Universe Today

June 9, 2008December 24, 2015 by Nancy Atkinson

Phoenix Will Try New “Sprinkle” Technique

Phoenix “vibrates” to move soil through a screen.

New motto for the Phoenix spacecraft: If at first you don’t succeed, then dust yourself off and try again. Since the Martian soil is proving to be a challenge for the Mars lander, engineers will try a new technique to try delivering the frozen arctic soil into the TEGA, or the Thermal and Evolved-Gas Anaylzer, designed to bake and sniff samples to identify key ingredients in the soil. The soil is clumping together, and won’t pass through a screen that brings it to the ovens on board the spacecraft. Engineers operating the Robotic Arm on Phoenix Lander are testing a revised method they are calling the sprinkle technique.

“We’re a little surprised at how much this material is clumping together when we dig into it,” said Doug Ming a Phoenix science team member from NASA’s Johnson Space Center, Houston.

Engineers commanded the spacecraft to vibrate the screen for 20 minutes on Sunday but detected only a few particles getting through the screen, not enough to fill the tiny oven below.

“We are going to try vibrating it one more time, and if that doesn’t work, it is likely we will use our new, revised delivery method on another thermal analyzer cell,” said William Boynton of the University of Arizona, lead scientist for the instrument.

The arm delivered the first sample to TEGA on Friday by turning the scoop over to release its contents. The revised delivery method, which Phoenix is testing for the first time today, will hold the scoop at an angle above the delivery target and sprinkle out a small amount of the sample by vibrating the scoop. The vibration comes from running a motorized rasp on the bottom of the scoop.

Phoenix used the arm Sunday to collect a soil sample for the spacecraft’s Optical Microscope, so look for images of that procedure soon. Today’s plans include a practice of the sprinkle technique, using a small amount of soil from the sample collected Sunday. If that goes well, the Phoenix team assembled at the University of Arizona plans to sprinkle material from the same scoopful onto the microscope later this week.

The Phoenix team also discussed this picture, showing a spring on the ground near a footpad of the spacecraft. It came from Phoenix itself, when the biobarrier was opened to free the robotic arm back on May 30, the sixth Martian day of the mission.

Phoenix News

June 9, 2008December 24, 2015 by Ian O'Neill

Can Light be “Squeezed” to Improve Sensitivity of Gravitational Wave Detectors?

Visualization of a massive body generating gravitational waves (UWM)

The search is on to detect the first evidence of gravitational waves travelling around the cosmos. How can we do this? The Laser Interferometer Gravitational-Wave Observatory (LIGO) uses a system of laser beams fired over a distance of 4 km (2.5 miles) and reflected back and forth by a system of mirrors. Should a gravitational wave pass through the volume of space-time surrounding the Earth, in theory the laser beam will detect a small change as the passing wave slightly alters the distance between mirrors. It is worth noting that this slight change will be small; so small in fact that LIGO has been designed to detect a distance fluctuation of less than one-thousandth of the width of a proton. This is impressive, but it could be better. Now scientists think they have found a way of increasing the sensitivity of LIGO; use the strange quantum properties of the photon to “squeeze” the laser beam so an increase in sensitivity can be achieved…

LIGO was designed by collaborators from MIT and Caltech to search for observational evidence of theoretical gravitational waves. Gravitational waves are thought to propagate throughout the Universe as massive objects disturb space-time. For example, if two black holes collided and merged (or collided and blasted away from each other), Einstein’s theory of general relativity predicts that a ripple will be sent throughout the fabric of space-time. To prove gravitational waves do exist, a totally different type of observatory needed to be built, not to observe electromagnetic emissions from the source, but to detect the passage of these perturbations travelling through our planet. LIGO is an attempt to measure these waves, and with a gargantuan set-up cost of $365 million, there is huge pressure for the facility to discover the first gravitational wave and its source (for more information on LIGO, see “Listening” for Gravitational Waves to Track Down Black Holes). Alas, after several years of science, none have been found. Is this because there are no gravitational waves out there? Or is LIGO simply not sensitive enough?

