Universe Today

August 13, 2013April 26, 2016 by Shannon Hall

How Do Black Holes Get Super Massive?

A binary black hole pair with an accretion disk inclined 45 degrees. Source: Nixon et al.

Since their discovery, supermassive black holes – the giants lurking in the center of every galaxy – have been mysterious in origin. Astronomers remain baffled as to how these supermassive black holes became so massive.

New research explains how a supermassive black hole might begin as a normal black hole, tens to hundreds of solar masses, and slowly accrete more matter, becoming more massive over time. The trick is in looking at a binary black hole system. When two galaxies collide the two supermassive black holes sink to the center of the merged galaxy and form a binary pair. The accretion disk surrounding the two black holes becomes misaligned with respect to the orbit of the binary pair. It tears and falls onto the black hole pair, allowing it to become more massive.

In a merging galaxy the gas flows are turbulent and chaotic. Because of this “any gas feeding the supermassive black hole binary is likely to have angular momentum that is uncorrelated with the binary orbit,” Dr. Chris Nixon, lead author on the paper, told Universe Today. “This makes any disc form at a random angle to the binary orbit.

Nixon et al. examined the evolution of a misaligned disk around a binary black hole system using computer simulations. For simplicity they analyzed a circular binary system of equal mass, acting under the effects of Newtonian gravity. The only variable in their models was the inclination of the disk, which they varied from 0 degrees (perfectly aligned) to 120 degrees.

After running multiple calculations, the results show that all misaligned disks tear. Watch tearing in action below:

In most cases this leads to direct accretion onto the binary.

“The gravitational torques from the binary are capable of overpowering the internal communication in the gas disc (by pressure and viscosity),” explains Nixon. “This allows gas rings to be torn off, which can then be accreted much faster.”

Such tearing can produce accretion rates that are 10,000 times faster than if the exact same disk were aligned.

In all cases the gas will dynamically interact with the binary. If it is not accreted directly onto the black hole, it will be kicked out to large radii. This will cause observable signatures in the form of shocks or star formation. Future observing campaigns will look for these signatures.

In the meantime, Nixon et al. plan to continue their simulations by studying the effects of different mass ratios and eccentricities. By slowly making their models more complicated, the team will be able to better mimic reality.

Quick interjection: I love the simplicity of this analysis. These results provide an understandable mechanism as to how some supermassive black holes may have formed.

While these results are interesting alone – based on that sheer curiosity that drives the discipline of astronomy forward – they may also play a more prominent role in our local universe.

Before we know it (please read with a hint of sarcasm as this event will happen in 4 billion years) we will collide with the Andromeda galaxy. This rather boring event will lead to zero stellar collisions and a single black hole collision – as the two supermassive black holes will form a binary pair and then eventually merge.

Without waiting for this spectacular event to occur, we can estimate and model the black hole collision. In 4 billion years the video above may be a pretty good representation of our collision with the Andromeda galaxy.

The results have been published in the Astrophysical Journal Letters (preprint available here). (Link was corrected to correct paper on 8/15/2013).

August 13, 2013December 23, 2015 by Elizabeth Howell

What Is Elon Musk’s Hyperloop, And Why Is It Important?

Artist's conception of Elon Musk's hyperloop high-speed travel concept. Credit: Elon Musk/SpaceX/Tesla Motors

This week, SpaceX founder and billionaire Elon Musk (who also founded electric vehicle manufacturer Tesla Motors) released his vision for a futuristic transportation system. Called hyperloop, it’s supposed to be better than flying supersonic over short distances. To give you a quick overview, we’ve summarized a portion of his paper below.

What is a hyperloop? In Musk’s words, a hyperloop is a system to “build a tube over or under the ground that contains a special environment.” Cars would basically be propelled in this tube. One example could be a huge sort of pneumatic tube where high-speed fans would compress and push the air — although the friction implications make Musk skeptical that it would work. Another option is having a vacuum in the tube and using electromagnetic suspension instead. Musk acknowledges it is hard to maintain a vacuum (one small leak in hundreds of miles of tubing, and the system shuts down), but there are pumping solutions to overcome this. He favors the second solution.

