Discoveries
Shuttle Endeavour finally heads for the International Space Station
After one month and five false starts, NASA's space shuttle Endeavour and its seven-member crew headed for the International Space Station today in a near flawless launch.
On the way up, several pieces of foam broke loose from the external fuel tank. Some struck the orbiter's underside.
The foam loss and any damage to the shuttle's heat-shedding tiles will be the focus of attention for the next several days as engineers review photos, video clips, and radar data taken during the launch and ascent.
In addition, the shuttle and station crews will conduct a pair of scheduled on-orbit inspections, which occur before the orbiter docks with the space station.
Some of the debris came off fairly late in the ascent, according to Mike Moses, the shuttle's payload integration manger, and so would be relatively harmless. At a post-launch briefing he explained during that phase of the flight the shuttle and any loose foam would be traveling at the same speed. So foam coming in contact with the orbiter at that stage would do little or no damage.
The biggest concern centers around foam that breaks free while the atmosphere is still thick enough to dramatically slow the foam down, increasing the relative speed at which the rapidly rising shuttle collides with it.
"We saw some stuff. Some of it doesn't concern us. Some of it you really just can't speculate on right now," Mr. Moses said.
Mission managers said that their initial impression was that a few tiles had been struck and some of the tiles' surface finish removed. If that proves to be the case, the crew has a repair kit on board that would allow them to repair the tiles during a space walk. If the tiles are gouged, the repair kit contains a putty-like substance astronauts can use to fill the voids.
"We have the tools in front of us and the processes in front of us to go clear this vehicle for entry" at the end of the mission. Mr. Moses said.
Endeavour is carrying the last two pieces of hardware needed to complete Japan's $1-billion Kibo laboratory. It's also carrying six fresh batteries -- each the size of a coffee table -- that will store electricity from some of the station's solar panels.
And one of the shuttle's outbound crew members, Tom Kopra, will remain on the station as part of a regular station-crew rotation. Japanese astronaut Koichi Wakata, who has been aboard the station since the end of March, will return with the shuttle.
With all the delays, mission planners had to juggle the schedule a bit to accommodate the previously scheduled arrival of a Russian Progress resupply capsule.
The shuttle mission will last it's originally scheduled 16 days But its 12-day stay at the station will be cut short a day to make way for the Progress's arrival. Shuttle tasks that would have been undertaken during the orbiter's final day at the station will instead be performed the day after the shuttle leaves.
Venus Express, launched in November 2005 and orbiting Venus since April 2006, is providing insights into the planet's geologic past. (ESA)
Fresh from Venus, hints of an ancient ocean and a restless crust
Recent maps of the surface of Venus suggest that early in the planet's history, it may have had a ocean, as well as a crust that underwent fragmentation and replenishment, just as Earth's does.
That's the word from a team of scientists led by Nils Müller, a researcher at the University of Münster and at the DLR Institute in Berlin. The group built its map from data gathered by the European Space Agency's Venus Express orbiter.
The map Müller & Co. put together provides some hints as to the chemical composition of the surface on Venus, particularly the highlands, where no lander has ever touched down to analyze the surface.
Rocks on two plateaus gave off infrared signatures similar to those given off by granite on Earth. Granite is reprocessed rock, forming under the intense heat and pressure that builds up when one crustal plate grinds beneath another.
The new map doesn't constitute proof, Müller cautions. "All we can really say at the moment is that the plateau rocks look different from elsewhere."
But, he adds, "If there is granite on Venus, there must have been an ocean and plate tectonics in the past."
The team published its results last December in the Journal of Geophysical Research. The European Space Agency -- in a bit of PR tectonics -- subducted the results, which resurfaced today.
The idea that Venus once had an ocean has been kicking around for years.
Generally, researchers have concluded that Venus is too close to the sun, and so is too hot, for water vapor in the atmosphere to condense and pool on the surface.
But other planetary scientists have long suggested that the planet could have hosted an ocean for perhaps its first 600 million years. Two years ago, a pair of US researchers noted that recent modeling studies of early Venus suggest that it could have hosted an ocean for more than a billion years.
Oceans on Venus?
The question of oceans on Earth's torrid twin (temperatures at its surface would melt lead) are intriguing for a couple of reasons.
