Universe Today: “Across the Universe” Day for NASA and Beatles Fans

Written by Nancy Atkinson

NASA will use its Deep Space Network to transmit a song across the universe. And fittingly, the song is “Across the Universe” by the Beatles. On Feb. 4 at 7 pm EST, the song will be beamed towards the North Star, Polaris, located 431 light years away from Earth, and will travel across the universe at 186,000 miles per second. Former Beatle Paul McCartney thinks this is a great idea. "Send my love to the aliens,” he said in a message to NASA. If there are any beings near Polaris, they’ll hear the song in about 431 years.

The song’s transmission will commemorate the 40th anniversary of the day The Beatles recorded the song, as well as the 50th anniversary of both NASA's founding and the beginning days of the Beatles. Two other anniversaries also are being honored: The launch 50 years ago this week of Explorer 1, the first U.S. satellite, and the founding 45 years ago of the Deep Space Network, an international network of antennas that supports missions to explore the universe.

Feb. 4 has been declared "Across The Universe Day" by Beatles fans to commemorate the anniversaries. As part of the celebration, the public around the world has been invited to participate in the event by simultaneously playing the song at the same time as the transmission by NASA.

John Lennon's widow, Yoko Ono, characterized the song's transmission as a significant event. "I see that this is the beginning of the new age in which we will communicate with billions of planets across the universe," she said.

Even though radio and television signals on Earth “leak” out into space all the time, hopefully NASA can use this event to generate enthusiasm and promote awareness of its history, as well as its plans for future missions. Additionally, this is a chance for the public to learn more about the Deep Space Network, NASA’s incredibly reliable system of radio antennas that is critical in supporting lunar and planetary exploration. The DSN is used for tracking of spacecraft, sending telemetry and commands, and for deep space navigation. Learn more about the DSN here.

Original News Source: NASA Press Release

Universe Today: Mercury is Less Like the Moon than Previously Believed

Written by Fraser Cain

With Mercury fading in MESSENGER's rear view mirror, scientists are just starting to pore through the torrent of images sent back. And as you can probably guess, the new mysteries are piling up fast and furious. The planet is much less like the Moon than scientists previously thought.

MESSENGER made its closest approach to Mercury on January 14, passing just a few hundred kilometres above its surface. During the flyby it captured a total of 1,213 images.

One of the most unique features discovered by MESSENGER has been dubbed "The Spider" by scientists. And that's what it looks like. The feature has a central crater surrounded by more than a hundred narrow, flat-floored troughs (called graben) radiating away.

Unlike the Moon, Mercury has huge cliffs or scarps, which can snake hundreds of kilometres across the planet's surface. They trace the lines of old volcanic faults, from when the planet was still geologically active.

Because of its small size and high density, Mercury has a surprisingly large pull of gravity. Astronauts walking around its surface would experience 38% of the Earth's gravity. This higher gravity means that the impact craters look different. Material doesn't splash out from the impact craters so far, and there are many more secondary crater chains.

“We have seen new craters along the terminator on the side of the planet viewed by Mariner 10 where the illumination of the MESSENGER images revealed very subtle features. Technological advances that have been incorporated in MESSENGER are effectively revealing an entirely new planet from what we saw over 30 years ago,” said Science Team Co-Investigator Robert Strom, professor emeritus at the University of Arizona and the only member of both the MESSENGER and Mariner 10 science teams.

MESSENGER wasn't just taking pictures. It also had a suite of scientific instruments measuring many features of the planet. Perhaps the most puzzling of these is its magnetic field. Even though Mercury cooled down and solidified eons ago, it still has an magnetic field. This was first detected by Mariner 10, and MESSENGER confirmed it.

This is just the beginning. MESSENGER will return to Mercury on October 6, 2008 to make a second flyby, and then a third on September 29, 2009. The spacecraft make its final return to the planet on March 18, 2011 when it'll begin a year-long orbital mission.

Original Source: MESSENGER News Release

Universe Today: ‘Suits and Ties’ Collaborate on Successful Space Station Repair

Written by Nancy Atkinson

At the end of Wednesday’s successful spacewalk to change out a faulty motor on one of the International Space Station’s solar array positioning devices, the astronauts outside the ISS and flight controllers in Houston were congratulating each other on the group effort it took to pull off this particularly tricky and potentially dangerous repair job.