What is the motivation? Musk is seeking an alternative to flying or driving that would be “actually better than flying or driving.” He expressed disappointment that a proposed high-speed rail project in California is actually one of the slowest and most expensive of its type in the world, and speculated that there must be a better way.

What is the biggest technical challenge? Overcoming something called the Kantrowitz limit. Musk describes this as the “top speed law for a given tube to pod area ratio”. More simply, if you have a vehicle moving into an air-filled tube, there needs to be a minimum distance between the walls of the vehicle and the walls of the tube. Otherwise, Musk writes, “the capsule will behave like a syringe and eventually be forced to push the entire column of air in the system. Not good.”

Artist concept of a futuristic 'flying wing' airplane. Credit: DLR — In Musk’s view, his hyperloop system would be better than futuristic (perhaps supersonic) aircraft over short distances. Artist concept of one potential airplane future design incorporating a ‘flying wing’. Credit: DLR

How will Musk overcome that challenge? The principal ways of getting around it is to move slowly or quickly. A hyperfast speed would be a “dodgy prospect”, Musk writes, so his solution is to put an electric compressor fan on the capsule nose that would move high-pressure air from the front to the back of the vehicle. As a bonus, this would reduce friction. Yes, there are batteries available that would have enough power to keep the fan running for the journey’s length, he says.

How is hyperloop powered? Solar panels would be placed on top of the tube, providing enough juice to keep the vehicles moving, according to Musk’s calculations.

What about earthquakes? Musk acknowledges that a long-range system is susceptible to earthquakes. “By building a system on pylons, where the tube is not rigidly fixed at any point, you can dramatically mitigate earthquake risk and avoid the need for expansion joints,” he writes.

Dragon in orbit during the CRS-2 mission. Credit: NASA/CSA/Chris Hadfield — One of Elon Musk’s greatest achievements is overseeing the build of a spacecraft, called Dragon, which now makes periodic runs to the International Space Station. Credit: NASA/CSA/Chris Hadfield

Where would hyperloop be used? In a description of the system, Musk says the hyperloop would be best served in “high-traffic city pairs that are less than about 1,500 km or 900 miles apart.” Anything more distant, and supersonic travel would be the best solution. (Short distance supersonic travel isn’t efficient because the plane would spend most of its time ascending and descending.)

Is it cost-effective? Musk estimates the tube would be “several billion dollars”, which he describes as low compared to the “tens of billion [sic] proposed for the track of the California rail project.” The individual capsules would be several hundred million dollars. Moreover, building a tube instead of a railway offers advantages, Musk says: it can be built on pylons (meaning you don’t need to buy the land), it’s less noisy, and there’s no need for fencing.

I want more information. Musk wrote a technical proposal that spans several dozens of pages, which you can check out here. He calls his system an open-source one and seems to be open to ideas to improve it.

Feel free to leave your feedback in the comments. Does this look feasible? Is there anything that could be added to make it a better system?

August 13, 2013December 29, 2015 by Nancy Atkinson

Carnival of Space #314

This week’s Carnival of Space is hosted by our pal Ray Sanders at his Dear Astronomer blog.

Click here to read Carnival of Space #314.

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.

August 13, 2013April 26, 2016 by David Dickinson

Is the Sun More Active Than it Looks? An Innovative Method to Characterize the Solar Cycle

A solar cycle montage from August 1991 to September 2001 in X-rays courtesy of the Yohkoh Solar Observatory. (Credit: David Chenette, Joseph B. Gurman, Loren W. Acton, image in the public Domain).

The Sun has provided no shortage of mysteries thus far during solar cycle #24.

And perhaps the biggest news story that the Sun has generated recently is what it isn’t doing. As Universe Today recently reported, this cycle has been an especially weak one in terms of performance. The magnetic polarity flip signifying the peak of the solar maximum is just now upon us, as the current solar cycle #24 got off to a late start after a profound minimum in 2009…

Or is it?

Exciting new research out of the University of Michigan in Ann Arbor’s Department of Atmospheric, Oceanic and Space Sciences published in The Astrophysical Journal this past week suggests that we’re only looking at a portion of the puzzle when it comes to solar cycle activity.

