Universe Today

March 3, 2008December 26, 2015 by Nancy Atkinson

Latest Mars Images Round-up

With three orbiters and two rovers currently at Mars, there are always interesting images coming back from the Red Planet. Here’s a round-up of the latest images from the five different spacecraft. First up is a fascinating image from the Mars Odyssey spacecraft of dust devil tracks. It’s amazing just how many tracks there are in just this one image. Martian dust devils can be up to fifty times as wide and ten times as high as dust devils seen on Earth. This image was taken by Odyssey’s Thermal Emission Imaging System (THEMIS), and shows an area in the south polar region, just east of Daly Crater. Resolution is about 17 meters per pixel. Original Image link.

NASA’s Mars Exploration Rover Spirit has this view northward from the position at the north edge of the “Home Plate” plateau where the rover will spend its third Martian winter. And no, that’s not a pool of water in the image. It’s just rippled sand in the “El Dorado” sand dune field, and the image is shown in false color.

Husband Hill is on the horizon. Spirit used its panoramic camera (Pancam) to capture this image during the rover’s 1,448th Martian day, on January 29, 2008.
Original image link.

This view from the Opportunity rover shows a close-up of bedrock from the inside of Victoria Crater, where the rover is currently studying a stratigraphic layer of rocks. This area is informally named “Lyell,” which is the lowermost of three layers the rover has examined at a bright band around the inside of the Crater.

Opportunity used its panoramic camera (Pancam) to capture this image with low-sun angle at a local solar time of 3:21 p.m. during the rover’s 1,433rd Martian day, on February 4, 2008. This image, too, is in false color to highlight the ripples and bands in the bedrock.
Original Image link.

ESA’s Mars Express took snapshots of Candor Chasma, a valley in the northern part of Mar’s huge canyon, Valles Marineris, as it was in orbit above the region on 6 July 2006.

The High Resolution Stereo Camera on the orbiter obtained the data,with a ground resolution of approximately 20 m/pixel. Candor Chasma lies at approximately 6Â° south and 290Â° east.
Original Image link.

This image taken by the Mars Reconnaissance Orbiter (MRO) shows a volcanic vent. A volcanic vent is an opening in the crust of a planet that emits lava (molten rock) and volcanic gases. The rough texture of the plains surrounding the vent iindicates that it is lava.

There is a large number of snake-like features emanating from the vent. The parallel lines that outline the features are levees, which mark the edges of channels that carried molten lava. As lava flows, it moves slowest at its edges and bottom because the lava sticks to the non-flowing rocks, and as the lava slows, it cools off and hardens.

Levees form when the sides harden but the center of the flow keeps moving. As the eruption episode ends, and the lava drains, the center is left lower than the sides producing these high-standing structures. Of course, these lava flows are very, very old.
Original Image page.

March 3, 2008December 26, 2015 by Ian O'Neill

UK Urged to Focus on Satellite Technology, not Manned Exploration of Space

The UK is the only G8 country (the eight richest countries in the world) without a manned space program. 20 years ago, Prime Minister Margaret Thatcher put pay to any hope for a British astronaut by opting out of plans citing it as “too expensive” for the island nation. However, the UK government signalled last month they were considering a review of this space exploration policy, receiving a mixed reaction. A prominent satellite manufacturer has come forward with a suggestion that the UK may after all be better suited to constructing a space exploration “infrastructure” and leaving manned exploration to the ESA and NASA…

In 1986, the UK was effectively ruled out of manned expeditions into space. Plans outlined by the European Space Agency (ESA) at the time were considered too expensive for the nation to pursue, so the UK concentrated on its civil and defence space capabilities through robotic explorers rather than participating in any national or international collaboration.

As of 2007, after two decades of research and development, Britain spends over Â£200 million ($400 million) a year on space initiatives, putting some of the world’s most advanced technology into space. UK companies such as SSTL, Qinetiq, Logica and Astrium are leading the world in certain space technology areas as a result. Many in the industry (especially the satellite manufacturing sector) would agree that the lack on participation in a manned space program has provided growth in robotic exploration sectors.

This may be the case, but there is pressure for the UK to catch up with the other seven nations of the G8 and begin sending British astronauts into space rather than depending on NASA and the ESA. British-born astronauts have been into space, such as Piers Sellers (pictured above), Michael Foale (dual nationality – Britain and USA) and Nicholas Patrick; Helen Sharman was the first Briton in space in 1991. All British astronauts were either naturalized American or involved with other space programs,Â little investment was made by the UK government in any manned mission.

