Hubble snaps view of dazzling celestial ‘snow angel’

Just in time for the holidays, the Hubble Space Telescope has snapped a spectacular view of a star-forming region in our Milky Way galaxy that looks like a snow angel in deep space.

This region, called Sharples 2-106 (or S106 for short) is located nearly 2,000 light-years away in the direction of the constellation of Cygnus (The Swan). The nebula is found in a relatively isolated part of the Milky Way, researchers said.

The S106 nebula measures several light-years across, and contains vast clouds of gas that resemble outstretched wings amidst an hourglass shape. The light from the glowing gas is colored blue in this image. A video and photo of the “snow angel” based on Hubble’s observations reveal a spectacular view of the cosmic sight.

Hubble’s view captures furious activity in the nebula, with ridges and ripples of super-hot gas mixing with the cooler interstellar medium. A massive young star, called Infrared Source 4 or IRS 4, is responsible for this turbulence, scientists said.

Radiation from IRS 4 makes the lobes of gas glow bright blue in the image, as they stretch outward from the central star. Luminous red veins also appear throughout the nebula creating intricate patterns.

A ring of dust and gas around the star squeezes the expanding nebula into its apparent hourglass shape. Faint light from the central star reflects off tiny dust particles, making the surrounding environment glow, and revealing darker filaments of dust beneath the blue dust clouds, the researchers said.

Astronomers have studied S106 and found several hundred brown dwarfs, which are cool, failed stars. When the nebula is viewed in infrared wavelengths, more than 600 of these misfit stars appear, scientists said.

Brown dwarfs weigh less than a tenth of our sun, and because of this low mass, they are unable to trigger enough energy through nuclear fusion. These cosmic objects encompass the S106 nebula in a small cluster, the researchers said.

S106 was the 106th object to be cataloged by astronomer Stewart Sharpless in the 1950s, the researchers said.

The newly released image was taken by Hubble in February. The composite picture was created by stitching together two images taken in infrared light.

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Alien Planets With No Spin May Be Too Harsh for Life

By Nola Taylor Redd, SPACE.com Contributor
Space.com | SPACE.com – Fri, Dec 16, 2011

Tidally-locked planets — planets with one side perpetually facing their star while the other remains shrouded in darkness — tend to be warmer on one side than the other. The presence of an atmosphere can help distribute the heat across the planet, equalizing the temperatures. But tidal locking could result in wide climate variations, a result that could threaten the evolution of life on the surface of these planets.

Tidal locking depends on the planet’s mass and its distance from its star. For planets orbiting M-type stars, which are slightly smaller than our sun, the region where planets become tidally locked overlaps with the so-called habitable zone, where water can remain as a liquid on a planet’s surface.

In the solar system, the moon is tidally locked in orbit around Earth.

According to new research published in the December edition of the Astrophysical Journal,strong heating of a planet at a single point can change or even control how much weathering occurs on the planet, which can lead to significant and even unstable climate changes. These dramatic climate effects could make planets that otherwise have the potential for life to instead be uninhabitable.

Whatever the weather
When rocks and minerals are exposed to the air, they react to the gases within it. As the rocks erode, a fresh face comes into contact with the air, allowing even more gas to be converted. If the erosion process keeps pace with the output of fresh gas into the atmosphere — say, from volcanic eruptions — the climate remains stable.

On tidally-locked planets, a single region is consistently close to the star. Known as the substellar point, this region receives more direct sunlight, and thus more heat. The recent paper proposes that such constant attention could affect weathering, and thus could influence the climate of the atmosphere. [Photos: The Strangest Alien Planets]

The process, referred to as enhanced substellar weathering instability (ESWI), is based on the fact that the influx of heat would cause an increase of weathering at the substellar point. The higher temperatures can also result in stronger rainfall, which go on to affect weathering.

“The harder it rains, the more it erodes,” said principal investigator Edwin Kite, of the University of California at Berkeley.

More rain means an abundance of fresh rock to react with the atmosphere, removing more of its components.

Similarly, if the substellar point cools for any reason, the weathering process slows. Less rock is available to chemically react, and the atmospheric gas builds up. Volcanism could put more material into the atmosphere than the rocks can absorb — and since volcanoes on Earth release greenhouse gases like sulfur dioxide and carbon dioxide, presumably a runaway greenhouse effect could take flight, leading to additional heating.

All of this happens because the heat is focused on a single region that is constantly closest to its star.

“What controls the weathering rate of the planet is just that patch,” Kite said.

On Earth, carbon dioxide from the air reacts with calcium silicate, creating calcium carbonate and silicone dioxide. The process removes carbon dioxide from the air and controls the greenhouse effect.

“Weathering regulates the climate on Earth on long time scales, and makes sure it doesn’t get too hot or too cold,” explained Dorian Abbot, of the University of Chicago. Abbot studies climate dynamics on Earth and on extrasolar planets.

