Posted on by Fraser Cain

Black Holes Can Be Ejected From Galaxies

Image credit: Hubble
When black holes collide, look out! An enormous burst of gravitational radiation results as they violently merge into one massive black hole. The ?kick? that occurs during the collision could knock the black hole clear out of its galaxy.

A new study describes the consequences of such an intergalactic collision.

Astrophysicist David Merritt, professor at Rochester Institute of Technology, and co-authors Milos Milosavljevic (Caltech), Marc Favata (Cornell University), Scott Hughes (Massachusetts Institute of Technology) and Daniel Holz (University of Chicago) explore the consequences of kicks induced by gravitational waves in their article, ?Consequences of Gravitational Radiation Recoil,? recently submitted to the Astrophysical Journal and posted online at http://arXiv.org/abs/astro-ph/0402057.

Virtually all galaxies are believed to contain supermassive black holes at their centers. According to current theory, galaxies grow through mergers with other galaxies. When two galaxies merge, their central black holes form a binary system and revolve around each other, eventually coalescing into a single black hole. The coalescence is driven by the emission of gravitational radiation, as predicted by Einstein?s theory of relativity.

Merritt and his colleagues determined how fast a black hole has to move to completely escape a galaxy?s gravitational field. They found that larger and brighter galaxies have stronger gravitational fields and would require a bigger kick to eject a black hole than the smaller systems. Likewise, less forceful impacts could jar the black hole out of its home at the center of a galaxy, only to later rebound back into position.

The kicks also call into question theories that would grow supermassive black holes from hierarchical mergers of smaller black holes, starting in the early universe. ?The reason is that galaxies were smaller long ago, and the kicks would easily have removed the black holes from them,? Merritt says.

According to Merritt and his co-authors, it is more likely that supermassive black holes attained most of their mass through the accretion of gas and that mergers with other black holes only took place after the galaxies had reached roughly their current sizes.

?We know that supermassive black holes exist at the centers of giant galaxies like our own Milky Way,? says Merritt. ?But as far as we know, the smaller stellar systems do not have any black holes. Perhaps they used to, but they were kicked out.?

The kick?a consequence of Einstein?s relativity equations?occurs because gravitational waves emitted during the final plunge are anisotropic, producing recoil. The effect is maximized when one black hole is appreciably larger than the other one.

While astrophysicists have been aware of this phenomenon since the 1960s, until now no one has had the analytical tools necessary to accurately calculate the size of the effect. The first accurate calculation of the size of the kicks was reported in a companion paper by Favata, Hughes and Holz, which also appears online at http://arXiv.org.

Merritt notes that there is no clear observational evidence that the kicks have taken place. He contends that the best chance of finding direct evidence would be locating a black hole shortly after the kick occurs, perhaps in a galaxy that has recently undergone a merger with another galaxy.

?You would see an off-center black hole that hasn?t quite made its way back to the center yet,? he says. ?Even though the probability of observing this is low, now that astronomers know what to look for, I wouldn?t be surprised if someone finds one eventually.?

Original Source: RIT News Release

Posted on by Fraser Cain

Opportunity Gets Rolling

Image credit: NASA/JPL
NASA’s Opportunity rover drove about 3.5 meters (11 feet) early Thursday toward a rock outcrop in the wall of a small crater on Mars, and mission controllers plan to send it the rest of the way to the outcrop late Thursday.

Opportunity’s twin, Spirit, successfully reformatted its flash memory on Wednesday. Flash is a type of rewritable memory used in many electronic devices, such as digital cameras, to retain information even while power is off. Problems with the flash memory interfered with Spirit’s operations from Jan. 22 until this week. Engineers prescribed the reformatting to prevent recurrence of the problem.

On Thursday, Spirit’s main assignment is to brush off an area on the rock nicknamed “Adirondack” to prepare for a dust-free examination of its surface. On Friday, controllers at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., plan to have Spirit grind off a small patch of Adirondack?s outer surface and inspect the rock’s interior. Spirit may start driving over the weekend toward a crater about 250 meters (about 270 yards) to the northeast.