The first question is quickly answered by LIGO scientists: more time is needed to collect a longer period of data (there needs to be more “exposure time” before gravitational waves are detected). There is also strong theoretical reasons why gravitational waves should exist. The second question is something scientists from the US and Australia hope to improve; perhaps LIGO needs a boost in sensitivity.

To make gravitational wave detectors more sensitive, Nergis Mavalvala leader of this new research and MIT physicist, has focused on the very small to help detect the very big. To understand what the researchers are hoping to achieve, a very brief crash course in quantum “fuzziness” is needed.

Detectors such as LIGO depend on highly accurate laser technology to measure perturbations in space-time. As gravitational waves travel through the Universe, they cause tiny changes in the distance between two positions in space (space is effectively being “warped” by these waves). Although LIGO has the ability to detect a perturbation of less than a thousandth of the width of a proton, it would be great if even more sensitivity is acquired. Although lasers are inherently accurate and very sensitive, laser photons are still governed by quantum dynamics. As the laser photons interact with the interferometer, there is a degree of quantum fuzziness meaning the photon is not a sharp pin-point, but slightly blurred by quantum noise. In an effort to reduce this noise, Mavalvala and her team have been able to “squeeze” laser photons.

Laser photons possess two quantities: phase and amplitude. Phase describes the photons position in time and amplitude describes the number of photons in the laser beam. In this quantum world, if the laser amplitude is reduced (removing some of the noise); quantum uncertainties in laser phase will increase (adding some noise). It is this trade-off that this new squeezing technique is base on. What is important is accuracy in the measurement of amplitude, not the phase, when trying to detect a gravitational wave with lasers.

It is hoped that this new technique can be applied to the multi-million dollar LIGO facility, possibly increasing LIGO’s sensitivity by 44%.

“The significance of this work is that it forced us to confront and solve some of the practical challenges of squeezed state injectionâ€”and there are many. We are now much better positioned to implement squeezing in the kilometer-scale detectors, and catch that elusive gravitational wave.” – Nergis Mavalvala.

Source: Physorg.com

June 9, 2008April 26, 2016 by Nancy Atkinson

Where Is the New Horizons Spacecraft?

Even though New Horizons is the speediest spacecraft ever to travel through our solar system, it still has a long way to go on its voyage to Pluto and the Kuiper Belt. However, New Horizons hit an interplanetary milepost yesterday, June 8, by crossing the orbit of Saturn. At 1.5 billion kilometers or 935 million miles (10.06 astronomical units) distant, that’s a mission’s worth of space for most spacecraft. But for New Horizons, it’s just another interplanetary point on its voyage to the outer reaches of our solar system. As a testament to New Horizons’ speed, the spacecraft set a record for the fastest transit to Saturn by any spacecraft, making the trip in two years and four months. Voyager 1, the previous record holder, made the journey in approximately three years and two months.

Still aiming for its arrival at the Pluto/Charon system in July of 2015, New Horizons’ mission managers tell us the spacecraft is healthy, and in electronic hibernation. After a productive two-week series of system checks, maintenance activities, and software and command uploads, New Horizons is humming through the outer solar system at 65,740 kilometers per hour (40,850 mph). The team expects to keep the spacecraft in hibernation until Sept. 2.

Although the first 13 months of the mission kept the New Horizons team pretty busy, through its encounter with and gravity assist from Jupiter in February 2007, the next few years will probably be fairly quiet for the mission’s scientists and engineers.

In a previous interview, Alan Stern, New Horizons’ Principle Investigator told Universe Today, “The middle years will be long and probably, and hopefully, pretty boring. But it will include yearly spacecraft and instrument checkouts, trajectory corrections, instrument calibrations and rehearsals for the main mission.” During the last three years of the interplanetary cruise mission, Stern said teams will be writing, testing and uploading the highly detailed command script for the Pluto/Charon encounter. The mission begins in earnest approximately a year before the spacecraft arrives at Pluto, as it begins to photograph the region.

As New Horizons crossed Saturn’s orbit yesterday, the ringed planet was nowhere to be seen, as it was more than 2.3 billion kilometers (1.4 billion miles) away from the spacecraft.

And speaking of the Voyager spacecraft (way back in the first paragraph), Voyagers 1 and 2 are at the edge of the Sunâ€™s heliosphere some 100 AU away, and are the only spacecraft operating farther out than New Horizons.

