Blue moon set to rise on New Year’s Eve.

If you can take a break from all that New Year’s Eve revelry on Thursday, take a look up in the sky.

Behold, the blue moon.

For those expecting a slight blue hue encircling the moon, you might be a little disappointed.

“It won’t be blue at all - it’s just a saying,” said David Richey, associate director of the James S. McDonnell Planetarium at the St. Louis Science Center.

Richey explained that a blue moon occurs when there is two full moons in a calendar month. The first full moon of this month occurred on Dec. 2 and the next happens Thursday.

Blue moons happen every two years or so. The last was May 31, 2007 and the next will be in November 2010. And there won’t be any blue moons in 2011, 2014 and 2017.

“It’s fun to have it fall on New Year’s Eve, but it’s really just a function of how the calendar plays out,” Richey said.

No doubt, it will also be a boon for Molson Coors, the maker of the Belgian beer, Blue Moon.

For example, it appears Blue Moon is one of the sponsors of the New Year’s Eve bash at the Hyatt Regency in St. Louis.

In case you were wondering, the last blue moon that fell on New Year’s Eve happened in 1990. The next will be 2028.

Winter Solstice 2009

The mid December solstice marks the beginning of winter in the Northern Hemisphere and summer in the Southern Hemisphere.

In the Northern Hemisphere, the Winter Solstice occurs on December 21, 2009 at 12:47 PM EST and 17:47 UT (Universal Time).

In the Southern Hemisphere, the Winter Solstice takes place on June 21, 2009 5:45 UT (Universal Time).

While the beginning of summer marks the longest day of the year, the winter solstice brings the shortest day - and the longest night! - of the year.

The reason for the different seasons in the two hemispheres is that while the earth rotates around the sun, it also spins on its axis, which is tilted some 23.5 degrees. Because of this tilt, the Northern Hemisphere receives less direct sunlight and the Southern Hemisphere receives more (and vice versa) depending on the season.

In the Northern Hemipshere, the gloomy winter solstice has been responsible for many symbols, ancient myths and religous beliefs over millennia.

In ancient Rome, the winter solstice was celebrated at the feast of Saturnalia, while in pre-christian Britain, the end of December centered around the pagan Yule log in a fiery display to melt the heart of a cold and dreary winter. Today, a similar response to winter doldrums is the celebration of Christmas by many cultures around the world complete with twinkling lights, holiday feasts & lively festivals.

To many pre-Christian culture, however, December was thought of as the most dreaded time of year, when the lack of heat and light and a limited supply of food spelled danger. The cold was stark and the darkness seemed perpetual.

Even today, modern science points to a mental disorder that is now officially recognized as SAD, or seasonal affective disorder that results in moodiness or depression during the winter months due to the lack of sunlight.

The cure? Turn up the wattage! — indeed, the use of artificial light is the only known treatment for SAD.

Yet as the old wise man once said, it truly is darkest before the dawn. After December 21, the light slowly begins its inevitable return, and the days begin to grow blessedly longer, flipping the switch to ON for the inevitable countdown to spring ...

A Great Year for Geminid Meteors

The strongest and most reliable meteor showers are the Perseids of August and December's Geminids. Balmy weather and summer vacations have made the Perseids well known and popular, but the Geminids are actually easier to view from mid-northern latitudes. For one thing, nights are much longer in December. And while the Perseids are best viewed just before dawn (as most showers are), you can easily get an eyeful of the Geminids during the evening hours.

This year the Moon will be nearly new when the Geminids peak on the night of December 13-14. The shower's radiant, the point in the sky from which they all seem to originate, is near Castor and Pollux. It's well up in the east by 9 or 10 p.m. and crosses near the zenith (for mid-northern observers) around 2 a.m.

The shower should peak around 5:00 Universal Time on the morning of the 14th, corresponding to midnight EST and on the 13th at 9 p.m. PST — excellent timing for North America and Western Europe. Under dark-sky conditions you might see as many as 120 medium-speed meteors per hour. (Light pollution reduces the numbers.) The shower is active to a lesser extent for at least a day or two beforehand and about one day after.

The Geminid meteor shower is extremely unusual in that its parent object isn't a comet. Instead, it's an asteroid, a chunk of rock roughly 3 miles across called Phaethon (pronounced FAY-uh-ton). How can an asteroid produce meteoroids? Nobody knows for sure. Many scientists believe that Phaethon is the core of a comet that's been baked completely dry. Maybe a smaller asteroid collided with it long ago. In any case, a ribbon of debris lines Phaethon's orbit.

Meteor watching couldn't be easier. Lie back in a reclining lawn chair, relax, and watch the sky overhead. Ideally, you want nothing but sky in your field of view — not trees, and certainly not the ground. That means that you should either lie flat on your back or recline so that you face at least 45° above the horizon. Also remember that December nights are cold at mid-northern latitudes. Normal winter clothing won't even come close to keeping you warm after you've been lying still for a couple of hours. The best solution is to use a sleeping bag. Second best is plenty of blankets over your warmest clothing. And don't forget a hat and gloves!

The arriving Geminids will cover the whole sky, so it doesn't really matter which way you're pointed. If you look straight at the radiant, you'll see meteors coming directly toward you, bright but with short trails. Look the opposite way, and you'll see lots of long meteors moving away from you.

Geminids - Location of the Geminids For Northern Hemisphere Observers

Location of the Geminids For Northern Hemisphere Observers

Observing the Geminids

This is one of the best meteor showers of the year and never seems to disappoint observers.

This meteor shower gets the name "Geminids" because it appears to radiate from the constellation Gemini. An observer in the Northern Hemisphere can start seeing Geminid meteors as early as December 6, when one meteor every hour or so could be visible. During the next week, rates increase until a peak of 50-80 meteors per hour is attained on the night of December 13/14. The last Geminids are seen on December 18, when an observer might see a rate of one every hour or so.

There are other, weaker meteor showers going on around the same time as the Geminids, but the best way to know if the meteor you see is a Geminid is to mentally trace the meteor backwards. If you end up at Gemini then you have probably seen a Geminid meteor.

Odyssey Orbiter Puts Itself Into Safe Standby

Artist concept of Odyssey Artist concept of Mars Odyssey.

Update:

As of Dec. 3, the Odyssey spacecraft resumed relay operations. Odyssey’s first task was to support a communications relay session for the Spirit rover. Science operations for the orbiter will resume on Dec. 4.

Mars Odyssey Mission Status Report

NASA's Mars Odyssey orbiter put itself into a safe standby mode on Saturday, Nov. 28, and the team operating the spacecraft has begun implementing careful steps designed to resume Odyssey's science and relay operations within about a week.

Engineers have diagnosed the cause of the Nov. 28 event as the spacecraft's proper response to a memory error with a known source. The likely cause is an upset in the orbiter's "memory error external bus," as was the case with a similar event in June 2008.

In safe mode over the weekend, Odyssey remained in communication with ground controllers and maintained healthy temperatures and power. To clear the memory error, the team commanded Odyssey today to perform a cold reboot of the orbiter's onboard computer. The spacecraft reported that the reboot had been completed successfully.

