Last week two teams of astronomers, one using the Hubble Space Telescope and the other using giant ground-based scopes with adaptive optics, released what they called the first direct images of extrasolar planets orbiting other stars; see our article.

Not to be outdone, a French team today released their image of a tiny but definitely real speck glowing in the infrared 0.4 arcsecond from Beta Pictoris, a young star 63 light-years away. The speck is just inside the inner edge of Beta Pic's enormous, famous debris disk — a wide platter of dust that we see nearly edge-on.

The astronomers, led by Anne-Marie Lagrange (University of Grenoble), used one of the 8.2-meter reflectors of the Very Large Telescope array run by the European Southern Observatory at Paranal in Chile. The speck, glowing in infrared light 1,000 times fainter than Beta Pic itself, was resolved by means of severe image processing to eliminate almost all of the star's dazzling glare. Beta Pic is a naked-eye star shining at 4th magnitude in the far-southern sky near Canopus. It is a hot, white, type-A3 star eight times as luminous as the Sun.

Beta Pic b lies about 8 astronomical units from the star, roughly Saturn's distance from the Sun. This puts it much closer to its star than last week's directly-imaged exoplanets. Gravitational effects perturbing the debris disk had already suggested that a giant planet ought to be there.

Given Beta Pic's very young age (10 or 20 million years) and the new object's apparent high temperature (about 1,500 kelvins), it should have a mass of about 8 Jupiters, which puts it within the planetary category.

Unlike the four planets in last week's images, "Beta Pictoris b" has not been observed long enough for it to show any sign of orbital motion around its star — or even to show that it is traveling with the star across the sky ("common proper motion"). Even so, the chance that it could be a background object unrelated to Beta Pic is extremely slim.

Read the full (and very informative) ESO press release.

And here is the team's discovery paper.

India's first deep-space mission has chalked up another success during its glitch-free mission. Having maneuvered into its final orbit, 60 miles (100 km) above the Moon, the Chandrayaan spacecraft released an instrumented, 75-pound (34-kg) probe on November 14th that slammed into the lunar surface 25 minutes later.

We've been using the Moon for target practice for decades. Back in the 1960s, the sole objective of U.S. Rangers and some Soviet Lunas was simply to crash into it. Apollo missions routinely slammed discarded hardware into the surface at high speed to trigger measurable seismic shocks. More recently, in July 1999, NASA's Lunar Prospector struck the Moon and, in the process, delivered cremains of the legendary lunar geologist Gene Shoemaker.

Indian space scientists had more modest ambitions for Chandrayaan 1's MIP (Moon Impact Probe). It carried three instruments: a camera, radar altimeter, and mass spectrometer. The first two helped determine the craft's location and altitude during the brief descent; the mass spectrometer sampled the extremely tenuous wisps of gas that surround the Moon.

The MIP's sides were emblazoned with the tricolored Indian flag, and an online announcement from the Indian Space Research Organization noted that the impact occurred on Pandit Jawaharlal Nehru’s birthday.

Meanwhile, instruments on the main spacecraft (10 in all) are being tested and calibrated for what promises to be a scientifically productive two-year mission.

Scientists reported interesting findings about Mars this week, and for a change the news didn't involve the landers Phoenix, Spirit, or Opportunity.

The first report comes from Mars Odyssey, which has been in orbit there since October 2001, and revives the idea that a vast expanse of water once covered up to a third of the Red Planet's surface. Roughly 10 times the size of the Mediterranean Sea, this alien ocean would have occupied much of the northern half of Mars, which is smooth, flat, and low lying — in stark contrast to heavily cratered highlands in the south.

In the late 1980s Timothy Parker, a Mars specialist at the Jet Propulsion Laboratory, turned up what appeared to be vestiges of ancient shorelines in Viking images. But the details were subtle and furtive, and enthusiasm for a paleo-ocean waned over the years as higher-resolution images from later spacecraft revealed little where Parker had looked.

