Posted on by Nancy Atkinson

No Joy for Dark Matter Detector’s First 100 Days

Bottom photomultiplier tube array on the XENON 100 detector. Credit: the XENON collaboration

[/caption]

We’re still mostly in the dark about Dark Matter, and the highly anticipated results from the XENON100 detector has perhaps shed a tad more light on the subject – by not making a detection in the first 100 days of the experiment. Researchers from the project say they have now been able to place the most stringent limits yet on the properties of dark matter.

To look for any possible hints of Dark Matter interacting with ordinary matter, the project has been looking for WIMPS — or weakly interacting massive particles – but for now, there is no new evidence for the existence of WIMPS, or Dark Matter either.

The extremely sensitive XENON100 detector is buried beneath the Gran Sasso mountain in central Italy, shielding it from cosmic radiation so it hopefully can detect WIMPS, hypothetical particles that might be heavier than atomic nuclei, and the most popular candidate for what Dark Matter might be made of. The detector consists of 62 kg of liquid xenon contained within a heavily shielded tank. If a WIMP would enter the detector, it should interact with the xenon nuclei to generate light and electric signals – which would be a kind of “You Have Won!” indicator.

Dark Matter is thought to make up more than 80% of all mass in the universe, but the nature of it is still unknown. Scientists believe that it is made up of exotic particles unlike the normal (baryonic) matter, which we, the Earth, Sun and stars are made of, and it is invisible so it has only been inferred from its gravitational effects.

The XENON detector ran from January to June 2010 for its first run, and in their paper on arxiv, the team revealed they found three candidate events that might be due to Dark Matter. But two of these were expected to appear anyway because of background noise, the team said, so their results are effectively negative.

Does this rule out the existence of WIMPS? Not necessarily – the team will keep working on their search. Plus, results from a preliminary analysis from11.2 days worth of data, taken during the experiment’s commissioning phase in October and November 2009, already set new upper limits on the interaction rate of WIMPs – the world’s best for WIMP masses below about 80 times the mass of a proton.

And the XENON100 team was optimistic. “These new results reveal the highest sensitivity reported as yet by any dark matter experiment, while placing the strongest constraints on new physics models for particles of dark matter,” the team said in a statement.

Read the team’s paper.

More info on XENON100

Sources: EurekAlert, physicsworld

Posted on by Nancy Atkinson

Cast Your Vote for Student “Spirit of Innovation” Awards

The Spirit of Innovation Award honors the memory of Pete Conrad

[/caption]

The Spirit of Innovation Awards is a wonderful competition that challenges teams of high school students to create innovative products using science, technology, and entrepreneurship to solve 21st century, real-world problems. Right now, the student teams are battling for top pick this week as public voting opens in the Conrad Foundation (named in memory of Apollo astronaut Pete Conrad)Spirit of Innovation People’s Choice Awards, so check out the various teams and cast your vote. But do it now: public voting is runs only through April 17.

“Science and technology studies improve life around the globe, and expand our reach off of it,” said Pete Worden, Director of NASA Ames Research Center. “The People’s Choice Awards is an opportunity for the public to engage with student innovators demonstrating fresh and exciting developments in these fields. It gives everybody the chance to participate in a program that benefits our future.”

Conrad was commander of Apollo 12 and the third man to walk on the Moon. He had a learning disability, but went on to earn a scholarship to Princeton and lead a mission to the Moon.

This year’s People’s Choice champion will be announced Sunday, May 1 during the closing ceremonies of the 2011 Innovation Summit at NASA’s Ames Research Center. The Summit, April 28 – May 1st, is the culmination of the Spirit of Innovation Awards as the student teams present their products to entrepreneurs, scientists, and industry professionals, and compete for $5,000 Next Step Grants. The People’s Choice votes will be incorporated as 10 percent of the final judging score for these scholarships.

Last year, Team AM Rocks and its Solar Flare Nutrition Bar took home the People’s Choice Award winning title. This year the teams that garner the most People’s Choice votes in each of the challenge
categories -aerospace exploration, clean energy and cyber security -will be awarded $250. Meet this year’s teams, explore the innovations, and cast your vote for favorite, at this link.

Find out more about the Conrad Foundation here.