For Opportunity, halfway around Mars from Spirit, controllers changed plans Thursday morning. They postponed a trenching operation until the rover gets to an area of its landing-site crater where the soil has a higher concentration of large- grain hematite. That mineral holds high interest because it usually forms under wet conditions. The main science goal for both rovers is to find geological clues about past environmental conditions at the landing sites, especially about whether conditions were ever watery and possibly suitable for sustaining life.

Instead of trenching, Opportunity will be commanded after it next wakes up to drive about 1.5 meters (about 5 feet) farther, possibly to within arm’s reach of one of the rocks in the exposed outcrop.

Before it began driving on Wednesday, Opportunity finished using its alpha particle X-ray spectrometer for the first time. This spectrometer, which assesses what chemical elements are present, took readings on an area of soil that the rover had previously examined with its microscope.

Each martian day, or “sol,” lasts about 40 minutes longer than an Earth day. Spirit begins its 34rd sol on Mars at 3:22 a.m. Thursday, Pacific Standard Time. Opportunity begins its 14th sol on Mars at 3:43 p.m. Friday, PST.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA’s Office of Space Science, Washington, D.C. Images and additional information about the project are available from JPL at http://marsrovers.jpl.nasa.gov and from Cornell University, Ithaca, N.Y., at http://athena.cornell.edu.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Atlas Rocket Launches AMC-10 Satellite

Image credit: ILS
International Launch Services (ILS) scored another success tonight, with the launch of the AMC-10 satellite on board a Lockheed Martin-built Atlas IIAS rocket.

The rocket lifted off at 6:46 p.m. from Cape Canaveral?s Space Launch Complex 36A, and placed the satellite into a transfer orbit 28 minutes later. The satellite is an A2100 model, built by Lockheed Martin for SES AMERICOM of Princeton, N.J. This was the first launch of the year for ILS. It also is one of four missions for SES AMERICOM on the ILS manifest this year.

?We are gratified and honored that such a prominent satellite operator as SES AMERICOM has signaled such confidence in our team,? said ILS President Mark Albrecht. ?Since the AMC-10 and AMC-11 satellites are two of a kind, we fully expect to be repeating another successful mission right here at the Cape in a few months? time.?

Albrecht noted the long-standing relationship with ILS and SES AMERICOM, and its parent company, SES GLOBAL. To date ILS has launched 15 satellites for companies affiliated with SES GLOBAL, including six for the SES AMERICOM fleet. ?With the SES family as the world?s largest satellite operator, it is no secret that we relish the fact that ILS is its largest launch services provider. We?re pleased to be welcoming them back again this year to both our launch sites ? at the Cape and in Kazakhstan ? for SES AMERICOM missions this year,? Albrecht said. Two SES AMERICOM satellites ? AMC-12 and AMC-15 ? are set to launch on Proton vehicles in 2004.

ILS is a joint venture of Lockheed Martin (NYSE:LMT) and Russian rocket builder Khrunichev State Research and Production Space Center. ILS markets and manages the missions on the Atlas rocket in the United States and on the Proton rocket at the Baikonur Cosmodrome, Kazakhstan. ILS was formed in 1995, and is based in McLean, Va., a suburb of Washington, D.C.

Dean Olmstead, president and CEO of SES AMERICOM, said: “The AMC-10 mission enables us to continue delivering the highest quality distribution services to the top-tier cable programmers who entrust us with more channels and their new high-definition services; in turn we have entrusted this satellite to ILS and its terrifically reliable Atlas IIAS launch vehicle. Our hope is that the AMC-11 launch planned for May will proceed just as flawlessly as tonight’s AMC-10 launch.”

Tonight?s rocket was the 27th flown in the Atlas IIAS configuration. Three more Atlas IIAS vehicles are scheduled to launch this year before the model is retired. ILS also has customers scheduled on Atlas III and Atlas V vehicles this year. The Atlas II, III and V series have achieved 100 percent success through 69 consecutive launches. The Atlas IIAS can lift 8,200 pounds to geosynchronous transfer orbit. The Atlas III can lift up to 9,920 pounds, and the current -production Atlas V is available in a range of configurations to lift payloads up to 19,000 pounds.