“You guys looked really good to us. Thanks for making it look so easy,” Mission Control in Houston radioed up to the spacewalkers after their seven-hour and 10 minutes EVA.

“Yeah,” said ISS astronaut Dan Tani. “And we didn’t even have to put on a tie.”

This spacewalk really was a collaboration between the “suits and ties” at NASA. The suits – spacesuits, that is – were worn by astronauts Tani and Peggy Whitson. The ties were sported by the engineers and astronauts in Mission Control who planned the repair and guided the spacewalkers during the entire EVA.

Tani and Whitson were thanking one tie-wearing astronaut in particular. Tom Marshburn had practiced the choreography of the spacewalk in the Neutral Buoyancy Lab in Houston, and shared his insights with the spacewalkers. Usually astronauts get to practice their own EVA’s in the enormous pool that contains a mock-up of the ISS. But the Bearing Motor Roll Ring Module on the starboard solar array quit working in December when Whitson and Tani were already on board the station. So the plan and nuances of the EVA were tested in the pool by Marshburn and former ISS resident Suni Williams and relayed up to Tani and Whitson.

The spacewalk was especially hazardous because of the risk of electrical shock from 160 volts of electricity that flows through the arrays. For safety, Whitson and Tani waited until the International Space Station was on the dark side of Earth, giving them only 33 minute increments to complete their tasks. Whitson had to squeeze inside the station's truss girder to swap out the 250 pound (113 kilograms) garbage can-sized motor.

The new motor successfully performed a 360-degree test spin during the spacewalk. It's power-generating capabilities were tested successfully as well.

"Yay, it works!" exclaimed Whitson as she and Tani watched the solar wing turn. "Excellent, outstanding…isn't that cool?"

The successful repair means the station should be able to generate enough power to support the new modules that will be brought on the next shuttle missions, the European Columbus science lab, and the Japanese Kibo labratory.

"Given the complexity of this spacewalk and the risks that we had to manage … we are exceptionally pleased with how things went," flight director Kwatsi Alibaruho said after the EVA.

In addition to the motor repair, Whitson and Tani also performed another inspection of the station's starboard Solar Alpha Rotary Joint, a 10-ft wide gear that keeps the solar wings pointing toward the sun The SARJ is not working and is contaminated with metal shavings. The spacewalkers evaluated damage from the debris and collected samples from areas previously unseen.

Alibaruho said the new debris samples will help determine what repairs will be done, perhaps later this year. NASA hopes to launch up to five shuttle flights to the ISS this year.

Wednesday's EVA was the final planned spacewalk of the Expedition 16 mission and the 101st dedicated to space station assembly and maintenance. The spacewalk also marked the sixth career EVA's for both Whitson and Tani.

So, there’s just one question for Dan Tani: Which is harder — donning a 280 lb spacesuit or tying a Windsor Knot?

Original News Source: NASA TV

Universe Today: 50 Years Ago: Explorer 1

Written by Nancy Atkinson

The launch of Sputnik in October 1957 changed the world overnight. And with the Soviet Union’s second successful launch of Sputnik 2 the following month, Americans were feeling a little left behind in the dust, especially after the US’s first satellite launch attempt with the Vanguard rocket exploded on the launchpad. But space pioneer Werner Von Braun, shown in this picture with JPL Director William Pickering and scientist James Van Allen, came through with his Jupiter C rocket that launched the US’s first satellite, Explorer 1, into space on January 31, 1958.

Explorer 1 was not all that big, with a length of 203 centimeters (80 inches), a diameter of 15.9 centimeters (6.25 inches), and a weight of 14 kilograms (30.8 pounds). But it did its job, which was, first and foremost, to reach orbit, and then return scientific information.

The Jet Propulsion Laboratory got the assignment of designing and building a scientific payload for the launch, which they accomplished in three months.

The primary science instrument on Explorer 1 was a cosmic ray detector designed to measure the radiation above the atmosphere. Dr. James Van Allen designed the experiment, which revealed a much lower cosmic ray count than expected. Van Allen theorized that the instrument may have been saturated by very strong radiation from a belt of charged particles trapped in space by Earth’s magnetic field. A subsequent launch by Explorer 3 two months later confirmed the existence of these radiation belts, which became known as the Van Allen Belts, in honor of their discoverer.

