Tuesday, July 8, 2014

PHOTOS ‘Time Capsule On Mars’ Team Hopes To Send a Spacecraft There With Your Messages

‘Time Capsule On Mars’ Team Hopes To Send a Spacecraft There With Your Messages:



Mars photographed with the Mars Global Surveyor.

Mars photographed with the Mars Global Surveyor.
It’s an ambitious goal: land three Cubesats on Mars sometime in the next few years for $25 million. And all this from a student-led team.

But the group, led by Duke University, is dutifully assembling sponsors and potential in-kind contributions from universities and companies to try to reach that goal. So far they have raised more than half a million dollars.

“We were thinking that something was missing,” said Emily Briere, the student team project lead who attends Duke University, explaining how it seemed few Mars missions were being done for the benefit of humanity in general.

“We want to get the whole world excited about space exploration, and why we go to space in the first place, which was to push forward mankind and to build new habitats,” she added. Prime among their objectives is to drive engagement in the kindergarten to Grade 12 audience by encouraging them to submit photos and videos to send to Mars.

Artist's conception of Mars, with asteroids nearby. Credit: NASA

Artist’s conception of Mars, with asteroids nearby. Credit: NASA
But that said, everyone can participate! The official launch of the project is today, and you can read more details about the crowdfunding campaign and how to get involved on the Time Capsule to Mars website. Contributions start at only a dollar, where you can send your picture to Mars. The spacecraft will be loaded with audio, video and text messages from Earth.

“Each satellite will contain a terabyte of data that will act as a digital ‘time capsule’ carrying messages, photos, audio clips and video contributed by tens of millions of people from all over the globe,” says the Time Capsule to Mars team. “The capsule will remain a vessel of captured moments of today’s human race on Earth in 2014, to be rediscovered by future colonists of the Red Planet.”

The team hopes to use ion electric propulsion to get their small spacecraft to the Red Planet. It would head to space itself on a secondary payload on a rocket. (Briere couldn’t disclose who they are talking to, but said ideally it would happen within the next two years.)

Some of the corporate sponsors including Boeing, Lockheed Martin and Aerojet while students come from universities such as Stanford, Duke and the Massachusetts Institute of Technology.

Tagged as:
CubeSat,
time capsule to mars
Posted by Nelio Inacio at 8:56 AM 0 comments

PHOTOS An Earth-size Diamond in the Sky: The Coolest Known White Dwarf Detected

An Earth-size Diamond in the Sky: The Coolest Known White Dwarf Detected:



Artist impression of a white dwarf star in orbit with pulsar PSR J2222-0137. It may be the coolest and dimmest white dwarf ever identified. Credit: B. Saxton (NRAO/AUI/NSF)

An artist’s conception of a white dwarf star in orbit with pulsar PSR J2222-0137. Image Credit: B. Saxton (NRAO/AUI/NSF)
We live in a vast, dark Universe, which makes the smallest and coolest objects extremely difficult to detect, save for a stroke of luck. Often times this luck comes in the form of a companion. Take, for example, the first exoplanet detected due to its orbit around a pulsar — a rapidly spinning neutron star.

A team of researchers using the National Radio Astronomy Observatory’s Green Bank Telescope and the Very Long Baseline Array (VLBA), as well as other observatories have repeated the story, detecting an object in orbit around a distant pulsar. Except this time it’s the coldest, faintest white dwarf ever detected. So cool, in fact, its carbon has crystallized.

The punch line is this: with the help of a pulsar, astronomers have detected an Earth-size diamond in the sky.

“It’s a really remarkable object,” said lead author David Kaplan from the University of Wisconsin-Milwaukee in a press release. “These things should be out there, but because they are so dim they are very hard to find.”

The story begins when Dr. Jason Boyles, then a graduate student at West Virginia University, identified a pulsar, dubbed PSR J2222-0127, 900 light-years away in the constellation Aquarius.

When the core of a massive star runs out of energy, it collapses to form an incredibly dense neutron star or black hole. Bring a teaspoon of neutron star to Earth and it would outweigh Mount Everest at about a billion tons. A pulsar is simply a spinning neutron star.

But as a pulsar spins, lighthouse-like beams of radio waves stream from the poles of its powerful magnetic field. If they sweep past the Earth, they’ll give rise to blips of radio waves, so regular that you could set your watch by them. But if the pulsar carries a companion in tow, the tiny gravitational tugs can offset that timing slightly.

The first observations of PSR J2222-0137 identified that it was spinning more than 30 times each second. It was then observed over a two-year period with the VLBA. By applying Einstein’s theory of relativity — which predicts that light slows in the presence of a gravitational field — the researchers studied how the gravity of the companion warped space, causing delays in the radio signal as the pulsar passed behind it.

The delayed travel times helped the researchers determine the individual masses of the two stars. The pulsar has a mass of 1.2 times that of the Sun and the companion a mass 1.05 times that of the Sun. Previously, researchers had thought the companion was likely another neutron star, or a white dwarf, the remnant of a Sun-like star.

But the timing variations made the neutron star scenario unlikely. The orbits were too orderly for a second supernova to have taken place. So knowing the typical brightness of a white dwarf and its distance, astronomers initially thought they would be able to detect the elusive companion in optical and infrared light.

An image taken in visible light at the SOAR telescope of the field of the pulsar/white dwarf pair. There is no evidence for the white dwarf at the position of the pulsar in this deep image, indicating that the white dwarf is much fainter, and therefore cooler, than any such known object. (The two large white circles mask bright, overexposed stars.)

An image taken in visible light at the SOAR telescope of the field of the pulsar/white dwarf pair. The exact location of the white dwarf is known to a pixel. But it’s not there. Image Credit: NOAO
However, neither the Southern Astrophysical Research telescope in Chile nor the 10-meter Keck telescope in Hawaii was able to detect it.

“Our final image should show us a companion 100 times fainter than any other white dwarf orbiting a neutron star and about 10 times fainter than any known white dwarf, but we don’t see a thing,” said coauthor Bart Dunlap, a graduate student at the University of North Carolina. “If there’s a white dwarf there, and there almost certainly is, it must be extremely cold.”

The research team calculated that the white dwarf would be no more than 3,000 degrees Kelvin. At such a low temperature, the collapsed star would be largely crystallized carbon, similar to diamond.

The paper has been accepted for publication in the Astrophysical Journal and may be viewed here.

