Universe Today

February 4, 2008December 26, 2015 by Ian O'Neill

Large Hadron Collider May Help Us Glimpse Into another Dimension

High energy collisions by the nearly-completed Large Hadron Collider (LHC) may be able to generate particles that are sensitive to dimensions beyond our four dimensional space-time. These exotic particles, called Kaluza-Klein gravitons, would be highly sensitive to the geometry of extra-dimensions, giving scientists an idea about what lies beyond our universe. If these particles are detected, and if their characteristics can be measured, then perhaps the extra dimensions predicted by string theoryÂ may be proven to exist…

How can you measure the size of a room without actually measuring it? Forget measuring the room, you can’t even see it! The room is invisible; it is outside your observational ability. But what if you could bounce sound off the walls? Even better, what if the walls of the invisible room were made up of resonant particles, producing their own sound? If the sound from these resonant particles could then be analyzed, the shape of the invisible room would be known.

According to string theory, there are many “invisible rooms” that we, as observers, cannot experience. We are confined to our three dimensions of space and one dimension of time (although this may not always be the case), otherwise known as four dimensional space-time. Elemental vibrating strings thread through our universe and predict that there may be six or seven extra dimensions coexisting. Although we cannot directly experience the dimensions beyond the normal four, can we measure the characteristics of string vibrations travelling from these extra dimensions into our observable universe?

In new research published by Gary Shiu, Bret Underwood, Kathryn Zurek at UW-Madison and Devin Walker at UC-Berkeley, quantum particles have been theorized to have the ability to resonate with dimensions beyond our universe; beyond the 4th dimension, considered to be time. From this resonance, signatures from extra-dimensions could pass through our four dimensional space-time to be measured. From this analysis, the “shape” of the extra dimensions may then be understood. This is not purely out of curiosity, according to string theory the shape of extra dimensions influences everything in our universe:

“The shape of the dimensions is crucial because, in string theory, the way the string vibrates determines the pattern of particle masses and the forces that we feel.” – UW-Madison physics professor, Gary Shiu.

The team predict particles carrying extra-dimensional signatures could be generated by the Large Hadron Collider at CERN (nr. Geneva, Switzerland). At very high energies, Kaluza-Klein (KK) gravitons may be created for a brief moment, carrying the signatures with them. Unfortunately KK gravitons will decay very quickly, but from this decay a shower of lower energy, detectable particles will be created. By analyzing the resulting shower, a fingerprint of the KK particle’s signature may be constructed. Any slight changes in the geometry of the detected particles may indicate a particular dimension, and many signatures may be mixed, so complex computer simulations are required to understand the results coming from the LHC.

Source: Science Daily

February 4, 2008December 26, 2015 by Fraser Cain

Venus Express Detects Water Vapour in Low Altitude Clouds

There’s a real advantage to having a spacecraft orbit a planet for days, months and even years. You have lots and lots of time to really pull in the science. And now, almost 2 years into its visit at our evil twin planet, ESA’s Venus Express has been able to map the planet’s atmosphere at lower altitudes, searching for chemicals that will help scientists understand the planet’s global climate and weather systems.

The planet’s clouds block the visible light from escaping the surface, but other wavelengths, such as infrared, do escape. Since temperatures can reach 200 degrees C at an altitude of 35 km, and more than 450 C at the surface, infrared – or heat – pours out, going right through the clouds. This radiation can then be analyzed to see the chemicals present.

ESA’s Venus Express spacecraft is equipped with a special instrument called the VIRTIS spectrometer, which can measure the atmosphere at various altitudes. It’s already mapped the high altitude clouds, and now VIRTIS has spent the last few orbits mapping the lower atmosphere.

Of course, like the rest of Venus’ atmosphere, the lower altitude clouds are dominated by carbon dioxide – the greenhouse gas that traps the heat in, raising temperatures. VIRTIS also detected carbon monoxide, a chemical that scientists weren’t expecting to see at such low altitudes.

