Universe Today

October 16, 2012December 23, 2015 by Nancy Atkinson

Hubble Studies Dark Matter Filament in 3-D

Hubble’s view of massive galaxy cluster MACS J0717.5+3745. The large field of view is a combination of 18 separate Hubble images. Credit:
NASA, ESA, Harald Ebeling (University of Hawaii at Manoa) & Jean-Paul Kneib (LAM)

Earlier this year, astronomers using the Hubble Space Telescope were able to identify a slim filament of dark matter that appeared to be binding a pair of distant galaxies together. Now, another filament has been found, and scientists a have been able to produce a 3-D view of the filament, the first time ever that the difficult-to-detect dark matter has been able to be measured in such detail. Their results suggest the filament has a high mass and, the researchers say, that if these measurements are representative of the rest of the Universe, then these structures may contain more than half of all the mass in the Universe.

Dark matter is thought to have been part of the Universe from the very beginning, a leftover from the Big Bang that created the backbone for the large-scale structure of the Universe.

“Filaments of the cosmic web are hugely extended and very diffuse, which makes them extremely difficult to detect, let alone study in 3D,” said Mathilde Jauzac, from Laboratoire d’Astrophysique de Marseille in France and University of KwaZulu-Natal, in South Africa, lead author of the study.

The team combined high resolution images of the region around the massive galaxy cluster MACS J0717.5+3745 (or MACS J0717 for short) – one of the most massive galaxy clusters known — and found the filament extends about 60 million light-years out from the cluster.

The team said their observations provide the first direct glimpse of the shape of the scaffolding that gives the Universe its structure. They used Hubble, NAOJ’s Subaru Telescope and the Canada-France-Hawaii Telescope, with spectroscopic data on the galaxies within it from the WM Keck Observatory and the Gemini Observatory. Analyzing these observations together gives a complete view of the shape of the filament as it extends out from the galaxy cluster almost along our line of sight.

The team detailed their “recipe” for studying the vast but diffuse filament. .

First ingredient: A promising target. Theories of cosmic evolution suggest that galaxy clusters form where filaments of the cosmic web meet, with the filaments slowly funnelling matter into the clusters. “From our earlier work on MACS J0717, we knew that this cluster is actively growing, and thus a prime target for a detailed study of the cosmic web,” explains co-author Harald Ebeling (University of Hawaii at Manoa, USA), who led the team that discovered MACS J0717 almost a decade ago.

Second ingredient: Advanced gravitational lensing techniques. Albert Einstein’s famous theory of general relativity says that the path of light is bent when it passes through or near objects with a large mass. Filaments of the cosmic web are largely made up of dark matter [2] which cannot be seen directly, but their mass is enough to bend the light and distort the images of galaxies in the background, in a process called gravitational lensing. The team has developed new tools to convert the image distortions into a mass map.

Third ingredient: High resolution images. Gravitational lensing is a subtle phenomenon, and studying it needs detailed images. Hubble observations let the team study the precise deformation in the shapes of numerous lensed galaxies. This in turn reveals where the hidden dark matter filament is located. “The challenge,” explains co-author Jean-Paul Kneib (LAM, France), “was to find a model of the cluster’s shape which fitted all the lensing features that we observed.”

Finally: Measurements of distances and motions. Hubble’s observations of the cluster give the best two-dimensional map yet of a filament, but to see its shape in 3D required additional observations. Colour images [3], as well as galaxy velocities measured with spectrometers [4], using data from the Subaru, CFHT, WM Keck, and Gemini North telescopes (all on Mauna Kea, Hawaii), allowed the team to locate thousands of galaxies within the filament and to detect the motions of many of them.

A model that combined positional and velocity information for all these galaxies was constructed and this then revealed the 3D shape and orientation of the filamentary structure. As a result, the team was able to measure the true properties of this elusive filamentary structure without the uncertainties and biases that come from projecting the structure onto two dimensions, as is common in such analyses.

The results obtained push the limits of predictions made by theoretical work and numerical simulations of the cosmic web. With a length of at least 60 million light-years, the MACS J0717 filament is extreme even on astronomical scales. And if its mass content as measured by the team can be taken to be representative of filaments near giant clusters, then these diffuse links between the nodes of the cosmic web may contain even more mass (in the form of dark matter) than theorists predicted.

Space Station Reaches Warp Speed?