Tagged as:
Neutron Star,
pulsar,
white dwarf
Posted by Nelio Inacio at 8:55 AM 0 comments

‘Ghost’ Object Appears, Disappears on Titan

‘Ghost’ Object Appears, Disappears on Titan:



During previous flybys, 'Magic Island' was not visible near Ligeia Mare's coastline (left). Then, during Cassini's July 20, 2013, flyby the feature appeared (right)/ Credit: NASA/JPL-CALTECH/ASI/Cornell University, image editing via Ian O'Neill/Discovery News.

During previous flybys, ‘Magic Island’ was not visible near Ligeia Mare’s coastline (left). Then, during Cassini’s July 20, 2013, flyby the feature appeared (right)/ Credit: NASA/JPL-CALTECH/ASI/Cornell University, image editing via Ian O’Neill/Discovery News.
Astronomers with the Cassini mission have detected a bright, mysterious geologic object on Saturn’s moon Titan that suddenly showed up in images from the mission’s radar instrument. The object appeared in Ligeia Mare, the second-largest sea Titan. The feature looks like an island and so the team named it “Magic Island.” However, it most likely is not an island that suddenly surfaced. But scientists say this may be the first observation of dynamic, geological processes in Titan’s northern hemisphere.



The object suddenly showed up in images beamed back from Cassini on July 10, 2013, showing regions of Ligeia Mare, a sea located near Titan’s north pole. But then just as suddenly, in a follow-up flyby only days later on July 26, the island was gone. Subsequent flybys confirmed that Magic Island had vanished and is what is known as a “transient feature.”

“This discovery tells us that the liquids in Titan’s northern hemisphere are not simply stagnant and unchanging, but rather that changes do occur,” said Jason Hofgartner, a Cornell graduate student in the and the lead author of a paper appearing in Nature Geoscience. “We don’t know precisely what caused this ‘magic island’ to appear, but we’d like to study it further.”

Map of Titan's northern region of hydrocarbon 'seas' created from Cassini radar imaging. Credit: NASA/JPL/USGS.

Map of Titan’s northern region of hydrocarbon ‘seas’ created from Cassini radar imaging. Credit: NASA/JPL/USGS.
Titan is currently the only other world besides Earth known to have stable bodies of liquid on its surface. But unlike Earth, Titan’s lakes aren’t filled with water — instead they’re full of liquid methane and ethane, organic compounds which are gases on Earth but liquids in Titan’s incredibly chilly -290º F (-180º C) environment.

So what was this object? Among the explanations from the team are:

  • Northern hemisphere winds may be kicking up and forming waves on Ligeia Mare. The radar imaging system might see the waves as a kind of “ghost” island. Scientists previously have seen what they think are waves in another nearby Titan sea, Punga Mare.
  • Gases may push out from the sea floor of Ligeia Mare, rising to the surface as bubbles.
  • Sunken solids formed by a wintry freeze could become buoyant with the onset of the late Titan spring warmer temperatures.
  • Suspended solids in Ligeia Mare, which are neither sunken nor floating, but act like silt in a terrestrial delta.
“Likely, several different processes – such as wind, rain and tides – might affect the methane and ethane lakes on Titan. We want to see the similarities and differences from geological processes that occur here on Earth,” Hofgartner said. “Ultimately, it will help us to understand better our own liquid environments here on the Earth.”

Source: Cornell University

Tagged as:
Cassini,
Ligeia Mare,
Saturn system,
Titan
Posted by Nelio Inacio at 8:55 AM 0 comments

Observing Alert: Distant Blazar 3C 454.3 in Outburst, Visible in Amateur Telescopes

Observing Alert: Distant Blazar 3C 454.3 in Outburst, Visible in Amateur Telescopes:



The blazar 3C 454.3 photographed by the Sloan Digital Sky Survey. It's currently in bright outburst and nearly as bright as the star next to it. Both are about magnitude +13.6. Credit: SDSS

The blazar 3C 454.3 photographed by the Sloan Digital Sky Survey. It’s currently in outburst and nearly as bright as the star just above it. Both are about magnitude +13.6. Click for more information and visuals. Credit: SDSS
Have an 8-inch or larger telescope? Don’t mind staying up late? Excellent. Here’s a chance to stare deeper into the known fabric of the universe than perhaps you’ve ever done before. The violent blazer  3C  454.3 is throwing a fit again, undergoing its most intense outburst seen since 2010. Normally it sleeps away the months around 17th magnitude but every few years, it can brighten up to 5 magnitudes and show in amateur telescopes. While magnitude +13 doesn’t sound impressive at first blush, consider that 3C 454.3 lies 7 billion light years from Earth. When light left the quasar, the sun and planets wouldn’t have skin in the game for another  two billion years.

If we could see the blazar 3C 354.3 up close it would look something like this. A bright accretion disk surrounds a black hole. Twin jets of radiation beam from the center. Credit: Cosmovision

If we could see the blazar 3C 354.3 up close it would look something like this. A bright accretion disk surrounds a black hole. Twin jets of radiation beam from the center. Credit: Cosmovision
Blazars form in the the cores of active galaxies where supermassive black holes reside. Matter falling into the black hole spreads into a spinning accretion disk before spiraling down the hole like water down a bathtub drain.

Superheated to millions of degrees by gravitational compression the disk glows brilliantly across the electromagnetic spectrum. Powerful spun-up magnetic fields focus twin beams of light and energetic particles called jets that blast into space perpendicular to the disk.

Blazars and quasars are thought to be one and the same, differing only by the angle at which we see them. Quasars – far more common – are actively- munching supermassive black holes seen from the side, while in blazars – far more rare – we stare directly or nearly so into the jet like looking into the beam of a flashlight.

An all-sky view in gamma ray light made with the Fermi gamma ray telescope shows bright gamma-ray emission in the plane of the Milky Way (center), bright pulsars and super-massive black holes including the active blazar 3C 454.3 at lower left. Credit: NASA/DOE/International LAT Team

An all-sky view in gamma ray light made with the Fermi Gamma-ray Space Telescope shows bright gamma-ray emission in the plane of the Milky Way (center), bright pulsars and super-massive black holes including the active blazar 3C 454.3 at lower left. Credit: NASA/DOE/International LAT Team
3C 454.3 is one of the top ten brightest gamma ray sources in the sky seen by the Fermi Gamma-ray Space Telescope. During its last major flare in 2005, the blazar blazed with the light of 550 billion suns. That’s more stars than the entire Milky Way galaxy! It’s still not known exactly what sets off these periodic outbursts but possible causes include radiation bursts from shocked particles within the jet or precession (twisting) of the jet bringing it close to our line of sight.