There were other scientific findings from Explorer 1 as well. Because of its symmetrical shape, Explorer 1 was used to help determine the upper atmospheric densities.

Two other instruments on board looked for micrometeorites in orbit, a micrometeorite detector and an acoustic microphone to detect the sound of an micrometeorite imipact. The micrometeorite detector was made of grid of electrical wires. A micrometeorite of about 10 microns would fracture a wire upon impact, destroy the electrical connection, and record the event. One or two of the wires were destroyed during launch. The equipment worked for about 60 days, but showed only one possible meteorite impact. Data from the acoustical sensor microphone were obtained only when an impact occurred while the satellite was over a ground recording station. However, over an 11-day period (February 1, 1958, to February 12, 1958), 145 impacts were recorded. The high impact rates on one portion of the orbit and the subsequent failures in the satellite's electronic system were attributed to a meteor shower.

The batteries ran out on Explorer 1 on May 23, 1958 when the last signal was recorded. The US’s first satellite burned up in re-entry of the atmosphere in March of 1970.

Original News Source: JPL

Universe Today: Carnival of Space #39

Written by Fraser Cain

We've got another first-time host for the Carnival of Space this week: Sean Welton and his website, Visual Astronomy. So please take a moment, visit his site, and enjoy the space articles prepared for your education and entertainment. Thanks Sean!

Click here to read the Carnival of Space #39

And if you're interested in looking back, here's an archive to all the past carnivals of space. If you've got a space-related blog, you should really join the carnival. Just email an entry to carnivalofspace@gmail.com, and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community - and community is what blogging is all about. And if you really want to help out, let me know if you can be a host, and I'll schedule you into the calendar.

Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.

Universe Today :The Environmental Impact of a Return to the Moon

Written by Fraser Cain

There are many ways space exploration can affect our environment right here on Earth: toxic chemicals used to manufacture the rocket, carbon dioxide pumped into the atmosphere and the energy used to manufacture the equipment and vehicles, just to name a few. For the next era in space exploration, the Constellation Program, NASA has released a 500-page document detailing its effect on the environment.

Back in September 2006, NASA solicited feedback from the public about their plans for the Constellation Program. They were looking for environmental issues and concerns that the people might have. The agency released a draft of their reply to these concerns in August 2007.

The document released Wednesday, is called the Final Constellation Programmatic Environmental Statement (PEIS), and it addresses the comments made to the draft version of the document.

The document explores each NASA centre across the United States, what parts of the Constellation Program it will work on, and the environmental impact the centre might have. This part of the document is fascinating to show how the whole program will come together - where each part will be built.

• Risks to the public associated with launch and Earth atmospheric entry
• Environmental impacts of the use of solid rocket fuels on the ozone layer and impacts associated with the deposition of combustion products near the launch area
• Impacts on local animal species (e.g., sea turtles and manatees) associated with construction and launch activities in the John F. Kennedy Space Center (KSC) area
• Noise impacts associated with launch events
• The relationship between the Constellation Program and the Space Shuttle Program, including how the socioeconomic impacts of the Space Shuttle retirement and the Constellation Program overlap.

Perhaps more interesting than the things they considered where the issues that the document won't consider. For example, the document expressly refuses to study the environmental impact on outer space itself, such as orbital debris. It also doesn't consider any military aspects associated with the program and the environmental impact of that. (If the Constellation Program helps launch orbital space lasers, and they're used to zap sea turtle habitats, that's not NASA's problem.)

Although they put in their questions, several submitters won't get an answer. For example, the document won't address how the Kennedy Space Center could manage its light pollution, monitor bird strikes, or raise awareness of metals in the environment. And the environmental impact on the Moon is right out of the question.

Anyway, if you're interested in this topic… and who wouldn't be, you can access the whole document online.

Original Source: NASA

Universe Today : Will Earth Survive When the Sun Becomes a Red Giant?

