Ian O'Neill, Author at Universe Today

October 23, 2008December 24, 2015 by Ian O'Neill

Life Will be Hard for Colonists – Kaguya Can’t Find Water on the Moon

High-resolution view of the lunar surface (JAXA/SELENE)

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It’s been a long-held belief that the Moon is hiding significant quantities of water ice, safe from the Sun’s ablative effects inside shady craters. One such crater is called Shackleton at the lunar South Pole and previous Moon missions have indicated it might hold a large reservoir of ice for all the water needs of future Moon colonists. Alas, the Japanese lunar mission Kaguya (or the Selenological and Engineering Explorer – “SELENE”) has taken a peek into the crater to find… nothing. At least, it hasn’t spotted any significant quantities of surface ice. So where does this leave future lunar colonies?

In 1994, the US Clementine lunar orbiter (a joint venture between NASA and the Ballistic Missile Defense Organization) carried out the “Bistatic Radar Experiment” which involved bouncing radio signals from the probe’s transmitter from the lunar poles. The reflected signal was then received by the Deep Space Network antennae on Earth. Scientists deduced from the reflected signal that volatile ices were present in the lunar regolith, most probably water ice. However, this claim was disputed after a similar experiment was done using the Arecibo radio telescope in Puerto Rico. This time, radio signals were reflected from regions on the Moon bathed in sunlight (where it would be impossible for water ice to survive) and identical results to the Clementine mission were found.

NASA’s 1998 Lunar Prospector also had mixed results. Using its Neutron Spectrometer (NS) instrument, the probe had detected large quantities of water, leading NASA to make the estimate that 3 billion metric tons of water ice was located at or near the surface of the Moon in its polar regions. However, when the mission ended in 1999, the Lunar Prospector was deliberately crashed into a crater in the lunar South Pole in the hope of kicking up a plume of lunar surface material and detecting water ice from Earth. Unfortunately, no water was discovered. (Out of interest, the Lunar Crater Observation and Sensing Satellite, set for launch in April 2009, has a similar suicidal goal to put a divot in the Moon.)

Now, using the Japanese lunar mission Kaguya, scientists have taken the opportunity to have a closer look into the Shackleton crater, the most likely candidate to have a supply of water ice shaded from the Sun. As there is no atmosphere (apart from some very tenuous outgassed chemicals), sunlight cannot be scattered into the bottom of the crater to illuminate its surface. However, scientists have taken images during lunar mid-summer when enough light is scattered off the crater’s upper inner wall to faintly brighten the darkness below.

Although it is very cold inside the crater (-183°C or -297°F), certainly ideal conditions to preserve ice, there is no visual evidence of any surface ice at all.

Although this isn’t great news for future lunar colonists, don’t pack up your Moon buggies quite yet. The Japanese team have concluded that although there is no visual brightening due to ice, water ice may be mixed in low quantities with the lunar dirt. Or there’s simply no ice in Shackleton crater. Either way, I wouldn’t suggest mounting a manned expedition to Shackleton any time soon…

Source: Space.com

October 23, 2008December 24, 2015 by Ian O'Neill

Where Have All the Gamma Ray Bursts Gone?

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Astronomers are confused.

As if gamma-ray bursts (GRBs) weren’t mysterious enough, there’s something else to add to the bag of confusion. GRB events are missing from the furthermost reaches of the Universe. Right around the time when there should be a lot of GRBs, during the “star forming epoch” (when stars were just beginning to evolve after the Big Bang), there appears to be none. Zero. There’s no ancient flashes of massive star death to be found. What’s more, there doesn’t appear to be any afterglow from previous gamma-ray bursts either.

So what’s going on? Were there no GRB events before 12.8 billion years ago? Possibly… although there might be another answer. They are out there but we just can’t see them.

Gamma-ray bursts are the biggest and brightest explosions in our Universe since the Big Bang. When a GRB detonates, it can easily outshine its host galaxy containing billions of stars. These energetic events have been observed since the 1960’s and only until recently have astronomers found an explanation as to what GRBs are. A GRB occurs when a young metal-poor massive star has used up all its fuel and, like a supernova, collapses under its own gravitational field. The rapid-spinning star then funnels intense beams of radiation from its poles in the form of gamma-rays. Should one of these beams be directed toward Earth, we see a disproportionately bright explosion (as a vast amount of energy is channelled through the poles). Until the “collapsar model” was devised, astronomers were at a loss to explain these energetic events.

