen from Earth.

So let's all hope Cassini keeps working overtime and catches the equinox in action!

—Image courtesy NASA/JPL-Caltech/Cornell University

Dubbed "Block Island," the conspicuous space rock is now the largest confirmed meteorite found on the red planet, NASA announced today.

The Mars rover Opportunity snapped the above portrait of Block Island on July 31, as it moved in closer to touch the meteorite.

Opportunity's examinations revealed that the two-foot-wide object is an iron-nickel meteorite, although where it came from exactly is still anybody's guess.

Although Opportunity and its twin, Spirit, have found several candidate rocks during their five-plus years on Mars, Block Island is only the second official Martian meteorite.

The first—known as Heat Shield Rock, but formally named Meridiani Planum—was found in late 2004.

On the flip side, meteorites from Mars are also pretty rare, all things considered.

According to NASA, of the 24,000 or so space rocks that have been found on Earth, just 34 are known to be from Mars, presumably broken off from the red planet when something else smashed into its surface.

—Image courtesy NASA/CXC/SAO

Yesterday, ten years to the day after the probe's July 23 launch, the Chandra team released this updated version of the supernova's portrait:

—X-ray (NASA/CXC/MIT/D.Dewey et al. & NASA/CXC/SAO/J.DePasquale); Optical (NASA/STScI)

In the immortal word of Keanu Reeves: Whoa.

The brilliant new picture (click here for a larger version) combines Chandra's x-ray data with a visible-light image from its orbiting partner the Hubble Space Telescope. Together the two orbiters show the supernova's hot outer blast wave as a blue halo around the cooler inner material, with bright stars glittering in the background.

The green blob in the lower right is a cloud of gas and dust being illuminated by one very massive star (not pictured), probably not unlike the one that went boom and created E0102.

While the x-ray data add some great visual details to the shot, Chandra also contributed to the scientific analysis of the remnant. The x-rays, for instance, have helped astronomers get a better picture of the geometry of the explosion.

That's because x-rays with different levels of energy shine differently for Chandra. Since energy levels are linked to direction, scientists can tell how the object's components are moving relative to each other.

To us, E0102 may look like a colorful cotton ball in space. But Chandra reveals that the supernova is actually shaped more like a cylinder, and we're simply seeing the rounded face. There's a nifty animation of this here, in case pictures speak loader than words...

Btw, in its ten years of data collection, it seems Chandra has done its share of capturing puffballs in outer space. Here's a "rogues gallery" of some of the more famous explosions:

Tycho's Remnant

• About 7,500 light-years away
• Danish astronomer Tycho Brahe saw light from the initial explosion in 1572
• Chandra snapped it in April 2003

—X-ray: NASA/CXC/SAO, Infrared: NASA/JPL-Caltech; Optical: MPIA, Calar Alto, O.Krause et al.

Kepler's Remnant

• About 13,000 light-years away
• Astronomer Johannes Kepler was among the first to see it as a new object in the sky in 1604
• Chandra studied it from April to August 2006

—Image courtesy NASA/CXC/NCSU/S.Reynolds et al.

Cassiopeia A

• About 10,000 light-years away
• Discovered in the constellation Cassiopeia via radio observations in 1947
• Chandra snapped it in December 2007

—Image courtesy NASA/CXC/MIT/UMass Amherst/M.D.Stage et al.

SN1006

• About 7,000 light-years away
• The brightest supernova ever seen from Earth, witnessed in Asia, Europe, and the Middle East in A.D. 1006
• Chandra snapped it in April 2003

—X-ray: NASA/CXC/Rutgers/G.Cassam-Chenai, J.Hughes et al.; Radio: NRAO/AUI/NSF/GBT/VLA/Dyer, Maddalena & Cornwell; Optical: Middlebury College/F.Winkler, NOAO/AURA/NSF/CTIO Schmidt & DSS

Did you hear? Today, July 20, 2009, is the 40th anniversary of the day humans first set foot on the moon.

Yeah, I know. If you read newspapers/watch TV/surf the web/opened your door this morning, you've probably been flooded with Apollo 11 news by now.

On one hand, it's quite the achievement worth celebrating. On the other, it's a reminder of all we have *not* accomplished in the field of human space travel over the past 40 years.

For our part, NatGeo has been busy creating some fascinating content to commemorate the heady days of the Apollo program.

One of my personal favorites is an interactive version of a pressed vinyl record called Sounds of the Space Age, which was an insert in the December 1969 issue of the magazine.

I may not be old enough to remember the moon landings (technically, I wasn't born yet!) but man, I do recall those wonderfully floppy records. I'm pretty sure I had one with a McDonald's song that had me crooning the ingredients in a Big Mac when I was 12...

