Improvements to Universe Today

The constant feedback I’ve had from readers is: more pictures. Okay, you want pictures? I’ll give you pictures. Here, have all the pictures you can handle. I’ve added a new type of story called “Photo Gallery”, which will showcase a few big pictures, plus have a link to a wallpaper version. I’ve also increased the size of pictures in the stories about 4X. Check them out, and then let me know what you else you might want to make this better.

I’ve also added a list of recent conversations in the forum beside every story in the site. Hopefully this will remind you that we’ve got a thriving forum for space enthusiasts. Come and join us!

Take care,

Fraser Cain
Publisher
Universe Today

Astronauts Find the Source of the Leak

The astronauts on board the International Space Station have finally located the tiny air leak that was puzzling them for several weeks; not to mention steadily dropping the air pressure on the station. The leak appears to be on a cable which equalizes pressure on the main window in the US-built Destiny laboratory module. Fortunately, the astronauts have the equipment they need to temporarily repair it, and a replacement part can be shipped up on the next Progress cargo flight.

Spirit Will Roll Off Secondary Ramp

Image credit: NASA/JPL

After several attempts to collapse the airbag which is blocking Spirit’s exit from the lander, controllers have given up that plan. Instead, they’ve decided to have the rover exit from one of the platform’s alternate ramps. In order to take this northeastern route, the rover will have to back up and then perform a three-point turn in the tight space. Controllers will also fire a pyro device which will sever an umbilical cord connecting the rover to the lander. If everything goes as planned, Spirit will roll off the lander on the evening of January 14.

NASA’s Spirit rover now has its arm and all six of its wheels free, and only a single cable must be cut before it can turn and roll off its lander onto the soil of Mars. As that milestone is completed, scientists are taking opportunities to take extra pictures and other data.

During the past 24 hours — the rover’s 8th martian day on the planet, or “sol 8” — pyro devices were fired slicing cables to free the rover’s middle wheels and releasing pins that held in place its instrumented arm. The arm was then locked onto a hook where it will be stowed when the rover is driving.

Because one airbag remains adjacent to the lander’s forward ramp, the rover will turn about 120 degrees to its right and exit the lander from the side facing west-northwest on the planet — also the direction of an intriguing depression that scientists have dubbed Sleepy Hollow.

Current plans call for the rover to complete that turn in three steps, said Arthur Amador, one of the mission managers at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. As currently envisioned, during the coming martian day engineers will complete ground tests and execute dress rehearsals of the drive-off, or “egress.”

On sol 10 — the night of Monday-Tuesday, Jan. 12-13, California time — engineers expect to sever the umbilical cord that connects the rover to its lander by firing a pyro device, the last of 126 pyro firings since Spirit separated from its cruise stage shortly before landing on Jan. 4 (Jan. 3 in U. S. time zones). Also on that day, the rover will execute the first of three parts of its turn when it moves clockwise (as viewed from above) about 45 degrees.

After taking and analyzing pictures to verify the first part of the turn, engineers anticipate completing it on sol 11 (night of Tuesday-Wednesday, Jan. 13-14). First, the rover will turn an additional 50 degrees and stop to take pictures. Then, if all is well, it will turn a final 20 to 25 degrees to position it precisely in front of one of its three exit ramps.

If no issues crop up as those steps are completed, the rover could drive off onto the martian soil no earlier than sol 12 (night of Wednesday-Thursday, Jan. 14-15). “But we adjust our schedule every day, based on flight events, so this remains an estimate,” said Amador.

The rover’s status overall is “pretty darn perfect,” said Amador. He described the communication link from Mars to Earth as excellent, allowing the team to receive 170 megabits of data during the past day. All science data stored on the rover has been sent to Earth. The rover is generating 900 watt-hours of power per day and using 750 watt-hours, and its thermal condition is good, he added.

While engineers are completing and testing commands to execute the rover’s turn and egress, the science team is enjoying an “unexpected dividend” of time to collect data, said Dr. John Callas, Mars Exploration Rover science manager at JPL.

Until now, all science observations have been planned far in advance, but the unfolding schedule of rover activities gave the team the opportunity to do their first on-the-fly planning for observations driven by previous results, Callas explained. In doing so they segued to a working style that they will practice on a day to day basis as the rover rolls across the surface of its landing site in Gusev Crater, named the Columbia Memorial Station.

In the next 24 hours, the team will collect 270 megabits of science data, considerably more than on any previous martian day. This will include a high-quality, 14-color mosaic taken by the panoramic camera of a third of the horizon toward Sleepy Hollow, the direction in which the rover will leave its lander.