Posted on by Jason Major

A Varying Venusian Vortex

Animation of Venus' southern polar vortex made from VIRTIS thermal infrared images; white is cooler clouds at higher altitudes.

Our neighboring planet Venus really is a world of extremes; searing surface temperatures, crushing air pressure, sulfuric acid clouds…Venus pretty much pushes the envelope on every aspect of rocky-planet existence. And now here’s one more thing that made scientists do a double-take: a shape-shifting vortex swirling around Venus’ south pole!

The presence of a cyclonic storm around Venus’ poles – both north and south –  has been known since Mariner 10’s pass in 1974 and then afterwards during the Pioneer Venus mission when a downwardly-spiraling formation of clouds over the planet’s north pole was imaged in infrared. It wasn’t until ESA’s Venus Express orbiter arrived in 2006 that the cyclone at the south pole was directly observed via the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument…and it proved to be much stranger than anything previously expected. Continue reading “A Varying Venusian Vortex”

Posted on by Nancy Atkinson

‘Sonic Booms’ in Space Linked to Star Formation

Dense filaments of gas in the IC5146 interstellar cloud. This image was taken by ESA’s Herschel space observatory at infrared wavelengths 70, 250 and 500 microns. Stars are forming along these filaments. Credits: ESA/Herschel/SPIRE/PACS/D. Arzoumanian (CEA Saclay) for the “Gould Belt survey” Key Programme Consortium.

[/caption]

Its true there is no sound in empty interstellar space, but the Herschel space observatory has observed the cosmic equivalent of sonic booms. Networks of tangled and tremendously large gaseous filaments seen within clouds of gas and dust between stars are likely to be remnants of slow shockwaves from supernovae, Herschel scientists say. And surprisingly, no matter what the length or density of these filaments are, the width is always roughly the same, about 0.3 light years across, or about 20,000 times the distance of Earth from the Sun. This consistency of the widths demands an explanation, scientists say.

And it’s possible these shockwaves could generate sound within an interstellar cloud – if something were there to hear it.

“Although the density in an interstellar cloud is lower than in a very good vacuum on Earth there are molecules in the order of 10^8 per cm^3” said Goeran Pilbratt, ESA’s Herschel mission scientist. “That should be enough for sound to propagate, apart from the fact that we do not have the instruments to measure it.”

Filaments like this have been sighted before by other infrared satellites, but they have never been seen clearly enough to have their widths measured. Herschel is seeing that the width of these filaments is nearly uniform across three nearby clouds: IC5146, Aquila, and Polaris. The Herschel team, lead by Doris Arzoumanian, Laboratoire AIM Paris-Saclay, CEA/IRFU, made observations of 90 filaments, and found all had nearly identical widths. “This is a very big surprise,” Arzoumanian said.

The network of interstellar filaments in Polaris as seen by Herschel. Credits: ESA/Herschel/SPIRE/Ph. André (CEA Saclay) for the Gould Belt survey Key Programme Consortium and A. Abergel (IAS Orsay) for the Evolution of Interstellar Dust Key Programme Consortium.

Also, newborn stars are often found in the densest parts of these filaments. One filament imaged by Herschel in the Aquila region contains a cluster of about 100 infant stars.

The Herschel team said their observations provide strong evidence for a connection between interstellar turbulence, the filaments and star formation.

“The connection between these filaments and star formation used to be unclear, but now thanks to Herschel, we can actually see stars forming like beads on strings in some of these filaments,” said Pilbratt.

Comparing the observations with computer models, the astronomers suggest that filaments are probably formed when slow shockwaves dissipate in the interstellar clouds. These shockwaves are mildly supersonic and are a result of the huge amounts of turbulent energy injected into interstellar space by exploding stars.

They travel through the dilute sea of gas found in the galaxy, compressing and sweeping it up into dense filaments as they go. As these “sonic booms” travel through the clouds, they lose energy and, where they finally dissipate, they leave these filaments of compressed material.

Interstellar clouds are usually extremely cold, about 10 degrees Kelvin above absolute zero, and this makes the speed of sound in them relatively slow at just 0.2 km/s, as opposed to 0.34 km/s in Earth’s atmosphere at sea-level.

