Posted on by Nicholos Wethington

Peruvian Meteorite May Rewrite Impact Theories

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On September 15th of last year, a meteorite impacted the Earth near the town of Carancas in Peru. The story made worldwide headlines when hundreds of people who flocked to see the crater reported getting ill. As it turned out, there were no mysterious space illnesses plaguing the population; the super-hot meteorite likely vaporized arsenic-containing water that was near the surface of the impact site, and onlookers and investigators breathed in the noxious gas. The meteorite is again in the spotlight, though not for making people sick.

Researchers estimate from their analysis of the crater that the meteorite was of a rocky composition, and that it impacted the ground at a whopping 15,000 miles (24,150 kilometers) per hour. That is really fast for a stony meteorite! It is calculated to have been between .2 and 2 meters at the point of impact, and upwards of 3 meters when it entered the atmosphere.

“Normally with a small object like this, the atmosphere slows it down, and it becomes the equivalent of a bowling ball dropping into the ground. It would make a hole in the ground, like a pit, but not a crater. But this meteorite kept on going at a speed about 40 to 50 times faster than it should have been going.” said Peter Schultz, professor of geological sciences at Brown University, who presented the findings of his travels to the impact site at the 39th annual Lunar and Planetary Science Conference in Texas last week. Schultz collaborated on his research with a team of scientist from Brown University, Peru and Uruguay.

Stony meteorites – called chondrites – generally break up in the atmosphere and impact the ground at rather slow speeds. In fact, most of the objects that enter Earth’s atmosphere end up never hitting the ground because the gases are so thick that the heat caused by air compression vaporizes them.

Schultz and his team think the Carancas meteorite may have initially broken up and then reformed in such a way as to make it more aerodynamic, allowing it to bullet through the atmosphere instead of being braked by the friction with the gases in our atmosphere. As opposed to dissipating and burning up like other chondrites, the meteorite landed as one large chunk.

This contradicts the conventional theory that small, rocky asteroids either can’t impact at all, or create only small impact pits. If the new theory is correct, we may have to rethink the history and influence of meteorite impacts on the Earth, as well as consider what kind of damage they are capable of doing in the future.

Source: Brown University News Release

Posted on by Nicholos Wethington

New, Unexpected Spots Found on Jupiter

Jupiter is a spotty place. There’s the aptly-named Great Red Spot – a large, long-lasting storm – that we all know and love, and new storms crop up every so often to create interesting features for astronomers both professional and amateur to study. The most recent discovery of new spots can only be seen in the UV, but they add a whole new level of complexity for scientists to chew on.

Io, one of Jupiter’s many moons, is volcanically active, and eruptions on the moon spew sulfur into the system. This sulfur is then ionized and swept up by Jupiter’s strong magnetosphere. Interactions between the ions and the magnetosphere cause aurora in the UV spectrum, similar to the phenomenon that makes the Northern Lights shine here on Earth. Io leaves a so-called ‘footprint’ on Jupiter in this way, and creates a glowing spiral shape on the northern and southern poles of the planet.

The rotation of Jupiter causes the spiral shape of the aurora: Io is ‘connected’ in one spot, and as Jupiter rotates it draws a glowing swirl of UV light around the pole. Astronomers had previously seen spots ‘downstream’ from the main spot caused by the interaction with Io, but these new images show a faint leading spot in front of the main one, essentially “upstream” in the flow of particles that causes the phenomenon.

A team from the University of Liège in Belgium discovered the spots in ultraviolet Hubble images taken of Jupiter. They found that when there were faint leading spots in one of the hemispheres, there were multiple spots in the other. The researchers propose that a beam of electrons is being transferred from one hemisphere to another, causing the fainter spots. The results of the study were published in the most recent edition of Geophysical Research Letters.

The image below illustrates the different mechanisms creating the auroral spots. The large torus around Jupiter is the plume of sulfur created by Io. The blue line between Io and Jupiter is where it is connected by the ionized sulfur, drawn in and funneled by Jupiter’s magnetosphere. The red lines illustrate the possible electron beams connecting the poles, which create the newly-discovered spots.