Since carbon monoxide is so rare, scientists can use this as a way to trace global winds that cycle across the planet – sort of like dropping ink into water to study turbulence. VIRTIS was able to determine the large-scale circulation of winds as they rise at the equator and then move north and south towards the poles. Once at the poles, the winds lose altitude again, and circulate back to the beginning.

Venus Express has also detected and mapped the amount of water vapour in the lower atmosphere with high resolution. Since this molecule is so difficult to detect, this has ended a scientific debate about how much there is on Venus.

Original Source: ESA News Release

February 4, 2008April 29, 2021 by Fraser Cain

Observatory Installed on the Coldest, Driest Place on Earth

If you can’t afford to send a telescope to space, you’ll want the next best thing; a location on Earth which is cold, dry and at a high altitude. Perhaps the best place on Earth is “Dome A”, a high altitude region in Antarctica – the coldest and driest place on Earth. A team of astronomers recently climbed the summit of Dome A, and installed a new robotic observatory that should see some amazingly clear skies.

The team of scientists that made the journey represents 6 international institutions, including Texas A&M University and the Polar Research Institute of China. They arrived at Dome A on January 11th, in the middle of the southern Summer, and completed the facility installation on Saturday.

The installation is called the PLATeau Observatory, or PLATO, and was built by the University of New South Wales in Australia. PLATO is equipped with a suite of instruments that will let it measure the quality of the conditions, to confirm that it really has the best seeing on Earth. But if the calculations are correct, a 2 metre telescope here would be the equivalent of an 8-metre telescope built somewhere else. And an 8-metre telescope would rival the 30-metre supertelescopes in the works at various locations around the world.

One of the most important instruments is a set of four telescopes built at Purple Mountain Observatory in Nanjing. These are 4 telescopes with 14.5-centimetre apertures. Each one is equipped with a different filter to view the night sky at a different color or wavelength.

The facility is powered by six diesel engines that use aviation fuel in the Winter, and then it switches over to solar energy in the Summer. It will be completely autonomous, operated remotely over the low-bandwidth Iridium satellite service. Workers will then pick up the bulk of its research at the annual servicing visits.

Even in the dead of Winter, where temperatures plunge to -82 degrees Celsius, the facility will be working away gathering images. That’s because the weather around Dome A is very calm and stable. You don’t get the ferocious storms here that you see in other parts of Antarctica. It’s just cold and calm.

With PLATO installed, the team turned around and left the region on a convey of snow tractors. They’ll travel non-stop for 18 days to the coast of Antarctica, and then back to civilization.

Original Source: Texas A&M University News Release

February 4, 2008December 26, 2015 by Fraser Cain

Atlantis Will Fly, Despite Bent Hose

On Wednesday I reported that NASA was looking into a bent coolant hose on the space shuttle Atlantis. They weren’t sure if this might cause a potential launch delay while it was repaired. Shuttle managers met over the weekend, and decided that it wasn’t enough of a problem to delay the launch.

The problem is with one of the shuttle’s four braided hoses that carry the coolant needed to dissipate heat generated while in space. During a routine inspection, workers noticed that this hose had a bit of a kink in it.

The worry is that the hose could be bent further, or even snapped when the shuttle’s payload bays are closed up Sunday night to prepare for next week’s launch. In order to prevent a problem, a worker will use a long pole with a hook to guide the hose into its retraction box with the bays are closed up. Assuming that goes as planned, the shuttle’s launch won’t be delayed.

And even if the hose does break while the shuttle’s in orbit, it’s not a huge problem, according to NASA. There are a total of 4 of these hoses on Atlantis, and it can get by with the remaining ones.

With that worry out of the way, Atlantis is still scheduled for its Thursday launch from Florida’s Cape Canaveral. The shuttle is carrying Europe’s main contribution to the International Space Station: the Columbus science lab. During their time in space, the astronauts will perform three spacewalks to install the laboratory and perform some experiments.