"This event is a type we have seen before, so we have a known and tested path to resuming normal operations," said Odyssey Project Manager Philip Varghese of NASA's Jet Propulsion Laboratory, Pasadena, Calif.

Odyssey has been orbiting Mars since 2001. In addition to its own major scientific discoveries and continuing studies of the planet, the Odyssey mission has played important roles in supporting the missions of the Mars rovers Spirit and Opportunity and the Phoenix Mars Lander.

Until Odyssey is available again as a communications relay, Spirit and Opportunity will be operating with direct communications to and from Earth.

Comet Theory Faces Mammoth Confusion

Nothing kills a beautiful theory faster than an ugly fact, to paraphrase Thomas Huxley. But what happens when you have three competing theories and two new facts that point in opposite directions? Welcome to the increasingly confusing picture of what happened to the mammoths and mastodons of North America, along with the other dominant mammal species of the late Pleistocene.

For a number of years, scientists have been debating over two possible culprits that might explain the big die-off of megafauna. One is severe climate change, brought about by the onset of the Younger Dryas global-cooling event. Another is overhunting by a newly arrived human population in North America known as the Clovis culture. More recently, a third hypothesis claims that a comet impact or airburst over the Laurentide ice sheet triggered the changes that caused the animal population collapse.

All of these scenarios, or any combination of them, hinge on the fact that the big mammals died off rather abruptly starting around 12,900 years ago. This matches the onset of the climate change and comes right after Clovis appears on the scene. It also coincides with evidence that appears to support the comet hypothesis, including lots of tiny “nanodiamonds” that proponents say may have been generated in the impact and subsequent fires.

Until now, the debate has revolved around what happened. Now there are new questions about when it happened.

In a new paper in the journal Science, Jacuelyn Gill and others suggest that megafauna were in decline well before the 12,900 date. Gill, a doctoral candidate at University of Wisconsin, looked for spores of the fungus Sporormiella, known to grow in the dung of large herbivores. Those spores start to disappear from sites in New York state and Indiana between 14,800 and 13,700 years ago, suggesting an early disappearance for the mastodon.

But wait. Another recent paper by Neal Woodman and others in Quaternary Research finds that a mastodon skeleton discovered in Indiana in 1976 (and now on display at the Cincinnati Museum of Natural History) was dated incorrectly. A new analysis by the Smithsonian researcher finds that the mastodon was alive about 10,055 years ago.

Granted, one mastodon doesn’t make an entire population. But it can’t have been the only one. This means that some of the megafauna survived for thousands of years after they were supposed to have disappeared at the onset of the Younger Dryas, and long after the early decline suggested by Gill.

The commentary accompanying the Gill paper suggests that both the climate change and the impact hypothesis ideas are dead. Instead, the suggestion is that overhunting by paleo-Indians, already established in North America before the Clovis people arrived, is responsible for the early decline.

These conclusions seem premature. What can be said, based on the Gill paper, is that at least some local populations of megafauna were in trouble before the Younger Dryas, for reasons that remain unclear. From the Woodman paper we can infer that some other populations survived well after. And we know already, that an awful lot happened in between — which may or may not have included a comet impact.

It’s ironic that this picture is so confusing when the extinction of the dinosaurs by a large asteroid 65 million years ago now seems quite clear. But this is partly an effect of distance. If we could have visited Earth 12,900 thousand years after the dinosaurs went extinct it’s likely we would have found all kinds of interesting evidence, no longer available, that would have complicated the picture. The loss of the megafauna is both intriguing and hard to understand because it is so recent and there are so many more pieces of the puzzle to play with.

The only solution, as Woodman points out, is even more information. He suggests that mammoth and mastodon fossils in museums around the world should be looked again and redated if necessary to improve consistency in the data. There’s still more work to be done in sampling the environment too.

This debate is far from over. Like North America at the end of the ice age, it’s just getting warmed up.

Bird's-Eye View of Tranquility Base

Apollo 11 landing site
Taken from just 30 miles (50 km) up, this view from the Lunar Reconnaissance Orbiter Camera reveals incredible details at Tranquility Base, the landing site for Apollo1 and its crew in July 1969. Click on the image for a larger view.

Exhibit A is this view of the Apollo 11 landing site acquired on October 1st (but not released until November 9th) by the spacecraft's high-resolution stereo camera, LROC. It reveals details at the Space Age's most hallowed ground down to about 2 feet (53 cm).

Spend a little time perusing the image at right — or go moonwalking yourself by downloading a larger version or even the original image. The LROC team released a lower-resolution view of the landing site a couple of months ago, but now the spacecraft is in its final mapping orbit, a scant 30 miles (50 km) above the lunar surface.

You can easily see the squarish descent stage of the lunar module Eagle, which looks washed out because of contrast enhancement — look closer, and you'll make out its footpads too. Dark trails are the paths made by astronauts Neil Armstrong and Buzz Aldrin as they walked near Eagle and around the Early Apollo Science Experiments Package (EASEP).

Buzz Aldrin on the Moon
Apollo 11 astronaut Buzz Aldrin deploys the EASEP instrument package on Moon, with the lunar module Eagle in the background.

A few weeks ago, the LROC team released a video tour of the Apollo 17 landing site — amazing stuff! I guess those who still believe that NASA faked the lunar landings would argue that these pictures have been doctored.

It's hard to believe, but just a year ago, five spacecraft were orbiting the Moon — none of them launched by NASA. India and China had one each (Chandrayaan 1 and Chang'e 1, respectively), while Japan's Kaguya and two small escorts, named Okina and Ouna, were mapping the Moon inside and out.

Waiting in the wings was LRO, which began circling the Moon last June. Designed and built at a time when the U.S. and its space agency were firmly committed to returning humans to the Moon, LRO is a recon mission in the truest sense. Its seven-instrument payload reflects NASA's desire to understand the lunar features and resources that could influence the design and placement of future lunar settlements.

For example, the spacecraft's low polar orbit should allow its cameras to record the entire globe with 100-meter resolution and up to 10% of the surface with unprecedented 0.5-meter resolution — good enough to spot hazardous boulders in likely landing sites. (In fact, the view here shows boulders from West crater, which lies out of view to the right in the Apollo11 view above.) A radar mapper and a laser altimeter are gauging the slope and roughness of the terrain. The Diviner instrument has been recording temperatures from pole to pole, and a Russian-built neutron spectrometer is finding the "sweet spots" where deposits of water ice lie buried. Finally, a cosmic-ray telescope has been assessing the hazard that space radiation poses for future explorers.

LRO's early efforts concentrated on the lunar poles, in order to pick the best target for LCROSS and the Centaur rocket that carried both craft to the Moon. But Vondrak hopes that LRO can continue clicking and scanning the lunar landscape for at least two more years. Plans call for modifying the orbit periodically to optimize coverage, ending with the spacecraft in a gravitationally stable "frozen orbit" with a low point almost directly over the Moon's south pole.