The International Space Station appears to go to warp speed — a la Star Trek, Star Wars and almost every other space flick — in this new video created by Christoph Malin, who “stacked” image sequences that the ISS crew at International Space Station have been taking lately. These are the images that have been used to create the great timelapse videos, that provide a sense of what it is like to fly over the Earth on the space station. But this one is different, and as Malin says, “Stacks make interesting patterns visible, for example lightning corridors within clouds. One can also sometimes recognize satellite tracks and meteors – patterns that are not amongst the main star trails.”

Also visible is the Moon disappearing into the atmosphere and views from the ISS Cupola — gorgeous!
Continue reading “Space Station Reaches Warp Speed?”

October 16, 2012December 23, 2015 by Nancy Atkinson

Timeline: 15 Years of Cassini

The Cassini spacecraft takes an angled view toward Saturn, showing the southern reaches of the planet with the rings on a dramatic diagonal. Credit: NASA/JPL-Caltech/Space Science Institute

The Cassini mission has been a source of awe-inspiring images, surprising science and incredible longevity. Since launching on Oct. 15, 1997, the Cassini spacecraft has logged more than 6.1 billion kilometers (3.8 billion miles)of exploration – enough to circle Earth more than 152,000 times. After flying by Venus twice, Earth, and then Jupiter on its way to Saturn, Cassini pulled into orbit around the ringed planet in 2004 and has been spending its last eight years weaving around Saturn, its glittering rings and intriguing moons.

The spacecraft has sent back some 444 gigabytes of scientific data so far, including more than 300,000 images. More than 2,500 reports have been published in scientific journals based on Cassini data, describing the discovery of the plume of water ice and organic particles spewing from the moon Enceladus; the first views of the hydrocarbon-filled lakes of Saturn’s largest moon Titan; the atmospheric upheaval from a rare, monstrous storm on Saturn and many other curious phenomena.

The folks from the Cassini mission have put together a great infographic that provides a timeline of Cassini’s mission and some of its “greatest hits” — major events and discoveries. See below:

October 16, 2012December 29, 2015 by Nancy Atkinson

Carnival of Space #271

This week’s Carnival of Space is hosted by Brie Allen at the Tranquility Base blog. This is Brie’s first time hosting, so you should definitely check out this “small website exploring a big universe!”

Click here to read Carnival of Space #271.

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.

October 16, 2012December 23, 2015 by Nancy Atkinson

Extreme Solar Systems: Why Aren’t We Finding Other Planetary Systems Like Our Own?

Artist concept of a previous multi-planet solar system found by the Kepler spacecraft. Credit: NASA/Tim Pyle

Most planetary systems found by astronomers so far are quite different than our own. Many have giant planets whizzing around in a compact configuration, very close to their star. An extreme case in point is a newly found solar system that was announced on October 15, 2012 which packs five — count ‘em — five planets into a region less than one-twelve the size of Earth’s orbit!

“This is an extreme example of a compact solar system,” said researcher Darin Ragozzine from the University of Florida, speaking at a press conference at the American Astronomical Society’s Division for Planetary Sciences meeting. “If we can understand this one, hopefully we can understand how these types of systems form and why most known planetary systems appear different from our own solar system.”

This new system, currently named KOI-500, was found with data from the Kepler planet-finding spacecraft, and Ragozzine said astronomers have now uncovered a new realm of exo-planetary systems.

“The real exciting thing is that Kepler has found hundreds of stars with multiple transiting planets,” he said. “These are the most information-rich systems, as they can tell you not only about the planets, but also the architecture of how solar systems are put together.”

The fact that almost all solar systems found so far are vastly different than our own has astronomers wondering if we are, in fact, the oddballs. A study from 2010 concluded that only about 10 – 15 percent of stars in the Universe host systems of planets like our own, with terrestrial planets nearer the star and several gas giant planets in the outer part of the solar system.

Part of the reason our dataset of exoplanets is skewed with planets that are close to the star is because currently, that is all we are capable of detecting.

But the surprising new population of planetary systems discovered in the Kepler data that contain several planets packed in a tiny space around their host stars does give credence to the thinking that our solar system may be somewhat unique.

However, perhaps KOI-500 used to be more like our solar system.

“From the architecture of this planetary system, we infer that these planets did not form at their current locations,” Ragozzine said. “The planets were originally more spread out and have ‘migrated’ into the ultra-compact configuration we see today.”