In addition, they plan to complete two remaining “octants” (each a pie slice showing an eighth of the horizon) with the rover’s miniature thermal emission spectrometer. These areas will also be rephotographed with the rover’s panoramic camera in order to allow the camera and spectrometer data to be co-registered. Plans also call for the spectrometer to “stare” at three selected sites to collect very low-noise data, as well as calibration of another science instrument, the alpha particle X-ray spectrometer.

Spirit’s twin Mars Exploration Rover, Opportunity, will reach Mars on Jan. 25 (Universal Time and EST; Jan. 24 PST). The rovers’ main task is to spend three months exploring for clues in rocks and soil about whether the landing sites may have had abundant water for long enough in the past for life to appear. Pictures and detailed information from the mission is available at the project’s Web site: http://marsrovers.jpl.nasa.gov.

JPL, a division of the California Institute of Technology, manages the Mars Exploration Rover project for NASA’s Office of Space Science, Washington.

Original Source: NASA/JPL News Release

Eye Tower Makes Hurricanes Stronger

Image credit: NASA

NASA scientists have discovered that a “hot tower” of cloud rising above the eye of a hurricane can increase its intensity. The scientists used data gathered by the TRMM satellite; a joint project by NASA and the Japanese Aerospace Exploration Agency. After compiling statistics from several storms, they found that when a hot tower forms up to 15 kilometres above the eye, the hurricane will become much more intense within six hours. This research could help improve forecasts of which hurricanes have the potential to cause the most damage.

They are called hurricanes in the Atlantic, typhoons in the West Pacific, and tropical cyclones worldwide; but wherever these storms roam, the forces that determine their severity now are a little less mysterious. NASA scientists, using data from the Tropical Rainfall Measuring Mission (TRMM) satellite, have found “hot tower” clouds are associated with tropical cyclone intensification.

Owen Kelley and John Stout of NASA’s Goddard Space Flight Center, Greenbelt, Md., and George Mason University will present their findings at the American Meteorological Society annual meeting in Seattle on Monday, January 12.

Kelley and Stout define a “hot tower” as a rain cloud that reaches at least to the top of the troposphere, the lowest layer of the atmosphere. It extends approximately nine miles (14.5 km) high in the tropics. These towers are called “hot” because they rise to such altitude due to the large amount of latent heat. Water vapor releases this latent heat as it condenses into liquid.

A particularly tall hot tower rose above Hurricane Bonnie in August 1998, as the storm intensified a few days before striking North Carolina. Bonnie caused more than $1 billion damage and three deaths, according to the National Oceanic and Atmospheric Administration National Hurricane Center.

Kelley said, “The motivation for this new research is that it is not enough to predict the birth of a tropical cyclone. We also want to improve our ability to predict the intensity of the storm and the damage it would cause if it struck the coast.” The pioneering work of Joanne Simpson, Jeffrey Halverson and others has already shown hot towers increase the chance a new tropical cyclone will form. Future work may use this association to improve forecasts of a cyclone’s destructive potential.

To achieve their goal, Kelley and Stout needed to compile a special kind of global statistics on the occurrence of hot towers inside tropical cyclones. The only possible data source was TRMM satellite, a joint effort of NASA and the Japan Aerospace Exploration Agency. “Many satellites can see the top of a hot tower, but what’s special about this satellite’s Precipitation Radar is that it gives you ‘X-ray vision’ so you can see inside a hot tower,” Kelley said. To compile global statistics, the radar needs to be orbiting the Earth.

After compiling the statistics, Kelley and Stout found a tropical cyclone with a hot tower in its eyewall was twice as likely to intensify within the next six hours than a cyclone that lacked a tower. The “eyewall” is the ring of clouds around a cyclone’s central eye. Kelley and Stout considered many alternative definitions for hot towers before concluding the nine-mile height threshold was statistically significant.

Funding for the research was provided by NASA’s Earth Science Enterprise. The Enterprise strives to advance Earth System Science and to improve the prediction of climate, weather and natural hazards from the unique vantage point of space.

Original Source: NASA News Release

Additional Attempts Fail to Reach Beagle 2

Image credit: Beagle 2

Mars Express has made several more attempts to reach the British-built Beagle 2 lander, and so far it hasn’t received any communications. At this point the European Space Agency will go into a phase of radio silence until January 22, when Beagle 2 is supposed to go into a new communications mode where it will attempt to transmit a signal throughout the Martian day. It’s expected that the teams will consider the probe a lost cause if it can’t be reached by March.

