Posted on by Fraser Cain

Powerful Flare Shook Up Our Understanding of the Sun

Artist illustration of magnetic lines stretching and twisting around sunspots. Image credit: NASA. Click to enlarge.
The most intense burst of solar radiation in five decades accompanied a large solar flare on January 20. It shook space weather theory and highlighted the need for new forecasting techniques, according to several presentations at the American Geophysical Union (AGU) meeting this week in New Orleans.

The solar flare, which occurred at 2 a.m. EST, tripped radiation monitors all over the planet and scrambled detectors on spacecraft. The shower of energetic protons came minutes after the first sign of the flare. This flare was an extreme example of the type of radiation storm that arrives too quickly to warn interplanetary astronauts.

“This flare produced the largest solar radiation signal on the ground in nearly 50 years,” said Dr. Richard Mewaldt of the California Institute of Technology, Pasadena, Calif. He is a co-investigator on NASA’s Advanced Composition Explorer (ACE) spacecraft. “But we were really surprised when we saw how fast the particles reached their peak intensity and arrived at Earth.”

Normally it takes two or more hours for a dangerous proton shower to reach maximum intensity at Earth after a solar flare. The particles from the January 20 flare peaked about 15 minutes after the first sign.

“That’s important because it’s too fast to respond with much warning to astronauts or spacecraft that might be outside Earth’s protective magnetosphere,” Mewaldt said. “In addition to monitoring the sun, we need to develop the ability to predict flares in advance if we are going to send humans to explore our solar system.”

The event shakes the theory about the origin of proton storms at Earth. “Since about 1990, we’ve believed proton storms at Earth are caused by shock waves in the inner solar system as coronal mass ejections plow through interplanetary space,” said Professor Robert Lin of the University of California at Berkeley. He is principal investigator for the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). “But the protons from this event may have come from the sun itself, which is very confusing.”

The origin of the protons is imprinted in their energy spectrum, as measured by ACE and other spacecraft, which matches the energy spectrum of gamma-rays thrown off by the flare, as measured by RHESSI. “This is surprising because in the past we believed the protons making gamma-rays at the flare were produced locally and the ones at the Earth were produced instead by shock acceleration in interplanetary space,” Lin said. “The similarity of the spectra suggests they are the same.”

Solar flares and coronal mass ejections (CMEs), associated giant clouds of plasma in space, are the largest explosions in the solar system. They are caused by the buildup and sudden release of magnetic stress in the solar atmosphere above the giant magnetic poles we see as sunspots. The Transitional Region and Coronal Explorer (TRACE) and the Solar and Heliospheric Observatory (SOHO) spacecraft are devoted to observing the sun and identifying the root causes of flares and CMEs, with an eye toward forecasting them.

“We do not know how to predict the flow of energy into and through these large flares”, said Dr. Richard Nightingale of the Lockheed Martin Solar and Astrophysics Laboratory in Palo Alta, Calif. “Instruments like TRACE give us new clues with each event we observe.”

TRACE has identified a possible source of the magnetic stress that causes solar flares. The sunspots that give off the very largest (X-class) flares appear to rotate in the days around the flare. “This rotation stretches and twists the magnetic field lines over the sunspots”, Nightingale said. “We have seen it before virtually every X-flare that TRACE has observed since it was launched and more than half of all flares in that time.”

However, rotating sunspots are not the whole story. The unique flare came at the end of a string of five other very large flares from the same sunspot group, and no one knows why this one produced more sudden high energy particles than the first four.

“It means we really don’t understand how the sun works,” Lin said. “We need to continue to operate and exploit our fleet of solar-observing spacecraft to identify how it works.”

Original Source: NASA News Release

Posted on by Fraser Cain

Audio: Unlikely Wormholes

Artist illustration of a spacecraft passing through a wormhole to a distant galaxy. Image credit: NASA. Click to enlarge.
Listen to the interview: Unlikely Wormholes (4.5 mb)

Or subscribe to the Podcast: universetoday.com/audio.xml

Fraser Cain: Now, I’ve watched my share of Star Trek episodes. How well has this prepared me for the actual scientific understanding of a wormhole?