Traditional models rely on the monthly averaged sunspot number. This number correlates a statistical estimation of the number of sunspots seen on the Earthward facing side of the Sun and has been in use since first proposed by Rudolf Wolf in 1848. That’s why you also hear the relative sunspot number sometimes referred to as the Wolf or Zürich Number.

But sunspot numbers may only tell one side of the story. In their recent paper titled Two Novel Parameters to Evaluate the Global Complexity of the Sun’s Magnetic Field and Track the Solar Cycle, researchers Liang Zhao, Enrico Landi and Sarah E. Gibson describe a fresh approach to model solar activity via looking at the 3-D dynamics heliospheric current sheet.

The spiralling curve of the heliospheric current sheet through the inner solar system. (Graphic credit: NASA). — The spiraling curve of the heliospheric current sheet through the inner solar system. (Graphic credit: NASA).

The heliospheric current sheet (or HCS) is the boundary of the Sun’s magnetic field separating the northern and southern polarity regions which extends out into the solar system. During the solar minimum, the sheet is almost flat and skirt-like. But during solar maximum, it’s tilted, wavy and complex.

Two variables, known as SD & SL were used by researchers in the study to produce a measurement that can characterize the 3-D complexity of the HCS. “SD is the standard deviation of the latitudes of the HCS’s position on each of the Carrington maps of the solar surface, which basically tells us how far away the HCS is distributed from the equator. And SL is the integral of the slope of HCS on that map, which can tell us how wavy the HCS is on each of the map,” Liang Zhao told Universe Today.

Ground and space-based observations of the Sun’s magnetic field exploit a phenomenon known as the Zeeman Effect, which was first demonstrated during solar observations conducted by George Ellery Hale using his new fangled invention of the spectrohelioscope in 1908. For the recent study, researchers used data covering a period from 1975 through 2013 to characterize the HCS data available online from the Wilcox Solar Observatory.

SD and SL perameters juxtaposed against the tradional monthly sunspot number. — SD and SL parameters juxtaposed against the traditional monthly sunspot number (SSN). Note the smooth fit until the end of solar cycle #23 around 2003. (Credit: Liang Zhao/*The Astrophysical Journal*).

Comparing the HCS value against previous sunspot cycles yields some intriguing results. In particular, comparing the SD and SL values with the monthly sunspot number provide a “good fit” for the previous three solar cycles— right up until cycle #24.

“Looking at the HCS, we can see that the Sun began to act strange as early as 2003,” Zhao said. “This current cycle as characterized by the monthly sunspot number started a year late, but in terms of HCS values, the maximum of cycle #24 occurred right on time, with a first peak in late 2011.”

“Scientists believe there will be two peaks in the sunspot number in this solar maximum as in the previous maximum (in ~2000 and ~2002),” Zhao continued, “since the Sun’s magnetic fields in the north and south hemispheres look asymmetric, and the north evolved faster than the south recently. But so far as I can see, the highest value of monthly-averaged sunspot number in this cycle 24 is still the one in the November 2011. So we can say the first peak of cycle 24 could be in November of 2011, since it is the highest monthly sunspot number so far in this cycle. If there is a second peak, we will see it sooner or later.”

The paper also notes that although cycle 24 is especially weak when compared to recent cycles, its range of activity is not unique when compared with solar cycles over the past 260 years.

HCS curves plotted on the surface of the Sun. Comparisons are made for the solar maximum on October 2000 (CR 1968), descending phase on April 2005 (2029), solar minimum on September 2009 (CR 2087), and ascending phase on March 2010 (CR2094). CR=Carrington Rotation. (Credit: Liang Zhao, *The Astrophysical Journal*).

The HCS value characterizes the Sun over one complete Carrington Rotation of 27 days. This is an averaged value for the rotation of the Sun, as the poles rotate slower than the equatorial regions.

The approximately 22 year span of time that it takes for the poles to reverse back to the same polarity again is equal to two average 11 year sunspot cycles. The Sun’s magnetic field has been exceptionally asymmetric during this cycle, and as of this writing, the Sun has already finished its reversal of the north pole first.

This sort of asymmetry during an imminent pole reversal was first recorded during solar cycle 19, which spanned 1954-1964. Solar cycles are numbered starting from observations which began in 1749, just four decades after the end of the 70-year Maunder Minimum.