The 2009 Leonids Are Coming!

Most meteor showers vary from year to year, but the Leonids are particularly capricious. Many years they chug along producing just 5 or 10 meteors visible per hour. But at the Leonids' historical greatest, in 1833, meteors were seen to fall "like snowflakes in a blizzard," with estimated rates of several dozen per second!

This year is expected to be better than average. The "traditional," most reliable part of the shower should peak around 4 a.m. EST (1 a.m. PST) on the morning of Tuesday, November 17th. You might see 20 or 30 meteors per hour under ideal dark-sky conditions. (Remember, if you want to stay up late instead of getting up early, you'll be staying up Monday night. It's easy to get the date wrong for events that happen after midnight!)

A second, briefer, but very intense outburst is expected about 12 hours later — during the early-morning hours of November 18th in Asia. (See "Will the Leonids Roar Again?".) There's only an off-chance that some activity from that burst will still be going on by the time the Earth turns halfway around and the Leonids become visible in the Americas on the morning of the 18th.

But if the sky is clear, why not go out again that morning — and also before the predicted peak, on the morning of the 16th? The Leonids have surprised the theorists before, and they surely will again.

Wherever you are, no Leonids will be visible before the shower's radiant point (in Leo) rises around local midnight. And peaks and bursts aside, the number of visible meteors increases steadily from radiant-rise until Leo is highest, just as the sky is starting to get light.

Be sure to bundle up warmly; meteor-watching is always colder than you expect. Ideal meteor-watching equipment is a comfortable lounge chair, a warm sleeping bag, and a pillow. If you live in a city or suburb, consider traveling to a dark location far from city skyglow. In any case, find a spot where no lights glare directly into your eyes.

The direction to watch is wherever your sky is darkest. Notice the meteors' flight paths; only those streaking away from the direction to the constellation Leo are Leonids.

Another, less-known meteor shower is going on simultaneously — the Taurids. They're sparse but tend to be very bright. If you see a slow, bright meteor heading away from the direction to Taurus, that's a Taurid.

And you're bound to see a few sporadics that aren't associated with any major shower.

Strange Brew at LCROSS's Crash Site

LCROSS and its Centaur rocket prepare to crash into the Moon.


It would be fair to say that the crashy culmination of NASA's LCROSS mission on October 9th was a technical success but a public-relations fizzle.

On the plus side, the engineering team for LCROSS (short for Lunar Crater Observation and Sensing Satellite) delivered as promised, deftly driving a spent 2½-ton Centaur rocket into a target zone near the Moon's south pole only 2 miles (3½ km) across. Four minutes later, after flying through the debris cloud raised by the rocket's crash, an instrument-packed 600-kg "shepherding spacecraft" augered in not far away.

But the team's hope of finding abundant water buried in the permanently shadowed floor of Cabeus, the 61-mile-wide target crater, has yet to pan out. Water molecules have strong spectral signatures in the near-infrared, and even one part water ice in 200 parts lunar dust should have been easy to spot.

So far, the LCROSS team has been mum on what's been found by the shepherd craft's nine instruments, apart from a heavily processed composite image showing a faint puff where the Centaur crashed.


Extensive image processing of images taken by the LCROSS shepherding spacecraft 15 seconds after the Centaur rocket's demise reveals a dim debris plume (6 to 8 km across) in the shadowed part of Cabeus crater.

Tony Colaprete, LCROSS's chief scientist, says that the rocket's impact created a pit about 92 feet (28 meters) across, close to expectations. And the debris plume from the crash attained roughly the size and height expected, though he concedes that it was only about a tenth as massive as he'd hoped (nowhere near the 350 tons touted in some predictions).

We may never learn the reasons for the paltry particle production, though right now Brown University impact specialists Peter Schultz and Brendan Hermalyn are saying, "Told ya so!" Their modeling, based on small-scale hypervelocity collisions at NASA's Ames Research Center, suggest that a low yield should have been expected — both because the empty Centaur collapsed into itself as it hit and because the spray of debris went mostly "out" instead of "up."

It's also possible that the Centaur pancaked into the crater's floor. "It was definitely rotating or tumbling," notes observer Marc Buie, who tracked the rocket's final hours with the 2.4-m telescope at Magdalena Ridge Observatory in New Mexico.

All this speculation is intriguing — but "Where's the beef?" you might ask. Colaprete assures me that all the instruments in the shepherding spacecraft got great results, and that the delay in revealing the compositional analyses stems from having lots of spectral signatures to sort through and categorize. Colaprete says some of these findings will be made public in a couple of weeks. (Don't be surprised if he announces that one of the spectrometers did, indeed, detect water in the plume.)

For now, let me tantalize you with a preliminary result from the Lunar Reconnaissance Orbiter, which viewed the Centaur's demise from nearly overhead and just 48 miles (76 km) up. An instrument dubbed the Lyman-Alpha Mapping Project (LAMP) probed the ultraviolet spectrum of the impact plume after it had risen high enough to be projected against black space above the lunar limb.

"We definitely saw something," notes LAMP scientist Randy Gladstone (Southwest Research Institute). But that "something" wasn't water. Nor was it oxygen or hydrogen atoms, both of which have strong ultraviolet emissions. There's some hint of hydrogen molecules (H2) — and though water is one source of hydrogen, it could also have come from silicate minerals, solar-wind gas trapped in the lunar soil, or (most likely) residual fuel in the Centaur's tanks.

LAMP's strongest and most intriguing observation came at the ultraviolet wavelength of 184-185 nanometers. Gladstone says the only known elements able to create that line are iron, perhaps magnesium … and mercury. "Both mercury and iron still look like the best bets for explaining the plume emission we see with LAMP," Gladstone reiterates, though the spectral match is still tentative and more data-crunching is in progress.

Liquid mercury on the Moon? Really? Gladstone directed me to an obscure, decade-old research paper titled "Don't Drink the Water" written by George W. Reed Jr. (Argonne National Laboratory). Reed describes how mercury was found in lunar regolith returned by the crews of Apollos 12, 15, 16, and 17, and other work suggests it might be present in the Moon's wispy-thin exosphere.

No matter what its source, Reed concludes, some of this mercury must end up as deposits in the ultracold interiors of permanently shadowed lunar craters. Moreover, the Centaur slam may not have created the big splash everyone wanted, but it only needed to heat the target area to about 200°F to release any mercury trapped in the dark dirt. And thermal imaging from the Diviner instrument aboard LRO argues that the impact site got that hot and then some.

This is all starting to make sense. Back in mid-September, UCLA scientist David Paige announced, based on Diviner's thermal mapping, that the lunar polar regions are far colder than expected, down near 35 kelvins (-397°F). This means the shadowed floors within Cabeus and its neighbors are the most frigid places known in the entire solar system. More to the point, Paige notes, "The temperatures in these super-cold regions are definitely low enough to cold-trap water ice, as well as other more volatile compounds for extended periods."

