Boomerang Nebula Even Colder than the Afterglow of the Big Bang

The far-off Boomerang Nebula in the constellation of Centaurus has earned the title of theUniverse’s Coldest Place. Yes, this planetary nebula is colder than the dark side of the moon, Buffalo, New York in January, and even your cheating girlfriend or boyfriend’s heart, registering in at a staggering one degree Kelvin. In Fahrenheit, that’s a minus 458 degrees. That’s believed to be even colder than the Big Bang’s afterglow.

Located in the constellation Centaurus, some 5,000 light-years distant, the Boomerang Nebula resembles, in some of photos of it, a glowing Halloween ghost. Astronomers have known about it for some time, though they have recently learned much more about the Boomerang Nebula through photos they’ve seen using ALMA, the Atacma Large Millimeter/submillimeter Array telescope.  

The Boomerang Nebula’s twin lobes may be an illusion

The twin lobes we see in NASA’s Hubble telescope photo of the somewhat bow tie-shaped Boomerang Nebula may be an illusion, a trick of the light, a bit of cosmic legerdemain. It’s what we see “at visible wavelengths,” according to NatMonitor.com.

The ultra-cold planetary nebula’s twin lobed shape is why some imaginative scientist decided that it resembled a boomerang more than a bow tie, and it’s how the space object ended up with a cooler-sounding name.

However, the shape we see in photos of it is not its actual shape.According to a researcher at NASA’s Jet Propulsion Laboratory, and lead author of a study about the Boomerang Nebula, Raghvendra Sahai, its real shape is “a much broader structure that is expanding rapidly into space.”

What is a “planetary nebula”?

Stars like our sun eventually become planetary nebulae at the end of their lives as stars. They shed their outer layers until only a white dwarf star remains. The white dwarf star gives off ultraviolet radiation. This, in turn, creates a colorful display by making the gas in the nebula radiate light and glow.

Currently, the Boomerang Nebula is a pre-planetary one, which means it’s not yet to the stage where it’s white dwarf star is hot enough to make the gases it emits glow even more. It will get even more colorful with time. It was detected due to the reflection of starlight off of its dust grains.

How were astronomers able to measure the coldness of the Boomerang Nebula?

The rate at which the white dwarf star at the center of the Boomerang Nebula is discharging gas is growing rapidly. As this is occurring, the space object is also cooling down.

The astronomers figured out how cold the Boomerang Nebula was by studying the speed at which it absorbed background microwave radiation, which is, itself, extremely cold. In Fahrenheit, it registers in at minus 455 degrees.

In 2003, using Hubble, astronomers saw a version of what the Boomerang Nebula looks like, according to Sahai, that was what appeared to be what they’d seen many times before, when they’d examined planetary nebulae. It resembled “a very classic ‘hourglass’ shape,” he said.

In the photographs taken by NASA’s Hubble telescope, the Boomerang Nebula’s narrow waist was not clearly apparent. Then, the Boomerang Nebula seemed to be giving off an outflow of material which was nearly spherical in shape.

With the ALMA telescope, the astronomers were able to determine more about the Boomerang Nebula. They detected the double-lobe structure of the Hubble photograph, but it was only in the Boomerang Nebula’s inner regions. As they analyzed the carbon monoxide particles that the Boomerang emitted, the astronomers noticed that further out, there was an almost round cloud of the cold gas.

Also, a thick lane of millimeter-sized dust particles encircled the dwarf white star at the center of the Boomerang Nebula. The particles of dust mask a portion of the dwarf white star and the light reflected off of the particles, which flow off in opposite directions, makes the space object appear to look like an hourglass.

According to Sahai, using ALMA helped his research team “to shed new light on the death throes of a Sun-like star.” ALMA also enabled them to discover that it was the coldest known place yet discovered, and is possibly even colder than the afterglow of the Big Bang. The findings of the study have been published in Astrophysical Journal.

Written by: Douglas Cobb

From Mars With Love...

First, Mars seemed to be greeting Mars Global Surveyor (MGS) with a Happy Face. Now, it seems as if the planet is sending its love with the this picture from MGS's Mars Orbiter Camera (MOC).