“This is an exciting time to study the magnetic field of the Sun, as we may be witnessing a return to a less-active type of cycle, more like those of 100 years ago,” NCAR/HAO senior scientist and co-author Sarah Gibson said.

A massive sunspot group that rotated into view in early July, 2013... one of the largest seen for solar cycle #24 thus far. (Credit: NASA/SDO). — A massive sunspot group that rotated into view in early July, 2013, one of the largest seen for solar cycle #24 thus far. (Credit: NASA/SDO).

But this time, an armada of space and ground-based observatories will scrutinize our host star like never before. The SOlar Heliospheric Observatory (SOHO) has already followed the Sun through the equivalent of one complete solar cycle— and it has now been joined in space by STEREO A & B, JAXA’s Hinode, ESA’s Proba-2 and NASA’s Solar Dynamics Observatory. NASA’s Interface Region Imaging Spectrograph (IRIS) was also launched earlier this year and has just recently opened for business.

Will there be a second peak following the magnetic polarity reversal of the Sun’s south pole, or is Cycle #24 about to “leave the building?” And will Cycle #25 be absent all together, as some researchers suggest? What role does the solar cycle play in the complex climate change puzzle? These next few years will prove to be exciting ones for solar science, as the predictive significance of HCS SD & SL values are put to the test… and that’s what good science is all about!

-Read the abstract with a link to the full paper in The Astrophysical Journal by University of Michigan researchers here.

August 13, 2013December 23, 2015 by Elizabeth Howell

How To Hit A Landing Target On Mars … Potentially, Precisely and Perfectly!

A Xombie technology demonstrator from Masten Space Systems. Credit: NASA/Masten

It’s frustrating to make it all the way to Mars, only to land in the wrong spot. So as Masten Space Systems tests its Xombie vertical-launch-vertical-landing rocket prototype on Earth, engineers are also examining a software solution to make Red Planet landings even more precise.

The software is called G-FOLD (for Fuel Optimal Large Divert Guidance algorithm) and is a product of NASA’s Jet Propulsion Laboratory and other NASA departments. The agency is using techniques for spacecraft landings that have origins from the Apollo moon missions of the 1960s, which have some limitations.

“These algorithms do not optimize fuel usage and significantly limit how far the landing craft can be diverted during descent,” JPL stated, adding that the new algorithm can figure out the best fuel-conserving paths in real time, along with a “key new technology required for planetary pinpoint landing.”

An artist's concept of Curiosity landing with the skycrane system. Credit: NASA/JPL — An artist’s concept of Curiosity landing with the skycrane system — demonstrating one recently used technique for landing on Mars. Credit: NASA/JPL

Hitting the target exactly is an exciting feat for researchers, JPL explained, because robotic missions can be steered to difficult-to-reach science targets and crewed missions could bring more cargo to their landing site rather than carrying extra fuel.

Xombie first tested out this technique on July 30 and nailed the landing — about half a mile away — when it received the commands while 90 feet in the air. A second flight is planned for August, providing the data analysis goes as planned.

The technology is still new, of course, and there are other concepts out there for pinpoint systems. In May, the European Space Agency released information on a concept it is funding. That system, which is also still being developed, uses a database of landmarks to assist a spacecraft with making landings.

Source: NASA

August 12, 2013December 23, 2015 by Ken Kremer

Aerospace Students Shoot for the Stars and Space Flight Dreams

Rocket science university students from Puerto Rico pose for photo op with the Terrier-Improved Malemute sounding rocket that will launch their own developed RockSat-X science experiments to space on Aug. 13 at 6 a.m. from NASA Wallops Flight Facility, VA.
Credit: Ken Kremer/kenkremer.com[/caption]

WALLOPS ISLAND, VA – How many of you have dreamed of flying yourselves or your breakthrough experiments to the High Frontier? Well if you are a talented student, NASA may have a ticket for you.

A diverse group of highly motivated aerospace students from seven universities spread across the United States have descended on NASA’s Wallops Flight Facility along the Eastern Shore of Virginia to fulfill the dream of their lifetimes – launching their very own science experiments aboard a rocket bound for space.

I met the thrilled students and professors today beside their rocket at the Wallops Island launch pad.