The collapsar model appears to explain GRBs lasting for two seconds or more. However, there is another class of GRB, of much shorter timescales, that does not fit in with the collapsar model. Short-period GRBs may be the result of violent interactions between black holes and a neutron stars.

So, does this mean GRBs are becoming less mysterious? Actually, GRB theory has just become a little more complicated. It would appear that no GRBs occurred before 12.8 billion years ago. Last month, the most distant (and therefore oldest) GRB was detected 12.8 billion light years away, but that in itself is strange.

During the time when the first stars started to form (around 13.4 billion years ago), they were by definition “metal-poor” stars (heavier elements, such as metals, were only possible after several generations of stellar evolution), so this should be a period of time when GRBs were regularly lighting up the night sky. However, according to observations of the most distant galaxies containing the youngest stars, GRB events seem to be non-existent.

One explanation put forward is the effect of red shift. As the Universe expands, space-time stretches. As light travels from the most distant reaches of the Universe, perhaps the light itself from GRBs has been so stretched (red-shifted) that the electromagnetic emissions simply cannot be detected by our instrumentation. These huge explosions could be happening, but as the emitted light has been so red-shifted, by the time the light reaches us, perhaps the emission does not resemble a GRB. Even the afterglow of one of these massive explosions would be unrecognisable in this case, the light observed would be shifted all the way into the infrared.

So will any GRBs be discovered further away than 12.8 billion light years? I think we’ll have to wait until we build some improved infrared observatories or recognise what a distant, ancient GRB looks like…

Source: NASA

October 23, 2008December 24, 2015 by Ian O'Neill

Asteroseismology: Observing Stars Vibrate with CoRoT

Modes of solar oscillation plotted over our Sun. Could the same things be done with other stars? (NASA/TRACE/NCAR)

[/caption]Observing a stars brightness pulsate may reveal its internal structure say researchers using the Convection Rotation and Planetary Transits (CoRoT) observatory. The highly sensitive orbital telescope can detect tiny variations in a distant star’s brightness, leading astronomers into a new field of stellar seismology called “asteroseismology.”

Seismology is more commonly used by scientists on Earth to see how waves travel through the terrestrial crust, thereby revealing the structure of the material below us. Even solar physicists use the method of helioseismology to understand the interior of our Sun by observing its wobble. Now, by observing the slight changes in stellar brightness, it is possible to remotely probe deep into the inner workings of a distant star…

CoRoT is a joint French Space Agency (CNES) and European Space Agency (ESA) mission to detect slight variations in the brightness of stars launched in 2006. As extrasolar planets pass in front of (or “transit”) a star, the brightness will decrease. The highly sensitive 27 cm-diameter telescope and spectroscopic instrumentation has the ability of detecting extrasolar rocky planets a few times the size of Earth and new gas giants (a.k.a. Hot Jupiters).

Another mission objective for the 630 kg satellite is to detect luminosity variations associated with acoustic pulsations passing through the body of the star. A similar method known as helioseismology uses the Solar and Heliospheric Observatory (SOHO) to detect the propagation of pressure waves through the Sun so a better idea of solar internal dynamics and structure can be gained.

CoRoT has been watching three stars, 20-40% more massive than the Sun, vibrate in reaction to the convective processes on the stellar surfaces. Some areas will expand and cool, whilst others with contract and heat up. This creates an oscillation, and a pulsation in brightness, providing information about the inner structure of these distant stars. The three stars brightened and dimmed 1.5 times more dramatically than solar helioseismology observations. However, this is still 25% weaker than expected from theory, so it would seem stellar physics still has a long way to go.

“This really marks the start of a completely new era of space-based asteroseismology,” said Joergen Christensen-Dalsgaard of the University of Aarhus in Denmark. “It shows that CoRoT can do what it set out to do.”