So is lunar water safe to drink? Future astronaut crews had better bring along some serious water-purification gear if they intend to live off what they scavenge from the lunar poles.

Cosmic Blast Rattles Indonesia

Back on October 8th, something big lit up the late-morning sky (at about 3:00 Universal Time) over the island nation of Indonesia.

I first learned of this event three days later, when few details were known. A smattering of news reports described an extremely bright daytime bolide that exploded high above the town of Bone in the province of South Sulawesi. One television station showed amateur video of a tortured smoke train lingering in the sky, and unconfirmed reports suggest that a 9-year-old child died of cardiac arrest from the thunderous air show.

Since then, however, impact specialists have been quietly working behind the scenes to try to determine how much punch this cosmic interloper packed. According to a preliminary analysis released October 20th by Elizabeth Silber and Peter Brown (University of Western Ontario), the sky really was falling that day. The blast registered as extremely low-frequency atmospheric waves at 11 of the infrasound stations maintained worldwide by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO).

Silber and Brown note that the high-altitude explosion was centered at 4½°S, 120°E, but it's been challenging to gauge the kinetic-energy punch it delivered. The most likely estimate is equivalent to some 40,000 tons of TNT, about three times the energy of the nuclear bomb dropped on Hiroshima in 1945. If that value is correct, this was the most powerful meteoric blast since 1994, when a "mini-Tunguska," nearly as bright as the Sun, exploded over the tiny Pacific island of Kosrae. Brown and others estimate that events like this should occur about once per decade.

Something this obvious would not have escaped the notice of various defense satellites, because these cosmic intrusions look much like nuclear weapons exploding high in the atmosphere. (Here's a list of previous airbursts picked up by the U.S. military's "orbital assets" and made public afterward.)

It'd take a chunk of asteroid about 20 to 30 feet (5 to 10 meters) across to deliver a 40-kiloton wallop. But no one has yet claimed to have found any meteorites, according to Thomas Djamaluddin, a government scientist who's been monitoring the situation. Odds are that any surviving fragments fell into offshore waters.

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And Then There Were 400

At an international conference on extrasolar planets being held in Portugal, a group of European astronomers unveiled on Monday a list of 30 new exoplanets and two brown dwarfs orbiting more-or-less Sun-like stars. This brings the known exoplanet catalog to a total of 403 worlds.

The new additions were all found by the radial-velocity wobbles that they induce in their host stars, as detected by the HARPS planet-hunting spectrograph on the European Southern Observatory's 3.6-meter telescope at La Silla, Chile.

The European astronomers say that HARPS can measure a star's radial-velocity patterns with an accuracy as fine as 1 meter per second: slow walking speed. This would put HARPS at the head of the accuracy list in the hotly competitive world of exoplanet hunting. Such precision is essential for detecting relatively low-mass planets — not just "super-Jupiters," "Jupiters," and "Saturns" of other stars, but the "Neptunes" and "super-Earths" that are at the limits of current technology.

According to a press release from the European Southern Observatory about the new finds, "HARPS has facilitated the discovery of 24 of the 28 planets known with masses below 20 Earth masses. As with the previously detected super-Earths, most of the new low-mass candidates reside in multi-planet systems, with up to five planets per system."

In particular, says Stephane Udry (Geneva Observatory), the HARPS project suggests that at least 40% of solar-type stars have these smaller planets. "These low-mass planets are everywhere basically."

Limits of Technology

To extract the very slight, periodic radial-velocity changes in a star that signify an orbiting planet, astronomers have to subtract out the much larger continual changes caused by the telescope's own motion on the rotating Earth, Earth's curving motion around the Sun (at about 30,000 meters per second), and even the gravitational influences of the Moon and our solar system's other planets on Earth. All these effects are precisely known. But there may be trickier confounding factors on the distant star itself, such as surface turbulence or starspots that mimic a change in the star's radial-velocity signature as the star's rotation carries the spots around.

Nevertheless, astronomers don't think they've yet hit the fundamental limits of the radial-velocity method for finding planets. For particularly good "quiet" stars, it may be possible to reach accuracies measured in centimeters per second, and thus planets as low-mass as Earth. Such hunts could become possible as early as next year.

Selections from the Harvest

What are the new planets and their stars like? The stars, according to a preliminary list, range from spectral type F6 to M: from somewhat larger and hotter, to much cooler and dimmer than the Sun. The orbiting objects have minimum masses (not necessarily the true mass, but probably not too far off) ranging from 53 down to 0.017 Jupiters. That's from 17,000 down to 5 Earth masses. Their announced orbital periods range from 4 days to 13 years (though HARPS has only been working for five years).

Of special note, three of the planets orbit stars with a lower proportion of heavy elements than are in the Sun — with a "metallicity" of only 1/3 to 1/2 the Sun's. It's well known that the greater a star's metallicity, the more likely it is to have planets detectable. A subgroup of the European astronomers targeted low-metallicity stars in particular, and their finds confirm that planets do sometimes form in a moderately heavy-element-poor environment. Clearly more than this one factor is at work in determining whether a star will have planets, even big ones.

Several systems also show radial-velocity hints of additional objects in longer-period orbits that will require years of further tracking to confirm.

Here's the ESO press release.

Here's the Extrasolar Planets Catalog reordered so the new discoveries form the top of the list.

P.S.: Don't expect the total to stay near 400 for too long. The Kepler mission should announce a whole flotilla of transiting exoplanets in the coming months.

December 21, 2012

In case you haven't heard, there's a piece of hysteria going around (pumped up by movie marketing) that the world will end on December 21, 2012, supposedly based on astronomy and an ancient Mayan prediction.

Did the Mayans really think this? Is the astronomy for real ?  Do we actually have anything to worry about ?  The answers, not surprisingly, are "no," "no," and "of course not."

To make a long story short, December 21, 2012, really is a big flip-the-page date in the ancient Mayans' calendar. But there's no evidence that they believed the world would end then, and a fair amount of evidence to the contrary. Not that it would matter if they did. As for the planetary and galactic lineups that latter-day doom-mongers have tried to associate with that date, they're flat-out wrong.

But you probably have friends and family who are getting nervous that America will crack apart into cookie crumbs, tsunamis will sweep over the Himalayas, Earth's poles will flip, and a secret invisible planet will smack us down like a bowling pin. And they will be turning to you, the astronomy person, to ask about it.

We have the stuff you need to tell them. Noted archaeoastronomer E. C. Krupp explains all the details, and the history of this mania, in the cover story of the November 2009 issue of Sky & Telescope, now available at a newsstand near you. You probably won't find it in your supermarket, but it should be on the magazine rack in any good bookstore. And if it's sold out, you can always subscribe!

Incidentally, in that same issue, S&T editor-in-chief Robert Naeye describes some cosmic catastrophes that actually could happen — and explains why they're not likely to strike in the next millennium or two. Humanity has more pressing things to worry about.