Many academics would disagree with the UK’s past unwillingness to “get involved” in a manned program. As the worlds nations become more and more space-worthy, many believe the UK is being left behind and the dependence on NASA and ESA will become problematic as time goes on. There would be economic and educational value in starting a UK manned space program too. Looking back on the stimulation that the Apollo program had on the US in the 1960’s, the nation saw a surge of interest in the sciences and engineering subjects. This educated an entire generation of college and university students who have formed the foundations of the hugely influential space program that exists today.

“The UK needs to take early steps for a future role in a human exploration programme. It can stimulate education and excite the young to get involved in science and technology.” – Professor Frank Close, Oxford University and Chairman of the UK Space Exploration Working Group (in an interview with The Independent Online).

But the idea of a UK manned space program may push the nation beyond its means according to David Williams, head of Avanti, a satellite communications company. Williams believes that the UK, after many years of space innovation and robotic exploration of space and the planets, is ideally placed to dominate the world’s communication ability with deep space missions.

“If mankind is going to exploit the resources of the solar system, you are going to have to travel over very long distances and you are going to have to communicate over very long distances and you will need a network of data-relay satellites. The UK has a big advantage. We have the opportunity to control the space internet, which is going to be this network of data-relay satellites.” – David Williams.

Following this logic, as space exploration is an international effort, letting big space agencies such as ones controlled by the USA, Russia and Europe pursue manned exploration, the UK has an important role to play to insure advanced communication technology keep the international manned space efforts in touch with Earth.

Either way, this is an exciting time for UK space efforts. Although recently buffeted by funding shortages, there appears to be some positive movement toward greater involvement in international collaboration and investment in satellite technologies.

Source: The Guardian Online, The Independent Online

March 1, 2008December 26, 2015 by Ian O'Neill

Mars Gullies Produced by Dry Granular Debris and Not by Recent Water Flow

The High Resolution Imaging Science Experiment (HiRISE) on board NASA’s Mars Reconnaissance Orbiter (MRO) observed what appeared to be fresh gullies formed by a rapid release of water on the Martian surface in 2006. However, new computer models simulating the creation of gullies on the surface of Mars suggest that they are in fact created by the flow of dry debris (i.e. landslides) and not by the flow of water. A blow for the microbial life hunters and a huge blow for mission planners looking for easy sources of water for manned missions…

The MRO isn’t the only orbiter to view apparent gullies forged by spurts of water. The Mars Orbiter Camera (MOC) onboard NASA’s Mars Global Surveyor (MGS) also made news in 2006 when scanning the cratered regions of Terra Sirenum and Centauri Montes. Images taken several years apart revealed some changes in the most recent pictures, highlighting what looked like outflow channels from surges of liquid water (pictured below). What made this especially exciting was that this was possible evidence for the existence of liquid water flowing on Mars within the past few years (albeit very quickly).

New work by scientists at the University of Arizona appears to conflict with these observations. In an attempt to demonstrate the characteristics of water flowing in Martian conditions, Associate Professor Jon D. Pelletier (Geophysics) and colleagues used topological data from the HiRISE instrument (the most advanced imaging system currently orbiting Mars) and modelled the flow of water down a slope. What the simulation showed was a surprise; the researchers went into the project thinking they were going to prove that the gullies were formed by water. Instead, they had shown that the shapes and characteristics of the observed gullies most resembled that of the modelled gullies shaped by dry debris tumbling down a slope.

“The dry granular case was the winner. I was surprised. I started off thinking we were going to prove it’s liquid water.” – Jon D. Pelletier

Looking at the comparison between the two cases (water and dry debris flow) and the HiRISE observations, it is very easy to see the striking resemblance between dry debris flow and what is actually observed. The water simulation appears to be more diffuse, lacking the characteristic “fingers” reaching down the slope.

On hearing the news in 2006 that there was a possibility of liquid water flowing on the Martian surface, biologists hoped that a new tool had been found to pinpoint where sub-surface deposits of liquid water may be stored. This will have provided future missions with a location to hunt for life in the most likely place, near fresh gullies, near a source of water. Unfortunately it seems that these gullies are in fact shaped by small landslides, not by surges of water from a sub-surface reservoir.

Research to be published in the March issue of Geology, entitled: “Recent bright gully deposits on Mars: wet or dry flow?“.

Source: University of Arizona News

February 29, 2008December 26, 2015 by Ian O'Neill

First Experiment Starts in ISS Columbus Module Testing Plant Growth

The brand new ESA Columbus Module installed on the International Space Station (ISS) by the STS-122 crew last week is beginning a first run of biological experiments. This first experiment tests the reaction of root growth in different gravitational states. Of particular interest is how the roots of seeds develop in space when compared to terrestrial conditions. This has obvious applications for growing plants in space, underpinning agricultural science in some of the most extreme and challenging environments man will experience.