This valentine from Mars is actually a pit formed by collapse within a straight-walled trough known in geological terms as a graben. Graben are formed along fault lines by expansion of the bedrock terrain. The heart-shaped pit is about 2.3 kilometers (1.4 miles) at its widest. The image was targeted by the MOC team in order to examine the relationship between a lava flow and the graben and pits that disrupted and cut across the flow. The graben, pit, and lava flow are located on the east flank of the Alba Patera volcano in northern Tharsis. The MOC images are illuminated from the left.

"We Will Send Robots to Read the Genomes of Alien Life Forms and Replicate Them Back on Earth"- Craig Venter

In 2010, Craig Venter, who helped map the human genome, became the first to successfully create “synthetic life,” using chemicals and inserting DNA into the cell of a bacteria —putting humankind at the threshold of the most important and exciting phase of biological research, one that will enable us to actually write the genetic code for designing new species to help us adapt and evolve for long-term survival.

Venter, the scientist famed for his role in sequencing the human genome, has answered a question that lies at the heart of biology: “What is life?” Life, he asserts, is wholly reducible to the “DNA machines” and “protein robots” that operate within cells, and he hopes to prove it by constructing organisms entirely from scratch, detailing an ambitious vision for a future in which custom-made organisms heal the planet, unlock life's origins and extend humanity's reach beyond Earth in his new book, Life at the Speed of Light: From the Double Helix to the Dawn of Digital Life.

Venter believes scientists will soon be designing basic organisms to include features useful in farming or medicine, as well as sending robots into space to read the sequence of alien life forms and replicate them back on Earth: “In years to come it will be increasingly possible to create a wide variety of [synthetic] cells from computer-designed software. The creation of cells from scratch will open up extraordinary possibilities.”

Venter predicts in the future machines will be able to analyse the make up of genomes and transmit this through the internet or even space, creating more possibilities in the search for alien life: “The day is not far off when we will be able to send a robotically controlled genome sequencing unit to other planets to read the DNA sequence of any alien microbe life that may be there. If we can . . . beam them back to Earth we should be able to reconstruct their genomes. The synthetic version of a Martian genome could then be used to recreate Martian life on Earth.”

Spitzer Gets A New Mission – Hunting For Exoplanets

Image Caption: Over its ten years in space, NASA's Spitzer Space Telescope has evolved into a premier tool for studying exoplanets. The engineers and scientists behind Spitzer did not have this goal in mind when they designed the observatory back in the 1990s. But thanks to its extraordinary stability, and a series of engineering reworks after launch, Spitzer now has observational powers far beyond its original limits and expectations. Credit: NASA/JPL-Caltech

Brett Smith for redOrbit.com – Your Universe Online

After 10 years of orbiting the sun, the Spitzer Space Telescope is now playing a completely different role than it was a decade ago – hunting for exoplanets outside the solar system.

“When Spitzer launched back in 2003, the idea that we would use it to study exoplanets was so crazy that no one considered it,” said Sean Carey of NASA’s Spitzer Science Center  in a statement. “But now the exoplanet science work has become a cornerstone of what we do with the telescope.”

NASA scientists use Spitzer’s capacity for seeing the universe in the infrared spectrum to scan the cosmos for exoplanets, or planets that orbit a star other than our Sun. When an exoplanet passes in front of its star in a process known as transiting, it obstructs a fraction of starlight reaching the telescope. These tiny eclipses can be used to reveal the size of an alien planet.

Thanks to some innovative thinking during the design stage, Spitzer has been able to continue operating far beyond its initial mission. The telescope was outfitted with enough coolant to maintain its three temperature-sensitive instruments for at least two-and-a-half years, however, the coolant actually ended up lasting over five years.

In addition to extending the life of its coolant, Spitzer also has a passive cooling system built in that kept one set of infrared cameras operational at a super-low operational temperature of minus 407 degrees Fahrenheit – just 29 degrees above absolute zero.

To transition the telescope into an exoplanet spotter demanded some in-flight adjustments, however. Despite the telescope’s stability as it orbits the sun, a small “wobbling” was occurring as it pointed at target stars. The cameras also showed small brightness changes when a star drifted slightly across one of the camera’s individual pixels. These two issues combined to make the sensitive task of recording accurate exoplanet transits that much more difficult.

To solve these problems, NASA engineers first had to find the source of the wobble – and they did: a heater that kicks on to keep Spitzer’s battery at a certain temperature. In October 2010, the engineers decided that the heater did not need to be cycled through its full hour and temperature range, cutting the telescope’s wobble in half.