The next big milepost on New Horizons’ journey? Crossing the orbit of Uranus, on March 18, 2011.

Original News Source: New Horizons Press Release

June 9, 2008December 24, 2015 by Tammy Plotner

Hanny’s Voorwerp – Still Alive and Kicking….

Back a few month’s ago, we had an article about Galaxy Zoo. In essence, it’s a type of consortium that studies galaxies and works towards classifying them. In the process of studying the images, they made a rather unusual discovery… One that’s still around.

According to the Galaxy Zoo blog: “Ever since it was first identified, Hanny’s Voorwerp has grabbed the attention of the Zookeepers and everyone else who comes across it. One reason we’ve been successful in getting such a wide range of observations over just a few months (and therefore why posts on here have been delayed!) has been that colleagues seem to find it equally compelling. So what is it? Our current best guess goes something like this:

A hundred thousand years ago, a quasar blazed behind the stars which would have already looked recognizably like the constellation Leo Minor. Barely 700 million light-years away, it would have been the nearest bright quasar, shining (had anyone had a telescope to look) around 13th magnitude, several times brighter than the light of the surrounding galaxy. This galaxy, much later cataloged as IC 2497, is a massive spiral galaxy which was in the process of tidally shredding a dwarf galaxy rich in gas – gas which absorbed the intense ultraviolet and X-ray output of the quasar and in turn glowed as it cooled. But something happened to the quasar. Whether it turned off, dropped to a barely simmering level of activity as its massive black hole became starved for gas to feed its accretion, or it was quickly shrouded in gas and dust, we don’t see it anymore. But we see its echo.”

But that was months ago. Is Hanny’s Voorwerp still alive and kicking? You betcha’. Astrophotographer Joe Brimacombe took this week’s image of the Voorwerp (Dutch for “what the heck is that?”) on May 25, 2008. Like Joe’s own interest, Galaxy Zoo didn’t stop searching out the meaning of Hanny’s Voorwerp, either. They kept right on photographing and analyzing. According to Bill Keel:

“At this point, we know that the object is rich in highly ionized gas. There is continuum light, especially at the northern tip, but the emission lines are so strong that we can as yet say little about its continuum structure. The high ionization might suggest shock ionization or photoionization by an active galactic nuclei, which would have to be much brighter than any we see in the neighborhood. If the AGN is in IC 2497, it must be highly obscured from our direction but not toward the gas. (It may be significant that the cloud lies near the galaxy’s projected minor axis). The FIRST survey at 20 cm shows weak emission from the cloud and a significant radio source in IC 2497. We are now pursuing further imaging, UV, and X-ray detections to work out what we are seeing here. Whatever it is, it seems to be unique in the SDSS imaging survey. Chris Lintott has queried the database and, after winnowing out imaging artifacts, found no objects with u-g and g-r colors within 0.15 magnitude of what we see in Hanny’s Voorwerp.

Our working hypothesis is that Hanny’s Voorwerp consists of dust and gas (maybe from a tidally disrupted dwarf galaxy) which is illuminated by a quasar outburst within IC 2497, an outburst which has faded dramatically within the last 100,000 years.”

What ever it might truly be is still somewhat a mystery… But it’s a great summer-hot object!

Image credits of Hanny’s Voorwerp belong to Galaxy Zoo and Joe Brimacombe.

June 9, 2008December 24, 2015 by Nancy Atkinson

Mystery Moonlets Cause Constant Changes in Saturn’s F Ring

Scientists from the Cassini mission are finding Saturn’s rings to be very dynamic; constantly changing and evolving. This is especially true for one of Saturn’s outermost rings, the F ring. This ring can change rapidly, sometimes on a timescale of hours, and astronomers believe it’s probably the only location in the solar system where large scale collisions happen on a daily basis. New images from the Cassini spacecraft have revealed unprecedented detail of this ring, including evidence that several small, unseen moons collide with other ring particles and cause perturbations called jets, streamers and fans.

