Universe Today

June 26, 2013December 23, 2015 by Elizabeth Howell

Discovery! More Planets Found Orbiting In A Star Cluster

An artist's conception of an exoplanet transiting its home star. Credit: NASA's Goddard Space Flight Center

As Earthlings, we’re so used to thinking about planets being in simple orbits around a single star. But the Sun likely didn’t begin its life alone. It formed as part of a cluster of stars, all feeding from the same well of gas.

Could star clusters also host planets? Or do they have to wait for the little guys until the stars evolve and move further apart? Well, astronomers have actually just found planets — yes, two planets — orbiting Sun-like stars in a cluster 3,000 light-years from Earth.

These are the third and fourth star cluster planets yet discovered, but the first found “transiting” or passing across the face of their stars as seen from Earth. (The others were found through detecting gravitational wobbles in the star.)

This is no small feat for a planet to survive. In a telescope, a star cluster might look pretty benign, but up close it’s pretty darn harsh. A press release about the discovery used a lot of words like “strong radiation”, “harsh stellar winds” and “stripping planet-forming materials” in a description of what NGC 6811 would feel like.

An artist's conception of a planet in a star cluster. Credit: Michael Bachofner — An artist’s conception of a planet in a star cluster. Credit: Michael Bachofner

“Old clusters represent a stellar environment much different than the birthplace of the Sun and other planet-hosting field stars,” stated lead author Soren Meibom of the Harvard-Smithsonian Center for Astrophysics.

“We thought maybe planets couldn’t easily form and survive in the stressful environments of dense clusters, in part because for a long time we couldn’t find them.”

The find, as you would expect, comes from the prolific planet-hunting NASA Kepler spacecraft that is now battling problems with pointing in the right direction. Although the telescope is in the penalty box, there still are reams of data waiting to be analyzed and released.

The planets are known as Kepler-66b and Kepler-67b, and are both approaching the size of Neptune (which is four times the size of Earth). Their parent cluster, NGC 6811, is one billion years old. Astronomers are still puzzled as to how these little worlds survived for so long.

“Highly energetic phenomena including explosions, outflows and winds often associated with massive stars would have been common in the young cluster,” stated the journal paper in Nature.

“The degree to which the formation and evolution of planets is influenced by a such a dense and dynamically and radiatively hostile environment is not well understood, either observationally or theoretically.”

Check out the entire study in the latest edition of Nature.

Source: Harvard-Smithsonian Center for Astrophysics

June 26, 2013December 23, 2015 by Nancy Atkinson

Astrophoto: Curtain of Crepuscular Rays at Dawn

Curtain of Crepuscular Rays at Dawn, on June 17, 2013. Taken from Coral Towers Observatory in Australia. Credit and copyright: Joseph Brimacombe.

Prolific astrophotographer and Australian astronomer Joseph Brimacombe captured this beautiful wide-field view of crepuscular rays from the Sun last week. You definitely want to click on this image to see a larger view on Flickr. This image is made of seven frames; three exposures each. Brimacombe was lucky to get this shot; just seven minutes later (see the view here), the spectacular curtain of rays were gone.

The word crepuscular means “relating to twilight,” and these rays occur when objects such as mountain peaks or clouds partially shadow the Sun’s rays, usually when the Sun is low on the horizon. These rays are visible only when the atmosphere contains enough haze or dust particles so that sunlight in unshadowed areas can be scattered toward the observer.

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

June 26, 2013December 23, 2015 by Nancy Atkinson

China’s Shenzhou-10 Crew Returns to Earth

Screenshot showing the Shenzou-10 capsule on the ground following a successful mission for China.

China successfully completed its longest human space mission as the Shenzhou-10 spacecraft and its crew of two men and one woman returned safely to Earth. The return capsule landed via parachute at 8:07 am local time (0007 UTC) Wednesday, June 26, 2013 on the grasslands of north China’s Inner Mongolia region. The 15-day “Divine Vessel” mission is part of the Chinese space program’s objective of building a permanent space station by 2020.

In the video below, enthusiastic applause comes when the parachute deploys and at other milestones of the return. The crew was quickly greeted and a smiling Nie Haisheng, the commander of the mission, emerged from the capsule first, and was followed by female astronaut Wang Yaping, and crewmember Zhang Xiaoguang.