On Aug 13, after years of hard work, an impressive array of research experiments developed by more than 40 university students will soar to space on the RockSat-X payload atop a 44-foot tall Terrier-Improved Malemute suborbital sounding rocket at 6 a.m. EDT.

Students from Northwest Nazarene University observe the pre-integration of their experiment into the RockSat-X payload at the NASA Wallops Flight Facility in June. Students from seven universities are participating in the program and will attend the launch on August 13. Credit: NASA/K. Koehler

The two stage rocket will rapidly ascend on a southeasterly trajectory to an altitude of some 97 miles and transmit valuable data in-flight during the 12-minute mission.

The launch will be visible to spectators in parts of Virginia, Maryland and Delaware, and perhaps a bit beyond. Check out the visibility map below.

The RockSat-X flight profile and visibility map. RockSat-X is scheduled to launch from NASA’s Wallops Flight Facility, VA on Aug. 13 at 6.a.m. EDT Credit: NASA

If you’re available, try venturing out to watch it. The available window lasts until 10 a.m. EDT if needed.

The students will put their classroom learning to the test with experiments and instruments built by their own hands and installed on the 20 foot long RockSat-X payload. The integrated payload accounts for nearly half the length of the Terrier Malamute suborbital rocket. It’s an out of this world application of the scientific method.

Terrier-Improved Malemute sounding rocket erected for launch of student experiments on RockSat-X payload on Aug. 13 at 6 a.m. from NASA Wallops Flight Facility, VA. Credit: Ken Kremer/kenkremer.com

Included among the dozens of custom built student experiments are HD cameras, investigations into crystal growth and ferro fluids in microgravity, measuring the electron density in the E region (90-120km), aerogel dust collection on an exposed telescoping arm from the rockets side, effects of radiation damage on various electrical components, determining the durability of flexible electronics in the cryogenic environment of space and creating a despun video of the flight.

At the conclusion of the flight, the payload will descend to Earth via a parachute and splash down in the Atlantic Ocean approximately 86 miles offshore from Wallops.

Commercial fishing ships under contract to NASA will then recover the RockSat-X payload and return it to the students a few hours later, NASA spokesman Keith Koehler told Universe Today.

They will tear apart the payload, disengage their experiments and begin analyzing the data to see how well their instruments performed compared to the preflight hypotheses’.

RockSat-X is a joint educational activity between NASA and the Colorado Space Grant Consortium. It is the third of three practical STEM educational programs where the students must master increasingly difficult skill level requirements leading to a series of sounding rocket liftoffs.

In mid-June, some 50 new students participated in the successful ‘RockOn’ introductory level payload launch from Wallops using a smaller Terrier-Improved Orion rocket.

“The goal of the RockSat-X program is to provide students a hands-on experience in developing experiments for space flight,” said Chris Koehler, Director of the Colorado Space Grant Consortium.

“This experience allows these students to apply what they have learned in the classroom to a real world hands-on project.”

The students participating in this year’s RockSat-X launch program hail from the University of Colorado at Boulder; the University of Puerto Rico at San Juan; the University of Maryland, College Park; Johns Hopkins University, Baltimore, Md.; West Virginia University, Morgantown; University of Minnesota, Twin Cities; and Northwest Nazarene University, Nampa, Idaho.

Panoramic view of the NASA Wallops Flight Facility launch range at Virginia’s Eastern Shore during prior launch of two suborbital sounding rockets as part of the Daytime Dynamo mission. RockSat-X payload will launch on a Terrier-Improved Malemute sounding rocket. Credit: Ken Kremer/kenkremer.com

Some of these students today could well become the pioneering aerospace industry leaders of tomorrow!

In the event of a delay forced by weather or technical glitches, August 14 is the backup launch day.

A great place to witness the blastoff is from the NASA Wallops Visitor Center, offering a clear view to the NASA launch range.

It opens at 5 a.m. on launch day and is a wonderful place to learn about NASA missions – especially the pair of exciting and unprecedented upcoming launches of the LADEE lunar science probe to the moon and the Cygnus cargo carrier to the ISS in September.

Both LADEE and Cygnus are historic first of their kind flights from NASA Wallops.