The astronaut crew arrived in Florida today, and the countdown is expected to begin later Monday afternoon. The weather might be a problem, however. Meteorologists are predicting that there’s only a 40% chance of suitable weather on launch day. Friday should be better, though. Even if rain and clouds hold back the launch, there’s an 80% chance the shuttle will be able to lift off at the end of the week.

NASA has already canceled two launch attempts back in December because of problems with the shuttle’s fuel tank sensors. With an already crowded launch schedule, this additional delay pushes back the rest of the shuttle launches.

Original Source: NASA Status Report

February 4, 2008December 26, 2015 by Fraser Cain

Podcast: Antimatter

Sometimes, we donâ€™t get to decide what our showâ€™s about. So many threads come together at the same time driving the decision for us. This is one of those situations. Weâ€™ve gotten so many questions from listeners in just the last week about antimatter that our show had just been chosen for it. You command, we obey. Letâ€™s talk about antimatter.

Click here to download the episode

Antimatter – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

February 4, 2008December 26, 2015 by Fraser Cain

Building a Map of Dark Energy

Understanding dark energy is probably one of the largest mysteries in cosmology right now. Figure this out, and a Nobel Prize in physics is assured. But it won’t give up its secrets so easily. Since they can’t measure dark energy directly, astronomers can only measure its effects on the large-scale structures of the Universe, and then tease out some of its characteristics.

In a recent survey using the European Southern Observatory’s Very Large Telescope, and international team of 51 astronomers from 24 institutions gathered the light from more than 13,000 galaxies. This survey contains galaxies within a 25 million cubic-light years volume.

Using this survey, they were able to map out the large scale structures in the nearby Universe, including clusters of galaxies and filamentary superclusters. By measuring the velocity of the different clusters as they speed away from us, at different times in the past, the astronomers were able to measure the speed distortion contributed by dark energy.

Their conclusions lend evidence to the so-called cosmological constant theory originally introduced by Albert Einstein – there’s some constant repulsive force that exists throughout space. But the uncertainties in their calculations doesn’t rule out other possibilities.

One of the most popular of these is known as modified gravity. In this situation, gravity just acts differently at large scales than it does in the small scale.

But the researchers feel that a measurement that might cover 10 times the volume of this survey could be able to tell the difference between a dark energy force of exotic origin or an actual modification of theory of gravity.

Original Source: ESO News Release

February 4, 2008January 24, 2021 by Fraser Cain

Astrosphere for February 4, 2008

Your image for the day is NGC 1514, captured by Stargazer 7000.

Space Politics has a look at NASA’s upcoming budget. There’s going to be a NASA briefing later today, so we’ll have more details soon.

Life everywhere? Centauri Dreams has an article about new research theorizing that terrestrial planets are common.

davep caught these cool pictures of star trails.

Astroprof talks about Mercury’s strange terrain.

Bad Astronomy reviews the presidential candidates’ views on science.

Caltech astronomer Mike Brown assures us he’s no fan of pseudo science.

February 4, 2008December 26, 2015 by Tammy Plotner

Centaurid Meteor Shower Delights Southern Hemisphere…

While normally our friends in the Southern Hemisphere get left out of most major meteor showers, now is the time to keep alert for the Alpha Centaurids which are active during the entire month of February. While the Alpha Centaurids are considered a minor meteor shower, they do create some interesting viewing during the summer nights south of the equator. The peak (time of most activity) should occur around the universal date of Februrary 6/7, but don’t wait until then to start your observations!

According to the American Meteor Society:

“The Alpha Centaurids (ACE) are active from a radiant located at 13:44 (206) -58. This area of the sky is located in southeastern Centaurus, four degrees northwest of the brilliant star Hadar (beta Centauri). Current rates would be near one shower member per hour. These meteors are best seen near 0500 local standard time when the radiant lies highest above the horizon. This shower is not visible north of 32 degrees north latitude and also poorly seen in the northern tropics. The southern hemisphere offers a much better view of this activity as the radiant lies much higher in the southern sky. Those located at high southern latitudes will actually encounter morning twilight before the radiant reaches culmination. At 56 km/sec. the Alpha Centaurids will usually produce meteors of swift velocity.