3c 454.3 is near the magnitude 2.5 magnitude star Alpha Pegasi just to the west of the Great Square. Use this chart to star hop from Alpha to IM Peg (mag. ~ 5.7). Once there, the detailed map below will guide you to the blazar. Stellarium

3c 454.3 is near the star Alpha Pegasi just to the west of the Great Square. Use this chart to star hop from Alpha to IM Peg (mag. ~ 5.7). Once there, the detailed map below will guide you to the blazar. Stellarium
The current outburst began in late May when the Italian Space Agency’s AGILE satellite detected an increase in gamma rays from the blazar. Now it’s bright visually at around magnitude +13.6 and fortunately not difficult to find, located in the constellation Pegasus near the bright star Alpha Pegasi (Markab) in the lower right corner of the Great Square asterism.

Using the wide view map, find your way to IM Peg via Markab and then make a copy of the detailed map below to use at the telescope to star hop to 3C 454.3. The blazar lies immediately south of a star of similar magnitude. If you see what looks like a ‘double star’ at the location, you’ve nailed it. Incredible isn’t it to look so far into space back to when the universe was just a teenager? Blows my mind every time.

Detailed map showing the location of the blazar 3C 454.3. I've created a small asterism with a group of brighter stars with their magnitudes marked. A scale showing 30 arc minutes (1/2 degree) is at right. Stars shown to about magnitude +15. Created with Chris Marriott's SkyMap software

Detailed map showing the location of the blazar 3C 454.3. I’ve drawn a small asterism using a group of brighter stars with their magnitudes marked. A scale showing 30 arc minutes (1/2 degree) is at right. Click to enlarge. Created with Chris Marriott’s SkyMap software
To further explore 3C 454.3 and blazars vs. quasars I encourage you to visit check out Stefan Karge’s excellent Frankfurt Quasar Monitoring site.  It’s packed with great information and maps for finding the best and brightest of this rarified group of observing targets. Karge suggests that flickering of the blazar may cause it to appear somewhat brighter or fainter than the current magnitude. You’re watching a violent event subject to rapid and erratic changes. For an in-depth study of 3C 454.3, check out the scientific paper that appeared in the 2010 Astrophysical Journal.



Learn more about quasars and blazers with a bit of great humor

Finally, I came across a wonderful video while doing research for this article I thought you’d enjoy as well.

Tagged as:
3C 454.3,
black hole,
Blazar,
Fermi Telescope,
Gamma rays,
jets,
Pegasus,
quasar
Posted by Nelio Inacio at 8:54 AM 0 comments

Intriguing X-Ray Signal Might be Dark Matter Candidate

Intriguing X-Ray Signal Might be Dark Matter Candidate:



A mysterious X-ray signal in the Perseus galaxy cluster. Credit: NASA/CXC/SAO/E.Bulbul, et al.

A mysterious X-ray signal in the Perseus galaxy cluster. Credit: NASA/CXC/SAO/E.Bulbul, et al.
Could a strange X-ray signal coming from the Perseus galaxy cluster be a hint of the elusive dark matter in our Universe?

Using archival data from the Chandra X-ray Observatory and the XMM-Newton mission, astronomers found an unidentified X-ray emission line, or a spike of intensity at a very specific wavelength of X-ray light. This spike was also found in 73 other galaxy clusters in XMM-Newton data.

The scientists propose that one intriguing possibility is that the X-rays are produced by the decay of sterile neutrinos, a hypothetical type of neutrino that has been proposed as a candidate for dark matter and is predicted to interact with normal matter only via gravity.

“We know that the dark matter explanation is a long shot, but the pay-off would be huge if we’re right,” said Esra Bulbul of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Massachusetts, who led the study. “So we’re going to keep testing this interpretation and see where it takes us.”



Astronomers estimate that roughly 85 percent of all matter in the Universe is dark matter, invisible to even the most powerful telescopes, but detectable by its gravitational pull.

Galaxy clusters are good places to look for dark matter. They contain hundreds of galaxies as well as a huge amount of hot gas filling the space between them. But measurements of the gravitational influence of galaxy clusters show that the galaxies and gas make up only about one-fifth of the total mass. The rest is thought to be dark matter.

Bulbul explained in a post on the Chandra blog that she wanted try hunting for dark matter by “stacking” (layering observations on top of each other) large numbers of observations of galaxy clusters to improve the sensitivity of the data coming from Chandra and XMM-Newton.

“The great advantage of stacking observations is not only an increased signal-to-noise ratio (that is, the amount of useful signal compared to background noise), but also the diminished effects of detector and background features,” wrote Bulbul. “The X-ray background emission and instrumental noise are the main obstacles in the analysis of faint objects, such as galaxy clusters.”

Her primary goal in using the stacking technique was to refine previous upper limits on the properties of dark matter particles and perhaps even find a weak emission line from previously undetected metals.

“These weak emission lines from metals originate from the known atomic transitions taking place in the hot atmospheres of galaxy clusters,” said Bulbul. “After spending a year reducing, carefully examining, and stacking the XMM-Newton X-ray observations of 73 galaxy clusters, I noticed an unexpected emission line at about 3.56 kiloelectron volts (keV), a specific energy in the X-ray range.”

In theory, a sterile neutrino decays into an active neutrino by emitting an X-ray photon in the keV range, which can be detectable through X-ray spectroscopy. Bulbul said that her team’s results are consistent with the theoretical expectations and the upper limits placed by previous X-ray searches.

Bulbul and her colleagues worked for a year to confirm the existence of the line in different subsamples, but they say they still have much work to do to confirm that they’ve actually detected sterile neutrinos.

“Our next step is to combine data from Chandra and JAXA’s Suzaku mission for a large number of galaxy clusters to see if we find the same X-ray signal,” said co-author Adam Foster, also of CfA. “There are lots of ideas out there about what these data could represent. We may not know for certain until Astro-H launches, with a new type of X-ray detector that will be able to measure the line with more precision than currently possible.”

Astro-H is another Japanese mission scheduled to launch in 2015 with a high-resolution instrument that should be able to see better detail in the spectra, and Bulbul said they hope to be able to “unambiguously distinguish an astrophysical line from a dark matter signal and tell us what this new X-ray emission truly is.”