The most obvious one: If Venus had an ocean for a billion years or longer and was tectonically active, the planet could have been quite hospitable to simple forms of life.
The other reason is a bit more subtle.
Dr. Müller and his colleagues point out that as humans hunt for Earth-like planets around other stars, they naturally hope to find such objects in a star's habitable zone -- a range of distances where temperatures would allow liquid water to accumulate on the surface and remain there.
If Venus is any indication, however, a position within a star's habitable zone -- in Venus's case, at the inner edge -- is no guarantee of long-term habitability.
Understanding Venus's early geophysical history would help researchers understand why the second rock from the sun drew the short straw on habitability -- thereby serving as a cautionary tale for scientists trying to interpret what they see around other stars.
In describing the recent modeling work on early oceans, the US duo -- David Grinspoon at the Denver Museum of Nature & Science and Mark Bullock at the Southwest Research Institute in Boulder, Colo. -- suggested lines of evidence that would bolster their case.
One of those lines: Finding granite-type rocks in the Venusian highlands.
Cosmic dehydration
Assuming Venus had an ocean, where did all that water go? Blown away by the solar wind, if earlier results from Venus Express are any indication.
Venus has no magnetic field to shield the planet from the effects of charged particles streaming from the sun. Collectively, these are known as the solar wind.
Last December, another Venus Express team reported that it had detected the solar wind blasting hydrogen gas away from the day side of the planet.
Earlier, the orbiter has detected hydrogen and oxygen streaming away from the planet on the night side -- a clear indication that water in Venus' atmosphere is being split into its hydrogen and oxygen atoms and carried into interplanetary space.
This was the first look at the daylight side of the process.
Turkey vultures ride the thermals in advance of a thunderstorm that forced the cancellation of July 13's scheduled launch of the space shuttle Endeavour and its crew to the International Space Station. (AFP/Stan Honda)
Bad weather grounds space shuttle for third time in four days
About the only things leaving the ground at the Kennedy Space Center today were the turkey vultures. Bad weather once again left a fully tanked space shuttle and a crew more than primed for space with another frustrated launch attempt.
The message for the seven-member crew aboard the shuttle Endeavour: "It wasn't our weather today."
That was the word from Mike Moses, who heads the mission management team, after the mission was scrubbed.
"When the time is right, we'll be ready," replied mission commander Mark Polansky from the crew module.
Today's launch cancellation was the mission's fifth in a month. The first two scrubs were triggered by a pesky hydrogen leak involving a fixture on the side of the shuttle's external fuel tank.
If there was any good news coming out of the latest delays, it was that the repairs to the tank are doing their job. On the hardware side of things, "we've been really clean," Mr. Moses said of the shuttle systems' performance.
Mission managers are now shooting for a launch on Wednesday at 6:03 P.M. EDT.
Planners could have tried again tomorrow. But the weather forecast for launch time on Tuesday looked as iffy as the weather turned out to be today. Forecasters predict a 60 percent chance that the weather will violate launch requirements tomorrow; on Wednesday, that falls to a 40 percent chance.
Rather than put the shuttle and supports crews through what likely would be another false start, NASA managers opted to try for a Wednesday launch.
The delay also buys time to replace Tyvek covers that protect the shuttle's nose thrusters from catching rain while on the pad. The shuttle sheds the covers in the early stages of lift-off.
One cover had come loose, potentially allowing rain to get into the thruster nozzle. The presence of water, especially if it remains in the nozzle and freezes during the shuttle's ascent, could lead to false readings from thruster sensors, leaving the shuttle's computers with the wrong information about whether the thruster would work when it comes time to use them.
The space shuttle Endeavour and its crew are scheduled to spend 12 days of a 16-day mission docked to the International Space Stationto install the final pieces of Japan's laboratory module Kibo as well as perform a variety of maintenance tasks.
Astronauts are scheduled to perform five spacewalks to get everything done -- if the shuttle can launch Wednesday.
If the mission gets put off until Thursday, another iffy weather day, mission managers will have to knock one spacewalk off the agenda in order to have enough time to complete all of the major jobs astronauts need to tackle.
And if they can't launch Thursday, the next opportunity comes on July 26.