Today saw the first ever experiment on the ESA Columbus Module on board the ISS. European astronaut LÃ©opold Eyharts activated the Waving and Coiling of Arabidopsis Roots at Different g-levels (WAICO) experiment, comparing two types of arabidopsis seed (one wild and one genetically modified) in gravity conditions from zero to one Earth gravity (or 1G). The arabidopsis seed is derived from the arabidopsis thaliana plant which copes very well in restricted space and thrives in hostile surroundings.

The WAICO experiment will last for 10 to 15 days and the sprouted seeds will be returned by the STS-123 Space Shuttle mission due for launch on March 11th so the results can be analysed. Throughout the experiment, using the brand new “Biolab” equipment (pictured), the advanced telemetry of the Columbus Module will relay real-time video of seed development to ESA scientists in Germany.

The development of the root growth will be scrutinized; especially the amount of “waving” and “coiling” that occurs as a reaction to different gravity conditions. These experiments will also help terrestrial farming methods, giving farmers the opportunity to optimize plant growing conditions.

Source: ESA

February 29, 2008December 26, 2015 by Ian O'Neill

Shuttle Endeavour to Launch on March 11th; View the STS-123 Interactive Mission Timeline

We haven’t had time to catch our breath after STS-122 touched down on February 20th, only nine days ago, and yet the next launch date to the International Space Station (ISS) has been announced today. The date? March 11th -Â only 11 days from now. This time NASA has put together a nice little interactive gadget so you can see the 17 day mission from day to day…

STS-122 was a highly successful round trip to the ISS. The Space Shuttle Atlantis crew delivered ESA’s Columbus science module without a hitch on February 11th. The only small problem arose when one of the crew members suffered an undisclosed minor medical problem, postponing installation for a day, but the crew adapted and performed excellently.

With Atlantis’ engines still warm, Endeavour is being prepared for launch on March 11th. This time the mission is to install a part of the Japanese laboratory complex called “Kibo”. In addition, a new Canadian robotics system will be attached to complement the existing robotic arm servicing the Harmony module.

STS-123 will be a complex mission for crew members Dominic Gorie (Commander), Gregory H. Johnson (Pilot), Rick Linnehan (Mission Specialist), Robert L. Behnken (Mission Specialist), Mike Foreman (Mission Specialist), Garret Reisman (Mission Specialist) and Japanese astronaut Takao Doi. Five spacewalks (EVAs) will need to be carried out to continue the expansion of the station.

The Associate Administrator for Space Operations, Bill Gerstenmaier, stated that there were very few issues with the pre-launch stages and said that Space Shuttle Endeavour is ready to blast off.

View the interactive guide of the STS-123 mission to the ISS.

Source: NASA

February 29, 2008December 26, 2015 by Fraser Cain

Final Detector in Place at the Large Hadron Collider

One of the most complicated construction projects ever attempted reached a major milestone today. The final large detector element for the ATLAS instrument was lowered into the Large Hadron Collider. And this baby’s big. Weighing in at 100 tonnes. When the collider finally comes online, this instrument will measure the cascade of particles generated in proton-proton collisions.

The ATLAS detector itself is enormous, weighing 7,000 tonnes and measuring 46 metres long, 25 metres high and 25 metres wide. It has 100 million sensors that will track all the particles that freeze out when protons are smashed together at tremendous energies.

And so today, the final element for ATLAS was plugged into its permanent home. It’s known as a “small wheel”, and there are two of them in the detector. Compared to the full ATLAS instrument, it only weighs 100 tonnes, and measures a mere 9.3 metres across.

Since the whole detector is located deep underground, engineers had to lower each piece down a 100 metre shaft. And they’ve been installing pieces this way since 2003. In the case of the small wheel, it was even harder to get it down.

“One of the major challenges is lowering the small wheel in a slow motion zigzag down the shaft,” explained Ariella Cattai, leader of the small wheel team, “and performing precision alignment of the detector within a millimetre of the other detectors already in the cavern.”

With all of ATLAS’ parts in place, it’s time to enter the commissioning phase. Researchers will test all of the parts together in preparation for the first tests this Summer.

By this time next year, physicists might have many more answers about the nature of gravity, dark matter, and nature’s preference for matter over dark matter. And I’m sure they’ll have even more new questions. But that’s how science works.

Original Source: CERN News Release

February 29, 2008December 26, 2015 by Fraser Cain

What Happens When Supermassive Black Holes Collide?