No signal was received from Beagle 2 this morning when ESA’s Mars Express orbiter passed over the landing site around 0220 GMT. Prof. Colin Pillinger, Beagle 2 Lead Scientist, was present at ESOC when the data came through and although the news was disappointing Prof. Pillinger was encouraged by the continued support and determination of the team at ESA’s mission control centre to continue the search. The next phase will be to initiate a period of radio silence where no communication attempts will be made with Beagle 2 until the 22 January. Adopting this approach will force Beagle 2 into communication search mode 2 [CSM2] where the probe will automatically transmit a signal throughout the Martian day [power is still conserved during the night].

The results from future communication attempts will be posted on the Beagle 2 and PPARC web sites.

Original Source: PPARC News Release

Photo Gallery: Southwest of Spirit’s Landing Site

This image mosaic was taken by the Mars Spirit rover while it was still sitting on its landing platform – the direction is to the southwest of the landing site. The landscape is very flat, scattered with small rocks and occasional shallow depressions; the narrow peak of a hill is visible seven to eight kilometres away. The image was taken using Spirit’s Panoramic Camera.

String of Galaxies Puzzles Astronomers

Image credit: NASA

Wide-field observations of the early Universe have turned up a strange string of galaxies 300 million light-years long that defy current theories about the evolution of the Universe shortly after the Big Bang. The astronomers who discovered the string of galaxies, which are more than 10 billion light-years away, compared it to supercomputer simulations of the early Universe, which wasn’t able to reproduce strings this large this early. The next step of this research will be to map an area of the sky ten times as large to get a better idea of the large scale structure of the Universe.

Wide-field telescope observations of the remote and therefore early Universe, looking back to a time when it was a fifth of its present age (redshift = 2.38), have revealed an enormous string of galaxies about 300 million light-years long. This new structure defies current models of how the Universe evolved, which can’t explain how a string this big could have formed so early.

The string is comparable in size to the “Great Wall” of galaxies found in the nearby Universe by Dr. John Huchra and Dr. Margaret Geller in 1989. This is the first time astronomers have been able to map an area in the early Universe big enough to reveal such a galaxy structure.

The string was discovered by Dr. Povilas Palunas (University of Texas, in Austin, Texas), Dr. Paul Francis (Australian National University, Canberra, Australia), Dr. Harry Teplitz (California Institute of Technology in Pasadena), Dr. Gerard Williger (Johns Hopkins University, Baltimore, Md.), and Dr. Bruce E. Woodgate (NASA Goddard Space Flight Center, Greenbelt, Md.). The initial observations were made with the 4-m (159-inch) Blanco Telescope at the National Science Foundation’s Cerro Tololo Inter-American Observatory in Chile, and confirmed with the 3.9-m (154-inch) Anglo-Australian Telescope at Siding Spring Observatory in eastern Australia. The team presents its finding today at the American Astronomical Society meeting in Atlanta, Georgia, and a paper describing this work will appear in the Astrophysical Journal in February.

The string lies 10,800 million light-years away in the direction of the southern constellation Grus (the Crane). The distance light travels in a year, almost six trillion miles or 9.5 trillion km., is one light-year, so we see the string as it appeared 10.8 billion years ago. It is at least 300 million light-years long and about 50 million light-years wide. (Refer to Movie 1 and Images 3 and 4 for an artist’s concept of the string.) The astronomers have detected 37 galaxies and one quasar in the string, but “there are almost certainly far more than this,” said Palunas. “The string probably contains many thousands of galaxies.” (Refer to Image 1 for an artist’s concept of these galaxies, and to Image 5 for a plot of their locations on the sky.)

“We are seeing this string as it was when the Universe was only a fifth of its present age,” said Woodgate. “That is, we are looking back four-fifths of the way to the beginning of the Universe as a result of the Big Bang.”

The team compared their observations to supercomputer simulations of the early Universe, which could not reproduce strings this large. “The simulations tell us that you cannot take the matter in the early Universe and line it up in strings this large,” said Francis. “There simply hasn’t been enough time since the Big Bang for it to form structures this colossal”.

“Our best guess right now is that it’s a tip-of-the-iceberg effect,” he said. “All we are seeing is the brightest few galaxies. That’s probably far less than 1% of what’s really out there, most of which is the mysterious invisible dark matter. It could be that the dark matter is not arranged in the same way as the galaxies we are seeing.” Recently, evidence has accumulated for the presence of dark matter in the Universe, an invisible form of matter only detectable by the gravitational pull it exerts on ordinary matter (and light). There are many possibilities for what dark matter might be, but its true nature is currently unknown.