There are several theories about the formation of the large planets in our outer solar system which involves the planets moving and migrating inward and outward during the formation process. But why didn’t the inner planets, including Earth, move in closer, too?

“We don’t know why this didn’t happen in our solar system,” Ragozzine said, but added that KOI-500 will “become a touchstone for future theories that will attempt to describe how compact planetary systems form. Learning about these systems will inspire a new generation of theories to explain why our solar system turned out so differently.”

A few notes of interest about KOI-500:

The five planets have “years” that are only 1.0, 3.1, 4.6, 7.1, and 9.5 days.

“All five planets zip around their star within a region 150 times smaller in area than the Earth’s orbit, despite containing more material than several Earths (the planets range from 1.3 to 2.6 times the size of the Earth). At this rate, you could easily pack in 10 more planets, and they would still all fit comfortably inside the Earth’s orbit,” Ragozzine noted. KOI-500 is approximately 1,100 light-years away in the constellation Lyra, the harp.

Four of the planets orbiting KOI-500 follow synchronized orbits around their host star in a completely unique way — no other known system contains a similar configuration. Work by Ragozzine and his colleagues suggests that planetary migration helped to synchronize the planets.

“KOI” stands for Kepler Object of Interest, and Ragozzine’s findings on this system have not yet been published, and so the system has yet to officially be considered a confirmed planetary system. “Every time we find something like this we give it a license-plate-like number starting with KOI,” Ragozzine said.

When does a KOI become an official planet? Ragozzine said the process is by confirming and validating the data. “Basically you need to prove statistically or by getting a specific measurement that it is not some other astronomical signal,” he said.

This infographic from Space.com supplies more visual details:

Sources: AAS, University of Florida

October 15, 2012December 23, 2015 by Jason Major

Watch: Incredible Headcam Video from Felix’s Freefall

Felix Baumgartner salutes his suit-mounted camera before stepping off his capsule’s platform at 128,000 feet (Red Bull Stratos)

Yesterday, October 14, Austrian pilot and BASE jumper Felix Baumgartner became the first person to skydive from over 128,000 feet, breaking the sound barrier during his 4 minute, 20 second plummet from the “edge of space.” A new video from Red Bull Stratos includes views from Felix’s suit-mounted cameras as he drops through virtually no atmosphere, smoothly at first but then going into a wild spin… but eventually stabilizing himself for the remainder of his fall and opening his chute at just over 6,000 feet. Incredible!

Check out the video below:

Here’s how Baumgartner described the spin and how he got out of it during the press conference after his jump yesterday:

“It started out really good because my exit was perfect, I did exactly what I was supposed to do… It looked like for a second I was going to tumble two more times and then get it under control, but for some reason that spin became so violent over all axis and it was hard to know how to get out of it, because, if you are trapped in a pressurized suit – normally as a skydiver you can feel the air and get direct feedback from the air — but here you are trapped in a suit that is pressurized at 3.5 PSI so you don’t know how to feel the air. It is like swimming without touching the water. And it’s hard because every when time it turns you around you have to figure out what to do. So I was sticking my arm out and it became worse and then I stuck arm out the other side and it became less, so I was fighting all the way down to regain control because I wanted to break the speed of sound. And I hit it. I don’t know how many seconds, but I could feel air was building up and then I hit it.”

So, in that quote, Baumgartner seemed to describe that he could feel when he broke the speed of sound, but in answering the next question of how it felt, he kind of backtracked and said he didn’t feel it.

“It’s hard to describe because I didn’t feel it. When you are in the pressure suit, you don’t feel anything, it is like being in a cast…. We have to look at the data – at what point did it happen — was I still spinning or was I under control? If you want to chart speed you need a reference point of things that pass you by, or sound, or your suit if flapping. I didn’t have that.”

Read more about Baumgartner’s record (and sound!) -breaking achievement and see lots more images and video here.

ADDED: A version of the video showing his chute opening (and with some background music added) can be found here on iloveskydiving.org.

October 15, 2012April 26, 2016 by Nancy Atkinson

Citizen Planet Hunters Find a Planet in a Four-Star System

A family portrait of the PH1 planetary system that was discovered in part due to crowdsourcing. Image Credit: Haven Giguere/Yale.

A family portrait of the PH1 planetary system: The newly discovered planet is depicted in this artist’s rendition transiting the larger of the two eclipsing stars it orbits. Off in the distance, well beyond the planet orbit, resides a second pair of stars bound to the planetary system. Image Credit: Haven Giguere/Yale.