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When Hubble is repaired in August, the researchers hope to take a closer look at the phenomenon and better understand this complex interaction.

Source: Eurekalert

Posted on by Nicholos Wethington

Plans for a “Doomsday Ark” on the Moon are in the Works

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Let’s say something terrible happens to your computer, like it crashes or you drop it. All of those movies you bought online are toast, as is your address book and most of your work. It’s always a good idea to have a backup somewhere else, right?

Having a backup of your computer is handy, but having a backup of the entire progress of human civilization is even more practical. If a major catastrophic event like nuclear war or an asteroid strike wipes out most of the humans on the planet, it would be helpful for the survivors to have a record of all the accomplishments we’ve made in the past few thousands of years to help rebuild and repopulate the Earth.

The closest off-world place to store such a structure and ensure its safety would be the Moon. The construction of such a “doomsday ark” was presented last month by William Burrough and Jim Burke at a symposium on “Space Solutions to Earth’s Global Challenges” at the International Space University in Strasbourg, France.

There are already gene banks – stores of plant seeds – around the world, one of which is the Svalbard Global Seed Vault, which officially opened last month. But having a backup inside your computer doesn’t help if you drop it in a lake, so taking such an important operation off the Earth would make it that much more likely to survive any major catastrophes.

The ark would contain hard disks that store the genetic information of humans, plants and animals, as well as information on necessary or helpful processes for survival such as smelting metal, planting crops and building houses. Like the seed vaults, the ark could be expanded to include actual seeds, plants and frozen genetic material, which would aid in the re-population of these species given that a spacecraft could be launched to retrieve them.

After being constructed underneath the surface of the Moon to protect it from the radiation from the Sun and the extreme temperatures of the Moon’s surface, the vault could be set to automatically transmit the information to the Earth in case of disaster. Outposts containing a receiver and supplies necessary for survival would be installed across our planet to aid in rebuilding and the reception of information. The databank would transmit in a variety of different languages to ensure that the survivors could actually read the sent instructions.

To start, the ark would be tended by robots, but a future base on the Moon might allow it to be maintained and improved by human beings (an even better safeguard against humanity being wiped out).The scientists think it would be possible to place such an ark on the Moon before 2020. This basic archive would have a 30-year lifespan, and could be followed up with a more complete archive by the year 2035.

Source: Telegraph.co.uk

Posted on by Nicholos Wethington

Ancient Lake on Mars Found by HiRISE a Good Place to Look for Life

Despite what it might look like, this is not the beach of a lakeside resort here on Earth. It’s what remains of a dried up lake on the surface of Mars, yet another fantastic image brought to us by the cameras on the High Resolution Imaging Science Experiment (HiRISE.) This is a closeup of the largest of the “fans” leftover from the lake in the bottom of Holden Crater, an 87-mile (140-kilometer) wide crater in the bottom of the larger Holden Basin on Mars.

What’s interesting about a dried up lake bed, besides the spectacular image? Well, it’s the perfect place to start a search for life on Mars. A nice, calm lake would be a likely place for life to form. This site is one of the six possible landing sites for the NASA’s Mars Science Laboratory, which launches next year and will try to answer the question of whether life on Mars existed at one time, or continues to thrive there.

In addition to the possiblity that the lake was at one time inhabited by Martian life, the crater is full of rocks and sediment that are of interest to geologists studying the history of Mars. Called “megabreccia”, the floor of the crater contains a mixture of boulders, sediment and clay. Before the impact that formed the crater, sediments were deposited in the bottom of Holden Basin by channels of water running across the basin. Blocks of the surface as large as 50 meters (164 feet) across were thrown up when the crater was made.

“When large craters form, they produce very large blocks of material. We see them on Earth. Popigai Crater in Russia is one example. But we’d never seen them on Mars, and we knew they ought to be there. Now we’ve seen them with HiRISE,” said John Grant of the Smithsonian National Air and Space Museum, who is the first author on a paper about Holden Crater recently published in the journal Geology.