P.S. A tidbit from Krupp's article: Boston University has a Center for Millennial Studies, and its director, historian Richard Landes, points out that throughout history, failed end-of-the-world movements have numbered in the "hundreds of thousands at least." There's never a shortage of people eager for everything to go kaput. Or at least to spin hoaxes about it.

For some interesting truth about December 21, 2012, check out my 2012 Learn The Truth Blog.

NASA Spacecraft Impacts Lunar Crater in Search for Water Ice

NASA's Lunar Crater Observation and Sensing Satellite, or LCROSS, created twin impacts on the moon's surface early Friday in a search for water ice. Scientists will analyze data from the spacecraft's instruments to assess whether water ice is present.

The satellite traveled 5.6 million miles during an historic 113-day mission that ended in the Cabeus crater, a permanently shadowed region near the moon's south pole. The spacecraft was launched June 18 as a companion mission to the Lunar Reconnaissance Orbiter from NASA's Kennedy Space Center in Florida.

"The LCROSS science instruments worked exceedingly well and returned a wealth of data that will greatly improve our understanding of our closest celestial neighbor," said Anthony Colaprete, LCROSS principal investigator and project scientist at NASA's Ames Research Center in Moffett Field, Calif. "The team is excited to dive into data."

In preparation for impact, LCROSS and its spent Centaur upper stage rocket separated about 54,000 miles above the surface of the moon on Thursday at approximately 6:50 p.m. PDT.

Moving at a speed of more than 1.5 miles per second, the Centaur hit the lunar surface shortly after 4:31 a.m. Oct. 9, creating an impact that instruments aboard LCROSS observed for approximately four minutes. LCROSS then impacted the surface at approximately 4:36 a.m.

"This is a great day for science and exploration," said Doug Cooke, associate administrator for the Exploration Systems Mission Directorate at NASA Headquarters in Washington. "The LCROSS data should prove to be an impressive addition to the tremendous leaps in knowledge about the moon that have been achieved in recent weeks. I want to congratulate the LCROSS team for their tremendous achievement in development of this low cost spacecraft and for their perseverance through a number of difficult technical and operational challenges."‪

Other observatories reported capturing both impacts. The data will be shared with the LCROSS science team for analysis. The LCROSS team expects it to take several weeks of analysis before it can make a definitive assessment of the presence or absence of water ice.

"I am very proud of the success of this LCROSS mission team," said Daniel Andrews, LCROSS project manager at Ames. "Whenever this team would hit a roadblock, it conceived a clever work-around allowing us to push forward with a successful mission."

The images and video collected by the amateur astronomer community and the public also will be used to enhance our knowledge about the moon.

"One of the early goals of the mission was to get as many people to look at the LCROSS impacts in as many ways possible, and we succeeded," said Jennifer Heldmann, Ames' coordinator of the LCROSS observation campaign. "The amount of corroborated information that can be pulled out of this one event is fascinating."

"It has been an incredible journey since LCROSS was selected in April 2006," said Andrews. "The LCROSS Project faced a very ambitious schedule and an uncommonly small budget for a mission of this size. LCROSS could be a model for how small robotic missions are executed. This is truly big science on a small budget."

Big Pix from Herschel

Europe's new Herschel Space Observatory is all checked out and in excellent working order, as the European Space Agency demonstrated this morning with its release of a gorgeous nebula picture.

With an aperture of 3.5 meters, Herschel is the largest space telescope yet flown (Hubble is 2.4 meters). Perhaps more importantly, Herschel works in the far-infrared part of the spectrum: a poorly explored realm between the familiar, shorter-wavelength "warm infrared" and the millimeter-wave and microwave radio bands. Its cameras can work at six far-infrared and submillimeter colors, with wavelengths around 70, 110, 160, 250, 350, and 500 microns. Such wavelengths are the ones most strongly emitted by objects that are extremely cold — not far above absolute zero.

What we see in the picture here (a mosaic of many small frames) is mostly very cold interstellar dust. It's not reflecting starlight but glowing with the characteristic, very weak thermal emission for such temperatures. Blue and green here represent two of Herschel's shorter wavelengths, highlighting less-cold dust. Red indicates longer wavelengths and colder material. Notice the bright points of star formation happening inside a few of the densest, coldest filaments, almost like pearls on a string.

This is just a taste. In the coming months and years there'll be lots more.

Northern Autumn marks the beginning of Aurora Season

The coming of Northern Autumn marks the beginning of aurora season. Sky watchers around the arctic circle should be alert for Northern Lights in Sept. and Oct.

Click Photos To Enlarge.

Lake Myvatn, Iceland Sept. 17, 2009

North Pole, Alaska Sept. 15, 2009

Yellowknife, Northwest Territories, Sept. 11, 2009

Kola peninsula, Russia, Mt. Khibiny Sept. 14, 2009

Little Crater Targeted for Big Splash

Planetary scientists won't get a re-do when NASA's LCROSS spacecraft and its Centaur carrier rocket slam into the Moon on October 9th. They've got one chance only to strike a permanently shadowed and presumably water-rich crater floor near the lunar south pole. So for weeks they've anguished over where ground zero will be. As noted by project scientist Anthony Colaprete notes, the selection process spawned a "vigorous debate" among researchers.

With just under a month to go, they've announced their choice: an unnamed 11-mile-wide (17-km) craterlet astride the rim of Cabeus A. It's got desirable target characteristics — a flat boulder-free floor, for instance, and a location favorable for telescopes back on Earth to watch the resulting plume of debris that should balloon above the crash site.

Mostly, they've picked what they've dubbed Cabeus A1 because it's what one official calls a "sweet spot," a spot where detectors aboard the Lunar Reconnaissance Orbiter (which accompanied LCROSS to the Moon) hint that the always-dark dust might contain roughly 1½% water ice.

Neither Cabeus A1 nor nearby Cabeus A were on the list of candidate target craters announced back in July, and frankly the project's pick is surprisingly far from the lunar south pole (latitude –81½°). This is good news for both professional and amateur astronomers hoping to catch a glimpse of the impacts.

Officials aren't saying how much they've determined about the crater, but LRO carries two instruments that potentially could have moved the bull's eye squarely onto Cabeus A1.

One is the Lyman-Alpha Mapping Project (LAMP)can literally see in the dark, using reflected ultraviolet radiation from starlight to image the permanently shadowed lunar terrain.

Meanwhile, the Lunar Exploration Neutron Detector (LEND) can detect the presence of hydrogen, which almost has to be in water ice, down to 100 parts per million. LEND was built by the Moscow's Space Research Institute, and as best I know this is the first and only time a Russian-built instrument has flown on one of NASA's spacecraft (not counting the International Space Station).

At today's press briefing, Daniel Andrews (LCROSS project manager at NASA-Ames Research Center) assured everyone that the spacecraft was ready for its big finale. The team had a scare last month when an errant sensor caused wild thruster firings that squandered about half of the spacecraft's maneuvering fuel. Andrews also announced that the LCROSS mission has been dedicated to the memory of the late Walter Cronkite, the longtime television news reporter and anchor who followed NASA's missions from the Mercury program in the early 1960s to Space Shuttle.