But now scientists from the University of Arizona and elsewhere report that there might be something to the ocean idea after all. Again the evidence is subtle — nothing so obvious as gigantic seashells — emerging from geochemical signatures of the rocks themselves. Based on a global survey of elemental abundances compiled by Odyssey's gamma-ray spectrometer, there seems to be more potassium, thorium and iron in the putative ancient seabed than in the higher terrain that surrounds it.

Why should that be the case? James M. Dohm (University of Arizona), who led the work, explains in a press release that these three elements should be more concentrated within seafloor sediments because water flowing out of the southern highlands would have leached the elements from planet's ancient crust.

These days most planetary scientists think Mars has been in a bone-dry deep freeze for most of its history. Yet the planet does have plenty of water stashed away as ice. Victor Baker, one of Dohm's Arizona coauthors, has long argued that Mars has been sporadically wet and warm, but he's failed to sway most other scientists.

Is the jury still out in "The Case of the Martian Ocean"? Let's see what kind of reaction ensues when the Mars Odyssey work appears in a forthcoming issue of Planetary and Space Science.

Meanwhile, more detective work by orbital spacecraft reveals that that a glacier's worth of ice appears to lie just under a thin veneer of topsoil. This finding wouldn't ordinarily be news — after all, Phoenix landed atop a thinly disguised slab of frozen water, and previous work suggests that buried ice likely extends for hundreds of miles beyond both of the planet's polar caps.

However, an article appearing in today's issue of Science argues that glaciers of ice also lie buried lie near the giant basin Hellas at a southern latitude of 45° — much closer to the planet's equator than previously thought possible.

The stealthy glaciers were revealed by radar soundings from NASA's Mars Reconnaissance Orbiter. Tens of miles long and and up to a half mile (1 km) thick, they're probably remnants from an ice sheet covering the planet's middle latitudes during colder climes. Since then they've been capped by a layer of dusty debris, which insulated them from direct sunlight.

You'll find a nice summary of the Science paper, written by John W. Holt (University of Texas at Austin) and 11 others, in this online press release. Detailed images of the suspected glaciers (and a 97-megabyte animation) are here.

Late last week scientists from many countries gathered at the foot of the Andes to inaugurate the Pierre Auger Observatory in Malargüe, Argentina.

This event marked the completion of a vast complex of cosmic-ray detectors — 1,600 of them, spread across some 1,200 square miles (3,000 square kilometers) — designed to detect the collision of ultrahigh-energy particles with Earth's atmosphere and to deduce their origin. The most potent cosmic rays, which are atomic nuclei traveling at relativistic speeds, can carry up to 10 million times more kinetic energy than those created in particle accelerators on Earth.

When a potent cosmic ray strikes Earth, it slams into the nucleus of a gas molecule high in the atmosphere. This collision triggers a chain reaction of secondary particles (termed an air shower) that cascade down to lower levels. Cosmic rays strike our planet constantly, but the most powerful ones — packing 10 million trillion electron volts — are extremely rare. On average, only one of these arrives over each square kilometer of ground per year.

The Pierre Auger Observatory, named a pioneering French cosmic-ray researcher, employs two independent methods to detect and study high-energy cosmic rays. One technique senses the light emitted when secondary particles interact with water one or more of the 1,600 tanks. The other method records ultraviolet light emitted high in the atmosphere during each air shower. (You can learn more about the air showers and their detection here.)

I'll bet the celebration in Argentina had the feel of a new company that made its first big sale a year before the official grand opening. Construction of Pierre Auger Observatory began in 2000, and it went online in 2004 with only about half of its detectors in place. By late last year its researchers had deduced that the most powerful cosmic rays come appear to emanate from active galactic nuclei (AGNs), ultrabright objects powered by supermassive black holes.

So far, the $53 million Pierre Auger Observatory has involved more than 350 physicists from 70 institutions in 17 countries. However, there's more work to be done. A second field of detectors will also be built in southeastern Colorado, providing sky coverage on both sides of the equator.