Live coverage of the launch is available via UStream beginning at 5 a.m. on launch day at:
http://www.ustream.tv/channel/nasa-tv-wallops

Ken Kremer

…………….
Learn more about Suborbital Science, Cygnus, Antares, LADEE, MAVEN and Mars rovers and more at Ken’s upcoming presentations

Aug 12/13: “RockSat-X Suborbital Launch, LADEE Lunar & Antares Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM

Sep 5/6/16/17: LADEE Lunar & Antares/Cygnus ISS Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM

Oct 3: “Curiosity, MAVEN and the Search for Life on Mars – (3-D)”, STAR Astronomy Club, Brookdale Community College & Monmouth Museum, Lincroft, NJ, 8 PM

More than 40 University students participating in the Aug. 13 RockSat-X science payload pose for photo op with the Terrier-Improved Malemute sounding rocket that will launch their own experiments to space from NASA Wallops Flight Facility, VA. Credit: Ken Kremer/kenkremer.com

August 12, 2013December 23, 2015 by Katrina Cain

Giveaway: Star Walk: Stargazing App for the iPhone

We have another great app giveaway for you, our valued readers. Star Walk is an app that allows you to point your iPhone at the night sky to provide names and descriptions of all the objects you are seeing. Furthermore, you can click on any individual star, satellite, planet or constellation and an in depth description will conveniently pop up on your screen. Whether you live in the city with lots of light pollution or in the country where there are more stars than black, this app will fill you in on all of the celestial objects you can (or can’t) see.

From the developer:

Star Walk is an award-winning Education app that allows users to easily locate and identify 20,000+ objects in the night sky. The 360-degree, touch control star map displays constellations, stars, planets, satellites, and galaxies currently overhead from anywhere on Earth. Highly praised and the winner of a 2010 Apple Design Award, the latest update allows users to enjoy unprecedented eye candy and interactivity of the star map, achieved with the new camera and high resolution of the new device.

Enter to win one of 10 free copies of this app for your iPhone. How?

In order to be entered into the giveaway drawing, just put your email address into the box at the bottom of this post (where it says “Enter the Giveaway”) before Monday, August 19, 2013. We’ll send you a confirmation email, so you’ll need to click that to be entered into the drawing.

August 12, 2013December 23, 2015 by Nancy Atkinson

Perseid Meteor Shower 2013: Images from Around the World

A composite of stacked images of the Perseid Meteor Shower on August 11, 2013 seen from Lindisfarne (Holy Island) off the northeast coast of England. Credit and copyright: Peter Greig.

The Perseid Meteor Shower peaks tonight, but already astrophotographers have been out, enjoying the view of a little cosmic rain. This weekend provided good views for many, as these images and videos will attest. We’ll keep adding more images as they come in, but enjoy these wonderful images we’ve received so far. Our lead image is a wowza from Peter Greig from the UK. He traveled to an island off the coast of England and found exactly what he was looking for.

“This is the exact image that I imagined and planned to come home with from that trip,” Peter said via Flickr. “It is a composite of stacked images (or pieces of images). I chose the clearest background image to use for the starry sky then chose the best light painted foreground and layered it over my background. I then went through all of my images and gathered all the shots that contained a meteor, cut them out and layered them on top of my background image to demonstrate the radiant point to which the Perseid Meteors originate.”

Just gorgeous! If you’re looking to get out tonight and see the Perseids for yourself, here our “explainer” from David Dickenson of how to best see this meteor shower!

See more from our astrophotographer friends below:

Perseid Meteor and the Milky Way, in the Red Desert of Wyoming, August 11, 2013. Credit and copyright: Randy Halverson/dakotalapse.

Early Perseids from the Washburn-Norlands Living History Center in Livermore, Maine, taken August 5, 2013. Credit and copyright: Steven Coates.

This video is from John Chumack, who captured 142 Perseids from my backyard in Dayton, Ohio! “My video cameras actually caught many more than I had seen visually,” John said via email, expressing a little disapointment in this year’s Persieds, “from past years experiences I was expecting more Perseids!”

A persistent Perseid on August 11, 2013. Shot with Canon T1i/500D with Samyang 8mm fisheye. F5.6 / 3200ISO / 30s. Credit and copyright: darethehair on Flickr.