So now it's time to start getting ready to observe lunar fireworks on October 9th. The timing, 4:30 a.m. Pacific Daylight Time, favors the big guns atop Mauna Kea in Hawaii in throughout western North America.

Sadly, I'll be in Puerto Rico that week — attending, ironically, a meeting of planetary scientists. Will someone please let us all know how things turn out?

Refurbished Hubble Shows Its Stuff

After the huge success of the Hubble Space Telescope repair mission last May, and the nailbiting suspense as astronauts wrestled to swap out much of the telescope's gear, the world was eager for new pictures and science. But it has taken several months to test and calibrate the new instruments and bring everything up to speed.

The first big public release was an unscheduled image of a surprise event: the appearance in mid-July of a black impact mark in Jupiter's south polar region. Now Hubble's handlers are throwing their previously scheduled coming-out party.

From a NASA press release:

"Topping the list of new views are colorful, multi-wavelength pictures of far-flung galaxies, a densely packed star cluster, an eerie "pillar of creation," and a "butterfly" nebula. Hubble's suite of new instruments allows it to study the universe across a wide swath of the light spectrum, from ultraviolet all the way to near-infrared. In addition, scientists released spectroscopic observations that slice across billions of light-years to probe the cosmic-web structure of the universe and map the distribution of elements that are fundamental to life as we know it.

"This marks a new beginning for Hubble," said Ed Weiler, associate administrator for NASA's Science Mission Directorate at NASA Headquarters in Washington. "The telescope was given an extreme makeover and now is significantly more powerful than ever, well-equipped to last into the next decade."

Leading the morning press conference was Sen. Barbara Mikulski (D-MD), who can take credit for pushing the repair mission to happen despite NASA's initial reluctance. “I fought for the Hubble repair mission because Hubble is the people’s telescope,” said Mikulski, chair of the subcommittee that funds NASA. “I also fought for Hubble because it constantly rewrites the science textbooks. It has more discoveries than any other science mission. Hubble is our greatest example of our astronauts working together with scientists to show American leadership and ingenuity."

Jupiter dominates the Evening Sky & Dazzling Venus the Morning Sky

Jupiter continues to dominate the evening sky. Based on the comments left on this blog, many people have been noticing Jupiter in the southeast sky during the evening. At magnitude -2.8, Jupiter is ~13 times brighter than the brightest stars in the sky this month. Of all the planets, only Venus, and on very rare occasions Mars, are brighter.



Venus is the brightest “star” in the sky a hour or so before dawn. It was at its highest in the morning sky last month but now begins its slow crawl lower though it will remain an easy object for early risers  over the next 2-3 months. For binocular and telescope users, Venus will appear nearly full and is much smaller than it appeared this spring (now 12″ across versus 50″ last spring).

Jupiter Rules September Night Skies

Jupiter is always an easy planet to pick out. This month Jupiter is brighter than usual as it reaches opposition. Saturn is rising on Jupiter?s heels and is a show all of its own. And for the early risers, there is a lovely show of Mercury, Venus, Mars and the bright star Regulus in Leo.

Other than the Moon, Jupiter outshines anything else in the sky (and there are some pretty bright stars out there to compete with, but Jupiter wins hands down!) Jupiter is so bright because it is at opposition. This means that it is opposite the Sun in a line drawn through Jupiter, the Earth and the Sun (with the Earth in the middle.) This is a position similar to the full Moon. And like the full Moon, Jupiter rises at sunset and is up all night, making it a great viewing spectacle.

Jupiter rises nearly due east just after sunset. The king of the planets is so bright because it is at opposition and also because it is so big. If you lumped together all of the planets and moons in the solar system, Jupiter would be 70 percent of the total mass! Jupiter?s diameter is 11 times that of the Earth?s.

With binoculars or a small telescope you can easily see the four big moons of Jupiter. They are known as the Gallilean moons because they were discovered by the astronomer Galileo, the first person to turn a telescope to the night sky. The individual moons are Io, Europa, Ganymede and Callisto. It is interesting to watch the moon?s cross Jupiter?s diameter and disappear behind the giant planet and pop out on the other side. Jupiter is residing in the constellation Aquarius the water bearer.

For all Jupiter's glory and brightness, it is Saturn that most often fascinates people. Though Saturn is not the only planet known to have rings, indeed rings have become a common occurrence in the solar system, but Saturn was the first, and remains the best! Saturn rises about one and a half hours after Jupiter. Saturn is also approaching an opposition on October 6. Binoculars will show Saturn?s rings and a good pair or a small telescope will show the shadow of the planet on the rings. An interesting fact about Saturn is though it is nearly 9.5 times the diameter of the Earth, this giant planet has an average density less than water,. If you had an ocean large enough, Saturn would float!

As if to avoid being lost in the glory of Jupiter and Saturn, the smaller planets are hanging out in the morning sky but you?ll have to catch them during the first half of the month. It?s quite a treat if you?re an early riser. Venus is the brightest of the three planets and the easiest to spot. Mercury is about as bright as it ever gets, and it only a few degrees away from brilliant Venus. Mars is about 5 degrees above those two. About three degrees below Venus is the bright star Regulus in Leo.

The waning crescent Moon does a dance among the morning stars and planets. On September 17 the moon slides past Mars and on the Sept 18 the Moon slides past Regulus. On Sept 19, the moon is 3 degrees away from Venus. Happy stargazing !

SETI@home

What is SETI@home ?

SETI@home is a scientific experiment that uses Internet-connected
computers in the Search for Extraterrestrial Intelligence (SETI). You
can participate by running a free program that downloads and analyzes
radio telescope data.

The Science of SETI@home

SETI (Search for Extraterrestrial Intelligence) is a scientific
area whose goal is to detect intelligent life outside Earth. One
approach, known as radio SETI, uses radio telescopes to listen
for narrow-bandwidth radio signals from space. Such signals are not
known to occur naturally, so a detection would provide evidence of
extraterrestrial technology.

Radio telescope signals consist primarily of noise (from celestial
sources and the receiver's electronics) and man-made signals such as TV
stations, radar, and satellites. Modern radio SETI projects analyze the
data digitally. More computing power enables searches to cover greater
frequency ranges with more sensitivity. Radio SETI, therefore, has an
insatiable appetite for computing power.

Previous radio SETI projects have used special-purpose
supercomputers, located at the telescope, to do the bulk of the data
analysis. In 1995, David Gedye proposed doing radio SETI using a
virtual supercomputer composed of large numbers of Internet-connected
computers, and he organized the SETI@home project to explore this idea.
SETI@home was originally launched in May 1999.

If you are interested in participating Click Here.

Goal of Returning to Moon Could Be Slipping Further Away

NASA's goal of putting astronauts back on the moon by 2020 is all but impossible to achieve, a presidential panel was told Wednesday.

An independent analysis concluded there is little hope NASA could replicate any time soon what Apollo 11 accomplished 40 years ago. And sources said an undisclosed part of the study showed it may take until 2028 -- nearly 60 years after America's first moon landing -- to get back.