Since the emission line is weak, this detection is pushing the capabilities Chandra and XMM Newton in terms of sensitivity. Also, the team says there may be explanations other than sterile neutrinos if this X-ray emission line is deemed to be real. There are ways that normal matter in the cluster could have produced the line, although the team’s analysis suggested that all of these would involve unlikely changes to our understanding of physical conditions in the galaxy cluster or the details of the atomic physics of extremely hot gases.

The authors also note that even if the sterile neutrino interpretation is correct, their detection does not necessarily imply that all of dark matter is composed of these particles.

The Chandra press release shared an interesting behind-the-scenes look into how science is shared and discussed among scientists:

Because of the tantalizing potential of these results, after submitting to The Astrophysical Journal the authors posted a copy of the paper to a publicly accessible database, arXiv. This forum allows scientists to examine a paper prior to its acceptance into a peer-reviewed journal. The paper ignited a flurry of activity, with 55 new papers having already cited this work, mostly involving theories discussing the emission line as possible evidence for dark matter. Some of the papers explore the sterile neutrino interpretation, but others suggest different types of candidate dark matter particles, such as the axion, may have been detected.

Only a week after Bulbul et al. placed their paper on the arXiv, a different group, led by Alexey Boyarsky of Leiden University in the Netherlands, placed a paper on the arXiv reporting evidence for an emission line at the same energy in XMM-Newton observations of the galaxy M31 and the outskirts of the Perseus cluster. This strengthens the evidence that the emission line is real and not an instrumental artifact.
Further reading:

Paper by Bulbul et al.

Chandra press release

ESA press release

Chandra blog

Tagged as:
Chandra,
Chandra X-ray Observatory,
Dark Matter,
X-ray astronomy,
x-rays,
XMM-Newton
Posted by Nelio Inacio at 8:54 AM 0 comments

Titan May be Older than Saturn, a New Study Suggests

Titan May be Older than Saturn, a New Study Suggests:



Titan's atmosphere makes Saturn's largest moon look like a fuzzy orange ball in this natural-color view from the Cassini spacecraft. Cassini captured this image in 2012. Image Credit: NASA/JPL-Caltech/Space Science Institute

Titan’s atmosphere makes Saturn’s largest moon look like a fuzzy orange ball. Image Credit: NASA / JPL-Caltech / Space Science Institute
It’s well accepted that moons form after planets. In fact, only a few months ago, astronomers spotted a new moon forming deep within Saturn’s rings, 4.5 billion years after the planet initially formed.

But new research suggests Saturn’s icy moon Titan — famous for its rivers and lakes of liquid methane — may have formed before its parent planet, contradicting the theory that Titan formed within the warm disk surrounding an infant Saturn.

A combined NASA and ESA-funded study has found firm evidence that the nitrogen in Titan’s atmosphere originated in conditions similar to the cold birthplace of the most ancient comets from the Oort cloud — a spherical shell of icy particles that enshrouds the Solar System.

The hint comes in the form of a ratio. All elements have a certain number of known isotopes — variants of that element with the same number of protons that differ in their number of neutrons. The ratio of one isotope to another isotope is a crucial diagnostic tool.

In planetary atmospheres and surface materials, the amount of one isotope relative to another isotope is closely tied to the conditions under which materials form. Any change in the ratio will allow scientists to deduce an age for that material.

Kathleen Mandt from the Southwest Research Institute in San Antonio and colleagues analyzed the ratio of nitrogen-14 (seven protons and seven neutrons) to nitrogen-15 (seven protons and eight neutrons) in Titan’s atmosphere.

“When we looked closely at how this ratio could evolve with time, we found that it was impossible for it to change significantly,” Mandt said in a press release. “Titan’s atmosphere contains so much nitrogen that no process can significantly modify this tracer even given more than four billion years of Solar System history.”

The team found that our Solar System is not old enough for this nitrogen isotope ratio to have changed as much as it has. By comparing the small change within this ratio, Mandt and colleagues found that it seemed more similar to Oort cloud comets than to Solar System bodies including planets and comets born in the Kuiper belt. The team is eager to see whether their findings are supported by data from ESA’s Rosetta mission, which will study comet 67P/Churyumov-Gerasimenko later this year.

Finally, the study also has implications for Earth. In the past, researchers assumed a connection between comets, Titan and Earth. But these results show that the nitrogen isotope ratio is different on Titan and Earth, suggesting the sources of Earth’s and Titan’s nitrogen must have been different.

It’s unclear whether Earth received nitrogen from early meteorites or if it was captured directly from the disk of gas that formed the Solar System.

“This exciting result is a key example of Cassini science informing our knowledge of the history of [the] Solar System and how Earth formed,” said Scott Edgington, Cassini deputy project scientist at NASA’s Jet Propulsion Laboratory.

The research was published this week in the Astrophysical Journal Letters.

Tagged as:
age of solar system,
Cassini,
Saturn,
Titan
Posted by Nelio Inacio at 8:53 AM 0 comments

The Place Where Earth from Space Looks Like a Floating Piece of Cardboard

The Place Where Earth from Space Looks Like a Floating Piece of Cardboard:



An image taken from the International Space Station taken on Jun 23, 2014 showing Western Sahara , near El Aaiun. Credit: Reid Wiseman/NASA.

An image taken from the International Space Station taken on Jun 23, 2014 showing Western Sahara , near El Aaiun. Credit: Reid Wiseman/NASA.
As we’ve noted before, astronaut Reid Wiseman is sending out a bevy of tweets and pictures from his perch on board the International Space Station, but this recent image got our attention.

“Can’t explain it, just looked oddly unnatural to me and I liked it,” Wiseman said on Twitter, leaving no info on what Earthly feature might be.

Floating cardboard? That’s what many people thought. Comments from Twitter:



So what is this image and where on Earth is it?
I checked with Peter Caltner, who regularly tweets information on astronaut photos and he said the image shows Western Sahara, near El Aaiun (coordinates 26.824071,-13.222504) and the straight white line is a conveyor belt facility from a phosphate mine at Bou Craa that goes to a loading port at the coast. The conveyer belt is about 60 miles/100 km long, Peter noted.

You can see more images of this feature in this Google search, but none of them have quite the angle Wiseman had, which gave it a box-like appearance from space.

See more comments about the image here.

Thanks again to Peter Caltner for his assistance!