Dr. Stephen Hsu: In Star Trek they don’t really use wormholes, but maybe the best treatment in sci-fi for wormholes was in the movie Contact, which is based on a book by Carl Sagan. And actually historically, when Sagan was writing the novel – Sagan was an astronomy professor – he contacted an expert in General Relativity, a guy named Kip Thorne, at Caltech, and wanted to make sure that the way wormholes were treated in Contact was actually as close to being scientifically correct as possible. And that actually stimulated Thorne to do a lot of research on wormholes. Our work is actually an extension of things that he did.

Fraser: So if you wanted to build a wormhole, theoretically, what would you do?

Hsu: You need to have a very weird or exotic kind of matter and that matter has to have highly negative pressure. It turns out that to stabilize the throat or the tube of the wormhole you need very strange matter and our work has to do with how possible that kind of matter would be in models of particle physics.

Fraser: Let’s say you build a tear in spacetime and you fill it with exotic matter to keep it open, and then you could move the two end points of the wormhole around the Universe and they would connect both in space and in time.

Hsu: But in some science fiction stories they postulate that there are just some wormholes left over from the Big Bang, and we would just discover one and start using it. But the constructive model is that humans, or some alien civilization, actually build their own, and in that case the two ends of the wormhole probably are pretty close together at the beginning but then you pull them apart.

Fraser: Where has your research led you to look at wormholes?

Hsu: We were studying fundamental constraints on something called the “equation of state of matter” – what properties, like pressure or energy density can matter have. We found some very strong constraints, and it turns out those constraints are very negative for the possibility of building a wormhole.

Fraser: What effect will they have on the wormhole?

Hsu: To get the very weird exotic matter that I mentioned before with very negative pressure, it turns out the equations show that when you force the pressure to be that negative, there always some unstable mode in the matter, which means that if you were to bump your apparatus, you might find the exotic matter – which is stabilizing the wormhole – just collapses into a bunch of photos or something.

Fraser: Is it a matter of not bumping your apparatus, or is it theoretically impossible to reach a stable point?

Hsu: I would say it’s theoretically impossible to build classical matter which is stable and can stabilize a wormhole. You might ask, well maybe I’ll just avoid bumping the thing, but if you were to send a person through the wormhole, that itself would provide a bump and would very likely cause the whole thing to fall apart.

Fraser: Let’s say you didn’t want to send people, you just wanted some way of sending information – talking back in time.

Hsu: That’s not excluded. It turns out the constraints we derive have to do with matter in which quantum effects are relatively small. If you have matter in which quantum effects are very big, then you could still have a stable wormhole. The wormhole itself would be fuzzy in a quantum way. The tube of the wormhole would be fluctuating like a quantum state. Now, that doesn’t prevent you from sending a message back in time; you might have to try to send the message many times to get it to go where you want it to go. But, perhaps you could still send a message. Sending a person might be dangerous if the wormhole is fluctuating because the person might end up in the wrong place or the wrong time.

Fraser: I’d heard estimations that building a wormhole would require more energy than the entire Universe. Have you got some kind of calculations to that effect?

Hsu: Our calculations don’t necessarily show that. It does take a tremendous amount of energy density to create a wormhole which is big enough for a human to fit through. But, usually considering this kind of problem, you assume that whatever civilization is trying to do this has arbitrarily advanced technology. What we’re trying to understand is whether there’s a limitation not coming from technology but really coming from the fundamental laws of physics.

Fraser: And where will your research lead you from this point on? Is there something that you’re still a little unsure about?

Hsu: Our result mainly has to deal with the classical wormholes, or wormholes whose spacetime is not very quantum mechanical, and we’re still interested to see if we can extend our results to cover wormholes in which spacetime is fuzzy.

Fraser: There’s some new work on dark energy where they’re saying that the dark energy effect seems to be happening in the Universe, that it’s accelerating. Either there’s a new form of energy that’s not been seen before, or maybe it’s a breakdown in Einstein’s theories at a large level. If some of that work starts to show that maybe Einstein’s relativity isn’t able to explain it at the larger level, will it have an implication on the classical understanding of what a wormhole is?

Hsu: In the context of dark energy, since it’s something that affects the large scale structure of the Universe, the behaviour of the Universe on length scales of megaparsecs, it’s always possible that General Relativity as a theory is modified at very large distances and because we haven’t been able to test it on those distances. So it’s always possible that conclusions you get from Relativity are just not applicable. In our case, the length scale over which we’re using General Relativity is on the size of a human. So, it would be somewhat surprising if General Relativity were to break down already at those length scales, though it’s possible.