In September 2011, the NASA engineers then solved their pixel problem by repurposing Spitzer’s Pointing Control Reference Sensor “Peak-Up” camera. This camera was used to collect infrared light precisely into a spectrometer and to calibrate the telescope’s star-trackers, which help direct the observatory. Knowing it would allow for the placement of observed stars precisely on the center of a camera pixel, the NASA engineers applied the Peak-Up to the infrared camera observations.

The scientists took their use of the Peak-Up camera a step further by carefully “mapping” the idiosyncrasies of a single pixel within the camera. They were eventually able to finely target 90 percent Spitzer’s exoplanet observations down to a particular quarter of a pixel.

“We can use the Peak-Up camera to position ourselves very precisely on the camera and put light right on the best part of a pixel,” said Carey. “So you put the light on the sweet spot and just let Spitzer stare.” These three in-flight tweaks have more than doubled the telescope’s steadiness and targeting, giving Spitzer superb sensitivity when it comes to capturing exoplanet measurements.

“Because of these engineering modifications, Spitzer has been transformed into an exoplanet-studying telescope,” said Carey. “We expect plenty of great exoplanetary science to come from Spitzer in the future.”

Source: Brett Smith for redOrbit.com - Your Universe Online

Aliens may have lived on Earth-like planet - before an asteroid apocalypse

Shredded remains of a watery asteroid suggest that hundreds of millions of years ago planetary system may have harboured Earth-like planets

Apocalypse wow: Artist's impression of the shattered remains of an asteroid

Evidence of an apocalypse in a planetary system similar to our own has been uncovered by astronomers studying a dying star.
The shredded remains of a watery asteroid suggest that hundreds of millions of years ago the system may have harboured Earth-like habitable planets.
But any intelligent beings living there must have departed - assuming they had mastered space travel - or been killed off as their sun blew up and then collapsed into a "white dwarf".
Scientists believe six billion years from now, alien astronomers studying the burned out remains of our Sun may come to the same conclusion.
Like the white dwarf GD 61, the Sun is destined to end its life by first expanding into a Red Giant then shedding its outer layers and contracting into a super-dense glowing ember just a few thousand miles in diameter.
The dying Sun will radiate what is left of its heat over billions of years before finishing its life as a dead, cold, "black dwarf".
Astronomers studying the light emitted by GD 61, located 150 light years away from the Earth, detected an abundance of "rocky" elements such as magnesium, silicon and iron.
They also found oxygen in quantities that indicated a very large amount of water.
Only a water-rich massive asteroid, or minor planet, can explain the observations, say the scientists.
The giant rock, at least 90 kilometres in diameter, would have been drawn in by the white dwarf's powerful gravity and ripped apart.
If such an asteroid existed in the system, it is highly likely that rocky, water-covered, Earth-like planets did too.
Since only 0.02% of the Earth's mass consists of water, the oceans that cover its surface were probably delivered by impacts from watery asteroids and comets.

 
Dr Jay Farihi, from the Institute of Astronomy at Cambridge University, said: "The finding of water in a large asteroid means the building blocks of habitable planets existed - and maybe still exist - in the GD 61 system, and likely also around substantial number of similar parent stars.
"These water-rich building blocks, and the terrestrial planets they build, may in fact be common - a system cannot create things as big as asteroids and avoid building planets, and GD 61 had the ingredients to deliver lots of water to their surfaces.
"Our results demonstrate that there was definitely potential for habitable planets in this exoplanetary system."
The research appears in the latest issue of the journal Science.
Asteroids are essentially the building blocks of rocky planets. Water would have accounted for more than a quarter of the mass of the one believed to have orbited GD 61.
In our own Solar System, the giant asteroid Ceres contains a similar proportion of water in the form of subsurface ice.
The tell-tale excess oxygen in the dust and debris surrounding GD 61 was detected using powerful spectrograph techniques that look for chemical signatures in light.
Astronomers made the observations using the Hubble Space Telescope and the large Keck telescope on Hawaii.
"This oxygen excess can be carried by either water or carbon, and in this star there is virtually no carbon - indicating there must have been substantial water," said co-author Professor Boris Gansicke, from the University of Warwick.
"This also rules out comets, which are rich in both water and carbon compounds, so we knew we were looking at a rocky asteroid with substantial water content."
In its heyday, before becoming a white dwarf around 200 million years ago, the star had about three times the mass of the Sun.
The astronomers believe giant planets, such as Jupiter and Saturn, may still survive in the outer reaches of the system.
Their gravity probably upset the asteroid's orbit and nudged it close enough to the white dwarf to be shredded.
"This supports the idea that the star originally had a full complement of terrestrial planets, and probably gas giant planets orbiting it - a complex system similar to our own," said Dr Farihi.
Water buried under the asteroid's surface may have survived the expansion phase of the dying star, the scientists believe.