For years, astronomers have been racing one another to take the first picture of a planet orbiting another star. Over the past few years, several teams have claimed to have directly imaged an extrasolar planet. But in each case, there were lingering questions about the nature of the purported planet. The objects seem unusually massive for planets, and each orbits much farther from its host star than Pluto orbits the Sun. Many astronomers argue that these objects are more accurately described as failed stars (known as brown dwarfs) rather than true planets, because they probably formed from collapsing gas clouds, like stars.

Today, two teams of astronomers announced new exoplanet images, and in each case, I think they have the real deal. Only time and future observations will let us know for certain, but these objects have the look and feel of bona fide planets. One group found a planet orbiting Fomalhaut, the 18th brightest star in the night sky, and one of the Sun’s nearest stellar neighbors. The other team appears to have imaged three planets around a more obscure star known as HR 8799.

The Fomalhaut planet was imaged by Paul Kalas (University of California, Berkeley) and his colleagues. Kalas and his team used the Hubble Space Telescope, which comes with an occulting disk that was employed to block Fomalhaut’s blazing pinpoint of light. Observations taken over several years revealed an ultra-faint moving object orbiting at a large distance from Fomalhaut.

The purported planet orbits Fomalhaut at a whopping 119 astronomical units (1 a.u. is the average Earth-Sun distance). This puts it four times farther from Fomalhaut than Neptune is from the Sun. The planet, known as Fomalhaut b, orbits just inside a dusty ring of rubble that is Fomalhaut’s equivalent of our Kuiper Belt.

Kalas and his colleagues cite two lines of evidence to argue that Fomalhaut b is indeed a planet. First, its extreme faintness in visible light, coupled with Fomalhaut’s estimated 100- to 300-million-year age, argues that it cooled off too quickly to be a brown dwarf, and thus has at most 2 or 3 times the mass of Jupiter. Kalas also points out a second piece of evidence: "A brown dwarf could not sit so close to the belt without completely disrupting it by gravity."

Given these two completely independent lines of evidence that Fomalhaut b has a very low mass, I’m buying the argument that Fomalhaut b is a genuine planet. But there is still no universally accepted definition of what distinguishes a high-mass planet from a low-mass brown dwarf. According to some astronomers, the line should be drawn at about 13 Jupiter masses — the mass at which a gaseous body can briefly fuse deuterium atoms in its core. According to that definition, Fomalhaut b is clearly a planet.

But other astronomers think the distinction should be based on formation. If a 3-Jupiter-mass object formed like a star from a collapsing gas cloud, it’s a very-low-mass brown dwarf. If it formed inside a disk, then it’s a planet. Since it’s unclear how Fomalhaut b formed, one could argue either way.

The HR 8799 planets were imaged by a team led by Christian Marois (Herzberg Institute of Astrophysics, Canada). This group used the 10-meter Keck II telescope in Hawaii and the 8-meter Gemini telescope in Hawaii to image three pinpricks of infrared light orbiting HR 8799, a magnitude-6 star in the constellation Pegasus. Besides using an occulting mask to blot out the star’s light, the team used adaptive optics to compensate for the blurring effects of Earth’s atmosphere.

But are these pinpricks of light actually planets? Based on their separations from the star and HR 8799’s measured 128-light-year distance, the bodies orbit at distances of about 24, 38, and 68 a.u. The innermost object would be halfway between Uranus and Neptune in our solar system, and the outermost would be slightly more than twice Neptune’s distance.

Based on the infrared luminosity of the three companions, and the star’s estimated 60-million-year age, Marois and his team estimate the masses to be around 10, 10, and 7 Jupiters, respectively. These masses are getting uncomfortably close to the 13-Jupiter-mass lower limit for brown dwarfs. Moreover, the star’s age is not known to high precision, and astronomers have not thoroughly tested the cooling models they use to determine the masses of brown dwarfs and planets. In other words, the actual masses might exceed 13 Jupiters.

But as codiscoverer Bruce Macintosh (Lawrence Livermore National Laboratory) points out, "All three of these objects seem to be orbiting in the same plane, and they’re going around in the same direction. This would imply they formed in a protoplanetary disk, like planets do."

I’m ready to buy that argument, at least for now. With three substellar companions moving in the same direction and in the same plane, the HR 8799 system looks like a scaled-up version of our own solar system. It looks a heck of a lot more like a planetary system than it resembles a multiple-star system.