The face that launched a thousand trips -- to the food bowl. Researcher say the have uncovered a technique cats use to train humans to reach for the Tender Vittles. (Newscom)
Cats mix a cry and a purr to score a meal
House-cat behavior doesn't exactly draw the big research bucks. Sometimes it takes an observant scientist watching his or her "I've got your number" pet to ask the question: What's that feline's secret for pushing my buttons? In this case, the "feed me" button.
Enter Karen McComb, a behavioral ecologist at the University of Sussex in Britain. She and colleagues in Britain and the US have found that when cats are angling for a meal, they tend to blend purring and crying in a way that prompts us humans to grab the cat-food can, can opener and bowl to silence the sound.
This blend, which she and her colleagues dub "solicitation purring," is easier on the human ear than outright meowing, "which is likely to get cats ejected from the bedroom," Dr. McComb explains.
You can read a summary of the formal paper at Current Biology's site. You can read a plain-English version here.
How did McComb and her colleagues zero in on this particular question?
Well, she's been studying animal communication for years. And, she explains, she gets that kind of wake-up call from her cat. Similar tales emerged as she swapped pet stories with other cat owners.
So she and her team found some cat-owning volunteers, taught them to use sound recorders, then had them record their pets' purrs.
The team gathered up 50 volunteers and subjected them to each type of purr --normal and "solicitation." The team replayed both types at the same volume. The volunteers "consistently selected the solicitation purr as the more urgent," the scientists report. It didn't matter whether the volunteers were cat owners or not.
The team then built a spectrum of each type of purr by identifying the range of pitches, or frequencies, the purrs contained and how loud each one was compared with its neighbors. In other words, how loud was the "do," compared with the "re" and "mi?"
How low can you go?
They found that normal purring, which cats generate by activating muscles that make up their vocal cords, has a strong low-frequency component at around 27 cycles per second, or 27 Hertz (Hz). That's close to the bottom of the range of human hearing.
Mixed in, however, was another pitch, which averaged around 380 Hz -- within the range of the cry of a healthy human baby. It was formed by the cats moving air through their vocal cords, rather than by muscle activation alone. But this component was pretty weak.
During the solicitation purr, however, this higher-pitched component became far more pronounced.
To be sure, all cats do not purr equally. This "feed me" tool seems to crop up most frequently with cats owned by singles, rather than those who live in homes with lots of people. Too many folks for the cat to effectively train, perhaps.
While the "feed me" purr certainly lacks the urgency of a crying baby, the team concludes that it contains just enough of the humanly familiar to make the well-trained (by the cat) cat owner take notice.
Update on July 16, 2009:
To find out what the solicitation purrs sound like and how they compare with standard purrs, you can find samples here.
This is what NASA and US Air Force forecasters were contending with at launch time. All those angry yellows and reds? Thundershowers. They were heading toward the Kennedy Space Center (on that hump of coast just above Melbourne) and filled the sky within 20 miles of the runway the shuttle has to use if a malfunction required the orbiter to abort its ascent. (National Weather Service, Melbourne, Fla., forecast office)
Summer thunder gives shuttle Endeavour the summertime blues
Oh well, at least the Boston Red Sox go into the All-Star break in first place and 2-1/2 games ahead of the New York Yankees.
Otherwise, Sunday has been a washout, at least for the crew of NASA's space shuttle Endeavour. For the fifth time in a month, mission managers have had to scrub the shuttle's launch.
Twice last month, it was for a hydrogen leak, which technicians repaired. Then yesterday's launch was put off before the shuttle was fueled and before astronauts had boarded. Mission managers wanted to analyze data on the shuttle's systems after a series of lightning strikes during a storm on Friday. The verdict: No damage to any system.
This time, the shuttle was fueled up, the astronauts were strapped in, and they were a scant 10 minutes from lift-off when managers nixed the launch for weather reasons.
A line of thundershowers was encroaching on Kennedy Space Center -- too close for comfort, especially if the shuttle had to abort its ascent and return to Kennedy Space Center.
So, Endeavour's launch had been reschedule for July 13 at 6:51 P.M. Eastern Daylight Time. Stay tuned...