Tagged as:
Earth,
Earth Observation,
International Space Station (ISS),
reid wiseman,
Western Sahara
Posted by Nelio Inacio at 8:53 AM 0 comments

Three Supermassive Black Holes Tango in a Distant Galaxy, Marking a Huge Discovery

Three Supermassive Black Holes Tango in a Distant Galaxy, Marking a Huge Discovery:



"Helical jets from one supermassive black hole caused by a very closely orbiting companion (see blue dots). The third black hole is part of the system, but farther away and therefore emits relatively straight jets." Credit: Roger Deane (large image); NASA Goddard (inset bottom left; modified from original)

In this trio, the two close-in supermassive black holes emit helical jets, whereas the third more distant black hole emits relatively straight jets. Image Credit: Roger Deane (large image) / NASA Goddard (inset bottom left)
In a galaxy four billion light-years away, three supermassive black holes are locked in a whirling embrace. It’s the tightest trio of black holes known to date and even suggests that these closely packed systems are more common than previously thought.

“What remains extraordinary to me is that these black holes, which are at the very extreme of Einstein’s Theory of General Relativity, are orbiting one another at 300 times the speed of sound on Earth,” said lead author Roger Deane from the University of Cape Town in a press release.

“Not only that, but using the combined signals from radio telescopes on four continents we are able to observe this exotic system one third of the way across the Universe. It gives me great excitement as this is just scratching the surface of a long list of discoveries that will be made possible with the Square Kilometer Array.”

The system, dubbed SDSS J150243.091111557.3, was first identified as a quasar — a supermassive black hole at the center of a galaxy, which is rapidly accreting material and shining brightly — four years ago. But its spectrum was slightly wacky with its doubly ionized oxygen emission line [OIII] split into two peaks instead of one.

A favorable explanation suggested there were two active supermassive black holes hiding in the galaxy’s core.

An active galaxy typically shows single-peaked narrow emission lines, which stem from a surrounding region of ionized gas, Deane told Universe Today. The fact that this active galaxy shows double-peaked emission lines, suggests there are two surrounding regions of ionized gas and therefore two active supermassive black holes.

But one of the supermassive black holes was enshrouded in dust. So Deane and colleagues dug a little further. They used a technique called Very Long Baseline Interferometry (VLBI), which is a means of linking telescopes together, combining signals separated by up to 10,000 km to see detail 50 times greater than the Hubble Space Telescope.

Observations from the European VLBI network — an array of European, Chinese, Russian, and South American antennas — revealed that the dust-covered supermassive black hole was once again two instead of one, making the system three supermassive black holes in total.

The VLBI network. Image Credit: Deane

The VLBI network. Image Credit: Roger Deane
“This is what was so surprising,” Deane told Universe Today. “Our aim was to confirm the two suspected black holes. We did not expect one of these was in fact two, which could only be revealed by the European VLBI Network due [to the] very fine detail it is able to discern.”

Deane and colleagues looked through six similar galaxies before finding their first trio. The fact that they found one so quickly suggests that they’re more common than previously thought.

Before today, only four triple black hole systems were known, with the closest pair being 2.4 kiloparsecs apart — roughly 2,000 times the distance from Earth to the nearest star, Proxima Centauri. But the closest pair in this trio is separated by only 140 parsecs — roughly 10 times that same distance.

Although Deane and colleagues relied on the phenomenal resolution of the VLBI technique in order to spatially separate the two close-in black holes, they also showed that their presence could be inferred from larger-scale features. The orbital motion of the black hole, for instance, is imprinted on its large jets, twisting them into a helical-like shape. This may provide smaller telescopes with a tool to find them with much greater efficiency.

“If the result holds up, it’ll be very cool,” binary supermassive black hole expert Jessie Runnoe from Pennsylvania State University told Universe Today. This research has multiple implications for understanding further phenomena.

The first sheds light on galaxy evolution. Two or three supermassive black holes are the smoking gun that the galaxy has merged with another. So by looking at these galaxies in detail, astronomers can understand how galaxies have evolved into their present-day shapes and sizes.

The second sheds light on a phenomenon known as gravitational radiation. Einstein’s General Theory of Relativity predicts that when one of the two or three supermassive black holes spirals inward, gravitational waves — ripples in the fabric of space-time itself — propagate out into space.

Future radio telescopes should be able to measure gravitational waves from such systems as their orbits decay.

“Further in the future, the Square Kilometer Array will allow us to find and study these systems in exquisite detail, and really allow us [to] gain a much better understanding of how black holes shape galaxies over the history of the Universe,” said coauthor Matt Jarvis from the Universities of Oxford and Western Cape.

The research was published today in the journal Nature.

Tagged as:
active galaxies,
Black Holes,
Gravitational Waves,
quasars,
VLBI
Posted by Nelio Inacio at 8:52 AM 0 comments

Beautiful Astrophotos: Crescent Moon and Venus Rising

Beautiful Astrophotos: Crescent Moon and Venus Rising:



The waning crescent Moon below Venus, rising in the east on June 24, 2014 as seen from home over the flat prairie horizon of southern Alberta, Canada. Credit and copyright: Alan Dyer.

The waning crescent Moon below Venus, rising in the east on June 24, 2014 as seen from home over the flat prairie horizon of southern Alberta, Canada. Credit and copyright: Alan Dyer.
Did you see the crescent Moon near a bright star on Tuesday morning this week? Many of our Flickr group astrophotographers captured gorgeous shots of the two together in the sky, including this eye-candy image from Alan Dyer from Canada. Just take a look!

A beautiful conjunction between the Moon, the very bright planet Venus, and the easily recognizable open star cluster of the Pleiades from central Italy on the morning of June 24, 2014. Credit and copyright: Giuseppe Petricca.

A beautiful conjunction between the Moon, the very bright planet Venus, and the easily recognizable open star cluster of the Pleiades from central Italy on the morning of June 24, 2014. Credit and copyright: Giuseppe Petricca.
The waning crescent Moon and Venus as seen from the UK on June 24, 2014. Credit and copyright: Sculptor Lil on Flickr.

The waning crescent Moon and Venus as seen from the UK on June 24, 2014. Credit and copyright: Sculptor Lil on Flickr.
Moon and Venus Conjunction approximately 1 hour before sunrise on 24th June 2014. Looking east over central London with Canary Wharf on the horizon. Credit and copyright: Roger Hutchinson.