Fraser: So it’s more on the small side what you’re looking at. It still explains things quite nicely at this scale.

Hsu: Right, there are stronger experimental tests of General Relativity, or at least Newtonian gravity, on length scales of metres than on megaparsecs. So we’re a little more confident that the mathematical formulation of gravity that we’re using is correct.

Fraser: If I wanted to get across the Universe quite rapidly, I should look perhaps to the warp drive instead, or maybe just plain old moving in regular space.

Hsu: I’m a huge science fiction fan, and have been since I was a kid, but as a scientist, I’d have to say it’s looking like our Universe seems to not be constructed in a very convenient way for humans to get from star to star. And the sci-fi which we end up staying close to our Sun, but we do amazing things with bioengineering or information technology or A.I. seem more likely to be realizable with our physical laws, than Star Trek.

Posted on by Fraser Cain

Cassini Determines the Density of Saturn’s Rings

Cassini image of Saturn’s rings enhanced in false colours. Image credit: NASA/JPL/SSI. Click to enlarge.
The Cassini spacecraft has obtained the most detailed look ever at Saturn’s rings, including the B ring, which has eluded previous robotic explorers. Its structure seems remarkably different from its two neighbors, rings A and C.

The origin of Saturn’s rings is a mystery. The rings are an enormous, complex structure. From edge-to-edge, the ring system would not even fit in the distance between Earth and the Moon. The seven main rings are labeled in the order they were discovered. From the planet outward, they are D, C, B, A, F, G and E.

During a recent radio experiment, Cassini mapped this structure with clarity never before available. This is the first of many such observations Cassini will be conducting over the summer.

“The structure of those remarkable rings is a sight to behold. All ring features appear to be populated by a broad range of particle sizes that extend to many meters in diameter at the upper end,” said Dr. Essam Marouf, Cassini radio science team member and professor of electrical engineering, San Jose State University, San Jose, Calif.

Marouf said that at the lower end, particles of about 5 centimeters (roughly 2 inches) in diameter or less seem to be scarce in ring B and inner ring A. In rings C and outer ring A, particles of less than about 5 centimeters (2 inches) in diameter seem to be abundant.

Cassini found that the inner and outer parts of ring B contain rings that are hundreds of kilometers wide (hundreds of miles) and vary greatly in the amount of material they contain. A thick, 5,000-kilometer-wide (3,100-mile) core contains several bands with ring material that is nearly four times as dense as that of ring A and nearly 20 times as dense as that of ring C.

The dramatically varying structure of ring B is in sharp contrast to the relatively flat structure of ring A or the gentle, wavy structure of ring C, where many dense, narrow and sharp-edged ringlets permeate its outer part.

Cassini also detected more than 40 wavy features called “density waves” in ring A, many near its outer region, close to the moons orbiting just outside the ring. The density wave observations will tell more about the ring surface mass density, its vertical thickness and other physical properties.

“A marvelous array of waves, caused by gravitational interactions with nearby moons, has been uncovered throughout ring A,” said Marouf. “We also see a major density wave in the dense ring B. Some of these waves have been seen in Voyager and other Cassini observations, but not in this large number and not with this exceptional clarity.”

Cassini conducted this first radio occultation observation of Saturn’s rings, atmosphere and ionosphere on May 3, 2005. An occultation means that if you watch Cassini from Earth, Cassini would appear occulted, or hidden, behind the rings. During a radio occultation, Cassini sends a radio signal from the spacecraft through the rings to Earth. Scientists then watch how the strength of the radio signal is affected as the signal passes through ring material. The denser a ring is, the weaker the signal received. The experiment helps scientists map the distribution of the amount of ring material and determine the ring particle sizes.

The occultation was the first ever to use three radio signals of different frequencies (called Ka, X and S) transmitted simultaneously from a spacecraft to Earth-receiving stations of NASA’s Deep Space Network. Ring particles of different sizes affect each frequency differently.

The Cassini tour was specifically designed to optimize the geometry of the first radio occultation experiment and seven other occultations scheduled from May to September 2005. These observations are at the heart of Cassini’s fundamental science objectives of characterizing and understanding Saturn and its ring system. During its lifetime, Cassini will obtain 20 radio occultations and 80 stellar occultations, providing far more detailed knowledge of the ring structures.