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As galaxies merge together, you might be wondering what happens with the supermassive black holes that lurk at their centres. Just imagine the forces unleashed as two black holes with hundreds of millions of times the mass of the Sun come together. The answer will surprise you. Fortunately, it’s an event that we should be able to detect from here on Earth, if we know what we’re looking for.

Most, if not all, galaxies in the Universe seem to contain supermassive blackholes. Some of the biggest can contain hundreds of millions, or even billions of times the mass of our own Sun. And the environments around them can only be called “extreme”. Researchers think that many could be spinning at the maximum rates predicted by Einstein’s theories of relativity – a significant fraction of the speed of light.

As two galaxies merge, their supermassive black holes have to eventually interact. Either through a direct collision, or by spiraling inward until they eventually merge as well.

And that’s when things get interesting.

According to simulations made by G.A. Shields from the University of Texas, Austin, and E.W. Bonning, from Yale University, the result is often a powerful recoil. Instead of coming together nicely, the forces are so extreme that one black holes is kicked away at a tremendous velocity.

The maximum kick happens with the two black holes are spinning in opposite directions, but they’re on the same orbital plane – imagine two spinning tops coming together. In a fraction of a second, one black hole is given enough of a kick to send it right out of the newly merged galaxy, never to return.

As one black hole is given a kick, the other receives a tremendous amount of energy, injected into the disk of gas and dust surrounding it. The accretion disk will blaze with a soft X-ray flare that should last thousands of years.

So even though mergers between supermassive black holes are extremely rare events, the afterglow lasts long enough that we should be able to detect a large number out there in space right now. The researchers estimate that there could be as many as 100 of these recent recoil events happening within 5 billion light-years of the Earth.

Their recently updated journal article, entitled Powerful Flares from Recoiling Black Holes in Quasars will be published in an upcoming issue of the Astrophysics Journal.

Original Source: Arxiv

February 29, 2008December 26, 2015 by Ian O'Neill

Massive Stars Need Their Smaller Siblings To Grow

So how do rare massive stars grow 10 to 150 times the mass of our Sun? It turns out that a standard star-forming nebula is way too cold for big stars to form. So how can these clouds of gas and dust be prepared so massive stars can develop? Answer: Let small stars do the hard work and heat that nebula up…

This is the ultimate stellar crÃ¨che. Star-forming nebulae are vast regions of space filled with gas and dust. Proto-stars need a lot of hydrogen to form and begin fusion reactions in their young cores. The bigger the nebula, the bigger the star… or so you’d think.

The problem with these young nebulae is that they are cold; in fact they are very cold. Typical interstellar clouds of hydrogen have temperatures very close to absolute zero (the lowest temperature possible) due to the lack of heat in the far-off reaches of the cosmos. Cold clouds will fragment very easily, breaking up and forming smaller clouds of hydrogen. Eventually they will collapse to form stars, but these stars will be very small due to the lack of fuel in the nebula fragment. If this is the case, how are massive stars – the ones responsible for producing heavy elements including anything heavier than helium – formed at all? Surely all clouds of dust and gas are cold, and therefore fragment, only producing small stars?

From research publishedÂ in Nature this weekby Christopher F. McKee (a professor from UC Berkeley) and Mark R. Krumholz (Hubble postdoctoral fellow at Princeton), there is a possible solution to this problem. Perhaps young stars provide a heating source to warm up the surrounding nebula,Â preventing the surroundingÂ gas from fragmenting, allowing itÂ to collapse into progressively bigger stars.

Starting at temperatures only 10-20 degrees above absolute zero, clouds heated by young stars may increase in temperatures three-fold. However, researchers realize that a massive star-forming cloud needs to be several hundred degrees warmer than absolute zero to prevent the whole cloud from fragmenting, they also understand that the “zone of heating” forÂ each small star is limited in less dense clouds. This situation changes when the star-forming cloud is dense. The zone of influence each small star has will encompass the whole nebula. This collaborative heating effect by the small stars prevents fragmentation and allows larger volumes of gas to collapse, forming massive stars.

“It’s only the formation of these low-mass stars that heats up the cloud enough to cut off the fragmentation. It is as if the cold molecular cloud starts on the process of making low-mass stars but then, because of heating, that fragmentation is stopped and the rest of the gas goes into one large star.” – Christopher F. McKee.

A warmer cloud is a bigger cloud, providing more fuel, allowing massive stars to form. It is the ultimate stellar nursery; massive stars can only form once their smaller (and older) siblings warm up the cosmic nest for them to thrive.