I’d like to see both systems given further scrutiny so astronomers can better characterize the orbiting companions. I would also like to see detections around other stars, so we can start comparing different systems. But if I had to bet, I’d put my money on the claims that these are indeed planets. If Kalas, Marois, and their colleagues are right, they may go down in the history books as having taken the first images of extrasolar planets.

Regardless of the uncertainties in formation and semantics, these direct images represent a giant leap forward. "These discoveries are extraordinarily exciting for exoplanet science," says veteran exoplanet hunter Geoff Marcy (University of California, Berkeley). "We may be witnessing the birth of a new exoplanet era. For the first time, we may measure orbits, brightnesses, and spectra of other planets, just as astronomers have done for decades with stars, nebulae, and galaxies."

The Fomalhaut and HR 8799 results are published in today’s issue of the journal Science.

After looking, digging, scraping, sniffing, and tasting Mars for five months, the Phoenix lander has apparently called it a day. NASA's tracking stations haven't heard from the robotic probe in more than a week, likely signaling the end of mission operations.

Flight engineers had believed that the craft would last a few weeks longer, but those hopes were dashed when a dust storm bloomed over the landing site last month and robbed the lander of some of the already-waning sunlight used to power its transmitter, instruments, and other electronic systems.

At a hastily convened press briefing today, mission officials lauded all that the lander had accomplished. "It's really an Irish wake and not a funeral," noted Doug McCuistion, who manages the space agency's Mars-exploration program. "We should celebrate what Phoenix has done."

Principal investigator Peter Smith, who's been working on the spacecraft for nearly 7 years, ticked off some of the scientific highlights to date: the discovery of extensive water ice underlying the landing site; some 25,000 images of the surface and atmosphere, from macro to microscopic scales; a complete 5-month-long weather record; chemical analyses showing that the surrounding dirt is mildly alkaline; and compositional results revealing the presence of carbonates, clay minerals, salts, and perchlorate (a minerals used as an energy source by some primitive organisms on Earth).

Smith acknowledged that the "sticky," cohesive character of the surface samples posed problems for getting it into Phoenix's miniaturized laboratories. One missed opportunity was the chance to get a really thorough analysis of the ice itself. But Smith hinted that detailed studies of the results in hand may yet reveal the presence of organic matter in one ice-rich sample.

The spacecraft is unlikely to survive the coming Martian winter, during which temperatures are expected to plunge to -240°F (-150°C). "We expect that it will become encased in frozen CO2," notes mission manager Barry Goldstein. Phoenix's fragile solar-cell arrays, not designed to support much weight, will "likely crack and fall off the vehicle."

You can read more about the bad news here, or instead you can revel in all that Phoenix has accomplished here.

Earlier today the Indian Space Research Organization announced that its first foray into deep-space exploration, Chandrayaan 1, has begun orbiting the Moon.

Rather than sending Chandrayaan 1 straight for the Moon following its launch on October 22nd, Indian flight controllers took a step-by-step approach to get the craft to its destination. And today, as it passed with 300 miles (500 km) of the Moon at 11:21 Universal Time, the spacecraft fired a braking rocket for nearly 14 minutes to allow its capture by lunar gravity.

For the moment, Chandrayaan 1 is looping around the Moon every 11 hours in a highly elliptical polar orbit that extends out to some 4,700 miles (7,500 km). Over the next few days, however, additional rocket burns will shrink this to a final orbit just 60 miles (100 km) high. After that observations with an international suite of 11 instruments should commence, beginning with the release of a small Moon Impact Probe. The mission is expected to last two years.

As the ISRO notes in its celebratory press release, India has become the sixth spacefaring power to place a craft in lunar orbit — having followed the lead of the United States, Soviet Union, European Space Agency, Japan, and China.

Today's "Word of the Day" is ferrofluid. It's what chemists call a suspension of extremely small iron-based particles in some kind of liquid. The result is a room-temperature fluid with magnetic properties.