For images and information on the Cassini mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini .

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Podcast: Unlikely Wormholes

Wormholes are a mainstay in science fiction, providing our heroes with a quick and easy way to instantly travel around the Universe. Enter a wormhole near the Earth and you come out on the other side of the galaxy. Even though science fiction made them popular, wormholes had their origins in science – distorting spacetime like this was theoretically possible. But according to Dr. Stephen Hsu from the University of Oregon building a wormhole is probably impossible.
Continue reading “Podcast: Unlikely Wormholes”

Posted on by Fraser Cain

What’s Up This Week – May 23 – May 29, 2005

Image credit: Steve Mandel. Click to enlarge.
Monday, May 23 – Tonight at 20:18 UT the Moon is officially “full”. Also known as “Flower Moon” or “Corn Planting Moon”, we often overlook the simple beauty of practicing astronomy without a telescope. This evening as the Sun sets and the Moon rises opposite of it, take advantage of some quiet time and really stop to look at the eastern horizon. If you are lucky enough to have clear skies, you will see the Earth’s shadow rising – like a dark, sometimes blue band – that stretches around 180 degrees of horizon. Look just above it for a Rayleigh scattering effect known as the “Belt of Venus”. This beautiful pinkish glow is caused by the backscattering of sunlight and is often referred to as the anti-twilight arch. As the Sun continues to set, this boundary between our shadow and the arch rises higher in the sky and gently blends with the coming night. What you are seeing is the shadow of the Earth’s translucent atmosphere, casting a shadow back upon itself. This happens every night! Pretty cool, huh?

Tuesday, May 24 – This morning will be an early wake up call for Canada, the United States and Mexico as the opportunity arises for most viewers across the continent to see bright Antares occulted by the Moon! Easily viewed without special equipment, an occultation of this type is quite wonderful to watch. I urge you to visit the IOTA webpage to get complete information for your area. Wishing you clear skies…

With just a short time before the Moon rises tonight, why not try your hand at locating globular cluster M68 with binoculars or small scopes. Start by identifying the lopsided rectangle of Corvus to the south and the lower left-hand star, Beta. About two finger widths south of Beta, you will see a 5th magnitude star – aim there. This is ADS 8612 (a telescopic double) and you’ll find M68 easily about 45′ to the northeast.

Discovered 1780 by Charles Messier, this near 8th magnitude globular cluster lies at a distance of about 33,000 light years and is somewhat difficult for Northern observers because of its southern position. It will be seen as a round, faint patch in binoculars but the brightest stars of M68 can resolved by telescopes starting at 4-inch aperture. Larger scopes will enjoy its bright core and resolved stars fading out to the edges.

Wednesday, May 25 – With plenty of time to spare before “moonrise” tonight, let’s go hunting a spectacular globular cluster well suited to all instruments – M5. To find M5 easily, head southeast of Arcturus and north of Beta Librae to identify 5 Serpentis. At low power, or in binoculars you will see this handsome globular in the same field to the northwest.

First discovered by Gottfried Kirch and his wife in 1702, while observing a comet, Charles Messier found it on his own on May 23, 1764. Although Messier said it was a round nebula that “doesn’t contain any stars”, even smaller scopes can resolve out the curved patterns of stars that extend from M5’s bright nucleus. Binoculars will reveal it with ease and for a real challenge, large telescopes can find about 11.8 magnitude globular Palomar 5 about 40′ south of the star 4 Serpentis. Under very dark, clear skies, M5 can just be glimpsed unaided, but telescopes will enjoy the slight ellipticity of this 13 billion year old ball of stars.

Thursday, May 26 – Have you checked your equinox marker lately? If not, then have a look when the Sun reaches the zenith today. For the northern hemisphere, you’ll find the shadow is almost 75% shorter!

Australia and New Zealand – it’s your turn as the Moon occults bright Tau Saggitarius for you on this universal date. Be sure to check IOTA for precise times in your location.

Tonight asteroid Pallas with be around one half degree north of star 5 Coma Berenices. At magnitude 8, it will be far brighter than any star nearby. Need a locator chart? Check with Heaven’s Above under the minor planets section. Or, if you’d rather take things a bit more Ceres-ly, try spotting 7.6 magnitude Ceres just about a degree west of Delta Librae with a similar magnitude apparent double star.