View theÂ stunningÂ simulation of a massive star forming in a warm cloud (24Mb, .mpg)

Source: UC Berkley News

February 28, 2008December 26, 2015 by Ian O'Neill

Development Problems May Delay Mars Science Laboratory Mission Until 2011

NASA’s over budget Mars Science Laboratory mission, scheduled for a 2009 launch, may be delayed due to problems with the atmospheric re-entry shield design. A new shield will cost up to $30 million, adding to the $1.8 billion price tag, $165 million more than planned. The mission uses innovative landing technologies and is powered by a mini-nuclear reactor, giving it the ability to travel faster and carry a bigger payload over the Martian terrain. This new setback may postpone the launch until 2011.

As the most advanced part of NASA’s Mars Exploration Program, the Mars Science Laboratory will be the most ambitious mission yet. Powered by a nuclear reactor, the large rover (measuring 9-foot long) will have a greater range and will be able to carry out a massive range of experiments on the planets surface. Complementing missions such as the Mars Exploration Rovers (Spirit and Opportunity, still making history as the longest ever Mars rover mission) and Phoenix (scheduled to arrive on May 25th this year), The Mars Science Laboratory will continue to see whether Mars might be able to sustain microbial life, take samples and analyse rocks plus provide us with detailed information about the landscape, atmosphere and whether water exists in large quantities. This is all in preparation of future manned exploration of the Red Planet.

Due to the adventurous nature of the project, there have been some setbacks and over-spending. The most recent problem focuses on the heat shield protecting the lander from extreme heat as it enters the atmosphere. The original design uses a similar shield to the one that protects the Shuttle’s external fuel tanks, but in tests engineers found that it could suffer catastrophic damage. Now, NASA has switched to a stronger cocoon-like shield similar to the one that protected the Stardust mission returning comet samples to Earth in 2006. But development and construction isn’t cheap, setting NASA back another $30 million.

“It kind of interrupts what has been an incredibly successful sequence of missions.” – John Mustard, Brown University Geologist and head of an advisory group giving scientific input on future Mars projects.

Many scientists believe that such ambitious projects will always stumble across unforeseen problems and expenses, after all, space agencies such as NASA are doing something extraordinary, spearheading mankind’s exploration of space. This is frustrating however, as the Mars Exploration Program has surpassed all expectations so far and it appears that the Mars Science Lab is slowing down progress, prompting worries that costs will soar should the launch date be postponed any longer.

Source: Physorg

February 28, 2008December 26, 2015 by Ian O'Neill

NASA and ESA Orbiters Join Forces to Prepare for Phoenix Arrival on May 25th, 2008

When the Phoenix lander hits the Martian atmosphere at over 20,000 km/h, at least it will feel safe in the knowledge that it has three buddiesÂ looking out for it. NASA’s Mars Reconnaissance Orbiter and Mars Odyssey are already preparing for Phoenixâ€™s arrival, and now ESA’s Mars Express has been asked to assist in watching the lander’s 13-minute descent.

The Phoenix Mars Mission will land on the Red Planet on May 25th of this year to search for evidence of life on Mars and seek out some good regions for future manned settlements. However, before it can begin its work, Phoenix must dive through the Martian atmosphere at high speed and complete a 13-minute entry, decent and landing (EDL phase). This is a critical part of any planetary lander mission. As highlighted by the British Beagle 2 lander when it separated from Mars Express in 2004, nobody should be complacent about atmospheric reentry.

Flight controllers had already begun adjusting Mars Express’ phase in November last year to optimize its orbit so it can get the best possible view of Phoenix’s entry. Orbital adjustments already had to be made, so NASA’s request did not cost too much in additional fuel.

Using instrumentation intended to track the descent of the ill-fated Beagle 2, Mars Express’ adopted lander will be tracked by the Mars Express Lander Communications system (MELACOM). Mars Express will perform a fast (three-times faster than normal operations) turn on one axis to follow Phoenix flying past and down to Mars. Mars Express will be an essential backup system to NASA’s orbiters, allowing NASA to confirm the correct measurements of speed and trajectory of Phoenix.

Having already been tested, ESA scientists are confident Mars Express will perform excellently:

“Last year, we practised relaying commands from NASA to Mars Express and then down to the surface, using NASA’s Mars Rovers as stand-in for Phoenix. It worked fine.” – Michel Denis, Mars Express Spacecraft Operations Manager.

Either way, the 13-minutes from entry to landing will be nerve-wracking for everyone involved, but it’s good to know the NASA and ESA missions already in orbit around Mars will be able to give a helping hand to the Mars rookie.

Source: ESA