Love you Pluto!

                                                

Although billions of kilometers from the sun, frigid Pluto has an Earthly air: an atmosphere made mostly of nitrogen, the same gas that constitutes 78 percent of the air we breathe. But Pluto pursues such an elliptical orbit around the sun that all of that gas might freeze onto its surface when farthest and coldest. On May 4, however, Pluto passed in front of a star in the constellation Sagittarius, allowing observers to watch the atmosphere block some of the star's light and deduce that the air is so substantial it never disappears.

That passage was key to understanding the atmosphere's future, says Catherine Olkin, a planetary scientist at the Southwest Research Institute in Boulder, Colo., whose team tracked the so-called occultation. In work submitted to Icarus she and her colleagues report that Pluto's atmosphere is now thicker than ever before seen.

Astronomers discovered the atmosphere in 1988, when Pluto occulted another star. An airless Pluto would have cut off the star's light abruptly, but instead the starlight faded gradually, revealing air with roughly one one-hundred-thousandth the surface pressure of our own—equivalent to the terrestrial atmosphere 80 kilometers high.

Pluto is so distant that completing a single orbit takes it 248 years. Pluto came closest to the sun in 1989 and has been receding from the star ever since. When Pluto ventures out to its most distant point, in 2113, it will be 3 billion kilometers farther, and sunlight on its surface will be 36 percent weaker, than in 1989. "Many scientists have predicted that Pluto's atmosphere would collapse as it traveled away from the sun," Olkin says. "Receiving less sunlight, the gas would condense onto the surface."Mars, whose orbit is also rather elliptical, temporarily loses a quarter of its air every time its southern hemisphere experiences winter, when Martian gas freezes onto the south polar cap.

Pluto is mostly rock, but its crust consists of water ice. At Pluto's temperature of approximately 40 kelvins (–233 Celsius), water is as hard as rock, constituting a stage on which nitrogen and also methane dance back and forth between ice and gas.

The new observations indicate that Pluto's air is now three times denser than in 1988, contradicting models that predicted the atmosphere would someday vanish. Instead, Olkin says, the higher pressure accords with a model indicating that the region around a hundred meters below the surface retains heat during Pluto's close encounters with the sun and releases that heat only slowly, thereby keeping the surface warm enough so that some of the nitrogen always stays gaseous. "As Pluto goes around the sun, its atmosphere does not completely condense," Olkin says. Her work implies that Pluto's water-ice layer is compact, because a porous subsurface would quickly lose its warmth.

"It's a nice piece of work," says John Stansberry, a planetary scientist at the Space Telescope Science Institute. "These kinds of observations are critical for studying seasonal evolution on Pluto." Stansberry worries, however, that Pluto is more complex than the model assumes, which means the atmosphere's behavior is less clear than Olkin asserts. "Based on these results, it's certainly fair to say that Pluto's atmosphere is not going to collapse any time soon, but to say it's going to be there in 2140 is maybe stretching it a bit," Stansberry says.

Both Olkin and Stansberry do agree on a far more famous controversy: Pluto is a planet. In 2005 astronomers discovered Eris, a distant world proclaimed to be larger than Pluto, adding to arguments that Pluto should lose its planetary status and prompting predictions that a plethora of worlds surpassing Pluto in size awaited discovery.

But things didn't work out that way. In 2010 Eris passed in front of a star and failed to live up to the hype. The short duration of the occultation revealed Eris to be just 2,326 kilometers across—versus about 2,350 kilometers for Pluto. And no one has ever found anything else orbiting the sun beyond Neptune's path exceeding Pluto’s size.