Friday, May 27 – Since the Moon will rise considerably later tonight, let’s try a series of challenges designed to intrigue all observers.
For visual observers, your goal lay mid-way between Saturn and bright Regulus. Allow your eyes plenty of time to dark adapt and look for a hazy patch of barely there stars. Congratulations! You’ve just spotted the M44 and seen the light – the light that left the cluster in the year 1480!

For binoculars, your challenge is to locate Theta Leonis (the southwestern-most star in the “hips” of Leo) and look directly between it and Iota to its south and spot dim star 73. Aim your binoculars there and discover the joy of galaxy-hunting as you view the M65 and M66 galaxies!

For smaller and mid-sized telescopes, make a fist at Spica – this is 10 degrees. No matter where you are, you’ll easily find the grand M104 “Sombrero” galaxy just 11 degrees due west of this bright blue star. (If you still have trouble finding the M104, don’t worry. Try this trick! Look for the upper left hand star in the rectangle of Corvus – Delta. Between Spica and Delta is a diamond-shaped pattern of 5th magnitude stars. Aim your scope or binoculars just above the one furthest south.)

For the large telescope and seasoned observer, your challenge for this evening will be five and a half degrees south of Beta Virginis and one half degree west. Classified as Arp 248, and more commonly known as “Wild’s Triplet”, these three very small interacting galaxies are a real treat! Best with around a 9mm eyepiece, use wide aversion and try to keep the star just north of the trio at the edge of the field to cut glare.

Best of luck!

Saturday, May 28 – On this day in 1959, the first primates made it to space. Abel (a rhesus monkey) and Baker (a squirrel monkey) lifted off in the nose cone of an Army Jupiter missile and were carried to sub-orbital flight. Recovered unharmed, Abel died just three days later from anesthesia during an electrode removal, but Baker lived on to a ripe old age of 27.

For viewers in Asia, tonight will present a rare occurrence of the position of Jupiter’s moons between 19:05 and 19:14 UT. At that time, Io will be transitting Jupiter, Ganymede will be eclipsed by its shadow and Europa will be occulted by Callisto.

If you haven’t checked on Comet Machholz lately, try looking around eight degrees southeast of Gamma Ursae Majoris tonight. Having quietly faded to around magnitude 9, you still might be able to spot a slight tail. For a very accurate locator chart, use Heaven’s Above and click on the appropriate link.

Sunday, May 29 – Today in 1919, a total eclipse of the Sun occurred and stellar measurements taken along the limb agreed with predictions based on Einstein’s General Relativity theory – a first! Although we call it gravity, the spacetime curve deflects the light of stars near the limb, causing their apparent position to differ slightly. Unlike today’s astronomy, at that time you could only observe stars near the Sun’s limb (less than an arc second) during an eclipse. It’s interesting to note that even Newton had his own theories on light and gravitation which predicted deflection!

If you haven’t looked for Venus lately, check out the lower western skyline tonight. Now clearing about 13 degrees above the horizon, it will “hang out” for about 90 minutes after sunset allowing you an opportunity to catch its almost full form.

So where’s comet 9/P Tempel 1 tonight? Easy enough! Look about a degree north of Delta Virginis. Although there are several small galaxies in the neighborhood, Tempel 1 is approaching magnitude 9 and will be far brighter than any galaxy. At my last observation with a large scope, Tempel 1 has developed a stellar nucleus and a short tail. Enjoy!

Suffering through the temperamental weather changes? Don’t despair. Remember that most of these observing tips can be practiced almost any night. Until next week? I’m looking forward to dark skies again and finding more challenges for you! May all your journeys be at Light Speed… ~Tammy Plotner

Posted on by Fraser Cain

Rocky Planets Form Further Away Than Previously Thought

Stellar nursery in the Orion Nebula. Image credit: ESO. Click to enlarge.
The most detailed measurements to date of the dusty disks around young stars confirm a new theory that the region where rocky planets such as Earth form is much farther away from the star than originally thought.

These first definitive measurements of planet-forming zones offer important clues to the initial conditions that give birth to planets. Understanding planet formation is key to understanding Earth’s origins, yet this remains a mysterious process, said John Monnier, assistant professor of astronomy at the University of Michigan and lead author on the paper, “The near-infrared size luminosity relations for Herbig Ae/Be disks” in a recent edition of Astrophysical Journal.