Asteroseismology can also be used to gauge the precise age of a star. Usually, the age of a star is determined by looking at a star cluster where it is assumed the majority of the stars are of a similar age. However, as a star ages, different elements undergo nuclear fusion at different times. This alters the star’s interior structure and therefore alters the vibrational characteristics of the star. This can be detected by CoRoT, hopefully aiding astronomers when deducing the precise ago of a particular star.

“In principle, you can look at one star all on its own and determine how old it is,” adds Michael Montgomery of the University of Texas.

Source: New Scientist

October 23, 2008December 24, 2015 by Ian O'Neill

Aldrin: Mars Pioneers Should Not Return to Earth

No coming back? The first Mars settlers should stay there (NASA/Ian O'Neill)

[/caption]Commenting on the strategy for the exploration of Mars, Buzz Aldrin, second man on the Moon and tireless space exploration advocate, has said that he believes the first explorers of the Red Planet should stay there. Following similar lines of the first European pioneers who settled in America, a small group of interplanetary explorers should expect to land, build, live and retire (probably even die) on Mars.

Setting up home on the Martian surface will be no easy thing (after all, the atmosphere is 100 times thinner than the Earth’s and the planet has no magnetic field to protect colonists from the ravages of solar radiation), but Mars offers far greater potential as a habitable world than any other Solar System option.

40 years after Aldrin landed on the Moon, one can understand his frustration that there is no current manned space exploration program leaving Earth orbit. Perhaps a pioneering effort to Mars will make all the difference – if we succeed there, who knows where it might lead…

The subject of sending a manned expedition to Mars has always been a controversial one. Who do we send? How long should the mission last? Is sending one explorer an option (it would certainly be cheaper)? Do we make plans for a return mission? What about the health risks? Do we set up a human colony in the first instance? Is it REALLY worth the effort and money? But whether you like it or not, mankind will always have the urge to venture beyond Planet Earth and colonize other worlds (whether the funding or political will is there or not, but that’s another story).

But how can it be done? There has been much speculation about the future of Mars exploration, and we are beginning to take the first baby-steps toward the ultimate goal – a manned mission. The Phoenix Mars lander is classed as a “scout mission” intended to aid the planning of future colonies; satellites such as the Mars Reconnaissance Orbiter (the clue is in the name – you have to do a bit of reconnaissance before sending in the troops!) has the The Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) on board with the primary task of finding mineral deposits on the surface that might be of use to a manned settlement. Every mission we send to the Red Planet has some function to aid the planning of a future human presence on the Martian surface.

As if commenting on his personal experience of the Apollo Program, Buzz Aldrin has shared his views on manned exploration of Mars. As any manned spaceship could take up to 18 months to travel to Mars, Aldrin believes it makes more sense for the first mission to be a one-way trip. “That’s why you [should] send people there permanently,” said Aldrin. “If we are not willing to do that, then I don’t think we should just go once and have the expense of doing that and then stop.”

“If we are going to put a few people down there and ensure their appropriate safety, would you then go through all that trouble and then bring them back immediately, after a year, a year and a half?” Buzz added.

Currently, NASA and the European Space Agency has tentatively said they are planning for a trip to Mars by 2030 or 2040. The current idea is to send a small group of explorers (possibly six individuals) to Mars, but have all the life support systems and supplies already set up on the surface before they arrive. Once an outpost is established, more colonists can be sent out to join them. The first operational manned colony will probably be 30-strong.

However, these colonists will need to be unique individuals. “They need to go there more with the psychology of knowing that you are a pioneering settler and you don’t look forward to go back home again after a couple a years,” Aldrin said. But that’s not to say they’ll never return to Earth. Years down the line, there may be the opportunity for a return mission, depending on technological advancements. “At age 30, they are given an opportunity. If they accept, then we train them, at age 35, we send them. At age 65, who knows what advances have taken place. They can retire there, or maybe we can bring them back.”

Many will argue that a manned mission to Mars is a “waste of money,” after all, why go through the expense and risk of sending humans when robots can do the same job. Aldrin disagrees with this stance, pointing out that it makes more sense to have humans on the ground, making on-the-spot decisions. I would argue that robotic explorers can only achieve so much; we can send the most advanced analysis equipment on board the most advanced robot, but there is no substitute for human ingenuity and experience. Far more science can be done on the Martian surface by an astronaut rather than a remote controlled robot. If life really does exist on the Martian surface, a man on Mars will find it far quicker than any rover.