Shuttle managers are aiming for 7:13 P.M. EDT launch today after the mission endured the fourth delay in a month. This time around, it was for weather. But last month, a hydrogen leak on the external fuel tank prompted two postponements and a longer time-out for repairs. (AP)
For space shuttle Endeavour, it's fill 'er time
Technicians are fueling the space shuttle Endeavour after a one-day delay to make sure nearby lightning strikes on Friday hadn't affected critical systems on the orbiter and its twin solid-fuel boosters.
During a severe storm on Friday afternoon, sensors recorded 11 lightning strikes within 0.3 nautical miles of the pad. Seven of those strikes hit the pad's lightning-protection system.
The system "did what it was designed to do," noted space shuttle payload integration manager Mike Moses, who also heads the mission-management team, during a briefing on Saturday. But, he added, engineers needed time to ensure that voltage spikes the lightning induced didn't fry on-board computers and sensitive electronics on the boosters.
An added benefit: Weather for today's scheduled launch at 7:13 P.M. Eastern Daylight Time stands only a 30 percent chance of violating launch requirements. On Friday, forecasters had predicted that conditions during the original launch time, 7:39 P.M. yesterday, stood only a 40 percent chance of meeting launch requirements.
During the 16-day mission the orbiter and its seven-member crew will spend 12 days at the space station to install the last major portion of Japan's laboratory module and perform a variety of maintenance tasks on the station. It's going to get quite chummy: During Endeavour's stay, the space station's population will expand from six to 13.
One of Endeavour's crew members, Timothy Kopra, will remain aboard the station as part of the normal crew-rotation process. Japanese astronaut Koichi Wakata, who has served at the orbiting outpost since March, will return with the shuttle.
The shuttle Endeavour during sunnier days. Mission managers hope to launch the orbiter and its crew the evening of July 11. It's the fourth launch date for a mission that has had to cope with hydrogen leaks in June, which were fixed, and most recently, lightning strikes July 10 that were too close for comfort. (NASA/Ken Thornsley)
Lightning puts shuttle launch off for at least a day
It's a tough weather break for the space shuttle Endeavour and its crew.
A violent thunderstorm moved over the Kennedy Space Center Friday around 3 p.m. Eleven bolts of lightning dropped down within 0.3 nautical miles of the launch pad. Of those, seven hit the orbiter's lightning protection system -- including a strike on the lightning mast that towers over the launch-pad service structure.
The concern: The closest strikes may have induced voltage spikes in circuits aboard the orbiter and in circuits that govern the pyrotechnic devices on the shuttle's twin solid-rocket motors.
The devices ignite the motors, blow the bolts attaching the boosters to the external fuel tank when the time comes to jettison the boosters, and fire motors that move the boosters away from the tank at separation time. Additional explosives are aboard to destroy the boosters if a malfunction makes that move necessary.
At a press briefing July 11, Mike Moses, who chairs the mission management team, said the group agreed to the delay to give engineers time to make sure the voltage spikes they saw from the lightning strikes didn't damage sensitive electronics aboard the craft.
"A lot of equipment has to be checked," he said.
NASA has tentatively rescheduled the launch for 7:13 P.M. Eastern Daylight Time July 12. But Mr. Moses acknowledged that if engineers felt they needed more time to check out the shuttle's and boosters' systems, the launch would get pushed off again.
Check out the video below to see what missions managers had to cope with from yesterday's thunderstorm.
The International Space Station as it appeared from Franklin, Mass., on July 10, 2009. Note how the streak grows brighter toward its middle, then the brightness tails off again before the streak stops. That represents a flaring of light as sunlight caught the station's solar panels full-on. (Peter N. Spotts/The Christian Science Monitor)
Grab your camera and nab that space station (or satellite)
With the space shuttle set to launch July 11 for a trip to the space station (you can read more about that here), it wasn't too big a stretch to get word that the space station would pass overhead for a full 6 minutes tonight and think: Man, I gotta try to get me a picture of that!
Others have snapped the ISS with more skill and agility. But, hey, it's like catching (and releasing) your first fish, turning the key in your first car, or your first ... you get the idea.
Step 1, of course, is knowing if the station is coming soon to a night sky near you. For that, Twitter is a big help. Check out Twisst, an alert service set up by a couple of Dutch science reporters, one of whom also develops web sites. Just sign up as a follower and you'll automatically get updates for your location. No muss. No fuss. The alert looks like this:
@pspotts ISS will cross the sky at your location at 9:12 pm! more details: http://twisst.nl/471
For those who haven't done the Twitter thing yet, the @pspotts is my Twitter ID. And the funny-looking web address corresponds to Twisst's website with my location information on it -- information the site gleans from the web.