Very young stars are surrounded by thick, rotating disks of gas and dust, which are expected to eventually disappear as material is either pulled into the star, is blown from the disk, or collects into larger pieces of debris. This transition marks the leap from star formation to planet formation.

The scientists examined the innermost region of such disks where the star’s energy heats the dust to extremely high temperatures. These dusty disks are where the seeds of planets form, where dusty particles stick together and eventually grow to large masses.

However, if the dust orbits too close to the star, it evaporates, shutting off any hope of planet formation. It’s important to know where the evaporation begins since it has a dramatic effect on planet formation, Monnier said. The initial temperature and density of dust surrounding young stars are critical ingredients for advanced computer models of planet formation.

For the study, scientists looked at young stars that are about one and a half times the mass of the sun. “We can study these stars more in-depth because they are brighter and easier to see,” Monnier said.

In the last decade or so, beliefs about the systems that build planets have changed drastically with the onset of powerful observatories that can take more precise measurements, Monnier said.

They found that measurements thought to be accurate were actually very different than originally thought.

For this work, scientists used the two largest telescopes in the world linked together to form the Keck Interferometer. This ultra-powerful duo acts as the ultimate zoom lens allowing astronomers to peer into planetary nurseries with 10X the detail of the Hubble Space Telescope. By combining the light from the two Keck Telescopes, researchers were able to achieve the capabilities of a single telescope that spans a football field, but for a fraction of the cost, Monnier said.

Other key authors were Rafael Millan-Gabet and Rachel Akeson of the Michelson Science Center. Other key institutions included the Caltech-run, NASA Jet Propulsion Laboratory and the W.M. Keck Observatory in Kamuela, Hawaii.

The Keck Interferometer was funded by NASA and developed and operated by Jet Propulsion Lab, W.M. Keck Observatory, and the Michelson Science Center.

Original Source: U of Michigan News Release

Posted on by Fraser Cain

Amateurs Help Discover Extrasolar Planet

Artist interpretation of an extrasolar planet. Image credit: NASA. Click to enlarge.
An international collaboration featuring Ohio State University astronomers has detected a planet in a solar system that, at roughly 15,000 light years from Earth, is one of the most distant ever discovered.
Andrew Gould

In a time when technology is starting to make such finds almost commonplace, this new planet — which is roughly three times the size of Jupiter — is special for several reasons, said Andrew Gould, professor of astronomy at Ohio State .

The technique that astronomers used to find the planet worked so well that he thinks it could be used to find much smaller planets — Earth-sized planets, even very distant ones.

And because two amateur astronomers in New Zealand helped detect the planet using only their backyard telescopes, the find suggests that anyone can become a planet hunter.

Gould and his colleagues have submitted a paper announcing the planet to Astrophysical Journal Letters, and have posted the paper on a publicly available Internet preprint server, http://arXiv.org . The team has secured use of NASA’s Hubble Space Telescope in late May to examine the star that the planet is orbiting.

The astronomers used a technique called gravitational microlensing, which occurs when a massive object in space, like a star or even a black hole, crosses in front of a star shining in the background. The object’s strong gravitational pull bends the light rays from the more distant star and magnifies them like a lens. Here on Earth, we see the star get brighter as the lens crosses in front of it, and then fade as the lens gets farther away.
Because the scientists were able to monitor the light signal with near-perfect precision, Gould thinks the technique could easily have revealed an even smaller planet. “If an Earth-mass planet was in the same position, we would have been able to detect it,” he said.

On March 17, 2005, Andrzej Udalski, professor of astronomy at Warsaw University and leader of the Optical Gravitational Lensing Experiment, or OGLE, noticed that a star located thousands of light years from Earth was starting to move in front of another star that was even farther away, near the center of our galaxy. A month later, when the more distant star had brightened a hundred-fold, astronomers from OGLE and from Gould’s collaboration (the Microlensing Follow Up Network, or MicroFUN) detected a new pattern in the signal — a rapid distortion of the brightening — that could only mean one thing.

“There’s absolutely no doubt that the star in front has a planet, which caused the deviation we saw,” Gould said.

Because the scientists were able to monitor the light signal with near-perfect precision, Gould thinks the technique could easily have revealed an even smaller planet.