Saturn’s F ring is very thin, just a few hundred kilometers wide, and is held together by two shepherd moons, Prometheus and Pandora, which orbit inside and outside the ring. For some time, scientists have suspected the presence of tiny moonlets that orbit Saturn in association with the clumpy F ring. As the small satellites move close to the F ring core they leave a gravitational signature. In some cases they can draw out material in the form of a “streamer.” Another perturbation called “jets” are the result of collisions between small nearby moonlets and the core of the F ring.

Scientists speculate that there could be several small moons with a variety of sizes that create these structures.

The leader of this analysis, Carl Murray of Queen Mary, University of London said, “Previous research has noted the features in the F ring and concluded that either another moon of radius about 100km must be present and scattering the particles in the ring, or a much smaller moonlet was colliding with its constituent particles. We can now say that the moonlet is the most likely explanation and even confirm the identity of one culprit.”

A ~5km object discovered by Cassini in 2004 (called S/2004 S 6) is the best candidate to explain some of the largest jets seen in the images.

The Cassini images also show new features called “fans” which result from the gravitational effect of small (~1km) satellites orbiting close to the F ring core.

Understanding these processes helps scientists understand the early stages of planet formation.

Professor Keith Mason, CEO of the Science and Technology Facilities Council which funds UK involvement in Cassini-Huygens said “This incredibly successful mission has taught us a great deal about the solar system and the processes at work in it. Understanding how small objects move within the dust rings around Saturn gives an insight into the processes that drive planetary formation, where the proto-planet collects material in its orbit through a dust plane and carves out similar grooves and tracks.”

Original News Source: Physorg

June 8, 2008December 24, 2015 by Ian O'Neill

Listen to Terra Chat Live Tonight: 2012 and the Mayan Prophecy (Updated)

Update (Monday, June 9th):
Listen to the recorded show from last night (June 8th) with Colin Knight and myself.

In response to my Universe Today 2012 articles (“No Doomsday in 2012” and “2012: No Planet X“), I’ve been invited by two radio shows to chat about the fuss surrounding the 2012 doomsday prophecies. I had no idea these articles would cause such a stir! I’ve taken the view that there is very little scientific evidence for many of the different “end of the world” scenarios, and I remain highly sceptical of any theory that proclaims to predict the future (especially the much-hyped Planet X). There are a few more articles in the pipeline, so watch this space.

If you are interested and want to listen in to Colin Knight’s Terra Chat show, with me as his guest, go to the Blog Talk Radio: Terra Chat homepage and you’ll find the live radio feed. Looks like fun!

Time: Sunday June 8th 2008, 10pm Eastern Time

More information on tonight’s show Â»

I have another show on Tuesday night, so I’ll post that information closer to the time. Cheers, Ian

June 7, 2008April 26, 2016 by Ian O'Neill

Can a Wormhole Generate its Own Magnetic Field?

Artist impression of what it could look like when entering a wormhole (http://en.wikipedia.org/wiki/Image:FY221c15.png)

Wormholes are a strange consequence of Einstein’s theory of general relativity. These “shortcuts” through the fabric of space and time may link two different locations in the universe; they may even connect two different universes together. This also leads to the possibility that wormholes can allow travel between two points in time. These strange entities have provided science fiction stories with material for many years, but there is credible physics behind wormholes. Now it seems that in theory slowly-rotating wormholes may be able to generate their own magnetic field. Could this be used to detect the presence of wormholes in our observable Universe?

In a previous Universe Today article, I found some interesting research about the possibility of observing a wormhole using sensitive radio telescopes. What’s more, an observer may be able to see the light from another part of the Universe that has travelled along the wormhole and then emitted through the wormhole’s mouth. An observer could expect to see a bubble-like sphere floating in space, with emitted light intensifying around the rim.

In a publication last month, Mubasher Jamil and Muneer Ahmad Rashid from the National University of Sciences and Technology in Pakistan investigates the properties of a slowly rotating wormhole and the effect this would have on a surrounding volume of space. Their calculations assume a cloud of charged particles (i.e. electrons) are gravitationally attracted to the entity, and as the wormhole rotates, it drags the cloud of electrons with it. This approach had already been carried out when considering the effects of a slowly rotating compact star on surrounding stellar plasma.