The same thing could happen on other planets, but if the conditions are right (or wrong) the results could be more detrimental.

“We sometimes see catastrophic exits from the habitable zone,” Kite said.

For instance, a habitable planet could find itself moving to a Venus-like situation, with clouds of gas significantly increasing the surface temperature to points where water would boil off.

Or it could simply boast wide swings over its lifetime, significant shifts from cold to hot and back again. Such fluctuations could mean trouble for life trying to evolve on a planet.

“It has taken a very long time for life to develop complexity on Earth,” Kite said.

Kite explained that a number of key steps were required to get life to the point as we know it today.

“It would require a long period of habitability on a planet to allow these different steps to take place,” he said. “It’s not enough just to rain on a planet for ten thousand years and expect interesting things to happen.”

Abbot agreed.

“Climate instabilities are not good for the life we usually think about.”

Catastrophic changes: Rare or common?
How many planets could find their atmosphere destabilized by tidal locking?

To narrow that down, one must first look at how frequently tidally-locked planets might exist.

For M-type stars, “We would expect that a lot of the planets in the habitable zone would be tidally locked,” Abbot said.

For ESWI to occur, certain conditions must be met on these planets.

The substellar point, closest to the star, cannot be underwater. Land is required for the strongly temperature-dependant weathering.

Similarly, the gas that is absorbed by weathering must be the prevalent gas in the atmosphere.

Kite notes that, even if Earth were moved to another star and became tidally locked, it would not be in danger. Though weathering on Earth consumes carbon dioxide, nitrogen makes up most of the atmosphere.

Such results are not just limited to planets that can only reveal a single face to their star.

According to Kite, “All that’s really important to get this process going is a large day/night temperature contrast.”

As an example, the team worked with Itay Halevy, of the Weizmann Institute of Science, to consider a Martian mystery. Mars is not tidally locked but has wide temperature variations across a Martian day.

The Red Planet lost its atmosphere long ago, and scientists are still trying to determine exactly how that happened. Kite thinks ESWI could be a potential contributor.

“It’s an open question whether enough weathering occurred over its geological history to draw down a significant amount of carbon dioxide,” he said.

But Kite was clear that such conditions shouldn’t stop astronomers from studying planets that fall in the danger zone. These bodies could still have the potential to be habitable.

“Ultimately, only observing can tell.”

This story was provided by Astrobiology Magazine, a web-based publication sponsored by the NASA astrobiology program.

NASA Scientists Build Harpoon to Shoot Comets

By Joseph Castro, InnovationNewsDaily Staff Writer
Space.com | SPACE.com – Fri, Dec 16, 2011

Captain Ahab may have wanted to harpoon a giant white whale, but NASA has a whole other target in mind.

Scientists at NASA’s Goddard Space Flight Center are designing a small harpoon that would fire into and collect samples from nearby comets. Because comets are frozen chunks of ice and dust dating back to the formation of our solar system, they may hold clues to the origin of the planets and life as we know it.

“One of the most inspiring reasons to go through the trouble and expense of collecting a comet sample is to get a look at the ‘primordial ooze’ – biomolecules in comets that may have assisted the origin of life,” Donald Wegel, lead engineer for the project, said in a statement.

Previous NASA missions have already found amino acids – molecules that are important for life and serve as the building blocks of proteins – in comets and meteorites. The new project could discover other ingredients necessary for life, supporting the theory that comet and meteorite impacts may have given a boost to the development of life on Earth by delivering vital biomolecules.

Another goal of collecting comet samples is to figure out how comets are formed. This information would provide scientists with important details on how best to deflect any dangerous space rocks hurling toward Earth.

The NASA team is currently trying to figure out the best tip design, explosive powder charge, mass and cross-section for the harpoon. To do this, they are using a six-foot tall crossbow with a half-inch thick steel cable bow string to fire harpoon tips at various speeds into different materials, such as sand, ice and rock salt. They are also developing a sample collection chamber to nestle into the hollow tip. “”[The chamber] has to remain reliably open as the tip penetrates the comet’s surface, but then it has to close tightly and detach from the tip so the sample can be pulled back into the spacecraft,” explained Wegel.

NASA envisions that a single spacecraft would carry multiple harpoons with a variety of powder charges to handle different areas on a comet. The spacecraft would rendezvous with a comet, choose a target and fire the appropriate harpoon based on the presumed material composition of the area. The open collection chamber will gather samples as the harpoon tip dives deeper into the surface of the comet. Once the harpoon reaches its maximum depth, the collection chamber will snap shut and the spacecraft will reel it in, leaving the harpoon tip in the comet. This design will allow scientists to collect comet samples without the difficulty of actually having land on the comet.