Speaking of Micky Ds, some good folks working out of a now-defunct restaurant in California have been restoring the original 1960s Lunar Orbiter pictures taken to help scout out landing sites for the Apollo program, and we've got a few examples of their work on display.

To get a real sense of how well satellites could see back then, check out a zoomable version of the famous "Earthrise" image taken by the first Lunar Orbiter.

Still not convinced man landed on the moon? Writer Ker Than interviewed a couple delightfully witty experts, who gave him the skinny on why some of the more common hoax theories are all wet. And if historic images don't seal the deal, check out pictures released this weekend showing quite clearly the shadow of a lunar lander.

Finally, here's a shameless plug for a piece I scared up on the question of who, exactly, can claim the moon.

There's a ton more from us, and so much good, funny, thoughtful, and touching Apollo coverage elsewhere online.

It might seem weird to get so excited at the 40th, with the 50th just a few short years away. But as one historian recently noted, this could be the last major anniversary when all of the original Apollo 11 crewmates can still gather to tell tales. So make the most of it, people, we're living history even as we relive that historic day.

On one side lies the realm of Pure Accuracy, filled with semantics and pedantry and enough qualifiers to turn the discovery of giant squid fossils on Mars into a 40-page report on "the theoretical life-cycle and behavioral dynamics of a novel Architeuthis species as revealed by spectroscopic analysis of Noachian coprolites in the Syrtis Major quadrangle."

Zzzzzzzzzzzzz.

But on the other side of the sword's edge lies Pandering Sensationalism, where almost every headline seems to end with an exclamation point [Missing Link Found!] and every discovery is hopelessly lacking in context.

Scientists rail about being misrepresented, misquoted, and full of misgivings when it comes to working with the press. Journos counter that if they don't make science palatable for the average American, science coverage in general will promptly disappear in a puff of logic.

It's a tough job finding the middle ground, for writers and for researchers.

For me, one of the hardest things to grapple with is the media's perpetuation of popular myths.

Gentle metaphors may not always be 100% accurate, but they serve a purpose. Solar wind, for example, is not *technically* wind, but it's a great, media-friendly name for the stream of ionized particles constantly emanating from the sun.

Some lay-language fallbacks, meanwhile, are totally wrong, totally unnecessary, and need to stop. Now.

Say it with me, now: Black holes DO NOT suck.

—Illustration of a star getting too close to a supermassive black hole courtesy NASA/CXC/M.Weiss

Via Merriam-Webster:

Main Entry: suck
Function: verb
Inflected Form(s): -ed/-ing/-s
Etymology: Middle English soken, souken, from Old English sumacrcan; akin to Old High German sumacrgan to suck, Old Norse sumacrga, Latin sugere to suck, Middle Breton sunaff juice, Greek hyei it is raining, Lithuanian sunkti to filter, ooze, Tocharian B swese rain transitive verb
1 a (1) : to draw (a liquid) into the mouth by a partial vacuum caused by motion of the mouth ...

A vacuum is a total absence of matter, even molecules of air. By creating a partial vacuum, someone sucking through a straw makes the liquid move toward them because, that's right, Nature abhors a vacuum and will want to fill the absence with whatever's close at hand.

By contrast, a black hole is what's left of a very massive star that went supernova. The darn thing is so dense that it exerts a gravitational pull so strong that not even light can escape.

Objects near the lip of the black hole, known as the event horizon, can be said to be getting pulled in or—since this is gravity we're talking about—to be falling in to the black hole.

They are NOT being sucked in. Different effect entirely.

Even more exciting and just as poorly understood, matter needs to be in just the right place near a black hole for it to be affected. Galaxy Girl has a great explanation for why, if the sun suddenly became a black hole, Earth would not get pulled in.

And now we know that it definitely wouldn't get sucked in.

Phew, what a mouthful!

But as we know from our own solar system, not all planets are created equal, and things get really interesting when we try to define the types of planets that might support life.

Traditionally when we think of a habitable world, we think of Earth. Makes sense: To date it's our only frame of reference for a planet that supports plants, animals, even microbes. So it's as good a model as any in terms of what we'd want habitable exoplanets to look like.

A 3-D view of Mount Kilimanjaro in Tanzania, compiled from satellite data
—Image courtesy NASA/JPL/NIMA

Hence the huge emphasis among planet hunters on the so-called Goldilocks Zone, where it's not too hot and not too cold. A planet inside this zone would be just right for liquid water and life-giving sunshine.

In recent years that hypothetical zone has been getting bigger, it seems, especially as expeditions to the deep ocean and volcanic peaks have expanded the conditions in which we thought life could exist.

Enter Rory Barnes, a University of Washington postdoctoral researcher who's here to rain on that parade.