Why else send man to Mars? To “do things that are innovative, new, pioneering,” rather than letting manned space flight continue to be a disappointment, Buzz added. After all, the International Space Station hasn’t lived up to many expectations, and the last time we walked on the Moon was in 1972… perhaps we need to start making some bold moves in the direction of Mars before we can consider ourselves to be a space faring race.

Source: Physorg.com

October 21, 2008December 24, 2015 by Ian O'Neill

The Martian Ice-Filled, Oyster Shell-Shaped Crater (HiRISE Images)

The unusually-shaped polar crater is filled with ice (HiRISE/NASA)

[/caption]This striking view of the Martian surface shows a stark contrast (false colour) between ice deposits and layered deposits (composed mainly of ice, rock and regolith) on the edge of the polar ice cap. In the centre, there is a lone crater, approximately 200 meters in diameter, collecting a basinful of ice. The ice is thought to have been there for about 10,000 years.

However, there are some oddities in this scene. Why is the crater abnormally shaped? After all, craters are normally circular, not oyster shell-shaped. Why is it an isolated crater? On viewing the entire region, only one crater appears to be present for several kilometres. Does this mean the landscape is fairly young? If so, what geological processes are shaping the surface?

The High Resolution Imaging Science Experiment (HiRISE) on board the Mars Reconnaissance Orbiter (MRO) continues to return some of the most striking views from its Martian orbit. The camera can resolve objects less than a meter in diameter, picking out everything from sand dunes, eroding mesas, rolling rocks, avalanches (in action) to tiny secondary craters. These are some of the most detailed views we’ve ever had of the Red Planet’s surface. HiRISE can even keep an eye on our robotic explorers, like spotting Phoenix shortly after it landed and the tread marks of the rover Opportunity.

The polar ice cap, layered deposits and lonely crater in the centre (HiRISE/NASA)

Although this image of a rather odd-looking crater in the North Polar Region of Mars may seem a little mundane when compared with the list of HiRISE accolades, it is no less important. It is the sole impact crater for miles, hugging the edge of the polar ice cap, carved into layered deposits of rock, soil and lumps of ice. Using the crater count as a guide (i.e. the lower the count, the younger the surface is) HiRISE scientists believe the layered deposits may only be a few million years old. This may sound like a long time, but for a planet thought to be geologically inactive, the resurfacing rate seems pretty rapid. In this case, it is also believed the ice deposits in the crater are only 10,000 years old.

Geological activity destroys evidence of craters, although this region will have been hit by a similar number of meteorite impacts as crater-covered regions, rapid processes appear to be constantly reshaping the landscape. It is thought that the ice flow rate would be quite low, but on observing the strange shape of the central crater, it seems it is being warped by the motion of the surrounding deposits. The bright white ice deposits inside the crater are being protected from ablation as it is being shaded from the Sun by the crater walls. This is a common feature in polar craters.

So much for Mars being a “dead” planet, then. As seen with the dynamic avalanche processes and rolling boulders, Mars is far from being geologically inactive…

Source: HiRISE

October 16, 2008December 24, 2015 by Ian O'Neill

The Zero-Gravity Coffee Maker: Space Station Luxury or Necessity?

The secret design will allow astronauts to enjoy the rich taste and aroma of fresh coffee in space (Telegraph)

Costa Rican engineering students invent a coffee percolator for use in orbit

[/caption]Imagine: You’ve just woken up on board the space station half-way through your six-month mission in zero-gravity. You probably feel a little home sick and you crave a drink that will pick up your mood, preparing you for a tough day of overseeing experiments in Kibo and keeping up with your station schedule for the day. You go to the galley for some coffee. Instant, bad tasting coffee at that. You put the instant coffee container into the microwave and heat up the sour, plastic-tasting brew. Did that make you feel any better? Or did it just make you crave the smell of real, freshly ground coffee beans you’re used to on Earth?