The Atlas rockets and their Centaur upper stages are built by Lockheed Martin Space Systems Company in Denver, Colo.; Harlingen, Texas; and San Diego, Calif. The A2100 satellite is built by Lockheed Martin Commercial Space Systems in New Town, Pa., and Sunnyvale, Calif.

Original Source: ILS News Release

Posted on by Fraser Cain

I’m Looking for Experts to Answer Reader Questions

We get a lot of space and astronomy questions on the Universe Today forum, and we answer what we can. Many times, though, the question is more detailed and technical and really requires an expert to answer. I’ve got a list of astronomers and scientists that I sometimes turn to, but I could always use more.

If you’re working in space and astronomy, and willing to answer the occasional reader question, please drop me an email. I would really appreciate it. It probably wouldn’t be more than a question every few months, so nothing too onerous.

Oh? and keep asking your questions, we’ll keep looking for the answers.

Thanks!

Fraser Cain
Publisher
Universe Today

Posted on by Fraser Cain

More Support for Life in Martian Meteorite

Image credit: NASA
University of Queensland researchers have confirmed the theory life once existed on Mars.

Dr John Barry, from UQ?s Centre for Microscopy and Microanalysis, together with former UQ researcher Dr Tony Taylor, found their proof in the water trap at the ninth hole of the Howestern golf course at Birkdale.

Mud samples from the golf course contained magnetic crystals which matched those found in a meteorite discovered in Antartica in 1984.

In 1996 NASA announced it had found primitive bacteria in that meteorite and since then debate has raged in the scientific community whether the organism were from Mars.

Dr Taylor, together with his PhD co-supervisor Dr Barry, examined the mud samples using a world-first breakthrough in electron microscopy and found the fossil bacteria and the new samples were identical.

?Tony developed a new technique to capture specimens for the electron microscope which allowed us to see through the bacteria and into the gel surrounding the magnetic crystals inside the bacterium,? Dr Barry said.

?This gave us a lot more information about the structure than what we would have seen before.?

Dr Taylor, who now works for the Australian Nuclear Science and Technology Organisation in Sydney, said this research seriously challenges doubts of sceptical scientists by discovering that many bacteria match the features found in the Martian meteorite.

?Our research shows that the structures found in the NASA meteorite were more than likely made by bacteria present on Mars four billion years ago, before life even started on Earth,? said Dr Taylor.

Dr Taylor said the discovery was the product of painstaking research conducted with other scientists in the 1990s that vastly improved imaging techniques to study bacterial structures. Ultraviolet light was the key and resulted in the detailed analysis of 82 different bacterial types – a major improvement on the 25 identified at that time.

?We became very excited when we discovered that many of the bacteria found had the same biosignature, which resembles a tiny backbone surrounded by cartilage, as that of the Martian fossils,? Dr Taylor said.

Emeritus Professor Imre Friedmann, one of the original NASA scientists to make the life on Mars claim said he was thrilled by the news.

?The Study of Taylor and Barry now presents evidence that the same features occur in a wide range of bacteria that live on Earth today. The tiny structures, chains of crystals of the mineral magnetite, are comparable to animal skeletons on a microscopic scale, ? Professor Friedmann said.

Dr Barry and Dr Taylor?s research was published recently in the Journal of Microscopy.

Original Source: University of Queensland News Release

Posted on by Fraser Cain

Rosetta Lander Named Philae

Image credit: ESA
With just 21 days to the launch of the European Space Agency’s Rosetta comet mission, the spacecraft’s lander has been named “Philae”. Rosetta embarks on a 10-year journey to Comet 67P/Churyumov-Gerasimenko from Kourou, French Guiana, on 26 February.