Sound travels in waves like light or heat does, but unlike them, sound travels by making molecules vibrate. So, in order for sound to travel, there has to be something with molecules for it to travel through. On Earth, sound travels to your ears by vibrating air molecules. In deep space, the large empty areas between stars and planets, there are no molecules to vibrate.

Read the team’s paper: Characterizing Interstellar Filaments with Herschel in IC5146

Sources: ESA email exchange with Pilbratt

Posted on by Jason Rhian

Iridium Next Prepares to Ride the Falcon

Iridium Next might have launched their last suite of satellites on Deltas, Protons and on the Long March - but the next wave will be all about the Falcon 9. Photo Credit: Alan Walters/awaltersphoto.com

[/caption]

To date, Iridium NEXT is the largest commercial space launch contract with any single entity. All total, the contract is worth an estimated $3 billion. As part of that Iridium Communications Inc. signed into a deal with Space Explorations Technologies (SpaceX) as its major launch provider of its communications satellites on SpaceX’s Falcon 9 rocket. The manner in which the Iridium NEXT family of satellites is launched will be a dramatic departure from how Iridium launched its first suite of satellites back in the 90s.

Iridium launched this first constellation of communications satellites within the time span of a single year, from 1997 until 1998. Iridium sent this constellation into orbit on multiple different launch vehicles. The original deployment was a distinctly international affair, with the U.S. Delta II, the Russian Proton and the Chinese Long March rockets all playing a role in putting the entire fleet of satellites into orbit.

Iridium Communications plans to launch the 72 satellites of the Iridium Next constellation atop eight Falcon 9 rockets. Image Credit: Iridium Communications

This time, only a single launch provider, SpaceX, and their twice-flown Falcon 9 rocket have been given the nod to accomplish the job. They will also complete the planned 72 satellite fleet in only eight launches of nine satellites each. Sixty-six of these satellites will be fully operational; the remaining six will be on-orbit spares (in case there is a contingency with any of the operating satellites). Iridium will also have nine additional ground spares.

But Iridium has plans to further maximize the value of these satellites by selling space on them so that other firms can attach sensors or experiments.

“Every one of these satellites has a budget of about 110 pounds that can be used to fly extra payloads from different customers,” said Iridium’s CEO Matt Desch during a recent interview. “We will be hosting other people’s sensors on our satellites.”

The arrangement between Iridium and the NewSpace firm was just one in a string of successes as far as SpaceX is concerned. With the first two successful flights of the Falcon 9 rocket, the unspoken-but-obvious backing of the White House and the contract with Iridium, SpaceX is on a winning streak that shows little signs of abating. With the second launch of its Falcon 9 rocket, SpaceX became the first company to do what only nations had done before – send a spacecraft into orbit and have it return safely to Earth (the Dragon spacecraft splashed down in the Pacific Ocean a few hours after launch).

Every Falcon 9 rocket with an Iridium Next payload would carry nine satellites each. Photo Credit: SpaceX

The contract with Iridium Communications is set to see its first launch during the first quarter of 2015. With the system fully financed (as of this past fall) the company now has to build it on orbit. When the constellation of satellites is on orbit it is expected to be functioning for many years to come.

“It was an innovative system that broke all the rules, and now we’re going to do it again,” said Desch. “A lot of people don’t realize what a powerful system we are today. They probably only remember us from 10-15 years ago. We’re going to remind them of who we are and what we are capable of, the replacement system will last until 2030 and what we will do today will last for years to come.”

SpaceX has had two successful launches of its Falcon 9 rocket, the third test flight is currently scheduled to take place this summer. Photo Credit: SpaceX
Posted on by Nancy Atkinson

Where In The Universe Challenge #144

Here’s this week’s image for the Where In The Universe Challenge, to test your visual knowledge of the cosmos. You know what to do: take a look at this image and see if you can determine where in the universe this image is from; give yourself extra points if you can name the spacecraft/telescope responsible for the image. We’ll provide the image today, but won’t reveal the answer until later. This gives you a chance to mull over the image and provide your answer/guess in the comment section. Please, no links or extensive explanations of what you think this is — give everyone the chance to guess.

UPDATE: Answer is now posted below.