So why are you reading about this here and not in the Chemistry Junkies Forum? Because someday soon you might be ogling amazing images of deep space taken by a telescope with a ferrofluid mirror.

Astronomers have toyed with liquid-mirror telescopes for decades. In theory, a shallow vat of fluid, when spun slowly, assumes the paraboloidal shade needed for a reflecting telescope's primary mirror. This quirk of gravity is the key to the highly successful Steward Observatory Mirror Lab in Tucson, Arizona, where spinning ovens cast glass blanks for some of the world's largest telescopes.

The only suitably reflective liquid for spin-table mirrors has been mercury — not exactly the kind of material you want to spend any time with. Yet, despite mercury's toxicity, curious opticians continue to experiment with it. In fact, an international team is building a giant mercury-mirror telescope on a mountaintop in India, with the hope of getting "first light" sometime next year.

Yesterday I learned of a remarkable finding by three researchers at Université Laval in Québec, Canada. In their work with ferrofluids, Jean-Philippe Déry, Ermanno Borra, and Anna Ritcey have chanced upon a concoction consisting of ethylene glycol — the antifreeze in our cars — mixed with maghemite, an iron oxide. The maghemite particles are no more than 10 nanometers (100 angstroms) across, and they get coated with a type of acetic acid that prevents them from clumping together while in suspension.

The team's real breakthrough has been to add (by spraying) a small amount of similarly tiny silver particles. These then float atop the ferrodfluid to create a mirror-smooth surface that's more reflective than liquid mercury. Better still, the shape of the surface can be altered by placing electromagnets beneath the container and adjusting the voltage applied to them — no spinning is needed.

As the trio reports in the November 25th issue of Chemistry of Materials, a biweekly journal of the American Chemical Society, so far they've created a lab-bench liquid mirror 2.7 inches (7 cm) across.

What's most amazing is that its surface is accurate to 1/20 the wavelength of red light (624 nanometers) — easily accurate enough for telescopic optics. They haven't yet tried to deform the silvery surface into a paraboloid, but Anna Ritcey told me that she's confident that can be achieved with the right combination of electromagnets.

You won't likely see antifreeze-and-silver reflectors in backyard settings — among other things, they have to be pointed straight up. But it's certainly a technology that bears watching closely.

Are you ready for a just-in spacecraft result that will blow your mind?

Have a close look at this image. It's one of many ultra-high-resolution images of Saturn's moon Enceladus (near its south pole, to be precise) taken by the Cassini spacecraft a few days ago, on October 31st.

This is just a small snippet (about 1%) of the full image mosaic, which measures 2,531 by 2,376 pixels. What's shown here is a swatch of icy terrain about 2 miles (3 km) on a side. The smallest details are just 40 feet (12 m) across — about the size of a house. It's the eyeball view you'd get from an altitude of about 12 miles (20 km).

If I were to track down Saturn in the predawn sky from my light-polluted backyard, glimpsing 12th-magnitude Enceladus would be a real challenge. But, thanks to Cassini's Imaging Science System ("cameras" for short), with a few mouse clicks I can achieve a virtual magnification of 75,000,000× — and no Barlow is needed!

The spacecraft took this view and others just after passing within 107 miles (171 km) of Enceladus. That's close — too close in some respects. We've all had the problem of trying to photograph the scenery from a fast-moving car, and Cassini's images would likewise have been badly smeared were it not for a "skeet-shoot" technique first tried last August. Essentially, the spacecraft slews its cameras as fast as it can to track the icy moonscape whizzing by. As you can see, it worked really, really well.

So kudos to the Cassini flight team for providing this Halloween treat. You can get the encounter's play-by-play at ciclops.org, the website maintained by ISS principal investigator Carolyn Porco and her team.

Cassini's next brush with Enceladus won't occur until this time next year. And by then, as Porco notes in her NASA blog, the Sun will be slowly setting on the south polar terrain. "So take your fill of this fabulous place now," she writes, "because it will be a very, very long time before you see it like this again."