The crater’s history is even more complicated: the rim of the crater was breached by surrounding water, creating a massive flood that stirred up the sediments on the bottom and re-filled the crater. Boulders and debris from the event are strewn over the top of the megabreccia, and are also covered in fine sediment and clay that settled on them from the lake before it dried up. The volume of water in this catastrophic flood would have been larger than that contained within Lake Huron.

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Both images used here are in false color to help reveal details. This second image shows the layers produced by the impact and subsequent flooding, most noticeable on the walls in the upper left-hand corner. Mars was likely wetter during its early history, and the flow of water later in its life was probably reserved to catastrophic events such as the breach of Holden crater.

Images like this and more have been really pouring in from HiRISE. To see more, check out their site and our coverage here at UT on this fantastic image of an avalanche in progress on Mars, and this picture of the Earth and Moon together in one beautiful shot.

Source: University of Arizona Press Release

Posted on by Nicholos Wethington

Hyperfast Star Ejected from the Large Magellenic Cloud

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Occasionally, stars minding their own business around the supermassive black hole at the center of our galaxy get chucked out of the Milky Way, never to return. Fraser wrote about the discovery of two of these exiled stars, hurling away at the mind-blowing speed of over 1 million miles an hour. A recent study of another shows that not all of them originate in the center of our own galaxy.

New results from astronomers at the Carnegie Institute show that one star rocketing away from the Milky Way hearkens from the Large Magellanic Cloud, our neighboring galaxy. There have been ten such hypervelocity stars discovered, but where this one came from was quite a conunudrum.

Named HE 0437-5439, it’s nine times the mass of the Sun, and is traveling at 1.6 million miles an hour (2.6 million km an hour). The origin of the star has been a mystery until now because of its youth: it is 35 million years old, but it would have taken 100 million years to get to its current location if it were from the center of the Milky Way.

This meant that the star either came from somewhere else, or had to have formed out of the merger of two low-mass stars from the Milky Way, a so-called “blue straggler.”

Carnegie astronomers Alceste Bonanos and Mercedes López-Morales, and collaborators Ian Hunter and Robert Ryans from Queen’s University Belfast took measurements of the composition of the star – the first time this has been done on any hypervelocity star – and determined that its metal-poor makeup pointed towards the Large Magellanic Cloud as the former home of the castaway.

Bonanos said,“We’ve ruled out that the star came from the Milky Way. The concentration of [heavy] elements in Large Magellanic Cloud stars are about half those in our Sun. Like evidence from a crime scene, the fingerprints point to an origin in the Large Magellanic Cloud.�

Hypervelocity stars get their kick of energy from their interaction with a black hole. The stars were once part of a binary system, and as one star in the system gets captured by the black hole, the other is abruptly released, booting it clear out of the galaxy.

The mere fact that the Large Magellanic Cloud produced this hyperfast star hints at the presence of a black hole there, which has never previously been observed to exist.

Source: Carnegie Institute Press Release

Posted on by Nicholos Wethington

Paper Boomerang will be Tested on Space Station

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You know this is a burning question on the minds of eight-year olds everywhere: if you threw a boomerang in zero-gravity, would it come back to you? Japanese astronaut Takao Doi plans to test this very premise when he travels to the International Space Station in March 2008.

Doi plans to bring a paper boomerang to the ISS to test whether it will perform the trick of returning to the thrower in zero-gravity. He reportedly decided to test the boomerang at the behest of Yasuhiro Togai, a world boomerang champion from Osaka, Japan. With the announcement that a paper airplane will be launched from the ISS, space is beginning to look like an unruly high school classroom. But these experiments aren’t all fun and games, as there are underlying physical principles that can be explored by such simple tests.

A returning boomerang – when thrown properly – will travel in a circular path which brings it back around to the thrower. The two (or three) fins of a boomerang are shaped like an airplane wing, so when thrown the shape provides lift and causes the boomerang to fly.

Boomerangs fly in a circle because of the lift provided by the leading fin of the boomerang. Because it is spinning around a central axis, one fin provides lift in the direction of travel, then the other does the same. This force in the same direction makes the path of the boomerang form a circle, and as it loses energy because of the pull of gravity the boomerang comes back down to the ground.