"We can't see [the gap] closing," Gary Pulliam, an analyst with Aerospace Corp., told a near-silent audience in Huntsville, Ala., where engineers at the Marshall Space Flight Center have spent the past four years designing new rockets for NASA's Constellation program.

One NASA analyst, who spoke on the condition of anonymity because he is not authorized to speak on behalf of NASA or the review panel, said astronauts might be able to return to the moon by 2028, although another source said 2035 was more likely.

The grim assessment, delivered on the second day of hearings this week on NASA's human spaceflight program, is the latest blow to the Constellation program, a 4-year-old effort to design new rockets and a crew capsule to take astronauts to the moon and eventually Mars.

On Tuesday, former astronaut Sally Ride told the full panel, led by former Lockheed Martin CEO Norm Augustine, that she did not expect that Constellation's Ares I rocket and Orion capsule could complete a first mission into low-Earth orbit before 2017 -- two years after its current target date.

A second estimate, calculated by Pulliam on Wednesday, was even more pessimistic. Because of ongoing technical troubles and insufficient funding, he said, Constellation's first mission could be delayed to 2019. "It should not surprise anyone that problems exist," he said.

The findings of the panel build on months of increasingly critical reports on Constellation, which ex-NASA Administrator Michael Griffin chose in 2005 to fulfill then- President George W. Bush's vision of returning astronauts to the moon by 2020 to prepare for an eventual Mars mission.

There are already signs that the panel is preparing options that would dramatically change NASA's current plans to build two big rockets: the Ares I to take crew to the space station and low-Earth orbit, and the Ares V heavy-cargo lifter that would take up a moon lander and propellant to take the Orion capsule and astronauts to the moon for extended visits.

One of the panel's subgroups, led by retired Air Force Gen. Lester Lyles, recommended that the group consider allowing America's international partners to participate in the development of NASA's human spaceflight plans.

Another far-reaching recommendation came from a subgroup headed by former space-shuttle engineer and Boeing executive Bohdan Bejmuk. It called for NASA to give up flying to low-Earth orbit, including to the international space station.

"Let's turn it over to the newcomers," he said, referring to companies such as SpaceX of California and Orbital Sciences Corp. of Virginia, which have NASA contracts to develop rockets and unmanned capsules that can reach the space station.

Doubts about the direction of the manned-space program spurred President Barack Obama to name the committee, which has until late August to present financial and policy options as to how NASA should proceed.

To stay on the current course, the White House would have to pump billions of dollars more into Constellation -- or completely rethink how, and why, NASA sends astronauts into space. In the meantime, with the space shuttle slated to retire by 2010 or 2011, the U.S. will confront a years-long gap when it has no capacity to send humans into space and must pay the Russians for trips to the space station.

An option to narrow that gap, suggested by Ride on Tuesday, is to extend the shuttle program past 2011. When the panel meets in Cocoa Beach today, U.S. Sen. Bill Nelson is expected to advocate this idea, according to an advance transcript.

"I wish you would consider extending the shuttle to a point in time that would lessen the gap so that we can have Americans riding American vehicles to get to our station, and then on to the moon, and then on to Mars," said Nelson, D-Fla.

A shuttle extension would prevent devastating job losses at Kennedy Space Center, which prepares NASA spacecraft for launch. One upcoming report estimates 7,000 job losses at KSC after the shuttle's retirement.

Jeff Hanley, manager of the Constellation program, appeared resigned to the bleak reports that the rockets would be years late. He said that predicting when a new rocket would launch was akin to "hurricane forecasting."

During the daylong hearing, however, several of Hanley's midlevel managers defended the beleaguered program. They offered their draft solutions to ongoing technical problems, including the Ares I rocket's tendency to shake violently on liftoff and potentially drift into its launch tower.

"We believe [Constellation rockets] are the fastest, most proven [vehicles] to close the human spaceflight gap," said Steve Cook, manager of the Ares program.

Vigorous defense from ex-chief But the most vigorous defense came from Griffin, who left the agency when Obama took office and is now a professor at the University of Alabama at Huntsville.

In a letter to the panel, he said NASA and the Constellation program were "targets of broad but shallow criticism." And he said Constellation was the "most expeditiously attainable, broadly capable, lowest risk, and lowest life cycle cost design" under review. "Do not allow the parochial voices of the small-minded, the self-interested, and the uninformed to prevail. Choose the future," he concluded -- a parting shot aimed at commercial carriers and military rocket companies competing to bury the Constellation program.

Among the options being considered by the committee are designs that would put the Orion capsule atop military rockets and another system that would use the shuttle's engines, giant fuel tank and solid-rocket boosters.

Hubble Readies for Full Operation

It's hard to believe that 2½ months have passed since the crew of Atlantis wrapped up their extensive repairs and refurbishment of the Hubble Space Telescope.

So when will Hubble get back to work? In a sense, it already has. When Australian amateur Anthony Wesley spotted the "powder burn" in Jupiter's atmosphere from an apparent impact on July 19th, Hubble managers hustled to turn its 94-inch (2.4-meter) eye on the new feature so that the just-installed Wide Field Camera 3 could take some snapshots.

But HST isn't yet fully ready to return to duty. Engineers are still stepping their way through the long "to do" list known as the Servicing Mission Observation Verification (SMOV), and a few glitches have come up.

For one thing, the Science Instrument Command and Data Handler — think of it as the router for Hubble's science data — acted up not long after the servicing mission concluded. (Remember: NASA delayed STS 125, the fifth and final Space Shuttle servicing mission, by some six months so that this last-minute replacement could be recalled from storage, checked out, added to the payload, and installed by spacewalking astronauts.) Fortunately, this anomaly resolved itself after engineers shut down the SI-C&DH and powered it back up.

A few days later two Hubble instruments, the patched-up Advanced Camera for Surveys (ACS) and the brand-new Cosmic Origins Spectrograph, hiccupped. Both have since resumed operation.

Then on July 6th the Space Telescope Imaging Spectrograph shut itself down and didn't return to operation on July 28th. STIS still has a problem with its near-ultraviolet channel: a mysterious fluorescence on its optical window is creating detector noise (dark current) that degrades the instrument's performance.

All this might seem ominous for Hubble's prospects for long-term success. But according to Preston Burch, program manager for HST at NASA’s Goddard Space Flight Center, the team is just being cautious. "We want to be careful that we don't break something," he says. In fact, Burch seems quite upbeat because the post-repair checkout is actually quite far along.

Even NICMOS, the Near Infrared Camera and Multi-Object Spectrometer, will soon be back in operation after a year-long hiatus. On August 1st the instrument's finicky cryogenic cooling system finally responded to coaxing from ground controllers after many months of failed restart attempts. NICMOS must operate at very cold temperatures — at or below –321°F (77 K) — to ensure that its sensitive detectors are recording feeble infrared light from space instead of heat from its own electronics.