By the way, Cassini had another brush with Enceladus back on October 9th. That one was incredibly close — just 15 miles (25 km) from the surface! — and it carried the spacecraft right through the icy plumes rising from the eight geysers concentrated near the moon's south pole. Some instruments should have determined what's in those plumes, but for now their science teams are keeping mum on what they've learned. Stay tuned!

There's good news and bad news this week regarding the Hubble Space Telescope.

The good news is that NASA's 18½-year-old flagship has begun observing again, one month after data-handling electronics failed on September 27th. The loss of the Control Unit/Science Data Formatter (CU/SDF) never really threatened the observatory's mission, but it's taken flight engineers a few weeks to complete the switchover to a redundant "B" unit on board.

"We're operating just fine on side B," reports Preston Burch, HST program manager at NASA's Goddard Space Flight Center. So far two instruments have been powered up, including the Wide Field and Planetary Camera (WFPC) 2. A third, the Near-Infrared Camera and Multi-Object Spectrometer (NICMOS), should resume operation soon after its cooling system is restarted on November 10th.

To celebrate Hubble's return to duty, NASA and the European Space Agency released a WFPC 2 image of Arp 147, a pair of interacting galaxies in the constellation Cetus some 400 million light-years away.

The bad news is that astronauts will have to wait a few more months before rocketing into orbit abaord STS 125, the fifth and final Hubble servicing mission. The flight had been slated to begin October 14th — with the Space Shuttle Atlantis on the pad awaiting launch — when the malfunction occurred.

Initially NASA managers announced a delay until February so that a replacement unit could be readied for flight. The CU/SDF is part of a larger assembly called the Science Instrument Command and Data Handling system (SIC&DHS). Now they say the spare won't be fully inspected and tested until April, likely pushing liftoff of STS 125 to next May at the earliest.

Part of the delay stems from the realization that the spare SIC&DHS, which has been in storage since 1991, had a few pieces missing. Over the years engineers have removed a few parts for use in ground tests of other systems, and it's going to take extra time to get it put back together — a detail missing from NASA's press release.

Another issue is that the replacement's A-side CU/SDF didn't work when technicians attempted to turn it on last Friday. "We're looking at workmanship and parts problems to troubleshoot this glitch," Burch told reporters today.

The silver lining in all this is that the malfunction occurred before the repair mission, not after it, and that it can be fixed with relative ease. Replacing the SIC&DHS should add only about 1½ hours of spacewalking time, which the astronauts plan to squeeze into their already lengthy "to-do" list.

Thirty-fours years ago, as a cub reporter on the Sky & Telescope staff, I headed to the Jet Propulsion Laboratory in Pasadena, California, on my first real assignment. I have a vivid recollection of looking over 8-by-10 glossies of Mercury, taken weeks before by Mariner 10. Back then, scientists created whole-planet mosaics by carefully cutting up photos and pasting them together.

These days, making beautiful, seamless composite views is a snap. Exhibit A is the set of wonderful views of Mercury unveiled during a NASA press briefing yesterday. These came courtesy of Messenger, short for "Mercury Surface, Space Environment, Geochemistry, and Ranging," which made its second flyby of the innermost planet three weeks ago.

NASA's press release makes the point that much of the territory recorded on October 6th's pass has never been seen at close range. (Due to Mercury's quirky rotation, three full spins every two orbits, Mariner 10 saw only 45% of the surface despite flying past three times in 1974-75.) All told, Messenger has now scrutinized the lion's share its target, and some "global" properties are becoming apparent.

For example, after examining the topographic heights measured along a 1,000-mile (1,600-km) swath of terrain, investigator Maria Zuber (MIT) concludes that the just-seen hemisphere is about 30% smoother than the one seen last January. Planetary scientists have seen these two-faced appearances elsewhere, on the Moon, Mars, and Iapetus, for example. In Mercury's case, the dichotomy might reflect cratering differences (rougher implying older), or it might be a manifestation of goings on in the planet's interior.