“At this moment what I most want to say is that space is our dream and our motherland is forever our home,” Nie said. “I wish our motherland to thrive even more and our people to become happier and happier. I thank the entire nation for their concern and support for us.”

During the mission, the Shenzou spacecraft docked with China’s orbiting space module Tiangong-1 in tests intended to prepare for the building of the space station. The crew also spoke via video to school children in China, showing how different objects behave in zero-G. The crew conducted several experiments and medical tests while in space. The official mission duration was 14 days 14 hours and 29 minutes.

This was China’s fifth manned space mission since 2003. China plans to launch the Tiangong-2 space lab around 2015, according to the official Chinese Xinhua news agency, quoting Wang Zhaoyao, director of China’s manned space program office. He said there are plans to put an experimental core module of a space station in orbit in 2018, with the manned space station itself being built around 2020.

Besides building a space station, China also hopes to send astronauts to the Moon.

Sources: Xinhua, Space Daily

June 26, 2013December 23, 2015 by Astronomy Cast

Podcast: Equilibrium in Space

So many of the forces in space depend on equilibrium, that point where forces perfectly balance out. It defines the shape of stars, the orbits of planets, even the forces at the cores of galaxies. Let’s take a look at how parts of the Universe are in perfect balance.

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

“Equilibrium” on the Astronomy Cast website, with shownotes and transcript.

And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout:

June 26, 2013December 23, 2015 by Astronomy Cast

Podcast: Death of a Spacecraft

The Spirit Mars Exploration Rover 'died' in 2010. Credit: NASA — The Spirit Mars Exploration Rover. Credit: NASA

In the end, everything dies, even plucky space robots. Today we examine the last days of a series of missions. How do spacecraft tend to die, and what did in such heroes as Kepler, Spirit, and Galileo (the missions… not the people).

Click here to download the episode.

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

“Death of a Spacecraft” on the Astronomy Cast website, with shownotes and transcript.

And the podcast is also available as a video, as Fraser and Pamela now record Astronomy Cast as part of a Google+ Hangout:

June 26, 2013December 29, 2015 by Nancy Atkinson

Carnival of Space #307

This week’s Carnival of Space is hosted by Stefan Lamoureux at the Links Through Space blog.

Click here to read Carnival of Space #307.

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.

June 25, 2013December 23, 2015 by Bob King

Gesundheit! Hairy And Sneeze-worthy Rings Snare Summer Sun

Billions of aspen seeds float by the sun on tiny hairs creating a multicolored corona around the sun yesterday. To see and photograph the rings, I used a power pole to block the sun. Credit: Bob King

For the past two weeks puffy clumps of seeds have been riding the air in my town. You can’t avoid them. Open a door and they’ll breeze right in. Take a deep breath and you’d better be careful you don’t take a few down the windpipe.

Every June the many aspen trees that call northern Minnesota home release their booty of tiny seeds that parachute through the air on tiny clusters of hairs. And while they all have no particular place to go, their combined and unintentional effect is to create a series of beautiful colored rings about the Sun called a corona.

A single aspen seed (left) only about 1 mm across embedded in a cottony fluff of tiny hairs. At right is a spider web. Both show colors caused by bending and interference of light, a phenomenon called diffraction. Credit: Bob King (left) and Andrew Kirk

Reach your hand up to block the Sun and if your eyes can stand the glare of blue-white sky, you’ll see bazillions of tiny flecks a-flying. If you were to capture one and study it up close, you’d see it diffract light in tiny glimmers of chrome green and purple.

When light from the sun or moon strikes a tiny water droplet, speck of pollen or aspen seed hairs, it's scattered in different directions. Some of the scattered waves reinforce each other to make a bright ring of light in the sky while other waves cancel each other out to create a dimmer ring. A series of alternating rings around the sun is called a diffraction pattern or corona. Credit and copyright: Les Cowley www.atoptics.co.uk — When light from the sun or moon strikes a tiny water droplet, speck of pollen or aspen seed hairs, it’s scattered in different directions. Some of the scattered waves reinforce each other to make a bright ring of light in the sky while other waves cancel each other out to create a dimmer ring. A series of alternating rings around the sun is called a diffraction pattern or corona. Credit and copyright: Les Cowley www.atoptics.co.uk

Light is always getting messed with by tiny things. When it comes to aspen seeds, as rays of light – made of every color of the rainbow – bend around the hairy obstacles they interfere with one another like overlapping, expanding wave circles in a pond. Some of the waves reinforce each another and others cancel out. Our eyes see a series of colored fringes that flash about the tiny hairs.