Philae is the island in the river Nile on which an obelisk was found that had a bilingual inscription including the names of Cleopatra and Ptolemy in Egyptian hieroglyphs. This provided the French historian Jean-Fran?ois Champollion with the final clues that enabled him to decipher the hieroglyphs of the Rosetta Stone and unlock the secrets of the civilisation of ancient Egypt.

Just as the Philae Obelisk and the Rosetta Stone provided the keys to an ancient civilisation, the Philae lander and the Rosetta orbiter aim to unlock the mysteries of the oldest building blocks of our Solar System – comets.

Germany, France, Italy and Hungary are the main contributors to the lander, working together with Austria, Finland, Ireland and the UK. The main contributors held national competitions to select the most appropriate name. Philae was proposed by 15-year-old Serena Olga Vismara from Arluno near Milan, Italy. Her hobbies are reading and surfing the internet, where she got the idea of naming the lander Philae. Her prize will be a visit to Kourou to attend the Rosetta launch.

Study of Comet Churyumov-Gerasimenko will allow scientists to look back 4600 million years to an epoch when no planets existed and only a vast swarm of asteroids and comets surrounded the Sun. On arrival at the comet in 2014, Philae will be commanded to self-eject from the orbiter and unfold its three legs, ready for a gentle touchdown. Immediately after touchdown, a harpoon will be fired to anchor Philae to the ground and prevent it escaping from the comet’s extremely weak gravity. The legs can rotate, lift or tilt to return Philae to an upright position.

Philae will determine the physical properties of the comet’s surface and subsurface and their chemical, mineralogical and isotopic composition. This will complement the orbiter’s studies of the overall characterisation of the comet’s dynamic properties and surface morphology. Philae may provide the final clues enabling the Rosetta mission to unlock the secrets of how life began on Earth.

?Whilst Rosetta?s lander now has a name of its own, it is still only a part of the overall Rosetta mission. Let us look forward to seeing the Philae lander, Osiris, Midas and all the other instruments on board Rosetta start off on their great journey this month,? said Professor David Southwood, ESA Director of Science.

Original Source: ESA News Release

Posted on by Fraser Cain

Rover Sees Spheres in the Martian Soil

Image credit: NASA/JPL
NASA’s Opportunity has examined its first patch of soil in the small crater where the rover landed on Mars and found strikingly spherical pebbles among the mix of particles there.

“There are features in this soil unlike anything ever seen on Mars before,” said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the science instruments on the two Mars Exploration Rovers.

For better understanding of the soil, mission controllers at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., plan to use Opportunity’s wheels later this week to scoop a trench to expose deeper material. One front wheel will rotate to dig the hole while the other five wheels hold still.

The spherical particles appear in new pictures from Opportunity’s microscopic imager, the last of 20 cameras to be used on the two rover missions. Other particles in the image have jagged shapes. “The variety of shapes and colors indicates we’re having particles brought in from a variety of sources,” said Dr. Ken Herkenhoff of the U.S. Geological Survey’s Astrogeology Team, Flagstaff, Ariz.

The shapes by themselves don’t reveal the particles’ origin with certainty. “A number of straightforward geological processes can yield round shapes,” said Dr. Hap McSween, a rover science team member from the University of Tennessee, Knoxville. They include accretion under water, but apparent pores in the particles make alternative possibilities of meteor impacts or volcanic eruptions more likely origins, he said.

A new mineral map of Opportunity’s surroundings, the first ever done from the surface of another planet, shows that concentrations of coarse-grained hematite vary in different parts of the crater. The soil patch in the new microscopic images is in an area low in hematite. The map shows higher hematite concentrations inside the crater in a layer above an outcrop of bedrock and on the slope just under the outcrop.

Hematite usually forms in association with liquid water, so it holds special interest for the scientists trying to determine whether the rover landing sites ever had watery environments possibly suitable for sustaining life. The map uses data from Opportunity’s miniature thermal emission spectrometer, which identifies rock types from a distance.

“We’re seeing little bits and pieces of this mystery, but we haven’t pieced all the clues together yet,” Squyres said.