The NASA team is still in the proof-of-concept stage for the project. Once they prove that the harpoon will work, they will have to apply for funding to build the instrument.

Comet Lovejoy Survives Fiery Plunge Through Sun, NASA Says

By Mike Wall , SPACE.com Senior Writer Space.com
SPACE.com – Fri, Dec 16, 2011

A newfound comet defied long odds on Thursday (Dec. 15), surviving a suicidal dive through the sun’s hellishly hot atmosphere, according to NASA scientists.

Comet Lovejoy's Death-defying Escape

Comet Lovejoy plunged through the sun’s corona at about 7 p.m. EST (midnight GMT on Dec. 16), coming within 87,000 miles (140,000 kilometers) of our star’s surface. Temperatures in the corona can reach 2 million degrees Fahrenheit (1.1 million degrees Celsius), so most researchers expected the icy wanderer to be completely destroyed.

But Lovejoy proved to be made of tough stuff. A video taken by NASA’s Solar Dynamics Observatory (SDO) spacecraft showed the icy object emerging from behind the sun and zipping back off into space.

“Breaking News! Lovejoy lives! The comet Lovejoy has survived its journey around the sun to reemerge on the other side,” SDO researchers tweeted.

SDO is one of many instruments that scientists — eager to record and study the comet’s presumed demise — trained on Lovejoy as it streaked toward the sun.

“We have here an exceptionally rare opportunity to observe the complete vaporization of a relatively large comet, and we have approximately 18 instruments on five different satellites that are trying to do just that,” Karl Battams, a scientist at the Naval Research Laboratory in Washington, D.C., wrote on the Sungrazing Comets website, before Lovejoy’s closest solar approach.

Battams runs the website, which is devoted to comets discovered by two different spacecraft: NASA’s Solar Terrestrial Relations Observatory (STEREO) and the Solar and Heliospheric Observatory (SOHO), which is operated jointly by NASA and the European Space Agency (ESA).

Battams greeted news of Lovejoy’s improbable escape with surprise and delight.

“I expected a diffuse dust tail to survive (for several hours) before fading away but NOT any kind of nucleus!” he tweeted. “I’ve worked with sungrazers for 8yrs; today was the most amazing day I’ve ever had with them!”

Preparing for the end
Lovejoy has a core about 660 feet (200 meters) wide. It belongs to a class of comets known as Kreutz sungrazers, whose orbits bring them very close to the sun.

All Kreutz sungrazers are thought to be the remnants of a single giant comet that broke apart several centuries ago. They’re named after the 19th-century German astronomer Heinrich Kreutz, who first showed that such comets are related.

Comets plunge into the sun on a regular basis, but they rarely give much advance notice of their suicidal intentions. That’s why scientists were so excited about Lovejoy. Australian amateur astronomer Terry Lovejoy discovered the icy wanderer on Nov. 27, giving researchers plenty of time to map out their observation campaign.

And that campaign has been intense, involving five different spacecraft. In addition to SDO, SOHO and STEREO, scientists planned to use Japan’s Hinode satellite and ESA’s Proba spacecraft to track Lovejoy’s movements, Battams wrote.

NASA also created a website providing updates about the comet’s pass through the corona, as well as images of the event beamed down by SDO. It can be found here: http://sdo.gsfc.nasa.gov/data/lovejoy.php

For his part, Terry Lovejoy said he was happy to have made a contribution, and he marveled a bit at all the attention the comet has been getting.

“It’s been tremendous,” Lovejoy told SPACE.com. “Apparently it’s all over Facebook, and I don’t use Facebook. But there’s a lot of interest. I think a lot of people like the name — the Lovejoy name seems to strike a chord with people.”

A dramatic escape
Lovejoy is quite large for a sungrazing comet, and experts expected it to die an impressive death. The website Spaceweather.com, for example, predicted Lovejoy would blaze as brightly as Jupiter or Venus in the sky as it neared the sun.

Battams also expected a good show, saying the comet might even be visible from the ground around sunset today in the Northern Hemisphere.

“I do think that it will put on a spectacular show for us and will be the brightest Kreutz-group comet that SOHO has ever observed,” Battams wrote last week.

Though the early returns are still coming in, those forecasts appear to be on the money. Observations from various spacecraft do indeed show Lovejoy flaring up significantly as it neared our star.

Researchers will keep analyzing the images to better understand the comet’s daring solar approach. And now skywatchers apparently have another shot to catch a glimpse of the resilient Lovejoy on Friday morning (Dec. 16).

For observers in North America, the comet will rise approximately 5 to 10 minutes before dawn and will be situated to the upper right of the sun. If Lovejoy is still shining at least as brightly as Venus, it may be visible, experts say.