"If all goes well," comments Glenn Schneider, instrument scientist at the University of Arizona, "it will take about a month for NICMOS to cool down so that we can begin the re-enabling and recalibrating the instrument."

 "We're over the hump," Burch told me this afternoon, "and starting to do routine science operations." Within two weeks, he estimates, HST will be observing a third of the time, and that should rise to nearly full-time by early September.

Astronomers have already been zeroing in on deep-space targets with ACS and WFC3 that will showcase the orbiting observatory's enhanced capabilities. Circle September 9th on your calendars — that's when NASA managers plan to release some eye-popping new views from the rehabbed, restored, refurbished, and remarkable Hubble Space Telescope.

The Moon Trees

Apollo 14 launched in the late afternoon of January 31, 1971 on what was to be our third trip to the lunar surface. Five days later Alan Shepard and Edgar Mitchell walked on the Moon while Stuart Roosa, a former U.S. Forest Service smoke jumper, orbited above in the command module. Packed in small containers in Roosa's personal kit were hundreds of tree seeds, part of a joint NASA/USFS project. Upon return to Earth, the seeds were germinated by the Forest Service. Known as the "Moon Trees", the resulting seedlings were planted throughout the United States (often as part of the nation's bicentennial in 1976) and the world. They stand as a tribute to astronaut Roosa and the Apollo program.

The project began after Roosa was chosen for the Apollo 14 mission. Ed Cliff, Chief of the Forest Service, knew of Stuart Roosa from his days as a smoke jumper and contacted him about bringing seeds into space. Stan Krugman of the Forest Service was put in charge of the project and selected the seeds for the experiment. Seeds were chosen from five different types of trees: Loblolly Pine, Sycamore, Sweetgum, Redwood, and Douglas Fir. The seeds were classified and sorted, and control seeds were kept on Earth for later comparison. Roosa carried about 400 - 500 seeds in his personal kit which stayed with him as he orbited the Moon in the command module "Kitty Hawk" in February, 1971. Unfortunately, the seed cannisters burst open during the decontamination procedures after their return to Earth, and the seeds got mixed together and were presumed to be no longer viable.

Stan Krugman had the seeds sent to the southern Forest Service station in Gulfport, Mississippi and to the western station in Placerville, California to attempt germination. Surprisingly, nearly all the seeds germinated successfully, and the Forest Service had some 420 to 450 seedlings after a few years (some from cuttings). Some of these were planted with their earth-bound counterparts as controls, (as would be expected, after over twenty years there is no discernable difference) but most were given away in 1975 and 1976 to many state forestry organizations to be planted as part of the nation's bicentennial celebration. These trees were southern and western species, so not all states received trees. A Loblolly Pine was planted at the White House, and trees were planted in Brazil, Switzerland, and presented to the Emperor of Japan, among others. Trees have also been planted in Washington Square in Philadelphia, at Valley Forge, in the International Forest of Friendship, and at various universities and NASA centers. The Moon Tree shown at top left is a sycamore growing at Koch Girl Scout Camp in Cannelton, Indiana and at top right at Goddard Space Flight Center in Greenbelt, Maryland. A list of Moon Tree locations can be found at the bottom of the page.

Stuart Roosa was born on 16 August 1933, in Durango, Colorado. He worked for the Forest Service in the early 1950's as a smoke jumper fighting fires and later joined the Air Force and became a test pilot. He was one of 19 people selected for the astronaut class of 1966 and was part of the astronaut support crew for Apollo 9. Following Apollo 14, Roosa was backup command module pilot for Apollo's 16 and 17. He then worked on the Space Shuttle program until his retirement as a Colonel in the Air Force in 1976, the time when many of his trees were being planted.

Sadly, Stuart Roosa passed away in December, 1994. The Moon Trees continue to flourish, a living monument to our first visits to the Moon and a fitting memorial to Stuart Roosa. Believed locations of some Moon Trees are listed below, but no list was ever kept nor any systematic tracking made of the disposition of all the trees. If you know of a Moon Tree, please send a message to dave.williams@nasa.gov.

Perseid Meteors by Moonlight - Peaks Tonight

The little bits of interplanetary grit making up the Perseid meteoroid stream orbit the Sun with a period of about 130 years, like their object of origin, Comet 109P/Swift-Tuttle. The richest part of the stream is strung out near the comet itself, which last dipped through the inner solar system in 1992. So the shower's annual sky show has waned of late — gone are the great Perseid meteor displays of the early 1990s.

This year's Perseid peak is predicted to come around 18h Universal Time (2 p.m. Eastern Daylight Time) on August 12th. That's good timing for the Far East, but for North America it splits the difference between the nights of August 11-12 and 12-13. Flip a coin — or watch the evening weather forecast — to decide which night to watch for them. The shower is also active to a lesser degree for many days beforehand and several days afterward.

The waning Moon is nearly at last quarter those two nights. It rises an hour or two after dark and will brighten the sky somewhat during the best Perseid-activity hours, from 11 p.m. until dawn. Nevertheless, this is a pretty reliable shower, and some Perseids should be there for the catching.

Moreover, meteor specialists Esko Lyytinen and Mikhail Maslov suggest we may encounter a ribbon of very old debris (ejected by the comet in 1610) on August 12th near 9h UT, which could briefly up the count by a few to tens or meteors per hour for West Coast skywatchers. Both researchers also believe that Earth's proximity to the stream's core might produce an additional burst a few hours earlier, at around 5h UT.

You may also see occasional meteors from two lesser showers that are also active: the Delta Aquarids and Kappa Cygnids. These move noticeably slower than Perseids, and they travel in different directions as if originating from their respective constellations.

Meteor watching is great "eyeball astronomy." Find a spot with an open view of the sky, wrap up warmly in winter clothes or a sleeping bag, and use mosquito repellent where you're not wrapped. Lie back in a lounge chair and watch whatever part of your sky is darkest. Be patient. You may see a meteor zipping into the upper atmosphere every few minutes on average.

August night sky offers Summer Triangle and more

August is perhaps the best month to enjoy the night sky.

As soon as it is dark, look almost directly overhead to find the bright-blue star Vega, which is part of the constellation Lyra. Look a few degrees to the northeast and find the bright star Deneb, which is the tail of the constellation Cygnus, the swan. Then look a few degrees due south and you find Altair, the heart of Aquila, the eagle. These stars make up the asterism known as the Summer Triangle.

Away from city lights you can view this same area of the sky and see that the Milky Way runs right down the center. The dark patches in the middle of this mass of stars are caused by clouds of interstellar dust that block the light from the more distant stars.

Jupiter has now reached opposition, which means that it rises when the sun sets and is ideal for viewing. You have to wait for it to rise above the thick atmosphere. About 11 p.m. you will find it in the southeast. It is the brightest object in that portion of the sky; after viewing it for a few moments you will notice that it does not twinkle.

Again, away from city lights, using binoculars and a star map from the Internet, you can locate Neptune, following close behind Jupiter. You will also be able to view Jupiter's four primary moons, which Galileo first saw 400 years ago.