Opportunity’s Moessbauer spectrometer, an instrument on the rover’s robotic arm designed to identify the types of iron- bearing minerals in a target, found a strong signal in the soil patch for olivine. Olivine is a common ingredient in volcanic rocks. A few days of analysis may be needed to discern whether any fainter signals are from hematite, said Dr. Franz Renz, science team member from the University of Mainz, Germany.

To get a better look at the hematite closer to the outcrop, Opportunity will go there. It will begin by driving about 3 meters (10 feet) tomorrow, taking it about halfway to the outcrop. On Friday it will dig a trench with one of its front wheels, said JPL’s Dr. Mark Adler, mission manager.

Opportunity’s twin, Spirit, today is reformatting its flash memory, a preventive measure that had been planned for earlier in the week. “We spent the last four days in the testbed testing this,” Adler said. “It’s not an operation we do lightly. We’ve got to be sure it works right.” Tomorrow, Spirit will resume examining a rock called Adirondack after a two-week interruption by computer memory problems. Controllers plan to tell Spirit to brush dust off of a rock and examine the cleaned surface tomorrow.

Each martian day, or “sol,” lasts about 40 minutes longer than an Earth day. Spirit begins its 33rd sol on Mars at 2:43 a.m. Thursday, Pacific Standard Time. Opportunity begins its 13th sol on Mars at 3:04 p.m. Thursday, PST.

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA’s Office of Space Science, Washington, D.C. Images and additional information about the project are available from JPL at http://marsrovers.jpl.nasa.gov and from Cornell University at http://athena.cornell.edu.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Wallpaper: Hubble’s View of M64

Image credit: Hubble
A collision of two galaxies has left a merged star system with an unusual appearance as well as bizarre internal motions. Messier 64 (M64) has a spectacular dark band of absorbing dust in front of the galaxy’s bright nucleus, giving rise to its nicknames of the “Black Eye” or “Evil Eye” galaxy.

Fine details of the dark band are revealed in this image of the central portion of M64 obtained with the Hubble Space Telescope. M64 is well known among amateur astronomers because of its appearance in small telescopes. It was first cataloged in the 18th century by the French astronomer Messier. Located in the northern constellation Coma Berenices, M64 resides roughly 17 million light-years from Earth.

At first glance, M64 appears to be a fairly normal pinwheel-shaped spiral galaxy. As in the majority of galaxies, all of the stars in M64 are rotating in the same direction, clockwise as seen in the Hubble image. However, detailed studies in the 1990’s led to the remarkable discovery that the interstellar gas in the outer regions of M64 rotates in the opposite direction from the gas and stars in the inner regions.

Active formation of new stars is occurring in the shear region where the oppositely rotating gases collide, are compressed, and contract. Particularly noticeable in the image are hot, blue young stars that have just formed, along with pink clouds of glowing hydrogen gas that fluoresce when exposed to ultraviolet light from newly formed stars.

Astronomers believe that the oppositely rotating gas arose when M64 absorbed a satellite galaxy that collided with it, perhaps more than one billion years ago. This small galaxy has now been almost completely destroyed, but signs of the collision persist in the backward motion of gas at the outer edge of M64.

This image of M64 was taken with Hubble’s Wide Field Planetary Camera 2 (WFPC2). The color image is a composite prepared by the Hubble Heritage Team from pictures taken through four different color filters. These filters isolate blue and near-infrared light, along with red light emitted by hydrogen atoms and green light from Str?mgren y.

Original Source: Hubble News Release

Posted on by Fraser Cain

Nearby Galaxy is Hotbed of Star Formation

Image credit: Hubble
The nearby dwarf galaxy NGC 1569 is a hotbed of vigorous star birth activity which blows huge bubbles that riddle the main body of the galaxy. The galaxy’s “star factories” are also manufacturing brilliant blue star clusters. This galaxy had a sudden onset of star birth about 25 million years ago, which subsided about the time the very earliest human ancestors appeared on Earth.