Moon and Venus Conjunction approximately 1 hour before sunrise on 24th June 2014. Looking east over central London with Canary Wharf on the horizon. Credit and copyright: Roger Hutchinson.
Venus and Waning Crescent Moon on June 24, 2014. Credit and copyright: Stephen Rahn.

Venus and Waning Crescent Moon on June 24, 2014. Credit and copyright: Stephen Rahn.
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.

Tagged as:
Astrophotos,
Moon,
Venus
Posted by Nelio Inacio at 8:52 AM 0 comments

Nearby Super-Earth is Best Habitable Candidate So Far, Astronomers Say

Nearby Super-Earth is Best Habitable Candidate So Far, Astronomers Say:



rtistic representation of the potentially habitable Super-Earth Gliese 832 c against a stellar nebula background. Credit: Planetary Habitability Laboratory at the University of Puerto Rico, Arecibo, NASA/Hubble, Stellarium.

rtistic representation of the potentially habitable Super-Earth Gliese 832 c against a stellar nebula background. Credit: Planetary Habitability Laboratory at the University of Puerto Rico, Arecibo, NASA/Hubble, Stellarium.
On a clear night, you might be able to spot the red dwarf star Gliese 832 through a backyard telescope, as it is just 16 light years away. Today, astronomers announced the discovery of super-Earth planet orbiting this nearby star and say it might be the best candidate yet for habitable world.



Gliese 832c was spotted by an international team of astronomers, led by Robert A. Wittenmyer from UNSW Australia. They used high-precision radial-velocity data from HARPS-TERRA, the Planet Finder Spectrograph and the UCLES echelle spectrograph. This star is already known to have one additional planet, a cold Jupiter-like planet, Gliese 832 b, discovered in 2009.

Orbital analysis of Gliese 832 c, a potentially habitable world around the nearby red-dwarf star Gliese 832. Gliese 832 c orbits near the inner edge of the conservative habitable zone. Its average equilibrium temperature (253 K) is similar to Earth (255 K) but with large shifts (up to 25K) due to its high eccentricity (assuming a similar 0.3 albedo). Credit: Planetary Habitability Laboratory.

Orbital analysis of Gliese 832 c, a potentially habitable world around the nearby red-dwarf star Gliese 832. Gliese 832 c orbits near the inner edge of the conservative habitable zone. Its average equilibrium temperature (253 K) is similar to Earth (255 K) but with large shifts (up to 25K) due to its high eccentricity (assuming a similar 0.3 albedo). Credit: Planetary Habitability Laboratory.
Since red dwarf stars shine dimly, the habitable zones around these stars would be very close in. Gliese 832c complies with an orbital period of 36 days (it’s orbital companion Gliese 832 b orbits the star in 9.4 years.)

The newly found super-Earth has a mass at least five times that of Earth’s and the astronomers estimate it receives about the same average energy as Earth does from the Sun. “The planet might have Earth-like temperatures, albeit with large seasonal shifts, given a similar terrestrial atmosphere,” says a press release from the Planetary Habitability Laboratory. “A denser atmosphere, something expected for Super-Earths, could easily make this planet too hot for life and a ‘Super-Venus’ instead.”

Using the Earth Similarity Index (ESI) — a measure of how physically similar a planetary mass object is to Earth, where 1 equals the same qualities as Earth — Gliese 832 c has an ESI of 0.81. This is comparable to Gliese 667C c (ESI = 0.84) and Kepler-62 e (ESI = 0.83).

“This makes Gliese 832c one of the top three most Earth-like planets according to the ESI (i.e. with respect to Earth’s stellar flux and mass) and the closest one to Earth of all three, a prime object for follow-up observations. However, other unknowns such as the bulk composition and atmosphere of the planet could make this world quite different to Earth and non-habitable.”

Artistic representation of the potentially habitable exoplanet Gliese 832 c as compared with Earth. Gliese 832 c is represented here as a temperate world covered in clouds. The relative size of the planet in the figure assumes a rocky composition but could be larger for a ice/gas composition. Credit: Planetary Habitability Laboratory.

Artistic representation of the potentially habitable exoplanet Gliese 832 c as compared with Earth. Gliese 832 c is represented here as a temperate world covered in clouds. The relative size of the planet in the figure assumes a rocky composition but could be larger for a ice/gas composition. Credit: Planetary Habitability Laboratory.
In their paper, Wittenmyer and his colleagues noted that while Solar Systems like our own appear — so far — to be rare, the Gliese 832 system is like a scaled-down version of our own Solar System, with an inner potentially Earth-like planet and an outer Jupiter-like giant planet. They added that the giant outer planet may have played a similar dynamical role in the Gliese 832 system to that played by Jupiter in our Solar System.

Certainly, astronomers will be attempting to observe this system further to see if any additional planets can be found.

If you’re interested in trying to see this star, here’s our guide on red dwarf stars that are visible in backyard telescopes.

Tagged as:
exoplanets,
Extra Solar Planets,
Gliese 823c
Posted by Nelio Inacio at 8:51 AM 0 comments

The Making of the Pillars of Creation

The Making of the Pillars of Creation:



Credit:

The classic view of the Pillars of Creation as viewed by the Hubble Space Telescope in 1995. Credit: NASA/ESA/STScl/P. Scowen and J. Hester (Arizona State University).
It’s one of the most iconic images of the modern Space Age. In 1995, the Hubble Space Telescope team released an image of towering columns of gas and dust that contained newborn stars in the midst of formation. Dubbed the “Pillars of Creation,” these light-years long tendrils captivated the public imagination and now grace everything from screensavers to coffee mugs. This is a cosmic portrait of our possible past, and the essence of the universe giving birth to new stars and worlds in action.

Now, a study out on Thursday from the 2014 National Astronomy Meeting of the Royal Astronomical Society has shed new light on just how these pillars may have formed. The announcement comes out of Cardiff University, where astronomer Scott Balfour has run computer simulations that closely model the evolution and the outcome of what’s been observed by the Hubble Space Telescope.

The ‘Pillars’ lie in the Eagle Nebula, also known as Messier 16 (M16), which is situated in the constellation Serpens about 7,000 light years distant.  The pillars themselves have formed as intense radiation from young massive stars just beginning to shine erode and sculpt the immense columns.

The location of Messier 16 and the Pillars of Creation in the night sky. Credit: Stellarium.