A very bright fireball from the Perseid meteor shower, along with the Otto Struve Telescope from the McDonald Observatory in Texas and the Milky Way. Credit and copyright: Sergio Garcia Rill/SGR Photography.

You can read more about this image by Sergio Garcia Rill and the ‘persistent’ neon fireball at his website.

A Perseid meteor and the constellation Cassiopeia seen over Winchester, UK. Credit and copyright: Paul Williamson.

Now more:

Can you spot a total of 6 meteors in this image? (two are very faint). This is a composite of 3 pictures stacked, each picture taken with a Canon 550D @18mm 30s Exposure at ISO 3200. Credit and copyright: Andrei Juravle.

2013 Perseids Radiant Point: A composite shot of Perseid meteors emanating from the meteor shower radiant point. This composite features 9 total Perseid meteors. Credit and copyright: Scott MacNeill.

A Perseid meteor and the Milky Way. Credit and copyright: TheMagster3 on Flickr.

Perseid meteor shower (and equipment!) taken on August 11, 2013 near Monte Romano, Lazio, Italy, with a Nikon D5200. Credit and copyright: marcopics3000 on Flickr.

Perseid Meteor Shower and Milky Way image shot in Hampstead, North Carolina on a Canon 7D @10mm 30s f/4 ISO 2500. Credit and copyright: K.C. Goshert.

New images added 8/13/13:

Perseid meteor captured by Emilia Howes, aged 7, at Lacock in Wiltshire, England.

Perseid Meteors over Ancient Bristlecone Pine in the White Mountains of California. This is a composite shot of 73 meteors, aligned as they were captured according to where they were against the stars. Credit and copyright: Kenneth Brandon.

Perseids over Joshua Tree. This is a composite image composed of 180 stills from a static timelapse sequence, aiming towards the North Star. Taken on August 9, 2013. Credit and copyright: Sean Parker/Sean Parker Photography.

'My first-ever photo of a meteor!' said astrophotographer Dawn Sunrise on Flickr. Congrats! — ‘My first-ever photo of a meteor!’ said astrophotographer Dawn Sunrise on Flickr. Congrats!

Perseid meteor photographed on August 11, 2013 at 0255 EDT through broken clouds, Weatherly, PA. 20 second exposure, ISO 1600 using a Samyang 14mm lens. Credit and copyright: Tom Wildoner.

One Perseid meteor before the clouds rolled in over Blackrod, England, August 12, 2013. Credit and copyright: TheDaveWalker on Flickr.

Perseid meteor on August 12, 2013. Credit and copyright: Stephen Rahn.

Perseids Meteor 8/11/2013 El Dorado Lake, Kansas. Credit and copyright: Tom Wright.

More images added 8/15/13:

Meteor seen over Green Bay, Wisconsin on August 14, 2013 around 12:30 am central time. Photographer Michelle Madruga said, 'I used my measly Canon T3i and my 18-55mm lens set at 18mm. During my 30 sec exposure, this huge asteroid shot across the sky! I was lucky it was in my camera's view!' Credit and copyright: Michelle Madruga. — Meteor seen over Green Bay, Wisconsin on August 14, 2013 around 12:30 am central time. Photographer Michelle Madruga said, ‘I used my measly Canon T3i and my 18-55mm lens set at 18mm. During my 30 sec exposure, this huge asteroid shot across the sky! I was lucky it was in my camera’s view!’ Credit and copyright: Michelle Madruga.

Perseid meteor seen over the Rocky Mountains of Colorado, taken with a Canon 7D 18-55mm. Credit and copyright: Micah Holtgraves.

Perseid meteor. Credit and copyright: Val Camp.

Perseid meteor on August 13, 2013 seen over Kootwijkerzand, at the ‘de Hoge Veluwe’, one of the last dark spots in the Netherlands. This picture was taken with an EOS 60d with a 11-16 2.8 tokina lens. Credit and copyright: Freek vd Driesschen.

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.

August 12, 2013March 16, 2017 by Fraser Cain

What Is A Quasar?

I love it when scientists discover something unusual in nature. They have no idea what it is, and then over decades of research, evidence builds, and scientists grow to understand what’s going on.