Pluto's diameter, however, is uncertain: It could be as small as 2,300 kilometers or as large as 2,400 kilometers. Ironically, the villain is the atmosphere, which bends starlight during occultations and complicates measurements of its diameter.

Fortunately, help is on the way. In July 2015 NASA's New Horizons spacecraft will sail past Pluto and its five known moons. "I'm not sure what we'll see, but I can't wait to get there," Olkin says. "It's going to revolutionize our view."

Mars Crater May Actually Be Ancient Supervolcano

Oct. 2, 2013

Tucson, Ariz. -- A research project led by Joseph R. Michalski, Senior Scientist at the Planetary Science Institute, has identified what could be a supervolcano on Mars – the first discovery of its kind.

In a paper published Oct. 3 in the journal Nature, Michalski and co-author Jacob E. Bleacher of NASA Goddard Space Flight Center describe a new type of volcanic construction on Mars that until now has gone unrecognized.

 

The volcano in question, a vast circular basin on the face of the Red Planet, previously had been classified as an impact crater. Researchers now suggest the basin is actually the remains of an ancient supervolcano eruption. Their assessment is based on images and topographic data from NASA's Mars Odyssey, Mars Global Surveyor and Mars Reconnaissance Orbiter spacecraft, as well as the European Space Agency's Mars Express orbiter.

 

In the Nature paper Michalski and Bleacher lay out their case that the basin, recently named Eden Patera, is a volcanic caldera. Because a caldera is a depression, it can look like a crater formed by an impact, rather than a volcano.

 

"On Mars, young volcanoes have a very distinctive appearance that allows us to identify them," Michalski said. "The long-standing question has been what ancient volcanoes on Mars look like. Perhaps they look like this one."

 

The researchers also suggest a large body of magma loaded with dissolved gas (similar to the carbonation in soda) rose through thin crust to the surface quickly. Like a bottle of soda that has been shaken, this supervolcano would have blown its contents far and wide if the top came off suddenly.

 

"This highly explosive type of eruption is a game-changer, spewing many times more ash and other material than typical, younger Martian volcanoes," Bleacher said. "During these types of eruptions on Earth, the debris may spread so far through the atmosphere and remain so long that it alters the global temperature for years."

 

After the material is expelled from the eruption, the depression that is left can collapse even further, causing the ground around it to sink. Eruptions like these happened in ages past at what is now Yellowstone National Park in the western United States, Lake Toba in Indonesia and Lake Taupo in New Zealand.

 

Volcanoes previously had not been identified in the Arabia Terra region of Mars, where Eden Patera is located. The battered, heavily eroded terrain is known for its impact craters. But as Michalski examined this particular basin more closely, he noticed it lacked the typical raised rim of an impact crater. He also could not find a nearby blanket of ejecta, the melted rock that splashes outside the crater when an object hits.

 

The absence of such key features caused Michalski to suspect volcanic activity. He contacted Bleacher, a volcano specialist, who identified features at Eden Patera that usually indicate volcanism, such as a series of rock ledges that looked like the "bathtub rings" left after a lava lake slowly drains. In addition, the outside of the basin is ringed by the kinds of faults and valleys that occur when the ground collapses because of activity below the surface. The existence of these and other volcanic features in one place convinced the scientists Eden Patera should be reclassified.

 

The team found a few more basins that are candidate volcanoes nearby, suggesting conditions in Arabia Terra might have been favorable for supervolcanoes. It is also possible massive eruptions here could have been responsible for volcanic deposits elsewhere on Mars that have never been linked to a known volcano.

 

"If just a handful of volcanoes like these were once active, they could have had a major impact on the evolution of Mars," Bleacher said.

 

Project funding was provided by the NASA Mars Data Analysis program.

 

 

 

 

 

New research suggests the Eden Patera basin on Mars could have been formed by an explosive volcanic eruption, not the impact of a large object. 

 

Seen above, for the basin and surrounding area, higher elevations (reds and yellows) and lower elevations (blues and grays) are indicated.

Credit: NASA/JPL/GSFC

 

 

 

Above, the dark color indicates younger material draped across the Eden Patera depression.

Credit: ESA

 

Below, Michalski's paper was featured on the cover of Nature.

Credit: Nature, Mark Garlick

 

 

Credits: Planetary Science Institute