This is a closeup of part of the Helix Nebula, or NGC 7293. Produced in 2003, at the time it was one of the largest and most detailed celestial images ever made. The composite picture is a seamless blend of ultra-sharp images from NASA’s Hubble Space Telescope combined with the wide view of the Mosaic Camera on the National Science Foundation’s 0.9-meter telescope at Kitt Peak National Observatory near Tucson, Ariz. See more info on this picture at the HubbleSite.

Posted on by Nancy Atkinson

A Twisted Sister Galaxy

Galaxy ESO 510-G13. Credit: NASA/ESA and The Hubble Heritage Team STScI/AURA

[/caption]

This is an older image from Hubble but I came across it today and wanted to share it. It shows an unusual edge-on galaxy, that has been twisted by a recent collision with a nearby galaxy, and is in the process of being swallowed up. This could be a spiral sister to our own Milky Way, as the dust and arms of normal spiral galaxies appear flat when viewed edge-on. And the twisting effect could be an example of what could happen to our galaxy in about 3 billion years when it begins to collide with the Andromeda galaxy.


As the gravitational forces distort the structures of the galaxies as their stars, gas, and dust merge together, it also sparks star formation. In the outer regions of ESO 510-G13, especially on the right-hand side of the image, the twisted disk contains not only dark dust, but also bright clouds of new, blue stars.
Eventually, in millions of years, all the matter will coalesce and the activity and disturbances will die out, and ESO 510-G13 will become a normal-looking single galaxy.

This galaxy was first observed by ESO’s ground based telescopes, and Hubble’s Wide Field Planetary Camera 2 (WFPC2) observed ESO 510-G13 in April 2001.

See more about the image at the HubbleSite.

Posted on by Nancy Atkinson

Asteroid Observing Alert

2011 GP59 imaged remotely from the GRAS Observatory. Credit: Ernesto Guido & Giovanni Sostero

[/caption]

A newly discovered asteroid could provide one of the best recent viewing opportunities for amateur astronomers, according to the British Astronomical Association. “This is the best NEO close approach these past few years and is bright enough to be observed visually in large (>20cm., or 8-inch) aperture telescopes when on the night of Thursday 14th it will appear as a faint slow-moving star,” writes Richard Miles, the director of the BAA’s Asteroids and Remote Planets Section.

UPDATE: See a new picture of asteroid 2011 GP59 from Ernesto Guido & Giovanni Sostero taken on April 14, 2011, below.


2011 GP59 imaged remotely from the GRAS Observatory. Credit: Ernesto Guido & Giovanni Sostero

Guido & Sostero sent us a note that they imaged 2011 GP59 early on April 14, remotely from the GRAS Observatory (near Mayhill, New Mexico USA) through a 0.51-m, f/6.9 reflector + CCD.

“It’s a single unfiltered exposure of 600 seconds, showing 2011 GP59 as trail with brightness fluctuations clearly evident,” they said.

(end of 4/14 update)

2011 GP59 was discovered just a few days ago and will make its closest approach to the Earth on April 15 at 19h UT at 1.39 lunar-distances. But it will be brightest at an average magnitude of 13.2 around 00h UT on the night of April 14/15 when Miles says it will be very favorably placed in the sky for observers worldwide.
The asteroid is approximately 60 meters in diameter and appears to be rotating very quickly, about once every 7.35 minutes. Its oblong in shape and rotation will vary the object’s brightness every 4 minutes or so.

Miles reported that David Briggs observing with the Hampshire Astronomy Group’s 0.4-m instrument on the evening of April 11 commented, “This is probably the fastest rotator I’ve seen so far in that it completely disappears from view every 3 to 4 images.”

This object was discovered on the night of April 8/9 by the Observatorio Astronomico de Mallorca (OAM) using a 0.45-m f/2.8 reflector at their La Sagra facilities (J75) in Andalusia, Spain (see http://www.minorplanets.org/OLS/ ). The observers involved were S. Sanchez, J. Nomen, R. Stoss, M. Hurtado, J. A. Jaume and W. K. Y. Yeung.

Brian Skiff of Lowell Observatory has completed a lightcurve analysis which can be found at this link, and positions can be found using the Minor Planet Center’s ephemeris service at this link. You can also find more information on this object from the website of the Remanzacco Observatory in Italy.