Franklin Chang-Diaz, a veteran NASA astronaut who spent a lot of time on the International Space Station (ISS), knows all too well the taste of really bad microwaved space coffee. So, in an effort to make life a little better for the current astronauts in orbit, Chang has asked two engineering students to design a machine that can percolate fresh-ground coffee in zero gravity…

It may seem like a trivial problem. After all, astronauts on board the ISS are bound to suffer some inconveniences whilst working on space; they are strong, intelligent individuals who understand the sacrifices they need to make to belong to this exclusive group of space pioneers. However, as we spend more time in space, there is an increasing desire for the creature comforts of home, especially if you have to spend six months on board a cramped and (soon-to-be) crowded orbital outpost.

In an effort to confront a personal grievance with his experiences in space, Franklin Chang-Diaz, a seasoned NASA astronaut who has flown on seven Shuttle missions and helped to build the ISS, has approached two students at the Technological Institute of Costa Rica to design and build a coffee machine. But this isn’t any ordinary coffee machine, it is a coffee percolator that works in zero g, dispensing with the need for instant microwaved coffee.

View the Telegraph news report on the “Coffee Infuser” »

So, Daniel Rozen and Josue Solano came up with a solution. The biggest problems faced when wanting to percolate hot water through ground coffee in space are, a) there’s no gravity to draw the water through the coffee, b) liquids will float in globules and stick to instrumentation, and c) hot globules of water will create vapour and will probably be quite dangerous (after all, the last thing the ISS crew will need are scalding blobs of water flying around!). Enter the secretive “Coffee Infuser.”

The prototype coffee infuser (Telegraph)

“We turn on the switch. The machine will heat the water to 90 degrees centigrade, the ideal temperature for a cup of coffee,” Rozen explains. “Once the water reaches that temperature, we direct the water which is found in the heating chamber towards where the container is found, resulting in a delicious cup of coffee.”

In an intense environment where crew well-being is critical to mission success or failure, the idea of a space-age coffee infuser seems like a good idea. However, in space, where mass dictates how much a mission costs, the Costa Rican engineers will have to find a way of either making their prototype a lot smaller or integrate it seamlessly into a new piece of kit. Until a smaller version is available I doubt it will be considered to be a critical appliance for the station… (although it would be nice to wake up to the smell of freshly brewed coffee when the Sun is rising over the limb of the Earth…)

Source: Telegraph Online

October 15, 2008December 24, 2015 by Ian O'Neill

Feeding Time at the Stellar Zoo: Infant Stars Generate Lots of Gas

Artist's impression of a young star with surrounding disk of dust (ESO/L. Calçada)

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Understanding how stars form is critical to astronomers. If we can gain a better understanding of how intermediate-size infant stars grow, we can begin to answer some of the most perplexing questions hanging over the evolution of our own Solar System. Unfortunately, the nearest star forming regions are about 500 light years away, meaning that astronomers cannot simply use traditional optical telescopes to peer into star-forming disks of gas and dust. So, researchers working with the European Southern Observatory (ESO) are combining high resolution spectroscopic and interferometry observations to give the most detailed view yet of infant stars eating away at their proto-planetary disk, blasting out violent stellar winds as they do so…

It sounds like baby stars are very much like their human counterparts. They need a conveyor belt of food supplying their development and they blast huge amounts of waste back out in the form of gas. These findings come from researchers using the ESO’s Very Large Telescope Interferometer (VLTI), giving us milli-arcsecond resolution when focusing on these star-forming regions. The detail this provides is equivalent to studying the period (‘full stop’ as I prefer to call it) at the end of this sentence at a distance of 50 km (31 miles).

This high resolution is achieved by combining the light from two or more telescopes separated by a certain distance. This distance is known as the “baseline,” and interferometers such as the VLTI have a large baseline (of up to 200 metres), simulating a telescope diameter equivalent to this distance. However, the VLTI now has another trick up its sleeve. The AMBER spectrometer can be used in conjunction with the interferometer observations to give a more complete view of these feeding stars, probing deep into the spectrum of light being emitted from the region.

“So far interferometry has mostly been used to probe the dust that closely surrounds young stars. But dust is only one percent of the total mass of the discs. Their main component is gas, and its distribution may define the final architecture of planetary systems that are still forming.” – Eric Tatulli, co-leader of the VLTI international collaboration from Grenoble, France.