Written by Fraser Cain

Billions of years in the future, when our Sun bloats up into a red giant, it will expand to consume the Earth's orbit. But wait, you say, the Earth travels the Earth's orbit… what's going to happen to our beloved planet? Will it be gobbled up like poor Mercury and Venus?

Astronomers have been puzzling this question for decades. When the sun becomes a red giant, the simple calculation would put its equator out past Mars. All of the inner planets would be consumed.

However, as the Sun reaches this late stage in its stellar evolution, it loses a tremendous amount of mass through powerful stellar winds. As it grows, it loses mass, causing the planets to spiral outwards. So the question is, will the expanding Sun overtake the planets spiraling outwards, or will Earth (and maybe even Venus) escape its grasp.

K.-P Schroder and Robert Cannon Smith are two researchers trying to get to the bottom of this question. They've run the calculations with the most current models of stellar evolution, and published a research paper entitled, Distant Future of the Sun and Earth Revisted. It has been accepted for publication in the Monthly Notices of the Royal Astronomical Society.

According to Schroder and Smith, when the Sun becomes a red giant star 7.59 billion years, it will start to lose mass quickly. By the time it reaches its largest radius, 256 times its current size, it will be down to only 67% of its current mass.

When the Sun does begin to bloat up, it will go quickly, sweeping through the inner Solar System in just 5 million years. It will then enter its relatively brief (130 million year) helium-burning phase. It will expand past the orbit of Mercury, and then Venus. By the time it approaches the Earth, it will be losing 4.9 x 10²⁰ tonnes of mass every year (8% the mass of the Earth).

But the habitable zone will be gone much sooner. Astronomers estimate that will expand past the Earth's orbit in just a billion years. The heating Sun will evaporate the Earth's oceans away, and then solar radiation will blast away the hydrogen from the water. The Earth will never have oceans again. It will eventually become molten again.

One interesting side benefit for the Solar System. Even though the Earth, at a mere 1.5 astronomical units, will no longer be within the Sun's habitable zone, much of the Solar System will be. The new habitable zone will stretch from 49.4 AU to 71.4 AU, well into the Kuiper Belt. The formerly icy worlds will melt, and liquid water will be present beyond the orbit of Pluto. Perhaps Eris will be the new homeworld.

Back to the question… will the Earth survive?

According to Schroder and Smith, the answer is no. Even though the Earth could expand to an orbit 50% larger than today's orbit, it won't get the chance. The expanding Sun will engulf the Earth just before it reaches the tip of the red giant phase. And the Sun would still have another 0.25 AU and 500,000 years to grow.

Once inside the Sun's atmosphere, the Earth will collide with particles of gas. Its orbit will decay, and it will spiral inward.

If the Earth were just a little further from the Sun, at 1.15 AU, it would be able to survive the expansion phase. Although it's science fiction, the authors suggest that future technologies could be used to speed up the Earth's spiraling outward from the Sun.

I'm not sure why, but thinking about this far future of the Earth gives an insight into human psychology. People are genuinely worried about a future billions of years away. Even though the Earth will be scorched much sooner, its oceans boiled away, and turned into a molten ball of rock, it's this early destruction by the Sun that feels so sad.

Original Source: Arxiv

Universe Today :Global Map of Iapetus

Written by Fraser Cain

Here's a cool global map of Saturn's moon Iapetus, stitched together from the various Cassini flybys. Cassini didn't see the entire moon, so the imaging team put in photographs from Voyager to cover the missing polar regions.

You can see its distinct equatorial ridge on the left-hand side of the image, and the mottled dark and light patches that give the moon its Yin-Yang look. The image scale is 803 km per pixel.

It's a little old, but check out this video of the most recent Cassini Iapetus flyby back in September 2007.

Original Source: NASA/JPL/SSI News Release

Space.com : Galactic Wi-fi?

By Seth Shostak SETI Institute posted: 31 January 2008 06:39 am ET

Incredibly, it's been only a bit more than a century since Oliver Heaviside consolidated the work of several 19th century physicists into the four compact mathematical formulations known as Maxwell's Equations. You may gleefully recall them from sophomore physics.