This gravitational effect is known as “frame-dragging”. As the wormhole is predicted to have a gravitational influence on the space surrounding it, Einstein’s general relativity predicts that space-time will be warped. The best way to visualize this is to imagine a heavy ball on an elastic sheet; the ball causes the sheet to stretch downward, in a cone-shape. If the ball is spun on the sheet, friction between the ball and elastic will cause the sheet to distort in another way, it will begin to twist out of shape. If you apply this idea to space-time (the elastic sheet), and you have a slowly rotating wormhole (the ball), distortions in space-time will have a dragging effect on the surrounding particles, causing them to spin with the wormhole.

This is where Jamil and Rashid’s paper steps in. If you have a rotating mass of charged particles, a magnetic field may be generated (as a consequence of Maxwell’s equations). Therefore, in theory, a slowly-rotating wormhole could have its own magnetic field as a consequence of the electromagnetic field set up by the motion of charged particles.

So could a wormhole be detected by instrumentation? That depends on the magnitude of the warping of space-time a rotating wormhole has on local space; the smaller the wormhole, the smaller the density of rotating charged particles. As theorized natural wormholes are expected to be microscopic, I doubt there will be a large magnetic field generated. And besides, you’d have to be very close to the mouth of a wormhole to stand the chance of measuring its magnetic field. The possibility of detecting a wormhole may remain in the realms of science-fiction for a while yet…

Source: arXiv preprint server

June 7, 2008December 24, 2015 by Nancy Atkinson

Images From The STS-124 Mission

The crew of the STS-124 mission has been busy installing equipment on the International Space Station, fixing a toilet, and trying out the latest robotic arm that’s part of the shiny new Kibo module. The image above shows some of the new additions to the station, which just keeps growing in size with every mission. The mass of modules shown are: the Japanese Pressurized Module (left), the Japanese Logistics Module (top center), the Harmony node (center), the Destiny laboratory (right) of the ISS, and the forward section of Space Shuttle Discovery that is docked to the station.

Astronauts Mike Fossum (left) and Ron Garan, during the second EVA for the mission. The two astronauts installed television cameras on the Kibo Japanese Pressurized Module (JPM) that will aid in the Kibo robotic arm operations, they also removed thermal covers from the Kibo robotic arm, prepared an upper JPM docking port for flight day seven’s attachment of the Kibo logistics module, readied a spare nitrogen tank assembly for its installation during the third spacewalk, retrieved a failed television camera from the Port 1 truss, and inspected the port Solar Alpha Rotary Joint (SARJ). In looking at the SARJ, Fossum found grease streaks and a small amount of a dust-like material. In the third spacewalk, coming up on Sunday, the astronauts will take samples of the materials for further testing. They’ll also continue outfitting and activating the Kibo module.

Inside Kibo: STS 124 Commander Mark Kelly (right) and pilot Ken Ham add a rack inside the recently installed Kibo Pressurized Module.

This is a great image of Space Shuttle Discovery with Earth’s limb in the background. Also visible are parts of the shuttle: the Remote Manipulator System (RMS), the docking mechanism, vertical stabilizer and orbital maneuvering system (OMS) pods. This was taken on flight day two, before the shuttle docked with the space station.

Image Source: NASA Human Spaceflight Gallery

June 7, 2008December 24, 2015 by Jerry Coffey

Temperature of Mars

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Mars is farther from the Sun than the Earth, so, as you would expect, the temperature of Mars is colder. For the most part it is very cold on Mars. The only exception is during the summer days close to or at the equator. Even at the equator, the night time temperatures fall well below zero. On those summer days, it can be around 20 degrees Celsius then plummet to -90 C at night.

Mars follows a highly elliptical orbit, so temperatures vary quite a bit as the planet travels around the Sun. Since Mars has an axial tilt similar to Earth’s(25.19 for Mars and 26.27 for Earth), the planet has seasons as well. Add to that a thin atmosphere and you can see why the planet is unable to retain heat. The Martian atmosphere is over 96% carbon dioxide. If the planet had an atmosphere to retain heat, the carbon dioxide would cause a greenhouse effect that would heat Mars to jungle like temperatures.