The location of Messier 16 and the Pillars of Creation in the night sky. Credit: Stellarium.
But as is often the case in early stellar evolution, having massive siblings nearby is bad news for fledgling stars. Such large stars are of the O-type variety, and are more than 16 times as massive as our own Sun. Alnitak in Orion’s belt and the stars of the Trapezium in the Orion Nebula are examples of large O-type stars that can be found in the night sky. But such stars have a “burn fast and die young” credo when it comes to their take on nuclear fusion, spending mere millions of years along the Main Sequence of the Hertzsprung Russell diagram before promptly going supernova. Contrast this with a main sequence life expectancy of 10 billion years for our Sun, and life spans measured in the trillions of years — longer than the current age of the universe — for tiny red dwarf stars. The larger a star you are, the shorter your life span.

Credit:

A capture from the simulation, showing a cross-section 25 by 25 light years square and 0.2 light years thick. The simulation shows how the O-type star “sculpts” its surroundings over the span of 1.6 million years, carving out, in some cases, the famous “pillars”. Credit: S. Balfour/ University of Cardiff.
Such O-Type stars also have surface temperatures at a scorching 30,000 degrees Celsius, contrasted with a relatively ‘chilly’ 5,500 degree Celsius surface temperature for our Sun.

This also results in a prodigious output in energetic ultraviolet radiation by O-type stars, along with a blustery solar wind. This carves out massive bubbles in a typical stellar nursery, and while it may be bad news for planets and stars attempting to form nearby any such tempestuous stars, this wind can also compress and energize colder regions of gas and dust farther out and serve to trigger another round of star formation. Ironically, such stars are thus “cradle robbers” when it comes to potential stellar and planetary formation AND promoters of new star birth.

In his study, Scott looked at the way gas and dust would form in a typical proto-solar nebula over the span of 1.6 million years. Running the simulation over the span of several weeks, the model started with a massive O-type star that formed out of an initial collapsing smooth cloud of gas.

That’s not bad, a simulation where 1 week equals a few hundred million years…

As expected, said massive star did indeed carve out a spherical bubble given the initial conditions. But Scott also found something special: the interactions of the stellar winds with the local gas was much more complex than anticipated, with three basic results: either the bubble continued to expand unimpeded, the front would expand, contract slightly and then become a stationary barrier, or finally, it would expand and then eventually collapse back in on itself back to the source.



The study was notable because it’s only in the second circumstance that the situation is favorable for a new round of star formation that is seen in the Pillars of Creation.

“If I’m right, it means that O-type and other massive stars play a much more complex role than we previously thought in nursing a new generation of stellar siblings to life,” Scott said in a recent press release. “The model neatly produces exactly the same kind of structures seen by astronomers in the classic 1995 image, vindicating the idea that giant O-type stars have a major effect in sculpting their surroundings.”

Such visions as the Pillars of Creation give us a snapshot of a specific stage in stellar evolution and give us a chance to study what we may have looked like, just over four billion years ago. And as simulations such as those announced in this week’s study become more refined, we’ll be able to use them as a predictor and offer a prognosis for a prospective stellar nebula and gain further insight into the secret early lives of stars.

Tagged as:
eagle nebula,
Hubble,
Messier 16,
O-type stars,
Pillars of Creation,
star formation
Posted by Nelio Inacio at 8:51 AM 0 comments

Ceres and Vesta Converge in the Sky on July 5: How to See It

Ceres and Vesta Converge in the Sky on July 5: How to See It:



Ceres and Vesta are converging in Virgo not far from Mars and Spica. On July 5, the duo will be just 10' apart and visible in the high power telescope field of view. Positions are shown every 5 days for 10 p.m. EDT and stars to magnitude +8.5. Created with Chris Marriott's SkyMap software

Ceres and Vesta are converging in Virgo not far from Mars and Spica. On July 5, the duo will be just 10′ apart and visible in the high power telescope field of view. Positions are shown every 5 days for 10 p.m. EDT and stars to magnitude +8.5. Created with Chris Marriott’s SkyMap software
I bet you’ve forgotten. I almost did. In April, we reported that Ceres and Vesta, the largest and brightest asteroids respectively, were speeding through Virgo in tandem. Since then both have faded, but the best is yet to come. Converging closer by the day, on July 5, the two will make rare close pass of each other when they’ll be separated by just 10 minutes of arc or the thickness of a fat crescent moon.

Vesta (left) and Ceres. Vesta was photographed up close by the Dawn spacecraft from July 2011-Sept. 2012, while the best views we have to date of Ceres come from the Hubble Space Telescope. The bright white spot is still a mystery. Credit: NASA

Vesta (left) and Ceres. Vesta was photographed up close by the Dawn spacecraft from July 2011-Sept. 2012, while the best views we have to date of Ceres come from the Hubble Space Telescope. The bright white spot is still a mystery. NASA will plunk Dawn into orbit around Ceres next February.  Credit: NASA
Both asteroids are still within range of ordinary 35mm and larger binoculars; Vesta is easy at magnitude +7 while Ceres still manages a respectable +8.3. From an outer suburban or rural site, you can watch them draw together in the coming two weeks as if on a collision course. They won’t crash anytime soon. We merely see the two bodies along the same line of sight. Vesta’s closer to Earth at 164 million miles (264 million km) and moves more quickly across the sky compared to Ceres, which orbits 51 million miles (82 million km) farther out.

Ceres and Vesta are happily near an easy naked eye star, Zeta Virginis, which forms an isosceles triangle right now with Mars and Spica. The map shows the sky around 10 p.m. local time facing southwest. Stellarium

Ceres and Vesta lie near an easy naked eye star, Zeta Virginis, which forms an isosceles triangle right now with Mars and Spica. The map shows the sky around 10 p.m. local time tonight facing southwest. Stellarium
Right now the two asteroids are little more than a moon diameter apart not far from the 3rd magnitude star Zeta Virginis. Happily, nearby Mars and Spica make excellent guides for finding Zeta. Once you’re there, use binoculars and the more detailed map to track down Ceres and Vesta.

Virgo will be busy Saturday night July 5, 2014 when the waxing moon is in close conjunction with Mars with Ceres and Vesta at their closest. Stellarium

Virgo will be busy Saturday night July 5, 2014 when the waxing moon passes about 1/2 degree from Mars as Ceres and Vesta squeeze closest.  Stellarium
In early July they’ll look like a wide double star in binoculars and easily fit in the same high power telescopic view. Vesta has always looked pale yellow to my eye. Will its color differ from Ceres? Sitting side by side it will be easier than ever to compare them. Vesta is a stony asteroid with a surface composed of solidified (and meteoroid-battered) lavas; Ceres is darker and covered with a mix of water ice and carbonaceous materials.