My favorite example? Quasars.

Astronomers first knew they had a mystery on their hands in the 1960s when they turned the first radio telescopes to the sky.

They detected the radio waves streaming off the Sun, the Milky Way and a few stars, but they also turned up bizarre objects they couldn’t explain. These objects were small and incredibly bright.

They named them quasi-stellar-objects or “quasars”, and then began to argue about what might be causing them. The first was found to be moving away at more than a third the speed of light.

But was it really?

An artist's conception of jets protruding from an AGN. — An artist’s conception of jets protruding from an AGN.

Maybe we were seeing the distortion of gravity from a black hole, or could it be the white hole end of a wormhole. And If it was that fast, then it was really, really far… 4 billion light years away. And it generating as much energy as an entire galaxy with a hundred billion stars.

What could do this?

Here’s where Astronomers got creative. Maybe quasars weren’t really that bright, and it was our understanding of the size and expansion of the Universe that was wrong. Or maybe we were seeing the results of a civilization, who had harnessed all stars in their galaxy into some kind of energy source.

Then in the 1980s, astronomers started to agree on the active galaxy theory as the source of quasars. That, in fact, several different kinds of objects: quasars, blazars and radio galaxies were all the same thing, just seen from different angles. And that some mechanism was causing galaxies to blast out jets of radiation from their cores.

But what was that mechanism?

This artist's concept illustrates a quasar, or feeding black hole, similar to APM 08279+5255, where astronomers discovered huge amounts of water vapor. Gas and dust likely form a torus around the central black hole, with clouds of charged gas above and below. Image credit: NASA/ESA — This artist’s concept illustrates a quasar, or feeding black hole, similar to APM 08279+5255, where astronomers discovered huge amounts of water vapor. Gas and dust likely form a torus around the central black hole, with clouds of charged gas above and below. Image credit: NASA/ESA

We now know that all galaxies have supermassive black holes at their centers; some billions of times the mass of the Sun. When material gets too close, it forms an accretion disk around the black hole. It heats up to millions of degrees, blasting out an enormous amount of radiation.

The magnetic environment around the black hole forms twin jets of material which flow out into space for millions of light-years. This is an AGN, an active galactic nucleus.

When the jets are perpendicular to our view, we see a radio galaxy. If they’re at an angle, we see a quasar. And when we’re staring right down the barrel of the jet, that’s a blazar. It’s the same object, seen from three different perspectives.

Supermassive black holes aren’t always feeding. If a black hole runs out of food, the jets run out of power and shut down. Right up until something else gets too close, and the whole system starts up again.

The Milky Way has a supermassive black hole at its center, and it’s all out of food. It doesn’t have an active galactic nucleus, and so, we don’t appear as a quasar to some distant galaxy.

We may have in the past, and may again in the future. In 10 billion years or so, when the Milky way collides with Andromeda, our supermassive black hole may roar to life as a quasar, consuming all this new material.

If you’d like more information on Quasars, check out NASA’s Discussion on Quasars, and here’s a link to NASA’s Ask an Astrophysicist Page about Quasars.

We’ve also recorded an entire episode of Astronomy Cast all about Quasars Listen here, Episode 98: Quasars.

Sources: UT-Knoxville, NASA, Wikipedia

August 12, 2013December 23, 2015 by Nancy Atkinson

Beautiful Noctilucent Clouds 2013 — The Movie

Noctilucent clouds taken from the ISS Image Credit: NASA

Intrigued by mysterious noctilucent, or night-shining clouds? This beautiful new film from TWAN (The World At Night) photographer P-M Hedén combines timelapse and real-time footage to provide a stunning compilation of his month in the field in Sweden this summer to capture these lovely blue electric clouds. Noctilucent clouds are visible sometimes low in the northern sky during morning and evening twilight, usually through late May through August, and they seem to be increasing the past few years.

Enjoy the stunning, tranquil views (lots of wildlife and night sky imagery too!) and lovely music in this new film, just published yesterday.

For more information about NLCs, Bob King wrote a great overview for us earlier this year about these “visitors from the Twilight Zone!

Noctilucent clouds 2013 The Film from P-M Hedén on Vimeo.