*Most halos are circular but pollen halos like this one around the moon often have unusual shapes like this oval with bulging sides and top. Credit: Bob King*

The exact same thing happens when light has to step around minute water droplets, pollen grains and our hairy aspen fluffs when they’re drift through the air overhead. Overlapping wavelets of light “interfere” with one another to form a series of colorful concentric circles called a solar corona. While the same in name, this corona is an earthly one unrelated to the huge, hot coronal atmosphere that surrounds our star.

Oil-coated water droplets show beautiful diffraction colors for the same reason soap bubbles do. Light reflecting from the bottom surface of the oil film interferes light reflecting from the top of the layer creating fringes of color. Credit: Bob King — Oil-coated water droplets also show beautiful diffraction colors for a similar reason as clouds and pollen do . Light reflecting from the bottom surface of the oil film interferes with light reflecting off the top of the layer to create shifting patterns of color. Credit: Bob King

The ones created by seed hairs and pollen require clear skies and a safe way to block the Sun’s overwhelming light. My filter of choice is the power pole mostly because they’re handy. Sunglasses help to reduce the glare and eye-watering wincing.

While I can’t be 100% certain the chromatic bullseye was painted by poplar hair deflections – there’s always a chance pollen played a part – I’ve seen similar displays when the seeds have passed this way before.

*Iridescent clouds are another form of a corona formed by minute water droplets diffracting light. Credit: Bob King*

Coronas created by water droplets in mid-level clouds are much more common, and the familiar “ring around the sun” or solar halo is an entirely different creature. Here, light is bent or refracted through billions of microscopic six-sided ice crystals.

I figure that if the night is cloudy, the play of light and clouds in the daytime sky often makes for an enjoyable substitute.

June 25, 2013April 26, 2016 by Tammy Plotner

Astronomers Spy Early Galaxies Caught In A Cosmic Spiderweb

The Spiderweb, imaged by the Hubble Space Telescope – a central galaxy (MRC 1138-262) surrounded by hundreds of other star-forming 'clumps'. Credit: NASA, ESA, George Miley and Roderik Overzier (Leiden Observatory)

Once upon a time, when the Universe was just about three billion years old, galaxies started to form. Now astronomers using a CSIRO radio telescope have captured evidence of the raw materials these galaxies used to fashion their first stars… cold molecular hydrogen gas, H2. Even though we can’t see it directly, we know it is there by using another gas that reveals its presence – carbon monoxide (CO) – a radio wave emitter.

The telescope is CSIRO’s Australia Telescope Compact Array telescope near Narrabri, NSW. “It one of very few telescopes in the world that can do such difficult work, because it is both extremely sensitive and can receive radio waves of the right wavelengths,” says CSIRO astronomer Professor Ron Ekers.

One of the studies of these “raw” galaxies was performed by astronomer Dr. Bjorn Emonts of CSIRO Astronomy and Space Science. He and fellow researchers employed the Compact Array to observe and record a gigantic and distant amalgamation of “star forming clumps or proto-galaxies” which are congealing together to create a single massive galaxy. This framework is known as the “Spiderweb” and is theorized to be at least ten thousand million light years distant. The Compact Array radio telescope is capable of picking up the signature of star formation, giving astronomers vital clues about how early galaxies began star formation.

In blue, the carbon monoxide gas detected in and around the Spiderweb. Credit: B. Emonts et al (CSIRO/ATCA)

The “Spiderweb” was loaded. Here Dr. Emont and his colleagues found the molecular hydrogen gas fuel they were seeking. It covered an area of space almost a quarter of a million light-years across and contained at least sixty thousand million times the mass of the Sun! Surely this had to be the material responsible for the new stars seen sprinkled across the region. “Indeed, it is enough to keep stars forming for at least another 40 million years,” says Emonts.