Mariner 10 discovered that Mercury is magnetized, and Messenger's second flyby showed that the strength of the planet's magnetic field is nearly equal on opposite sides of its globe. As Brian Anderson of JHU's Applied Physics Laboratory explained, this matchup means that the planet's field is strongly dipolar (as is Earth's), very nearly centered on the planet's core, and aligned within 2° of the rotation axis. All this suggests that Mercury generates its field by churning motion within a partially liquid core.

OK, time for a pop quiz: Does Mercury have an atmosphere?

Answer: Yes and no.

There are wisps of vapor around the planet, but technically they're part of an exosphere — atoms that aren't really permanently bound by gravity but rather are streaming out into space. What's got the science team scratching its collective head is that Messenger has detected emissions from emission from sodium, calcium, magnesium, and hydrogen atoms, in amounts that differed between the flybys. These atoms must be coming from somewhere on the surface, but just how, where, and why are TBD.

Ah, yes, the pictures! To the eye, this world looks remarkably color free. "No matter how we combine the images," notes principal investigator Sean Solomon, "Mercury comes out pretty gray." But on this flyby alone, the spacecraft snapped its cameras' shutters 1,287 times through 11 different filters — plenty of fodder for geologists to start extracting the surface's secrets.

For example, Mark Robinson (University of Arizona) notes that mysteriously dark and ever-so-slightly-blue patches, first seen by Mariner 10, appear here and there all over Mercury's surface. The source of this material seems to be deep seated — it's unearthed by largish impacts — but he points out that it's not around every large crater.

Robinson and the mission's other geochemists will have a much easier time deducing the origin of these mysterious deposits once the spacecraft starts orbiting Mercury in 2011. For now, he can only speculate that the blue-tinged stains might contain the mineral ilmenite (iron-titanium oxide) or perhaps small grains of metallic iron.

A few weeks ago, there was giddy rush of adrenalin as these images came streaming in from the spacecraft. "It's sobering, it's exhilarating, and it's great fun," Solomon admitted, "to see an expanse of planetary surface bigger than South America" for the first time. But now the team has settled down to the task of figuring out what it all means. So consider yesterday's announcements just a status report, with more discoveries to come in the weeks and months ahead.

I'm no fashionista. Luckily, T-shirts and jeans are adequate apparel for the S&T offices. Although I've grown up (a little) to wear more golf-style shirts and other top garments with buttons, I still have drawers full of T-shirts and prefer to wear something that hints of my interests. Over the decades, such apparel has often been a conversation starter. Sporting a shirt or cap emblazoned with Sky & Telescope is also a source of pride.

We used to sell a variety of "logo wear" items. Some of it sold, much of it didn't. So, we stopped selling it. I was finally able to persuade the powers-that-be to put us back in the logo wear business by setting up a storefront with CafePress.com, an on-demand printing company. For the past few years I've run a CafePress store for the alumni of my long-closed high school. The school disappeared more than 20 years ago, so the realm of interest is limited. Nevertheless, we Huskies of Robert E. Peary High School have strong school spirit, so orders trickle in.

We're excited to use CafePress because it allows us to provide a variety of items that otherwise would be prohibitively expensive for us to keep in stock.

Speaking as a T-shirt connoisseur, I've been very happy with the quality of the items I've bought for myself. If you're not, CafePress.com's customer service is top notch. If you have problems with shipping or sizing, the staff is quick to help. A while back, a friend ordered one of my mugs and it arrived broken. She called and they sent out another one — for no cost. That arrived broken too. So they sent a third that arrived fine. If you're unhappy with your purchase in any way, they'll take it back within 30 days and refund your money.

When you visit the shop, be sure to sign up for the CafePress newsletters to find out about special offers, such as free shipping. We'll try to highlight such deals in ads in our Weekly News Bulletin, but we might not be able to if there's a special mid-week promotion.

Here's another reason to subscribe: CafePress often adds items to the product line. The embroidered cap is new to their stock. I hope they will offer other embroidered shirt options in the future. At the moment, the selection doesn't mesh with our rectangular logo design. We'll let you know via our CafePress.com newsletter when new items reach the shop.

If you have any questions, comments, or concerns about the new S&T logo offerings, please write to me at sgoldman@skyandtelescope.com

Parking in lunar orbit is about to get a little more crowded.