“If an Earth-mass planet was in the same position, we would have been able to detect it,” he said.

OGLE finds more than 600 microlensing events per year using a dedicated 1.3-meter telescope at Las Campanas Observatory in Chile (operated by Carnegie Institution of Washington). MicroFUN is a collaboration of astronomers from the US, Korea, New Zealand, and Israel that picks out those events that are most likely to reveal planets and monitors them from telescopes around the world.

“That allows us to watch these events 24/7,” Gould said. “When the sun rises at one location, we continue to monitor from the next.”

Two of these telescopes belong to two avid New Zealand amateur astronomers who were recruited by the MicroFUN team. Grant Christie of Auckland used a 14-inch telescope, and Jennie McCormick of Pakuranga used a 10-inch telescope. Both share co-authorship on the paper submitted to Astrophysical Journal Letters.

Two other collaborations — the Probing Lensing Anomalies NETwork (PLANET) and Microlensing Observations in Astrophysics (MOA) — also followed the event and contributed to the journal paper.

Ohio State scientists on the project included Darren DePoy and Richard Pogge, both professors of astronomy, and Subo Dong, a graduate student. Other partners hail from Warsaw University in Poland, Princeton University, Harvard-Smithsonian Center for Astrophysics, Universidad de Concepci?n in Chile, University of Manchester, California Institute of Technology, American Museum of Natural History, Chungbuk National University in Korea, Korea Astronomy and Space Science Institute, Massy University in New Zealand, Nagoya University in Japan, and the University of Auckland in New Zealand.

This is the second planet that astronomers have detected using microlensing. The first one, found a year ago, is estimated to be at a similar distance.

Gould’s initial estimate is that the new planet is approximately 15,000 light years away, but he will need more data to refine that distance, he said. A light year is the distance light travels in a year — approximately six trillion miles.

The OGLE collaboration is funded by the Polish Ministry of Scientific Research and Information Technology, the Foundation for Polish Science, the National Science Foundation, and NASA. Some MicroFUN team members received funding from the National Science Foundation, Harvard College Observatory, the Korea Science and Engineering Foundation, and the Korea Astronomy and Space Science Institute.

Original Source: OSU News Release

Posted on by Fraser Cain

Proton Launches DIRECTV Satellite

Proton rocket launching with DIRECTV 8 satellite. Image credit: ILS. Click to enlarge.
A Russian Proton Breeze M launcher placed the DIRECTV 8 satellite into orbit today, marking the fourth successful mission of the year for International Launch Services (ILS).

The Proton vehicle lifted off at 11:59 p.m. local time (1:59 p.m. EDT, 17:59 GMT). It continued its climb through space for nine hours and 15 minutes, after which time the satellite separated from the rocket into an elliptical geosynchronous transfer orbit. Satellite controllers confirm that DIRECTV 8 is functioning properly. Over the next ten days the satellite will be maneuvered into a circular geosynchronous orbit, 22,300 miles (36,000 km) above the equator.

“We’re pleased that DIRECTV chose ILS and Proton to launch this important satellite, which will provide support for the expansion of new digital and high-definition services,” said ILS President Mark Albrecht.

The DIRECTV 8 satellite, built by Space Systems/Loral, carries both Ku-band and Ka-band payloads. Its final operating position is 101 degrees West longitude.

“We congratulate the ILS launch team on their flawless execution in placing DIRECTV 8 into orbit today,” said Jim Butterworth, senior vice president, Communication Systems, DIRECTV, Inc. “DIRECTV 8 will play an important role in strengthening our satellite fleet and the rollout of new services for our more than 14.4 million customers.”

ILS markets launches and manages the missions on both the Russian Proton and the American Atlas rockets. The Proton vehicle is built by Khrunichev State Research and Production Space Center, and the Atlas is manufactured by Lockheed Martin (NYSE:LMT). This is the second spacecraft ILS has launched for DIRECTV on Proton; the previous launch was DIRECTV 5 in 2002. The Atlas vehicle also has launched two satellites for DIRECTV: DBS 2 and DIRECTV 6, in 1994 and 1997, respectively.

ILS is the global leader in launch services. With a remarkable launch rate of 74 missions since 2000, the Atlas and Proton launch vehicles have consistently demonstrated the reliability and flexibility that have made them preferred choice among satellite operators worldwide. Since the beginning of 2003, ILS has signed more new commercial contracts than all of its competitors combined. ILS was formed in 1995, and is based in McLean, Va., a suburb of Washington, D.C.