In recent years, Francis explained, it had been found that in the local Universe, dark matter is distributed on large scales in very much the same way the galaxies are, rather than being more clumpy, or less. But go back 10 billion years and it could be a very different story. Galaxies probably form in the center of dark matter clouds. But in the early Universe, most galaxies had not yet formed, and most dark matter clouds will not yet contain a galaxy.

“To explain our results,” said Francis, “the dark matter clouds that lie in strings must have formed galaxies, while the dark matter clouds elsewhere have not done so. We’ve no idea why this happened – it’s not what the models predict.”

To follow up this research, the astronomers say, the next step is to map an area of sky ten times larger, to get a better idea of the large-scale structure. Several such surveys are currently under way. The research was funded by NASA and the Australian National University.

Original Source: NASA News Release

Stars of All Ages Have Comets and Planets

Image credit: Harvard CfA

Astronomers from the Harvard Center for Astrophysics studied Comet Kudo-Fujikawa as it swept past the Sun in early 2003, and they noticed it was emitting large amounts of carbon and water vapour. This new view of the comet matches observations of other stars that indicate there could be comets emitting similar material. Since other stars probably have comets, it increases the likelihood that they could also have rocky planets, like the Earth.

In early 2003, Comet Kudo-Fujikawa (C/2002 X5) zipped past the Sun at a distance half that of Mercury’s orbit. Astronomers Matthew Povich and John Raymond (Harvard-Smithsonian Center for Astrophysics) and colleagues studied Kudo-Fujikawa during its close passage. Today at the 203rd meeting of the American Astronomical Society in Atlanta, they announced that they observed the comet puffing out huge amounts of carbon, one of the key elements for life. The comet also emitted large amounts of water vapor as the Sun’s heat baked its outer surface.

When combined with previous observations suggesting the presence of evaporating comets near young stars like Beta Pictoris and old stars like CW Leonis, these data show that stars of all ages vaporize comets that swing too close. Those observations also show that planetary systems like our own, complete with a collection of comets, likely are common throughout space.

“Now we can draw parallels between a comet close to home and cometary activity surrounding the star Beta Pictoris, which just might have newborn planets orbiting it. If comets are not unique to our Sun, then might not the same be true for Earth-like planets?” says Povich.

SOHO Sees Carbon
The team’s observations, reported in the December 12, 2003, issue of the journal Science, were made with the Ultraviolet Coronagraph Spectrometer (UVCS) instrument on board NASA’s Solar and Heliospheric Observatory (SOHO) spacecraft.

UVCS can only study a small slice of the sky at one time. By holding the spectrograph slit steady and allowing the comet to drift past, the team was able to assemble the slices into a full, two-dimensional picture of the comet.

The UVCS data revealed a dramatic tail of carbon ions streaming away from the comet, generated by evaporating dust. The instrument also captured a spectacular ‘disconnection event,’ in which a piece of the ion tail broke off and drifted away from the comet. Such events are relatively common, occurring when the comet passes through a region of space where the Sun’s magnetic field switches direction.

Cometary Building Blocks
More remarkable than the morphology of the carbon ion tail was its size. A single snapshot of Kudo-Fujikawa on one day showed that its ion tail contained at least 200 million pounds of doubly ionized carbon. The tail likely held more than 1.5 billion pounds of carbon in all forms.

“That’s a massive amount of carbon, weighing as much as five supertankers,” says Raymond.

Povich adds, “Now, consider that astronomers see evidence for comets like this around newly formed stars like Beta Pictoris. If such stars have comets, then perhaps they have planets, too. And if extrasolar comets are similar to comets in our solar system, then the building blocks for life may be quite common.”

Understanding Our Origins
In 2001, researcher Gary Melnick (CfA) and colleagues found evidence for comets in a very different system surrounding the aging red giant star CW Leonis. The Submillimeter Wave Astronomy Satellite (SWAS) detected huge clouds of water vapor released by a Kuiper Belt-like swarm of comets which are evaporating under the giant’s relentless heat.

“Taken together, the observations of comets around young stars like Beta Pictoris, middle-aged stars like our Sun, all planets, and old stars like CW Leonis strengthen the connection between our solar system and extrasolar planetary systems. By studying our own neighborhood, we hope to learn not only about our origins, but about what we might find out there orbiting other stars,” says Raymond.