Scientist know the current temperature of Mars, but what about the past. Rovers and orbiters have returned images that indicate erosion patterns that can only be caused by liquid water. That would seem to indicate that Mars was once much warmer and wetter. Here on Earth, those features would have been covered in soil after a few million years. So, was Mars warmer just a few million years ago? No, Mars has been a frigid planet for at least 3 billion years and some scientist believe it has been frozen for 4 billion years. The erosion features have not disappeared because there is no current liquid water or plate tectonics to change the landscape. What wind there is, does not seem strong enough to further erode the surface.

Tracking the presence of warmer weather and liquid water on Mars is important for a few reasons. One is that liquid water is essential for the evolution of life as we know it. Some scientists still hold out hope that there is microbial life deep beneath the surface where it is warmer and water may exist. Secondly, if humans are to ever explore the planet, they would need a water source. A human mission would take nearly two years to complete and storage space would be limited. Water ice may be melted upon arrival then purified, but finding a supply of liquid water would be even more expedient.

The temperature of Mars is a minor obstacle to early human exploration, while water is more pressing. Current spacesuits would survive the surface temperatures. Now, all we have to do is find a way to get there and back without having to spend two years in a cramped modern spacecraft.

Here’s news that Mars has probably been cold for billions of years, and more information about Mars, and just how cold it gets.

Here’s an overview of temperatures on Mars. Mars News has more info on Mars.

Finally, if you’d like to learn more about Mars in general, we have done several podcast episodes about the Red Planet at Astronomy Cast. Episode 52: Mars, and Episode 91: The Search for Water on Mars.

Sources:
http://www-k12.atmos.washington.edu/k12/resources/mars_data-information/temperature_overview.html
http://www.nasa.gov/multimedia/imagegallery/image_feature_1160.html
http://solarsystem.nasa.gov/planets/profile.cfm?Object=Mars&Display=Facts

June 7, 2008December 24, 2015 by Ian O'Neill

Possible Solution to Solar Flare Damage to Satellites

Powerful solar flares can cause charge build-up on satellites (NASA)

When a solar flare blasts energetic particles and magnetic flux at Earth, our satellites are on the front line. As coronal mass ejections (CMEs) interact with the Earth’s magnetosphere, there is a huge injection of energetic electrons into the Earth’s radiation belts. This can have dire consequences for the satellites that we depend on for communications around the globe. All is not lost however. An international team of scientists have stumbled upon a possible, innovative solution to discharge these troublesome electrons into the atmosphere: bathe the skies in radio waves.

The magnetosphere (protective layers of geomagnetic field lines) traps energetic particles in a volume of space known as the Van Allen belt. Our satellites are constantly travelling through this high radiation environment. Most satellites are shielded from all but the worst the Van Allen belt can throw at them, but should the Sun send a high concentration of energetic particles at the Earth after a solar flare, the environment in the magnetosphere becomes a very dangerous place. Should the delicate circuitry on board the spacecraft be hit by energetic particles (a situation that possibly caused Mars Odyssey to be switched to “safe-mode”), the satellite could be irreversibly damaged.

Now, a chance discovery by French and New Zealand scientists indicate that magnetospheric electrons can be discharged into the atmosphere by using ground-based radio transmitters. This finding comes from a new paper to be published in the journal Geophysical Research Letters. Rory Gamble, a PhD student of the University of Otago in Dunedin, New Zealand, and his colleagues were analysing the data from DEMETER (Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions), a satellite sensitive to radiation changes in the magnetosphere. As the satellite passed over a military transmitter in Western Australia, they noticed that magnetospheric electrons were discharged into the atmosphere, thereby removing them from the magnetosphere.

“We were able to determine that this transmitter has a direct effect on the electrons in the radiation belts [in the magnetosphere], it caused those electrons to crash into the top of the atmosphere and be removed from the radiation belts.” – Rory Gamble

This finding is a very exciting development for the human-influenced manipulation of the levels of radiation in the magnetosphere. During periods of high solar activity, when energetic electrons are expected to populate the radiation belts in higher densities, there could be a system in place to bathe the sky in radio waves, allowing safer passage for satellites. This phenomenon has been known to exist when transmitting radio waves in space, but this is the first example of electron discharge from a ground-based transmitter.

Source: ABC