An alternative is to visit NASA's Skywatch web page and use the tool in the left-hand column to select your country, state (for the US), and nearest city or town if yours isn't listed. Again, for my location the listing looked like this:
| ISS | Fri Jul 10/09:12 PM | 6 | 49 | 10 above WSW | 10 above NE |
Translation: The ISS will appear on Friday, July 10 at 9:12 p.m. The viewing opportunity will last for six minutes, and the station's high point will appear at 49 degrees above the horizon. It will first appear at 10 degrees above the horizon in the west southwest, and it will vanish about 10 degrees above the northeastern horizon.
Step 2, by all means check the weather. For my location tonight, the forecast was perfect: achingly clear skies. (Note the precise scientific term: achingly.)
Step 3, scout out a location where you'll get the best unobstructed view of as much of the predicted ISS path as possible. Set up a tripod to hold your camera (it's gonna be a long exposure) early, so you don't have to fiddle with it in the dark.
Step 4, go out about 10 to 15 minutes before the station is scheduled to appear to make you final adjustments, mount the camera, make sure it's aimed in the right direction (something you can adjust on the fly with a six-minute overflight), and swat at the mosquitoes looking for dinner.
'Scuze me sir, what shutter speed and f-stop are you using? You'll find some helpful guidance here. What? A 60-second (or much longer) exposure time? I don't have the recommended cable release for long exposures, and my camera only goes to 30 seconds before it hits "bulb." So I had to open up my lens a bit more than the web site recommends to compensate for the fact that I had to use a 30-second exposure, rather than a 1-minute exposure.
And no cable release? No problem. Just use your camera's self-timer -- the one that allows you to jump into the picture (but don't in this case). Be sure not to bump the tripod while the camera's shutter is open. Whistle a tune. Whittle a sailing ship. Go over to the fence, where your neighbors are having friends over for a cook-out, and point out the cool thing moving across the night sky. But don't bump the tripod.
If all goes well, you'll end up with a tidy streak across the sky in your image. The streak is even brighter when the space shuttle is docked to the station.
From there, you should be able to extend you night-time sky photography to include other satellites or the motion of stars across the sky. Play around with it. These days, when you no longer need to worry about "wasting" rolls of film, it's become a lot easier to dip your toes into this aspect of skywatching.
Delegates gather during global climate talks in Poznan in December 2008. One of the key issues revolves around how new emissions-reductions targets will be allocated. A international team of researchers has offered up a possible answer. (AP Photo/Alik Keplicz/File)
A new way for nations to divvy up greenhouse-gas cuts?
If you want to see how hard it will be to get the next round of cuts in greenhouse gases in any new global climate agreement, look at what happened today in Italy.
The good news: The G-8 countries declared that they "recognise the broad scientific view that the increase in global average temperature above pre-industrial levels ought not to exceed 2°C." The communique is available in pdf form on the G-8 meeting's website.
The statement is not exactly a hard and fast commitment to shoot for 2 degrees, but at least it acknowledges that the science points to that level as a kind of climatological line in the sand.
But climate talks between developed and developing countries, aimed at feeding into the broader UN negotiating process, fizzled out. Developing countries were unconvinced that their richer counterparts were willing to commit to rigorous mid-term emissions goals in exchange for developing countries backing a global reduction in emissions of 50 percent below 1990 levels by 2050 -- a goal that would require significant participation by developing countries.
Now along comes a team of researchers from the US, the Netherlands, and Italy that offers what it sees as a more equitable approach to divvying up emissions-reduction duties, at least for now.
It's based on a couple of premises: In the end, people as consumers of resources are ultimately responsible for carbon emissions, whether any one person's contribution is high or virtually nil; and all countries have a least some people whose wealth allows them to consume enough to be counted among "high emitters."
So, the argument goes, set a universal per-person emissions cap. (For a look at how they go about this, you can download a pdf of their research paper, which appears in the current issue of the Proceedings of the National Academy of Sciences.)