On the night of closest approach, it may be difficult to spot dimmer Ceres in binoculars. By coincidence, the 8-day-old moon will be very close to the planet Mars and brighten up the neighborhood. We’ll report more on that event in a future article.

With so much happening the evening of July 5, let’s hope for a good round of clear skies.

Tagged as:
asteroid,
ceres,
vesta
Posted by Nelio Inacio at 8:50 AM 0 comments

Nature & Man in One Astrophoto: Iridium Flare, Milky Way, Clouds and Light Pollution

Nature & Man in One Astrophoto: Iridium Flare, Milky Way, Clouds and Light Pollution:



An Iridium Flare flashes over western Maine in this beautiful night sky image from June 2014. Credit and copyright: Mike Taylor/Taylor Photography.

An Iridium Flare flashes over western Maine in this beautiful night sky image from June 2014. Credit and copyright: Mike Taylor/Taylor Photography.
Ever seen a flash in the night sky and wondered if you were seeing things? Iridium flares are often mistaken for meteors because of their notable bright flashes of light in the night sky but they are actually caused by a specific group of satellites that orbit our planet. The Iridium communication satellites are just in the right orbit that when sunlight reflects on their antennas, a flash — or flare — is visible down on Earth. There are currently about 66 Iridium satellites in orbit, so flares are a rather common occurrence.

This image from photographer Mike Taylor is one frame from a timelapse of the Milky Way and other features of the night sky in motion against a silhouetted foreground. “Photographed from western Maine, this shot includes quite a bit of light pollution and some fast moving cloud cover,” Mike told Universe Today via email. “Most of the light pollution in this image is coming from Farmington, Maine which is about 35 miles from this location.”



Mike added the footage from this timelapse will be featured in his upcoming short film “Shot In The Dark.”

He also provided this info about Iridium flares:

Iridium satellites are in near-polar orbits at an altitude of 485 miles. Their orbital period is approximately 100 minutes with a velocity of 16,800 miles per hour. The uniqueness of Iridium flares is that the spacecraft emits ‘flashes’ of very bright reflected light that sweep in narrow focused paths across the surface of the Earth. An Iridium communication satellite’s Main Mission Antenna is a silver-coated Teflon antenna array that mimics near-perfect mirrors and are angled at 40-degrees away from the axis of the body of the satellites. This can provide a specular reflection of the Sun’s disk, periodically causing a dazzling glint of reflected sunlight. At the Earth’s surface, the specular reflection is probably less than 50 miles wide, so each flare can only be viewed from a fairly small area. The flare duration can last from anywhere between 5 to 20 seconds and can easily be seen by the naked eye.
If you want to try and see an Iridum flare for yourself, check out Heavens Above for your location.

For this image Mike used:

Nikon D600 & 14-24 @ 14mm

f/2.8 – 30 secs – ISO 3200 – WB Kelvin 3570

06/23/14 – 11:07PM

Processed via Lightroom 5 & Photoshop CS5

Check out more of Mike’s work at his website: Taylor Photography. He also leads workshops on night sky photography.

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.

Tagged as:
Astrophotos,
Iridium Flare,
milky way
Posted by Nelio Inacio at 8:50 AM 0 comments

Why is Everything Spherical?

Why is Everything Spherical?:





Have you ever noticed that everything in space is a sphere? The Sun, the Earth, the Moon and the other planets and their moons… all spheres. Except for the stuff which isn’t spheres. What’s going on?



Have you noticed that a good portion of things in space are shaped like a sphere? Stars, planets, and moons are all spherical.

Why? It all comes down to gravity. All the atoms in an object pull towards a common center of gravity, and they’re resisted outwards by whatever force is holding them apart. The final result could be a sphere… but not always, as we’re about to learn.

Consider a glass of water. If you could see the individual molecules jostling around, you’d see them trying to fit in as snugly as they can, tension making the top of the water smooth and even.

Artist's impression of the planets in our solar system, along with the Sun (at bottom). Credit: NASA

Artist’s impression of the planets in our solar system, along with the Sun (at bottom). Credit: NASA
Imagine a planet made entirely of water. If there were no winds, it would be perfectly smooth. The water molecules on the north pole are pulling towards the molecules on the south pole. The ones on the left are pulling towards the right. With all points pulling towards the center of the mass you would get a perfect sphere.

Gravity and surface tension pull it in, and molecular forces are pushing it outward. If you could hold this massive water droplet in an environment where it would remain undisturbed, eventually the water would reach a perfect balance. This is known as “hydrostatic equilibrium”.

Stars, planets and moons can be made of gas, ice or rock. Get enough mass in one area, and it’s going to pull all that stuff into a roughly spherical shape. Less massive objects, such as asteroids, comets, and smaller moons have less gravity, so they may not pull into perfect spheres.

UT Jupiter Oval BA Chris Go

Jupiter Credit: Christopher Go
As you know, most of the celestial bodies we’ve mentioned rotate on an axis, and guess what, those ones aren’t actually spheres either. The rapid rotation flattens out the middle, and makes them wider across the equator than from pole to pole. Earth is perfect example of this, and we call its shape an oblate spheroid.

Jupiter is even more flattened because it spins more rapidly. A day on Jupiter is a short 9.9 hours long. Which leaves it a distorted imperfect sphere at 71,500 km across the equator and just 66,900 from pole to pole.

Stars are similar. Our Sun rotates slowly, so it’s almost a perfect sphere, but there are stars out there that spin very, very quickly. VFTS 102, a giant star in the Tarantula nebula is spinning 100 times faster than the Sun. Any faster and it would tear itself apart from centripetal forces.

This oblate spheroid shape helps indicate why there are lots of flattened disks out there. This rapid spinning, where centripetal forces overcome gravitational attraction that creates this shape. You can see it in black hole accretion disks, solar systems, and galaxies.

Objects tend to form into spheres. If they’re massive enough, they’ll overcome the forces preventing it. But… if they’re spinning rapidly enough, they’ll flatten out all the way into disks.

Podcast (audio): Download (Duration: 3:56 — 3.6MB)


Podcast (video): Download (88.2MB)


Tagged as:
Earth,
galaxies,
Jupiter,
solar systems,
spheres,
stars,
sun
Posted by Nelio Inacio at 8:49 AM 0 comments
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