Now, the question remains as to what will happen if the force of gravity is not present. The zero-gravity environment of the ISS is a perfect place to test this. The atmosphere of the ISS will still allow the boomerang to generate lift, but will it return to the sender, bounce off the walls, or just spin in place?

Source: Space Travel report

Posted on by Nicholos Wethington

Using GPS Could Better Tsunami Warning System

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When there is a tsunami coming towards your home, you want to know about it as far in advance as possible. An early warning about such a disaster could save countless lives, and using Global Positioning System information may just be the way to speed up our reaction time in the future.

The traditional tsunami warning system relies on measuring the magnitude of the earthquake that causes the tsunami. This method is not always reliable, though, as calculating accurately the power of the resulting ocean waves takes hours or days.

For example, 2005 Nias quake near Indonesia was estimated to cause about the same size of tsunami as the powerful 2004 Indian Ocean quake, which destroyed cities in portions of Indonesia, India and Thailand and killed more than 225,000 people. The 2005 tsunami did not nearly meet the same proportions as the earlier quake. There have been five false tsunami alarms between 2005 and 2007, which can reduce the effectiveness of the warnings in the eye of the public.

In a study published in the December Geophysical Research Letters, researcher Y. Tony Song of NASA’s Jet Propulsion Laboratory in Pasadena, California, showed that using GPS from coastal areas near the epicenter of the quake could help more accurately and quickly determine the scale of a tsunami.

Here’s how it would potentially work: data from seismometers near the earthquake’s epicenter is first registered, as in the traditional system. After that, GPS data of the seafloor displacement is factored in, which gives a more complete picture of the extent and power of the earthquake. The size of the predicted tsunami is then quickly calculated and given a number between 1 and 10 – 1 being the lowest – much like the Richter scale. This information could then be passed through the tsunami warning system to evacuate people to safety.

GPS data helps create a 3-dimensional model of the tsunami by giving details about the horizontal and vertical displacement of the seafloor, and this data can be sent and analyzed in minutes from coastal GPS stations. Song’s methods have accurately modeled three previous tsunamis: one in Alaska in 1964, the Indian Ocean tsunami in 2004, and the 2005 Nias tsunami.

Source: JPL Press Release

Posted on by Nicholos Wethington

Flying Telescope Passes Its First Stage of Tests

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Telescopes on the ground – while having all sorts of good qualities – have the disadvantage of peering through the whole of the atmosphere when looking at the stars. Space-based telescopes like Hubble are an effective way around this, but launching a telescope into space and maintaining it is not exactly cheap. What about something in between the two?

This is where SOFIA (Stratospheric Observatory for Infrared Astronomy) flies in. SOFIA is a converted 747SP airliner that used to carry passengers for United Airlines and Pan Am, but now only has one voyager: an infrared telescope.

SOFIA recently completed the first phase of flight tests to determine its structural integrity, aerodynamics and handling abilities. This first series of tests were done with the door through which the telescope will peer closed, and open-door testing will begin in late 2008.

What makes SOFIA valuable is its ability to fly high in the stratosphere for observations, at around 41,000 feet (12.5km). This eliminates the atmosphere in between the ground and space, which causes turbulence in the light coming through, and also absorbs almost completely some wavelengths of infrared light.

Cloudy nights, normally the bane of observational astronomy, will not impede the ability of SOFIA. Other advantages are that scientists will be able to add specialized observing instruments for specific observations, and fly to anywhere in the world.

The telescope is 10 feet across, and weighs around 19 tons. It will look through a 16-foot high door in the fuselage to study planetary atmospheres, star formation and comets in the infrared spectrum.

During this stage of testing, the ability of the telescope to compensate for the motion and vibrations of the airplane was checked. After the first open-door tests are run this year, the mobile observatory will begin making observations in 2009, and will be completely operational in 2014.

SOFIA is a cooperation between NASA, who will maintain the plane, and the German Aerospace Center, who built and will maintain the telescope.