Sporadic rates are now slowly falling no matter your location. One would expect to see approximately twelve random meteors during the last hour before dawn from rural observing sites in the northern hemisphere and fifteen from the southern hemisphere. During the first dark hour after the end of evening twilight, perhaps two random meteors can be seen per hour, no matter your location.”

While you’re out, take advantage of the opportunity to enjoy Centaurus! As one of the most inspiring constellations of the Southern Hemisphere, it also ranks as the ninth largest constellation and contains two of the ten brightest stars in the night sky – including the closest star to our own Sun. While the stargazers in the north rarely get an opportunity to explore the “Centaur”, nearly 2000 years ago precession allowed the ancient Greeks to observe the constellation during the spring. Even though they weren’t able to explore as we can today, they were still able to see Alpha and Beta Centauri, the third and tenth brightest stars in the sky. While many lists call Betelgeuse in Orion the tenth brightest star, remember… Betelgeuse is a variable!

Be sure to observe Alpha Centauri. One of the reasons it is so bright is not luminosity… but because it’s only 4.3 light years away. Rigel Kentaurius is a triple star system and a real beauty to binoculars and telescopes! Beta Centauri – Hadar – is a star on the move and in about 4000 years it will be close enough to Alpha to appear as a double star. While they won’t be gravitationally bound, a separation of 300 light years will make them a magnificent sight! Centaurus also contains Omega Centauri (NGC 5139), the largest and richest globular cluster in the sky. Centaurus also contains 20 open clusters and several galaxies including Centaurus A (NGC 5128), one of the brightest radio objects in the sky. While you’re there, be on the lookout because the a large portion of our own galaxy is also visible in Centaurus and there are over 100 easily visible stars.

Because you’re in for a moonless night and the days around the Centaurid Meteor shower peak will be of little moon-interference, this will be one of the best for Southern Hemsiphere SkyWatchers. If you live in the north? It never hurts to try. Even from my high latitude, I still get an occasional peek at some of Centaurus’ stars. Long noted for extremely bright meteors with persistent trails and flurries of high activity, I’m sure you’ll enjoy the incredible Centauri meteor shower!

February 4, 2008December 26, 2015 by Tammy Plotner

Solar Eclipse – Moon Takes a Bite Out of the Sun On February 7….

While the penguins in Antartica will be putting on their formal wear for the annular solar eclipse, a few lucky SkyWatchers in New Zealand and southeast Australia will still have a chance to see the Moon take a bite out of the solar disc roughly between 01:38:29 and 06:11:55 a.m. GMT. The best place to be is Auckland, New Zealand, where the partial eclipse begins at about 4:48 p.m. (Pacific/Auckland) local time (3:48 a.m. GMT) and ends at about 6:51 p.m. (5:51 a.m. GMT), a little more than two hours later.

The first eclipse of 2008 will travel over Antarctica and the waters surrounding the continent – not a hospitable area for visitors! While there are no permanent human residents in these areas, that won’t stop some travelers from heading towards the barren southern pole to take a look at the annular event. Unlike a total solar eclipse, the New Moon won’t completely cover the solar disc at maximum and a thin ring of the outer fringes of the Sun will still be visible – the annulus. If you were to be in the direct path, you’d enjoy the incredible view of the annular phase from 03:19:43 to 04:30:55 a.m. Greenwich Mean Time (GMT).

Fortunately for those of us who aren’t wearing a permanent tuxedo, the best place to observe will be in Auckland, where the Sun will be covered about 47% at around 5:52 p.m. local time. Considering they’re still enjoying more summer-like weather, it’s time to party! According to Fred Espenak:

“The most unusual characteristic of this eclipse is that it begins and ends along Earth’s sunset terminator. Most eclipse paths that travel from west to east. However, the 2008 annular eclipse path begins by running east to west and slowly turns north before curving west to east near its terminus. The annular path begins in Antarctica at 03:20 UT when the Moon’s antumbral shadow meets Earth and forms a 581 kilometre wide corridor near the base of the continent’s peninsula region. Traveling westward, the shadow quickly crosses Antarctica and turns north as it heads into the Pacific. Greatest eclipse takes place at 03:55:05 UT when the eclipse magnitude will reach 0.9650. At this instant, the annular duration is 2 minutes 12 seconds, the path width is 444 kilometres and the Sun is 16Â° above the featureless horizon of the open ocean. The central track continues north before gradually curving to the east where it ends at local sunset at 04:31 UT. During its 1 hour 10 minute flight across our planet, the Moon’s antumbra travels approximately 5,600 kilometres and covers 0.59% of Earth’s surface area.”

Remember when viewing a solar eclipse, to always do so safely. If you do not have a proper solar filter, use the projection method with your binoculars or telescopes. Safely cover one side of your binoculars or telescope’s finderscope and aim towards the Sun by aligning the shadow. Project the light onto a surface such as a paper plate or piece of cardboard and adjust the focus until you see a clear circle of light. If you do not have optics, simply punch a pinhole into a dark piece of cardboard and project it onto a makeshift screen. You won’t see solar details like sunspots, but you’ll easily see the progress of the shadow!

Wishing you all clear skies… And share your photos!

February 2, 2008December 26, 2015 by Ian O'Neill

Get a Better View of Saturn from Cassini, in 3D

Ever wondered what one of our robotic explorers can see right now? What can Cassini see as it orbits Saturn, continuing to explore the ringed gas giant? Now, in 3D, you can explore the probe yourself, seeing what Cassini sees with a neat 3D interactive viewer, imaging Saturn and her moons, accurately calculating where the probe was, is or will be. The best thing about this little online gadget is that you can speed through time, from the spaceship’s point of view, orbiting Saturn and working out when the next moon or ring flyby will be… A cool toy to waste some time playing with, especially when I really should be doing some work…

This gadget on the Cassini mission website really took me back to my childhood. For those of you who were addicted to the space exploration computer games Elite and Frontier: Elite 2 back in the early ’90s should be able to relate to this too. The Elite games were a groundbreaking series, using polygons to represent 3D objects, flying through space, trading, fighting and interacting with a basic, but engrossing, Universe. Based not on some mystical cosmos, Elite could be played in our solar system, allowing us for the first time to see an interactive 3D view of the Earth, Mars, Moon and the rest of the planets. I also remember zooming through Saturn’s blocky rings and wondered what that would really look like.

Of course, we now know what that does look like, in fact, Cassini is still out there, orbiting Saturn and analyzing Saturn’s moons: Mimas, Enceladus, Tethys, Dione, Rhea, Titan and Iapetus (inner to outer). The Cassini mission, launched in 1997, comprised of the NASA Cassini orbiter and ESA Huygens probe. After a long seven year journey, the pair arrived in Saturn orbit on July 1st, 2004 and on December 25th, 2004 the pair separated to send Huygens to Saturn’s largest moon, Titan. Huygens then made an exciting decent through Titan’s atmosphere and relayed vital information about the mysterious planet to the Cassini orbiter.

After all this excitement, Cassini carried on orbiting around Saturn and continues to this day transmitting amazing images and detailed information about Saturn’s interaction with the interplanetary medium, moons, atmosphere and magnetic field. Now, any online user can see what the historic orbiter is doing this very minute. Using NASA’s Cassini at Saturn Interactive Explorer (CASSIE), we can fast-forward or rewind to see Cassini’s most recent encounter with Titan, or see the probe pass through Saturn’s rings at our leisure. Not only is it fun, it helps us visualize where the craft is when we want to know.

Now thinking back to all those hundreds of hours I spent playing computer games, and comparing the graphics with this online gadget, I realize things have come a long way as far as 3D visualization is concerned. But I still get the same childish sense ofÂ awe about exploring the vastness of space, only this time I know I am seeing a 3D representation of the real view from Cassini.

Interestingly, on the box art of the Frontier: Elite 2 game (pictured left), Saturn is featured very boldly…

News source: SpaceRef.com