Other co-authors on the Science paper reporting these findings are Geraint Jones (JPL), Michael Uzzo and Yuan-Kuen Ko (CfA), Paul Feldman (Johns Hopkins), Peter Smith and Brian Marsden (CfA), and Thomas Woods (University of Colorado).

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

Original Source: Harvard CfA News Release

Spirit Stands Up

Image credit: NASA/JPL

NASA engineers confirmed today that the Spirit rover has successfully unfolded itself and “stood up” from its contracted travel position on the surface of Mars. The latest image taken by the rover shows its front wheels locked into the proper position. The lander’s airbag is still partially blocking the main exit ramp, so engineers are considering whether to continue trying to pull the airbag in, or use another ramp to roll off the lander. The second rover, Opportunity, is expected to arrive on Mars on January 24, 2004.

JPL engineers played Bob Marley’s “Get Up, Stand Up” in the control room as they watched new images confirming that the Mars Exploration Rover Spirit successfully stood up on its lander late Thursday night Pacific time, a major step in preparing for egress. This image from the rover’s front hazard avoidance camera shows the rover in the final stage of its stand-up process. The two wheels on the bottom right and left are locked into position, along with the suspension system. The martian landscape is in the background. With a deflated airbag partially blocking one exit route, engineers will decide whether Spirit should use a different route to roll off the lander.

Original Source: NASA/JPL News Release

Double Pulsar System Found

Image credit: RAS

An international team of astronomers have discovered a double pulsar system – the first ever seen. The two objects orbit a common centre of gravity once every 2.4 hours; one rotates at 3000 times a minute, while the other spins at only 22 times a minute. This discovery is important because it will allow astronomers to test various theories of relativity as the two objects interact with each other. The two pulsars will probably merge to become a black hole in 85 million years.

An international team of scientists from the UK, Australia, Italy and the USA have announced in today’s issue of the journal Science Express [ 8th January 2004 ] the first discovery of a double pulsar system.

They have shown that the compact object orbiting the 23-millisecond pulsar PSR J0737-3039A with a period of just 2.4 hours is not only, as suspected, another neutron star but is also a detectable pulsar, PSR J0737-3039B, that is rotating once every 2.8 seconds.

Professor Andrew Lyne of the University of Manchester points out that “While experiments on one pulsar in such an extreme system as this are exciting enough, the discovery of two pulsars orbiting one another opens up new precision tests of general relativity and the probing of pulsar magnetospheres.”

The same team previously reported [Nature 4th December 2003], the discovery of pulsar A in a close binary system which is rapidly losing energy by gravitational radiation. The stars will coalesce in only approximately 85 million years, sending a ripple of gravity waves across the Universe. The discovery of the system shows that such coalescences will occur more frequently than previously thought. “The news has been welcomed by gravitational wave hunters, since it boosts their hopes for detecting the gravitational waves” says Prof. Nichi D’Amico of Cagliari University.

The double neutron star system was first detected using the 64-m Parkes radio telescope in New South Wales, Australia. Subsequent observations were made both at Parkes and with the 76-m Lovell Telescope of the University of Manchester in Cheshire, UK and revealed the occasional presence of pulsations with a period of 2.8 seconds from the companion pulsar.

Already, four different effects beyond those explained with simple Newtonian gravity have been measured and are completely consistent with Albert Einstein’s theory. Dr. Richard Manchester of the Australia Telescope National Facility says “The fact that both objects are pulsars enables completely new high-precision tests of gravitational theories. This system is really extreme.” Future observations of the two stars will measure their slow spiral in towards each other as they radiate gravitational radiation – a dance of death leading to their ultimate fusion into what may become a black hole. General relativity predicts that the two stars will slowly wobble like spinning tops allowing new tests of the theory.

Another unique aspect of the new system is the strong interaction between radiation from the two stars. By chance, the orbit is seen nearly edge on to us, and the signal from one pulsar is eclipsed by the other. Dr. Andrea Possenti of Cagliari Astronomical Observatory says “This provides us with a wonderful opportunity to probe the physical conditions of a pulsar’s outer atmosphere, something we’ve never been able to do before.”

The surveys designed by the team to discover new pulsars at the Parkes Telescope have been extraordinarily successful. They have discovered over 700 pulsars in the last 5 years, nearly as many as were discovered in the preceding 30 years. The discovery of this double pulsar system will be the major jewel in the crown.

Original Source: RAS News Release