Source: NASA Press Release

Posted on by Nicholos Wethington

Regulating Traffic in the Final Frontier

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October of last year was the 50th anniversary of Sputnik, the first spacecraft to be launched into orbit. Since then, we’ve come a long, long way. Think of all the stuff that’s floating around our planet right now: GPS, television, and military satellites, the International Space Station and the Hubble telescope, and a host of debris. With more satellites and projects launching into space, the issue of regulating all of this space traffic is starting to become an issue.

Current regulations of space come from a series of treaties and agreements between nations and organizations, starting with the Outer Space Treaty created 40 years ago. But with private companies like Virgin Galactic merging into space traffic, as well as nations like Japan, India, and China, launching satellites and scientific spacecraft, the need for a defined set of regulations is in order.

“While the current state can be regarded as a “piecemeal engineering”, space traffic management would provide a regulatory “big bang”. Space traffic management would not tackle single issues, but regard the regulation of space activities as a comprehensive concept. This concept is based on functionality, aiming at the provision of a complete set of rules of the road for the current and future way,” wrote Kai-Uwe Schrogl of the European Space Policy Institute in a paper titled “Space traffic management: The new comprehensive approach for regulating the use of outer space – Results from the 2006 IAA cosmic study,” published in the most recent issue of Acta Astronautica.

Space law would be concerned with four areas: keeping tabs on the current space traffic, a system of notification between nations or companies planning launches and missions to space, comprehensive rules for traffic to follow and a way to enforce these rules.

Tracking and notifying are both important to help keep spacecraft from crashing into each other, and would improve the performance of those satellites able to make avoidance maneuvers of space debris. The ISS and Hubble both do this on a regular basis, but other satellites lack the ability to change their orbit on a, so minimizing and tracking the amount of space debris – at least in certain high-traffic areas in Earth’s orbit – is instrumental.

The organizations and means of implementing these rules are still being debated. Possibilities include the creation of World Space Organization, or placing the responsibilities on the shoulders of the existing International Civil Aviation Organization, which currently regulates the skies closer to Earth.

Schrogl writes that a comprehensive space law is a ways off, but the debate about what rules are needed – and how to go about keeping the increasing number of parties launching into space in check – is currently picking up speed. This means that you shouldn’t expect to see any space police pulling over NASA’s Atlantis Shuttle for littering anytime soon.

Source: Acta Astronautica

Posted on by Nicholos Wethington

MESSENGER Flyby of Mercury January 14th

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If you thought you were good at pool, think again: in a game of interplanetary billiards, the MESSENGER team has guided its spacecraft to pass by Mercury for the first time on Monday, after a dizzying path that has already taken it past the Earth once and Venus twice.

The MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging) spacecraft will make its very first flyby of the planet on January 14th at 2:04 EST. It will pass within 200 kilometers (124 miles) of the surface. During the flyby it will be taking images and scientific measurements of the planet’s features.

The data it will be taking this time around will complement the measurements it will make when finally in orbit. MESSENGER will map the composition of Mercury’s surface, capture images at a resolution of hundreds of meters, and measure the structure of the planet’s magnetosphere and magnetic and gravitational fields.

Monday’s flyby will be the first time a spacecraft has visited Mercury in 33 years, since Mariner 10 did a series of flybys in the mid-1970s. During that mission, the spacecraft only imaged one hemisphere of the planet. MESSENGER will complete the picture, so to speak, by taking close-up images for the very first time of the other hemisphere.

The flyby will allow the spacecraft to map several features of Mercury that it will not be able to measure when in orbit, such as the magnetotail – the drawn out tail of the planet’s magnetosphere as it travels through space. It will also take over 1,200 images of the planet.

MESSENGER was launched in August of 2004, and has been making its way to Mercury by a number of different flybys of the Earth and Venus. The journey, though, is far from over. The spacecraft will make two more flybys of Mercury in October 2008 and September 2009, finally settling into orbit of the planet in March 2011.

It will then start a yearlong comprehensive study with its seven scientific instruments. When the journey is over, it will have traveled 4.9 billion miles (7.9 billion kilometers).

For more information and photos of the flyby, visit the official MESSENGER website.

Source: Johns Hopkins University Applied Physics Laboratory Press Release