Original Source: ILS News Release

Posted on by Fraser Cain

I’m Looking for More Writers

As you’ve probably noticed, I’ve got a solid group of freelance writers working with me to help update Universe Today. There are a lot of stories that we just don’t have time to cover, though, so I’m looking to get more writers involved. If you’re a freelance science journalist, or want to become one and you have writing experience, please drop me an email with some of your writing samples. I’m especially looking for people with experience in space exploration news (NASA, Hubble, etc) as opposed to astronomy news (we’ve got lots of people for that).

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Fraser Cain
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Universe Today

Posted on by Mark Mortimer

Book Review: Space Tourism – Adventures in Earth Orbit and Beyond

Space tourism seems as obtainable to us as the sun was to Icarus. We struggle to maintain and inhabit a man made structure in the safety of low Earth orbit. Yet, we read about hotels that will allow honeymooners to gaze at the sun setting every 90 minutes. This may be a bit of a stretch, but space tourism can solidly generate revenue for some entrepreneur. As Van Pelt notes, two people have already paid significant amounts, $20 million each, to visit space. Further, as the attraction would easily better any other on planet Earth, all that’s needed is a price low enough. With this, hundreds of people each year would spend their annual vacations in orbit. It is an extreme engineering challenge if there ever was one. Still, from Van Pelt’s perspective, it’s quite obtainable.

Through the book, Van Pelt discusses the technical issues of space flight and pleasant issues of leisure time in space. In a neutral, analytical view, he considers technical issues, starting with the history of space activities, the progressive development of launch vehicles, existing state of the art capabilities and the steps needed to enable the space tourism industry. Practicalities like radiation dosimetres, pressure suits to counter g forces, pre-flight training and group interactions also get attention. These and other technical details are faithfully extended from current or historically established technology. However, launcher reusability is favoured without much supporting justification. Also, some of the later discussion about warp drives, transporters and faster than light travel seem a little out of place and add an incredulous tone to an otherwise rational and even presentation.

Van Pelt has much more fun with the leisure time activities. Using a first person perspective, he places the reader on a three day vacation to an orbiting hotel. The novelty of training, safety lessons and equipment fit-out comes through like any tourist getting ready to embark on some adventurous voyage to the big unknown. Continual comparisons to today’s commercial aeroplane flights enhance the nearness of this opportunity. Further chapters on the launch, ascent and commencement of microgravity quickly distance this trip from any commercial flight. The prose really puts the reader’s feet in the shoes of the starry eyed guest. The descent and landing give the pleasant denouement that would leave the space flyer, and presumably the reader, earnestly desiring another flight. Van Pelt also forays into predicting voyage highlights by imagining sports, games, trysts, and dancing in the realm of microgravity. He ably amplifies how common activities can take on exhilarating dimensions in the confines of a space hotel or on distant surfaces such as the 1/6’th gravity of the moon. There certainly shouldn’t be any lack of fun should his views come to pass.

To aid the reader, the two aspects of the book, the technical and first person view, come in their own chapters. Each follows along logically from the predecessor. For example, first the technical chapter discusses launch vehicles. Then, the first person view places the reader in the eyes of a person as they are launched. Despite these two aspects, the prose remains complimentary, the technical part not being too dry nor the first person view being too qualitative.

As well, the imagination and optimism shown in this book makes for an enjoyable and quick read. Quotes from science fiction writers shows how reality keeps catching up to the earlier imagination of writers from many years ago. Sometimes the optimism gets a bit much though. Van Pelt would have us believe that only a few different decisions at various stages in the United States’ space program would have had people on Mars by now. Also, the discussions about travelling to Mars and further distant planets or stars again raise incredulity rather than support the perceived industry. To build credence and optimism, these parts of the book should have been balanced with more details on means and methods of constructing the infrastructure.

Reality keeps catching up with science fiction. Scientists labour in labs while engineers construct in the field in order to bring the future a little closer to today. However, even they will need to rest and recharge. Michel Van Pelt describes the perfect travel location for recharging in his book, Space Tourism and shows what we need to get there and what may happen once we arrive.

Read more reviews online or purchase a copy from Amazon.com.

Review by Mark Mortimer.