A planet has been discovered orbiting in a four-star system — and no, that doesn’t mean the accommodations and conditions are excellent. It literally means four stars, where a planet is orbiting a binary star system that in turn is orbited by a second distant pair of stars. This is the first system like this that has ever been found, and its discovery demonstrates the power of citizen scientists, as it was found by a joint effort of amateurs participating on the Planet Hunters website under the guidance of professional astronomers.

This is might be an extremely rare planetary setup, astronomer Meg Schwamb from Yale says, as only six planets are currently known to orbit two stars, and none of these are orbited by other stellar companions. Astronomers are calling the newly found world a ‘circumbinary’ planet.

“Circumbinary planets are the extremes of planet formation,” said Schwamb, Planet Hunters scientist and lead author of a paper about the system presented Oct. 15 at the annual meeting of the Division for Planetary Sciences of the American Astronomical Society in Reno, Nevada. “The discovery of these systems is forcing us to go back to the drawing board to understand how such planets can assemble and evolve in these dynamically challenging environments.”

The planet is called PH1, for the first confirmed planet identified by the Planet Hunters citizen scientists, but it has the nickname of Tatooine, the planet in Star Wars that orbited two suns.

Planet Hunters uses data from the Kepler spacecraft, specially designed for looking for signs of planets.

The volunteers, Kian Jek of San Francisco and Robert Gagliano of Cottonwood, Arizona, spotted faint dips in light caused by the planet as it passed in front of its parent stars, a common method of finding extrasolar planets. Schwamb, a Yale postdoctoral researcher, led the team of professional astronomers that confirmed the discovery and characterized the planet, following observations from the Keck telescopes on Mauna Kea, Hawaii. PH1 is a gas giant with a radius about 6.2 times that of Earth, making it a bit bigger than Neptune.

“Planet Hunters is a symbiotic project, pairing the discovery power of the people with follow-up by a team of astronomers,” said Debra Fischer, a professor of astronomy at Yale and planet expert who helped launch Planet Hunters in 2010. “This unique system might have been entirely missed if not for the sharp eyes of the public.”

PH1 orbits outside the 20-day orbit of a pair of eclipsing stars that are 1.5 and 0.41 times the mass of the Sun. This planet is dense — it has perhaps about 170 times more mass than Earth — and is about half the diameter of Jupiter. It revolves around its host stars roughly every 138 days. Beyond the planet’s orbit at about 1000 AU (roughly 1000 times the distance between Earth and the Sun) is a second pair of stars orbiting the planetary system.

Gagliano, one of the two citizen scientists involved in the discovery, said he was “absolutely ecstatic to spot a small dip in the eclipsing binary star’s light curve from the Kepler telescope, the signature of a potential new circumbinary planet, ‘Tatooine,’ and it’s a great honor to be a Planet Hunter, citizen scientist, and work hand in hand with professional astronomers, making a real contribution to science.”

Jek expressed wonder at the possibility of the discovery: “It still continues to astonish me how we can detect, let alone glean so much information, about another planet thousands of light years away just by studying the light from its parent star.”

Read the paper here.

Source: Planet Hunters

October 15, 2012December 23, 2015 by Jason Major

The Moon’s Water Comes From the Sun

An image of debris, ejected from Cabeus crater and into the sunlight, about 20 seconds after the LCROSS impact. The inset shows a close-up with the direction of the sun and the Earth. Image courtesy of Science/AAAS

An image of water-filled debris ejected from Cabeus crater about 20 seconds after the 2009 LCROSS impact. Courtesy of Science/AAAS.

Comets? Asteroids? The Earth? The origins of water now known to exist within the Moon’s soil — thanks to recent observations by various lunar satellites and the impact of the LCROSS mission’s Centaur rocket in 2009 — has been an ongoing puzzle for scientists. Now, new research supports that the source of at least some of the Moon’s water is the Sun, with the answer blowing in the solar wind.

Spectroscopy research conducted on Apollo samples by a team from the University of Tennessee, University of Michigan and Caltech has revealed “significant amounts” of hydroxyl within microscopic glass particles found inside lunar soil, the results of micrometeorite impacts.

According to the research team, the hydroxyl “water” within the lunar glass was likely created by interactions with protons and hydrogen ions from the solar wind.