The Herbig Ae/Be star R Coronae Australis, a young intermediate-size star (2MASS)

Using the combined power of the VLTI and AMBER instrument, astronomers have been able to map this gas surrounding six stars belonging to the Herbig Ae/Be family. These particular stars are typically less than 10 million years old and a few times the mass of our Sun. They are very active stars in the process of forming, dragging huge amounts of material from a surrounding disk of dust.

Until now, astronomers have not been able to detect gas emission from young stars feeding on their stellar disks, thereby keeping the physical processes acting close to the star a mystery.

“Astronomers had very different ideas about the physical processes that have been traced by the gas. By combining spectroscopy and interferometry, the VLTI has given us the opportunity to distinguish between the physical mechanisms responsible for the observed gas emission,” says co-leader Stefan Kraus from Bonn in Germany. In two of the Herbig Ae/Be stars, there is evidence for a large quantity of dust falling into them, thereby increasing their masses. In four cases, there is evidence for a strong stellar wind, forming an extended stellar gas outflow.

The VLTI observations also reveal dust from the surrounding disk is much closer than one would expect. Usually there is a cut-off distance for dust location as the stars heat will cause it to vaporize. However, it would appear in one case that gas between the star and dusty disk shields the dust from evaporating; the gas acts as a radiation-block, allowing the dust to extend closer to the star.

“Future observations using VLTI spectro-interferometry will allow us to determine both the spatial distribution and motion of the gas, and might reveal whether the observed line emission is caused by a jet launched from the disc or by a stellar wind“, Kraus added.

These phenomenal observations of star-forming dust disks and gas emission, 500 light years away, open up a new kind of high-resolution astronomy. This will help us understand how our Sun fed off its surrounding disk of dust, eventually forming the planets and, ultimately, how life on Earth was possible…

Source: ESO

October 15, 2008December 24, 2015 by Ian O'Neill

Hottest Ever Exoplanet Discovered: WASP-12b

WASP-12b orbits so close to its star that it is heated to a record-breaking 2250°C (ESA/C Carreau)

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Planets approximately the size of Jupiter orbiting close to their star in other systems are often referred to as “Hot Jupiters.” It would appear that a new classification is required: Very Hot and Very Fast Jupiters. WASP-12b is an exoplanet, about 50% more massive than Jupiter, orbiting a star (imaginatively called WASP-12) over 800 light years away, but it isn’t any ordinary exoplanet. It orbits its host star 1/40^th of the distance at which the Earth orbits the Sun and it takes a breathtaking one day to complete one orbit. As a consequence, its host star heats WASP-12b to record-breaking temperatures; the planet is being toasted up to 2250 °C. For an exoplanet of this size, to be orbiting so close to a star has caused a stir amongst planet hunters. WASP-12b is and oddity, there’s nothing else like it… so far.

This new discovery originates from the UK’s Wide Area Search for Planets, a.k.a. “SuperWASP”. SuperWASP is a robotic system surveying both hemispheres, consisting of two observatories (one in the Canary Islands, off the coast of Africa, called SuperWASP-North; one in South Africa called SuperWASP-South) with eight cameras in both. The north and south observatories are on the look out for extrasolar planets, but rather than focusing on one star and seeing whether it wobbles (thereby giving away the presence of the gravitational pull of an orbiting planet), SuperWASP looks out for the periodic dimming of stars as their companion planets pass in front of them. Since it began operations in 2004, the two observatories have found 15 transiting exoplanets (as of April 2008).

Artist illustration of the planet orbiting the sun-like star HD 149026 (U.C. Santa Cruz)

Now, astronomers have focused their attentions on one rather strange exoplanet. When WASP-12b was first seen by the robotic planet spotters, researchers knew they were on to something special. The speed at which WASP-12b was transiting its host star (WASP-12) indicated that it had an orbital period of only 1.1 (Earth) days. This therefore meant that it had to be located very close to the star. This meant that it was going to be hot. Very, very hot in fact. Early estimates put WASP-12b’s surface temperature into the record-breaking range, possibly challenging the calculated temperature of HD 149026b, an exoplanet some 257 light-years away in the constellation of Hercules, with an estimated temperature of 2050°C. WASP-12b has an estimated surface temperature of 2250°C – that’s half as hot as the temperature of our Sun’s photosphere, and approximately the same temperature as many Class M stars.