Instead of haggling over which nations do what, the approach sets each country's national target by estimating how broad a swath of its population collectively exceeds the allowable per-capita emissions cap and by how much. Their "emissions" are derived from a country's population and income distribution figures and carbon-intensity estimates. For every ton of carbon the high emitters exceed the cap, that ton becomes part of the country's emission-reduction target.
Nearly everyone pitches in
Rich countries collectively still shoulder most of the load under this approach initially. But many developing countries still have to do something, because they have high emitters, however few they may be. And successive national targets for developing countries would become more ambitious as global targets tighten over time and the number of high emitters rises with a country's standard of living.
This approach doesn't aim emission-reduction policies directly at high emitters one by one or even as a group. Instead, a country would use whatever internationally agreed-upon, verifiable mix of tools -- say, cap and trade or approaches such as avoided deforestation -- to meet its national emissions-reduction target.
How might it work? The researchers give an example.
Let's say the world had agreed to cut annual carbon-dioxide emissions to 30 billion tons by 2030, starting in 2003. Compared with business as usual by 2030, the team calculates, that's a 30 percent cut, or 13 billion tons. Based on population trends, income distribution, and carbon intensity estimates, that cut translates into an emissions cap of 10.8 tons of CO2 for each person on the planet. For the record, the calculations also yield 1.13 billion "high emitters" globally.
Apply that cap to the estimated distribution of high emitters in each country, and emissions-reduction targets for some big names in the climate-negotiation game look like this, compared with business-as-usual in 2030:
And the cuts are?
Among industrial countries: the US cuts emissions by 55 percent; Japan cuts by 15 percent; Australia/New Zealand cut by 50 percent; Europe collectively cuts by 20 percent; Canada cuts by 43 percent; and Russia cuts by 45 percent.
Among developing countries: China cuts emissions by 25 percent; Mexico cuts by 14 percent; and Brazil and India get a pass for the period.
The team first offered up this approach at global climate talks in Bali in 2007, and received encouragement, said Princeton University physicist Shoibal Chakravarty during a phone chat. He is the lead author on the research paper.
The team acknowledges that nuances must be worked out before anyone could think of considering this approach for a formal treaty.
Still, Dr. Chakravarty says, "It's a very flexible approach. You don't have to bother about negotiating interim targets or a division of labor between countries. Once everybody decides on a global target, this mechanism automatically provides national targets."
A caution
But an approach that may look equitable and fair on the international stage may not play so well domestically.
Raymond Kopp, an economist with Resources for the Future in Washington and a self-described "inside the Beltway guy" offers a note of political pragmatism.
"I appreciate the elegance of these solutions for carving up the emissions of the world," he says, But in the end, politicians in individual countries still determine what they can or can't contribute to the cause -- assuming they agree a cause exists. They are unlikely to yield their roll as decision-makers to a set of mathematical equations, Dr. Kopp suggests.
The Swan Nebula is filled with gas and dust -- the building blocks for news stars. As the massive stars form and begin to shine, their solar winds and strong light etch random patterns in the interstellar medium. (ESO)
The splendor of the Milky Way's Swan Nebula
Welcome to the Swan Nebula, or, as a madrigal singer might think of it: Il Bianco e Dolce Cigno -- the gentle white swan.
This bird, however, is anything but gentle. The nebula, more widely known as the Omega nebula (yep, these are like Rorschach blot tests; other names include the Lobster Nebula and the Horseshoe Nebula), lies some 5,500 light-years away in the constellation Sagittarius, and stretches 15 light-years across.
Astronomers calculate that it's one of the youngest and most massive stellar nurseries in the galaxy. The nursery began forming new stars only a few million years ago. In May, a team of astronomers analyzing the nebula as seen via NASA's Spitzer Space Telescope estimated that more than 1,000 stars are forming in and around the nebula.
The image at the top of the page, released today, comes courtesy of the European Southern Observatory's New Technology Telescope at the observatory's facility at La Silla, Chile. Two more-detailed images from the Hubble space Telescope are included in the mini slide show at the top of the page.
As you peruse the images, feel free to trigger the King Singers in the video clip below. They are giving their rendition of Jacques Arcadelt's "Il Bianco e Dolce Cigno." It's a soothing listen; and for those of a choir-like bent, it's fun to sing.
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