On Wednesday the Indian Space Research Organization (ISRO) launched Chandrayaan 1, its first deep-space mission, from the Satish Dhawan Space Center in Sriharikota. In Hindi, Chandrayaan means "Journey to the Moon" (Chandra is Moon, and yaan is ship).

The space agency's proven Polar Satellite Launch Vehicle initially placed the spacecraft in a looping orbit that carried it 14,100 miles (22,860 km) from Earth. But a rocket firing yesterday nearly doubled the orbit's apogee, or high point. More maneuvers in the coming days will deliver Chandrayaan 1 to the Moon, where it should eventually settle into a low polar orbit only 60 miles (100 km) high.

Indian space scientists have high hopes for this mission. The spacecraft carries 11 instruments (three supplied by members of the European Space Agency and two by the United States). Most are designed to map the lunar terrain at high resolution and to assess surface composition at visible, near-infrared, microwave and X-ray wavelengths. ISRO has a nice online summary of the experiments and their objectives.

One novel twist is a 65-pound (29-kg) probe that will record video and analyze the Moon's extremely tenuous atmosphere for 20 minutes before it slams into the lunar dust. The impact won't be visible from Earth, but it'll certainly provide a challenging engineering test for the mission team.

Chandrayaan 1 joins a recent rush of exploratory missions to our neighbor world. Last week Japanese scientists showed off the latest results from their highly capable Kaguya spacecraft at a meeting of planetary specialists. (Check out the high-def video of a "full Earth" rising over the lunar landscape.) Team member Sho Sasaki told me that Kaguya has ample fuel reserves, enough to lower the orbital altitude from 60 to 30 miles and extend the mission through at least February.

Far more enigmatic is the Chinese orbiter Chang'e 1. A lot of hoopla accompanied its launch about this time last year. But few details have emerged since then. A small contingent of Chinese scientists had planned to describe early results from Chang'e 1 at a scientific meeting last March, but they were no-shows.

Finally, NASA plans to resume its exploration of the Moon next April, with the launch of the double-barrel LRO/LCROSS mission. Mapping and surveying by the Lunar Reconnaissance Orbiter should help pave the way for future astronaut sorties, while the piggybacking Lunar Crater Observation and Sensing Satellite (LCROSS) should strike the Moon with enough oomph to briefly loft a debris plume high enough to be observable from Earth.

Amateur astronomers, more than most, realize that artificial skyglow is slowly robbing us of the beauty of the night sky. But licking light pollution has not been easy.

For two decades the International Dark-Sky Association has waged a campaign to raise awareness about Public Enemy #1, astronomically speaking. There have been some modest, hard-won successes over the years. For example, lighting specialists and their companies have finally tooled up to make a variety of night-sky-friendly fixtures available to contractors and the general public. Also, hundreds of towns and a few states have enacted laws that require well-shielded lighting for new developments.

Yet drawing widespread attention to light pollution, especially at the state and federal level, has been difficult. As you might expect, Sky & Telescope has always supported the IDA's efforts, but coverage was spotty elsewhere in the news media.

My, how things have changed!

Over the summer, IDA teams presented the case against light pollution to both House and Senate staffers in Washington, and a bipartisan coalition of 11 House members sent a letter to the Environmental Protection Agency's administrator requesting action on the situation.

And the past year has seen a veritable explosion of light-pollution stories. The salvo began last year with a feature article in The New Yorker, followed by an editorial in the Boston Globe.

National Geographic Society

The pace picked up over this past summer: an in-depth story in July 25th's Wall Street Journal, a prominent op-ed piece in September 23rd's Boston Globe, and an October 7th editorial in the New York Times.

And, finally, the pièce de résistance: the cover story of National Geographic's November 2008 issue. The article is grippingly titled "The End of Night" — to which I might add: "Light Pollution — It's Not Just About Astronomers Any More."

But astronomers are still key allies in this fight, and now it's your turn to help: participate in the Great Worldwide Star Count from now through November 3rd — and become a member of the IDA.

Posted by Kelly Beatty, October 21, 2008

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