Although impressive, there may be hotter “Hot Jupiters” out there, but the orbital velocity of WASP-12b will be a tougher record to beat. To date, most Jupiter-sized exoplanets have orbital periods of a few days, which led astronomers to believe there was some planetary mechanism preventing these planets from migrating very close to their host stars. Although Jupiter-like planets will have formed further away from their stars, they drift closer as they evolve until they settle into a stable orbit. Usually these orbits are located far away from the star, but WASP-12b obviously didn’t read the rule book before it set up home in its stellar oven.

“When the planets form and migrate inward, something is causing them to stop and preferentially stop with a period of three days,” said Leslie Hebb of the University of St Andrews, UK. “I was surprised that the period could be so much shorter.”

So WASP-12b has a strange orbit, making it orbit very fast, causing it to be heated to astounding temperatures. But the strangeness doesn’t stop there. It has a diameter 1.8 times that of Jupiter, far bigger than gas giants are thought to grow. However, the extreme temperatures WASP-12b is experiencing may explain its obesity problem – the star could be causing the planet to “puff up,” making the gas giant less dense, but blowing it 80% larger than Jupiter proportions.

Now, SuperWASP researchers hope to probe the planetary system for UV light radiating from the exoplanet, possibly showing evidence that WASP-12b’s atmosphere is undergoing aggressive stripping or evaporation at such close proximity to the host star.

Source: New Scientist

October 15, 2008December 24, 2015 by Ian O'Neill

Space Tourist Garriott Docks with Station (Videos)

The Soyuz TMA-13 approaches the Space Station alongside another Soyuz spaceship, set to return Garriott in 10 days (NASA)

[/caption]The Soyuz TMA-13 carrying Expedition 18 to the International Space Station (ISS) has successfully docked, delivering astronaut Mike Fincke, cosmonaut Yuri Lonchakov and space tourist Richard Garriott. The Soyuz spaceship docked with the Zarya module ahead of schedule over breathtaking views of southern Asia. Richard Garriott, a 47 year-old computer games entrepreneur and son of retired US astronaut Owen Garriott, spent $30 million for the privilege of spending ten days travelling to, and living on the orbital outpost. To appreciate how the Earth has changed in the 35 years since his father first looked down on Earth from the US Skylab space station, Garriott Jr. will spend some of his time taking photos of our planet so the images can be compared…

It looked like a flawless docking procedure between the Soyuz spacecraft and the ISS over the scenic backdrop of the Earth. Soyuz gently floated toward its dock with the Russian-built Zarya module along side the Soyuz TMA-12 that carried Expedition 17 to the station back in April. The already parked Soyuz will be the return vehicle in eight days time (on October 23rd) for cosmonauts Sergei Volkov and Oleg Kononenko who will chaperone Richard Garriott back to solid ground at the end of his space “vacation.” Volkov and Kononenko, members of Expedition 17 have spent six months in space.

View the Soyuz TMA-13 dock with the space station »

'Running the lockers' inside Skylab. (NASA)

Now that Garriott is getting settled in his temporary orbital home, he only has a short time to complete all the tasks he has set. As the sixth space tourist to visit the space station, he will obviously enjoy the views, but Garriott is also keen to follow in his father’s footsteps. Owen Garriott lived and worked on Skylab in 1973 for 59 days and he found that by running around the circumference of the station, that he was able to build up enough centrifugal force to remain in contact with the sides. Although Garriott Jr. is keen to try this zero-gravity activity out for himself, the International Space Station doesn’t have a large enough volume.

“I have been trying to figure out where on the International Space Station could this best be performed,” Richard said. “One of the great things about Skylab is that it had this massive internal volume and this nice ring of lockers that gave you a relatively smooth surface to make that attempt and a reasonable diameter so that at a nice jog pace, the centrifugal force would do a reasonable job of holding you to the outside wall. The ISS’s diameter is much smaller.” So it would appear that “running the lockers” as Owen called it, will not be possible on board the ISS. I guess they don’t make space stations like they used to…

View the Expedition 18 crew arrive on the space station, being welcomed by Sergei Volkov and Oleg Kononenko »

Jogging inside the space station to one side, the Expedition 18 crew will begin to supervise the start-up of new life-support equipment for the station. This is one of the steps to ensure that the station can accommodate six full-time crewmembers as from the planned expansion in May 2009.