The British Astronomical Association is also seeking observations of the Moon on Friday, April 15, between 19:00 and 21:00 UT, when the Aristarchus and Herodotus area of the Moon will match the same illumination, to within +/- 0.5 degrees, as that observed during the famous Transient Lunar Phenomena (TLP) seen by Greenacre and Barr from Flagstaff observatory back on Oct. 30, 1963.

TLPs are very short changes in the brightness of patches on the face of the Moon, which can last anywhere from a few seconds to a few hours and can grow from less than a few to a hundred kilometers in size. This phenomenon has been observed by hundreds of amateur and professional astronomers, but how and why this occurs is not understood. Some astronomers believe that they are the outcome of lunar outgassing, where gas is being released from the surface of the Moon, but most commonly astronomers think it could be an effect from Earth’s own atmosphere.

If you want to help understand TLPs and perhaps observe an event like this for yourself, the BAA Lunar Section is looking for high resolution monochrome, or especially color, images of this area during this time period,, which favors observers in Europe.

But you can check this website from the University of Aberystwyth for many locations around the world of when would be a good time to observe a TLP.

See more information about how to observe a TLP and how to report your observations at the BAA website.

Sources: BAA, BAA (again) University of Aberystwyth

Posted on by Nancy Atkinson

A New Way to Visualize Warped Space and Time

By combining theory with computer simulations, Thorne and his colleagues at Two doughnut-shaped vortexes ejected by a pulsating black hole. Also shown at the center are two red and two blue vortex lines attached to the hole, which will be ejected as a third doughnut-shaped vortex in the next pulsation. Credit: The Caltech/Cornell SXS Collaboration

[/caption]

Trying to understand the warping of space and time is something like visualizing a scene from Alice in Wonderland where rooms can change sizes and locations. The most-used description of the warping of space-time is how a heavy object deforms a stretched elastic sheet. But in actuality, physicists say this warping is so complicated that they really haven’t been able to understand the details of what goes on. But new conceptual tools that combines theory and computer simulations are providing a better way to for scientists to visualize what takes place when gravity from an object or event changes the fabric of space.

Researchers at Caltech, Cornell University, and the National Institute for Theoretical Physics in South Africa developed conceptual tools that they call tendex lines and vortex lines which represent gravitation waves. The researchers say that tendex and vortex lines describe the gravitational forces caused by warped space-time and are analogous to the electric and magnetic field lines that describe electric and magnetic forces.

“Tendex lines describe the stretching force that warped space-time exerts on everything it encounters,” said says David Nichols, a Caltech graduate student who came up with the term ‘tendex.’. “Tendex lines sticking out of the Moon raise the tides on the Earth’s oceans, and the stretching force of these lines would rip apart an astronaut who falls into a black hole.”

Vortex lines, on the other hand, describe the twisting of space. So, if an astronaut’s body is aligned with a vortex line, it would get wrung like a wet towel.

Two spiral-shaped vortexes (yellow) of whirling space sticking out of a black hole, and the vortex lines (red curves) that form the vortexes. Credit: The Caltech/Cornell SXS Collaboration

They tried out the tools specifically on computer simulated black hole collisions, and saw that such impacts would produce doughnut-shaped vortex lines that fly away from the merged black hole like smoke rings. The researchers also found that a bundle of vortex lines spiral out of the black hole like water from a rotating sprinkler. Depending on the angles and speeds of the collisions, the vortex and tendex lines — or gravitational waves — would behave differently.

“Though we’ve developed these tools for black-hole collisions, they can be applied wherever space-time is warped,” says Dr. Geoffrey Lovelace, a member of the team from Cornell. “For instance, I expect that people will apply vortex and tendex lines to cosmology, to black holes ripping stars apart, and to the singularities that live inside black holes. They’ll become standard tools throughout general relativity.”

The researchers say the tendex and vortex lines provide a powerful new way to understand the nature of the universe. “Using these tools, we can now make much better sense of the tremendous amount of data that’s produced in our computer simulations,” says Dr. Mark Scheel, a senior researcher at Caltech and leader of the team’s simulation work.

Their paper has been published in the April 11 in the Physical Review Letters.

Source: CalTech