You could also try to spot Lovejoy after the sun comes up, if you’re exceedingly careful. Block the rising sun behind a distant building and focus on the part of the sky 3 to 4 degrees above and to the right of the sun (your clenched fist held at arm’s length is equal to roughly 10 degrees). CAUTION: Never point binoculars or a telescope at or near the sun, and never look directly at our star with the naked eye. Serious eye damage can result.

And don’t get your hopes up, either. The comet may well be too faint to see, experts say.

Note: If you take any good pictures of Comet Lovejoy and would like them to be considered for a future story or image gallery, contact SPACE.com managing editor Tariq Malik at tmalik@space.com.

SPACE.com assistant managing editor Clara Moskowitz (@ClaraMoskowitz) contributed to this story. You can follow SPACE.com senior writer Mike Wall on Twitter: @michaeldwall. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcom and on Facebook.

NASA Telescope Confirms Alien Planet in Habitable Zone

By Mike Wall, SPACE.com Senior Writer

MOUNTAIN VIEW, Calif. — NASA’s planet-hunting Kepler spacecraft has confirmed the discovery of its first alien world in its host star’s habitable zone — that just-right range of distances that could allow liquid water to exist — and found more than 1,000 new explanet candidates, researchers announced today (Dec. 5).

The new finds bring the Kepler space telescope’s total haul to 2,326 potential planets in its first 16 months of operation.These discoveries, if confirmed, would quadruple the current tally of worlds known to exist beyond our solar system, which recently topped 700.

The potentially habitable alien world, a first for Kepler, orbits a star very much like our own sun. The discovery brings scientists one step closer to finding a planet like our own — one which could conceivably harbor life, scientists said.

“We’re getting closer and closer to discovering the so-called ‘Goldilocks planet,'” Pete Worden, director of NASA’s Ames Research Center in Moffett Field, Calif., said during a press conference today. The newfound planet in the habitable zone is called Kepler-22b. It is located about 600 light-years away, orbiting a sun-like star.

Kepler-22b’s radius is 2.4 times that of Earth, and the two planets have roughly similar temperatures. If the greenhouse effect operates there similarly to how it does on Earth, the average surface temperature on Kepler-22b would be 72 degrees Fahrenheit (22 degrees Celsius).

Hunting down alien planets
The $600 million Kepler observatory launched in March 2009 to hunt for Earth-size alien planets in the habitable zone of their parent stars, where liquid water, and perhaps even life, might be able to exist.

Kepler detects alien planets using what’s called the “transit method.” It searches for tiny, telltale dips in a star’s brightness caused when a planet transits — or crosses in front of — the star from Earth’s perspective, blocking a fraction of the star’s light.

The finds graduate from “candidates” to full-fledged planets after follow-up observations confirm that they’re not false alarms. This process, which is usually done with large, ground-based telescopes, can take about a year.

The Kepler team released data from its first 13 months of operation back in February, announcing that the instrument had detected 1,235 planet candidates, including 54 in the habitable zone and 68 that are roughly Earth-size.

Of the total 2,326 candidate planets that Kepler has found to date, 207 are approximately Earth-size. More of them, 680, are a bit larger than our planet, falling into the “super-Earth” category. The total number of candidate planets in the habitable zones of their stars is now 48.

To date, just over two dozen of these potential exoplanets have been confirmed, but Kepler scientists have estimated that at least 80 percent of the instrument’s discoveries should end up being the real deal.

More discoveries to come
The newfound 1,094 planet candidates are the fruit of Kepler’s labors during its first 16 months of science work, from May 2009 to September 2010. And they won’t be the last of the prolific instrument’s discoveries.

“This is a major milestone on the road to finding Earth’s twin,” Douglas Hudgins, Kepler program scientist at NASA headquarters in Washington, D.C., said in a statement.

Mission scientists still need to analyze data from the last two years and on into the future. Kepler will be making observations for a while yet to come; its nominal mission is set to end in November 2012, but the Kepler team is preparing a proposal to extend the instrument’s operations for another year or more.

Kepler’s finds should only get more exciting as time goes on, researchers say.

“We’re pushing down to smaller planets and longer orbital periods,” said Natalie Batalha, Kepler deputy science team lead at Ames.

To flag a potential planet, the instrument generally needs to witness three transits. Planets that make three transits in just a few months must be pretty close to their parent stars; as a result, many of the alien worlds Kepler spotted early on have been blisteringly hot places that aren’t great candidates for harboring life as we know it.

Given more time, however, a wealth of more distantly orbiting — and perhaps more Earth-like — exoplanets should open up to Kepler. If intelligent aliens were studying our solar system with their own version of Kepler, after all, it would take them three years to detect our home planet.

“We are getting very close,” Batalha said. “We are homing in on the truly Earth-size, habitable planets.”

You can follow SPACE.com senior writer Mike Wall on Twitter: @michaeldwall. Follow SPACE.com for the latest in space science and exploration news on Twitter @Spacedotcomand on Facebook.