In another research project headed by Dr. Manuel Aravena of the European Southern Observatory, the scientists measured the CO – the indicator of H2 – in two very distant galaxies. The signal of the faint radio waves was amped up by the gravitational fields of the additional galaxies – the “line of sight” members – which created gravitational lensing. Says Dr. Aravena, “This acts like a magnifying lens and allows us to see even more distant objects than the Spiderweb.”

Dr. Aravena’s team went to work measuring the amount of H2 in both of their study galaxies. One of these, SPT-S 053816-5030.8, produced enough radio emissions to allow them to infer how quickly it was forming stars – “an estimate independent of the other ways astronomers measure this rate.”

The Compact Array was tuned in. Thanks to an upgrade which increased its bandwidth – the amount of the radio spectrum which can be observed at any particular time – it is now sixteen times stronger and capable of reaching a range from 256 MHz to 4 GHz. That makes it a very sensitive ear!

“The Compact Array complements the new ALMA telescope in Chile, which looks for the higher-frequency transitions of CO,” says Ron Ekers.

Original Story Source: CSIRO News Release

June 25, 2013December 23, 2015 by Elizabeth Howell

So You Wanna Go To Space. Can You Put Up With The Superpower Bacteria?

An artist's conception of future Mars astronauts. Credit: NASA/JPL-Caltech

We all love space here and we’re sure, given that thousands of people applied for a one-way trip to Mars, that at least some of you want to spend a long time in a spacecraft. But have you thought about the bacteria that will be going along with you?

If you don’t feel too squirmy to read on, understand this: one type of bacteria grown aboard two shuttle missions ended up being bigger and thicker than control colonies on Earth, new NASA research shows.

Two astronaut crews aboard space shuttle Atlantis grew colonies of bacteria (more properly speaking, biofilms) on behalf of researchers on Earth. Most biofilms are harmless, but a small number could be associated with disease.

Biofilms were all over the Mir space station, and managing them is also a “challenge” (according to NASA) on the International Space Station. Well, here’s how they appeared in this study:

“The space-grown communities of bacteria, called biofilms, formed a ‘column-and-canopy’ structure not previously observed on Earth,” NASA stated. “Biofilms grown during spaceflight had a greater number of live cells, more biomass, and were thicker than control biofilms grown under normal gravity conditions.”

Astronauts strut their superpowers on the final shuttle mission, STS-135, where they also examined bacteria growth. Credit: NASA — Astronauts strut their superpowers on the final shuttle mission, STS-135. Turns out bacteria acquire some super-growth in microgravity, too. Credit: NASA

The type of microorganism examined was Pseudomonas aeruginosa, which was grown for three days each on STS-132 and STS-135 in artificial urine. That was chosen because, a press release stated, “it is a physiologically relevant environment for the study of biofilms formed both inside and outside the human body, and due to the importance of waste and water recycling systems to long-term spaceflight.”

Each shuttle mission had several vials of this … stuff … in which to introduce the bacteria in orbit. The viles included cellulose membranes on which the bacteria could grow. Researchers also tested bacteria growth on Earth with similar vials. Then, all the samples were rounded up in the lab after the shuttle missions where the biofilms’ thickness, number of cells and volume was examined, as well as their structure.

This is still early-stage work, of course, requiring follow-up studies to find out how the low-gravity environment affects these microorganisms’ growth, according to lead researcher Cynthia Collins from the Rensselaer Polytechnic Institute. Metabolism and virulence are what the scientists are hoping to learn more about in the future.

Samples of bacteria Pseudomonas aeruginosa. Credit: NASA

“Before we start sending astronauts to Mars or embarking on other long-term spaceflight missions, we need to be as certain as possible that we have eliminated or significantly reduced the risk that biofilms pose to the human crew and their equipment,” stated Collins, an assistant professor in the department of chemical and biological engineering.

While this research has more immediate implications for astronaut health, the researchers added that better understanding the biofilms could lead to better treatment and prevention for Earth diseases.

“Examining the effects of spaceflight on biofilm formation can provide new insights into how different factors, such as gravity, fluid dynamics, and nutrient availability affect biofilm formation on Earth. Additionally, the research findings could one day help inform new, innovative approaches for curbing the spread of infections in hospitals,” a NASA press release stated.