In this new image, taken with NASA’s Hubble Space Telescope, the bubble structure is sculpted by the galactic super-winds and outflows caused by a colossal input of energy from collective supernova explosions that are linked with a massive episode of star birth.

One of the still unresolved mysteries in astronomy is how and when galaxies formed and how they evolved. Most of today’s galaxies seem to have been already fully formed very early on in the history of the universe (now corresponding to a large distance away from us), their formation involving one or more galaxy collisions and/or episodes of strongly enhanced star formation activity (so-called starbursts).

While any galaxies that are actually forming are too far away for detailed studies of their stellar populations even with Hubble, their local counterparts, nearby starburst and colliding galaxies, are far easier targets.

NGC 1569 is a particularly suitable example, being one of the closest starburst galaxies. It harbors two very prominent young, massive clusters plus a large number of smaller star clusters. The two young massive clusters match the globular star clusters we find in our own Milky Way galaxy, while the smaller ones are comparable with the less massive open clusters around us.

NGC 1569 was recently investigated in great detail by a group of European astronomers who published their results in the January 1, 2004 issue of the British journal, Monthly Notices of the Royal Astronomical Society. The group used several of Hubble’s high-resolution instruments, with deep observations spanning a wide wavelength range, to determine the parameters of the clusters more precisely than is currently possible from the ground.

The team found that the majority of clusters in NGC 1569 seem to have been produced in an energetic starburst that started around 25 million years ago and lasted for about 20 million years. First author Peter Anders from the Gottingen University Galaxy Evolution Group, Germany says “We are looking straight into the very creation processes of the stars and star clusters in this galaxy. The clusters themselves present us with a fossil record of NGC 1569’s intense star formation history.”

The bubble-like structures seen in this image are made of hydrogen gas that glows when hit by the fierce winds and radiation from hot young stars and is racked by supernovae shocks. The first supernovae blew up when the most massive stars reached the end of their lifetimes roughly 20-25 million years ago. The environment in NGC 1569 is still turbulent and the supernovae may not only deliver the gaseous raw material needed for the formation of further stars and star clusters, but also actually trigger their birth in the tortured swirls of gas.

The color image is composed of 4 different exposures with Hubble’s Wide Field and Planetary Camera 2 through the following filters: a wide ultraviolet filter (shown in blue), a green filter (shown in green), a wide red filter (shown in red), and a Hydrogen alpha filter (also shown in red).

Original Source: Hubble News Release

Posted on by Fraser Cain

Is NASA Following in the Footsteps of the X-Prize?

NASA has released its fiscal year 2005 budget, which includes specific prizes for the various activities outlined in President Bush’s new space initiative announced earlier in January. One interesting line item is $20 million set aside for something called the “Centennial Challenges“. Here’s the description:

Request includes funding to establish a series of annual prizes for revolutionary, breakthrough accomplishments that advance exploration of the solar system and beyond and other NASA goals. Some of the most difficult technical challenges to exploration will require very novel solutions from non-traditional sources of innovation. By making awards based on actual achievements instead of proposals, NASA will tap innovators in academia, industry, and the public who do not normally work on NASA issues. Centennial Challenges will be modeled on past successes, including 19th century navigation prizes, early 20th century aviation prizes, and more recent prizes offered by the U.S. government and private sector. Examples of potential Centennial Challenges include very-low-cost space missions, contests to demonstrate highly mobile, capable, and survivable robotic systems, and fundamental advances in technical areas like lander navigation, spacecraft power systems, life detection sensors, and nano-materials.

This sounds like NASA is going to be awarding prizes for successful space accomplishments, similar to the privately-funded $10 million X-Prize that will reward the first private firm to achieve sub-orbital flight twice within two weeks. Prizes like this have been one of the most successful technology drivers in the past; one of the best known examples is the Orteig Prize, won by Charles Lindbergh, which demonstrated that flights across the Atlantic Ocean were possible.

Pretty exciting news, we’ll see how this turns out.

Fraser Cain
Publisher
Universe Today

P.S. Thanks to Spaceprojects.com for the heads up.