Aside from their display by the rabidly nerdy on pretentious t-shirts, the formulae have a splendid utility: they describe all electromagnetic radiation — in particular, light and radio. In the short time since their discovery, we have been able to milk these elegant equations to build crude spark transmitters, and eventually to develop the diminutive cell phones that allow you to blithely ring up your pals while comfortably seated in restaurants and movie theaters. We have exploited Maxwell's Equations like an old-growth forest, and many technical types aver that we know all there is to know about them.

Not true. And the fact that it's untrue may affect our thinking about SETI.

Today's SETI experiments generally look for what are politely termed "narrow-band signals." In other words, the receivers at the back ends of our radio telescopes search wide swaths of the spectrum looking for a signal that's at one spot on the dial — a signal that's very constrained in frequency. By putting all the transmitted power into this small bandwidth, the aliens can ensure that their signal will stand out like Yao Ming at a Munchkin picnic.

That makes sense — at least if the aliens want only to help us find their signal. But they might have other priorities. In particular, the history of earthly communication suggests that there is an inexorable pressure to increase the bit rate of any transmission channel. A half-decade ago, most readers accessed this web site with a simple dial-up phone line. Today, you're more likely to have some sort of wide-band service, which is to say, you're inhaling Internet bits at least ten times quicker than before.

More generally, in 150 years, we've gone from telegraph wires, capable of a few bits per second, to optical fibers that are billions of times speedier. The idea of "more bandwidth" is so compelling, the phrase has entered the lexicon of everyday speech — even among those who couldn't tell a hertz from a hub nut. Communication technology is always driven to send more bits — more information — per second.

Now consider the plight of aliens wishing to get in touch. Because the separation between one civilization and another is likely to be at least hundreds — and maybe thousands — of light-years, any interstellar pinging is effectively one-way. Back and forth conversations will take too long. So perhaps the aliens will opt to send, not the easiest-to-find signal, but a signal that says it all — a signal bristling with information. If you're going to stuff a message into a bottle, why not use onion-skin paper and write small?

The straightforward way to get more information down a radio channel is, as everyone knows, by using greater bandwidth. Nearly once a week someone sends me an e-mail pointing this out, saying that SETI should be looking for wide-band signals, not narrow-band ones. But there's a problem here. While sending a wide-band, information-rich signal between nearby stars is perfectly practical (assuming you're willing to pay the power bill), once the distance exceeds a thousand light-years or so the billowing hot gas that permeates interstellar space begins to wreak havoc and destruction on the transmission. A process of "dispersion" occurs, which works to slow the broadcast — but it slows different frequencies by different amounts. The result is to distort a wide-bandwidth signal in much the way that a highly reverberant hall would distort the music from an orchestra. A narrow-band signal (the acoustical analog is a simple flute note) would not be adversely affected.

So it seems that there may be difficulties in sending certain kinds of complex radio signals over significant distances in the Galaxy. Interstellar correspondence could be restricted to mere postcards, which would be a disappointment to aliens interested in heavy-duty data distribution.

However, some Swedish physicists are pointing out a possible scheme for beating this rap. In careful analyses of some of the subtle properties of Maxwell's Equations, Bo Thide and Jan Bergman at the Swedish Institute of Space Physics in Uppsala have explored a property of radio waves called orbital angular momentum. You can think of this orbital momentum as a twisting of the wave's electric and magnetic fields — a twisting that would show up if you were measuring the wave with an array of antennas. The technical details are intricate, but suffice it to say that the Swedish scientists are noting another way to send information in a radio signal — even a narrow-band radio signal — by encoding it in the orbital angular momentum.

It's as if they've found "subspace channels," a là Star Trek. Hidden highways down which additional bits can be moved. And there's reason to think that these momentum channels might be impervious to the interstellar jumbling that afflicts the usual types of wide-band signals when sent over great distances.

So it may be that our search for narrow-band signals is actually a very good SETI strategy, and not just an obvious one. While such monotonic messages may seem to be elementary and devoid of much information, they could be laden with additional, hidden complexity.

The investigation of new transmission modes by Thide and Bergman hints that if we do find a signal from ET, we may wish to reconfigure our radio telescopes to look for encoding of the message via such subtle effects as orbital angular momentum. A simple signal may only be a cipher for a more complex message, and there may be more things in heaven and earth than even Maxwell had dreamt of …

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