If you’re not feeling too itchy by now, you can read the entire study in an April issue of PLOS ONE.

Credit: NASA

June 25, 2013April 26, 2016 by Nancy Atkinson

Three Potentially Habitable Planets Found Orbiting Gliese 667C

Nearby star Gliese 667C might have three potentially habitable planets. Credit: Planetary Habitability Laboratory, University of Puerto Rico Arecibo.

A closer look at the previously-studied nearby star Gliese 667C has revealed a treasure trove of planets – at least six – with three super-Earths in the habitable zone around the star. Gliese 667C is part of a triple star system (Gliese 667) and is just over one third of the mass of our Sun. Now that we know there are multiple planets in the so-called Goldilocks zone – a region where liquid water could exist — Gliese 667C might be the best candidate for harboring habitable exo-worlds.

“We knew that the star had three planets from previous studies, so we wanted to see whether there were any more,” said Mikko Tuomi from the University of Hertfordshire in the UK, one of the astronomers who led the new study of Gliese 667C. “By adding some new observations and revisiting existing data we were able to confirm these three and confidently reveal several more. Finding three low-mass planets in the star’s habitable zone is very exciting!”

Artist’s conception of the seven planets possibly found orbiting Gliese 667C. Three of them (c, f and e) orbit within the habitable zone of the star. Image is courtesy of Rene Heller/ Carnegie Institution for Science.

Tuomi, along with Guillem Anglada-Escudé of the University of Göttingen, Germany looked at existing radial velocity data from the HARPS spectrograph at ESO’s 3.6-metre telescope in Chile. The team said they are extremely confident on the data on the first five planets, while the sixth is tentative, and a potential seventh planet even more tentative.

The team writes in their paper:

Up to seven periodic signals are detected in the Doppler measurements of GJ 667C data, being the last (seventh) signal very close to our detection threshold.

The significance of the signals is not affected by correlations with activity indices and we could not identify any strong wavelength dependence with any of them.

The first six signals are strongly present in subsamples of the data. Only the seventh signal is unconfirmed using half of the data only. Our analysis indicates that any of the six stronger signals would had been robustly spotted with half the available data if each had been orbiting alone around the host star.

If all seven planets are confirmed, the system would consist of three habitable-zone super-Earths, two hot planets further in, and two cooler planets further out.

This diagram shows the system of planets around the star Gliese 667C. A record-breaking three planets in this system are super-Earths lying in the zone around the star where liquid water could exist, making them possible candidates for the presence of life. This is the first system found with a fully packed habitable zone. The relative approximate sizes of the planets and the parent star are shown to scale, but not their relative separations. Credit: ESO

But the team said the three in the habitable zone are confirmed to be super-Earths. These are planets more massive than Earth, but less massive than planets like Uranus or Neptune. This is the first time that three such planets have been spotted orbiting in this zone in the same system.

“The number of potentially habitable planets in our galaxy is much greater if we can expect to find several of them around each low-mass star,” said co-author Rory Barnes from the University of Washington, “instead of looking at ten stars to look for a single potentially habitable planet, we now know we can look at just one star and find several of them.”

Gliese 667 (a.k.a GJ 667) is 22 light-years away from Earth in the constellation of Scorpius.
The planets in the habitable zone and those closer to the star are expected to always have the same side facing the star, so that their day and year will be the same lengths, with one side in perpetual sunshine and the other always night.

The researchers say that the ‘f’ planet is “a prime candidate for habitability.”

“It likely absorbs less energy than the Earth, and hence habitability requires more greenhouse gases, like CO2 or CH4,” the team wrote in their paper. “Therefore a habitable version of this planet has to have a thicker atmosphere than the Earth, and we can assume a relatively uniform surface temperature.”

The other stars in the triple system would provide a unique sunset: the two other suns would look like a pair of very bright stars visible in the daytime and at night they would provide as much illumination as the full Moon.

Are there more planets to be found in this abundant system? Perhaps, but not in the habitable zone. The team said the new planets completely fill up the habitable zone of Gliese 667C, as there are no more stable orbits in which a planet could exist at the right distance to it.

An artist’s impression of the orbits of the planets in the Gliese 667C system:

Read the team’s paper.

Sources: ESO, Carnegie , Planetary Habitability Laboratory