Sources: BBC [1] [2], collectSPACE

October 13, 2008December 24, 2015 by Ian O'Neill

Violent Polar Cyclones on Saturn Imaged in Unprecedented Detail by Cassini

These two previously released infrared images of Saturn show the entire south polar region with the hurricane-like vortex in the center. The top image shows the polar region in false color, with red, green, and blue depicting the appearance of the pole in three different near-infrared colors (NASA/JPL/University of Arizona)

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The Cassini mission has released some of the most detailed images of Saturn’s poles yet, revealing vast cyclones churning up the gas giant’s atmosphere in the north and south. These observations show very similar storms to the south pole observations imaged by the NASA spacecraft in 2006, only in far better detail. It is believed the north and south cyclones are generated by violent thunderstorms deep inside Saturn’s atmosphere; water condensing inside these storms output heat, fuelling the vortex extending 2,500 miles (4,000 kilometres) in diameter. The smallest features resolved are 120 kilometre (75 mile)-wide cumulus clouds rotating at velocities in excess of 325 mph (530 kph), more than twice the wind speed possible on Earth…

…and the mystery north pole hexagon is still there.

This is a side-by-side view of large cyclones at the north (left) and south (right) poles of Saturn taken in June 2008 by the visual and infrared mapping spectrometer onboard the Cassini spacecraft (NASA/JPL/University of Arizona) — Images of the large cyclones at the north (left) and south (right) poles of Saturn taken in June 2008 by the visual and infrared mapping spectrometer onboard the Cassini spacecraft (NASA/JPL/University of Arizona)

Cassini has wowed scientists with these brand new views of Saturn’s north pole. With detail at 10-times higher resolution than previously attained, Cassini has shown that both poles have vast swirling cyclones that highlight regions of planet-wide storm activity.

“These are truly massive cyclones, hundreds of times stronger than the most giant hurricanes on Earth,” said Kevin Baines, Cassini scientist on the visual and infrared mapping spectrometer at NASA’s Jet Propulsion Laboratory. “Dozens of puffy, convectively formed cumulus clouds swirl around both poles, betraying the presence of giant thunderstorms lurking beneath. Thunderstorms are the likely engine for these giant weather systems.”

The Saturn hexagon as seen by Voyager 1 in 1980 (NASA)

Interestingly, the northern storm observation still shows the mysterious hexagonal shape (as originally verified in 2006, after a sighting by Voyager 1 in 1980), only in far greater detail. Scientists are still uncertain why the northern cyclone should take such a stable form; the clouds within the hexagonal shape spin at high speeds without interfering with its six-sided shape.

Previous observations appeared to show an outer ring of high clouds surrounding a region thought to be clear air with a few puffy clouds circulating around the pole. These brand new images reveal a far more complex picture. The circulating clouds are actually smaller convective storms forming other, more distinct rings.

Oblique view of Saturn's south polar vortex. The Sun is located above the top-right-hand corner, showing the shadows of clouds towering above the vortex (NASA) — Oblique view of Saturns south polar vortex (NASA)

Tony DelGenio of NASA’s Goddard Institute for Space Studies in New York and Cassini imaging team member explains the scene: “What looked like puffy clouds in lower resolution images [from 2006] are turning out to be deep convective structures seen through the atmospheric haze. One of them has punched through to a higher altitude and created its own little vortex.”

These clouds push high above the main weather system, casting long shadows, indicating they are 25-45 miles (40-70 km) above the vortex rings (pictured above). These also appears to be an inner ring of clear air (the “eye” of the storm) over the poles, that appeared bigger in previous observations.

For me, the most perplexing feature to come out of these new Cassini observations is the enduring hexagonal shape in the circulating clouds. In 2006 when the lower-resolution north pole observations were released, many made the assumption that it was an unstable transient feature, appearing for a short period, only to disappear soon afterwards. But over a year later, the hexagon remains, as six-sided as ever. I’d guess this shape could be some atmospheric standing wave, what do you think?

See the Cassini video of the north pole hexagon being buffetted by the high-speed winds surrounding it »

Source: Space.com