“We found that the ‘water’ component, the hydroxyl, in the lunar regolith is mostly from solar wind implantation of protons, which locally combined with oxygen to form hydroxyls that moved into the interior of glasses by impact melting,” said Youxue Zhang, Professor of Geological Sciences at the University of Michigan.

Hydroxyl is the pairing of a single oxygen atom to a single hydrogen atom (OH). Each molecule of water contains two hydroxyl groups.

Although such glass particles are widespread on the surface of the Moon — the researchers studied samples returned from Apollo 11, Apollo 16 and Apollo 17 missions — the water in hydroxyl form is not something that could be easily used by future lunar explorers. Still, the findings suggest that solar wind-derived hydroxyl may also exist on the surface of other airless worlds, like Mercury, Vesta or Eros… especially within permanently-shadowed craters and depressions.

“These planetary bodies have very different environments, but all have the potential to produce water,” said Yang Liu, University of Tennessee scientist and lead author of the team’s paper.

The discovery of hydroxyl within lunar glasses presents an “unanticipated, abundant reservoir” of water on the Moon, and possibly throughout the entire Solar System.

The study was published online Sunday in the journal Nature Geoscience.

Source: University of Michigan news release.

Inset image: a grain of lunar agglutinate glass from samples returned by Apollo astronauts (Yang Liu)

October 15, 2012December 23, 2015 by Nancy Atkinson

Weekend Aurora Gives Time for ‘Reflection’

The Northern Lights over Kilmany, Scotland reflect in a body of water. Credit: Corinne Mills

Wow, what a gorgeous view of the aurora in Scotland over the weekend, taken by astrophotographer Corine Mills! This image garnered dozens of rave reviews on Flickr, and rightly so. A solar wind stream struck Earth’s magnetic field over the weekend, igniting a G1-class geomagnetic storm that lasted more than 15 hours, according to SpaceWeather.com. Auroras with rare pulsations and vibrant colors were sighted in the northern latitudes. Below is an almost psychedelic “purple haze” aurora as seen over Saskatchewan, Canada.

Continue reading “Weekend Aurora Gives Time for ‘Reflection’”

October 15, 2012December 23, 2015 by Nancy Atkinson

Baumgartner’s Record-Breaking Jump: Images and Video

Pilot Felix Baumgartner of Austria jumps out of the capsule during the final manned flight for Red Bull Stratos in Roswell, New Mexico, USA on October 14, 2012. Credit: Red Bull Stratos.

Daredevil Felix Baumgartner broke the sound barrier today during a skydive from the stratosphere, from approximately 38.5 km (128,000 ft, 24.24 miles) above the Earth’s surface. Baumgartner reached Mach 1.24 or 1,342 km/h (833.9 miles per hour), going faster than the speed of sound. Here is a gallery of official images and video from Red Bull Stratos. You can find out more in our full article which provides all the details.

The crane that holds the capsule as the balloon ascends. Credit: Red Bull Stratos.

The crane follows the balloon with the capsule at the flight line during the launch of Baumgartner’s flight. Credit: Red Bull Stratos.

Baumgartner seen on a screen at mission control center while he is still inside the capsule, while he talks to Joe Kittinger (back of his head is visible). Kittinger previously held the record for longest and fastest freefall before Baumgartner’s jump today. Credit: Red Bull Stratos.

Screens at the mission control shows Felix Baumgartner of Austria as he jumps from the capsule. Credit: Red Bull Stratos.

The view from a camera inside the capsule as Baumgartner jumps. Credit: Red Bull Stratos.

Baumgartner moves from his seat to the ledge outside the capsule. Credit: Red Bull Stratos.

Baumgartner floats down to Earth on a parachute. Credit: Red Bull Stratos.

Just before Baumgartner lands. Credit: Red Bull Stratos.

Baumgartner lands on his feet and celebrates. Credit: Red Bull Stratos.

Baumgartner falls to his knees after landing successfully. Credit Red Bull Stratos.

Felix Baumgartner celebrates after successfully completing his record-breaking jump. Credit: Red Bull Stratos.

Baumgartner after his successful jump. Credit: Red Bull Stratos.

Baumgartner and Technical Project Director Art Thompson celebrate together after the successful jump. Credit: Red Bull Stratos.

Baumgartner with members of his family following the successful jump. Credit: Red Bull Stratos.

Baumgartner, Kittinger and the Red Bull Stratos team at a press conference following the jump. Credit: Red Bull