Enceladus’s subsurface ocean harbors complex organic molecules

Saturn moon is now the only solar system location other than Earth to meet all requirements for microbial life.

Analysis of mass spectroscopy data returned by NASA’s Cassini spacecraft indicates Saturn’s moon Enceladus harbors complex organic molecules in its subsurface ocean, which are ejected through cracks in surface ice.

Cassini made several close flybys of Enceladus, one of the solar system’s top contenders for hosting microbial life, before the spacecraft was plunged into Saturn in September 2017. These flybys found evidence for a subsurface ocean above the moon’s rocky core and detected molecular hydrogen in plumes coming from that ocean.

Scientists believe molecular hydrogen is produced by geochemical interactions between water and rocks in hydrothermal environments, according to a paper on the findings published in the journal Nature.

“Hydrogen provides a source of chemical energy supporting microbes that live in the Earth’s oceans near hydrothermal vents. Once you have identified a potential food source for microbes, the next question to ask is, ‘what is the nature of the complex organics in the ocean?’ This paper represents the first step in that understanding–complexity in the organic chemistry beyond our expectations!” stated Hunter Waite of the Southwest Research Institute (SwRI), who served as principal investigator for Cassini’s Ion and Neutral Mass Spectrometer (INMS).

Both INMS and Cassini’s Cosmic Dust Analyzer (CDA) measured the contents of Enceladus’s plumes and of material in Saturn’s E ring, which is composed of ice grains from those plumes.

“Previously, we’d only identified the simplest organic molecules containing a few carbon atoms, but even that was intriguing,” Christoper Glenn, also of SwRI and a specialist in extraterrestrial chemical oceanography, noted. “Now, we’ve found organic molecules with masses above 200 atomic mass units. That’s over 10 times heavier than methane.  With complex organic molecules emanating from its liquid water ocean, this moon is the only body besides Earth known to simultaneously satisfy all of the basic requirements for life as we know it.”

By working together, each with their own data set, the CDA and INMS teams achieved a better understanding of the organic chemistry in Enceladus’s ocean than either of the teams would have done with just their own data set, Glenn noted.

In their paper, the researchers recommend a future mission fly through Enceladus’s plumes and use a high-resolution mass spectrometer to analyze the complex organic molecules, with the goal of learning the process by which they formed.


Cyanobacteria study provides insight into future Mars colonization

Bacteria that conduct photosynthesis could provide human colonists with breathable air on other worlds.

A study at the Australian National University (ANU) that subjected cyanobacteria to inhospitable conditions is providing scientists with important insights into future human colonization of Mars.

Cyanobacteria are microbes that obtain their energy through photosynthesis and produce oxygen. One of the largest groups of bacteria on Earth, they have been around for more than 2.5 billion years.

Capable of adapting to harsh environments, cyanobacteria have been found in Antarctica, the Mojave Desert, and even the outside of the International Space Station (ISS).

Elmars Krausz of ANU suggested future human colonists on Mars and other solar system worlds could use cyanobacteria adapted to low-light environments to produce oxygen they could breathe and create a biosphere, an area where life could survive.

“This might sound like science fiction, but space agencies and private companies around the world are actively trying to turn this aspiration into reality in the not-too-distant future. Photosynthesis could theoretically be harnessed with these types of organisms to create air for humans to breathe on Mars,” Krausz said.

One particular type of chlorophyll, known as “red” chlorophyll, plays a key role in driving photosynthesis in low-light environments.

“Low-light adapted organisms, such as the cyanobacteria we’ve been studying, can grow under rocks and potentially survive the harsh conditions on the Red Planet,” he noted.

Through their pigments, “red” chlorophylls produce a signature fluorescence that colonizers of other worlds could use to track organisms indigenous to those worlds, stated Jenny Morton of ANU’s Research School of Chemistry.

Using a unique optical spectrometer along with computer modeling, the research team focused on better understanding the role of “red” chlorophylls in the process of photosynthesis.

“This work redefines the minimum energy needed in light to drive photosynthesis,” she added.

In experiments, organisms adapted to low-light environments died when exposed to full sunlight.

“All photosynthetic organisms, such as coral reefs, suffer severe environmental stresses from high temperatures, high light levels, and ultraviolet light, so this research helps scientists to better understand these limits,” Morton explained.

Findings of the study have been published in the journal Science.

Humans likely alone in universe, study reports

A new study shows that humans are likely the only intelligent life in the observable universe.

A team of international researchers have found evidence that humans are the only intelligent life in the known universe, according to a new study published online.

For the research, the team analyzed the so-called Fermi paradox that shows, while there are millions of celestial bodies throughout the cosmos, there is no concrete evidence of alien life. 

They broke down the equation initially proposed by Frank Drake in the 1960’s that states the vast size of the universe inherently suggests other intelligent life must exist.

However, when the team behind the recent study incorporated new elements into the equation they found it is open to both uncertainties and bias. As a result, it is likely not as accurate as previously believed.

“When the model is recast to represent realistic distributions of uncertainty, we find a substantial ex ante probability of there being no other intelligent life in our observable universe, and thus that there should be little surprise when we fail to detect any signs of it,” wrote the team in the research, according to Fox News. “This result dissolves the Fermi paradox, and in doing so removes any need to invoke speculative mechanisms by which civilizations would inevitably fail to have observable effects upon the universe.”

Their research revealed there is a 30 percent chance that humans are alone in the Milky Way galaxy. In addition, the team also found evidence that, should extraterrestrial life exist, it is likely less advanced that what we have on Earth.

”One can answer the Fermi Paradox by saying intelligence is very rare, but then it needs to be tremendously rare,” explained lead author Anders Sandberg, a researcher at Oxford University, according to International Business Times. “Another possibility is that intelligence doesn’t last very long, but it is enough that one civilization survives for it to become visible.”

While this suggests humans are alone, the study is not definitive. Many more processes need to be analyzed before that idea can be fully confirmed in one way or another.

Astronomers find galaxy cluster obscured by quasar

Search is on for more galaxy clusters hidden by very bright, active supermassive black holes.

Astronomers have discovered a large galaxy cluster with a mass of approximately 690 trillion suns that until now was obscured by an extremely bright quasar, an active supermassive black hole feeding on material surrounding it.

Composed of several hundred individual galaxies, the cluster is located about 2.4 billion light years from Earth and surrounds the quasar.

Designated PKS1353-341, the quasar, which is 46 billion times brighter than our Sun, was long thought to be alone in its region of space. It is surrounded by a huge disk of swirling material, of which large chunks are falling into it and in the process radiating high levels of energy as light.

“This might be a short-lived phase that clusters go through, where the central black hole has a quick meal, gets bright, and then fades away again. This could be a blip that we just happened to see. In a million years, this might look like a diffuse fuzzball,” explained Michael McDonald of MIT‘s Kavli Institute for Astrophysics and Space Research.

The discovery of the galaxy cluster suggests other, similar clusters could be hiding behind extremely bright objects. Such clusters provide important information about the amount of matter in the universe and the rate at which the universe is expanding, which is why astronomers are now searching for them.

One reason scientists missed this large cluster is their assumption that clusters appear “fluffy” and give off diffuse X-ray signals, very unlike quasars, which are bright, single-point sources.

“This idea that you could have a rapidly accreting black hole at the center of a cluster–we didn’t think that was something that happened in nature,” McDonald said.

To find more hidden clusters, he and fellow researchers set up a survey titled Clusters Hiding in Plain Sight (CHiPS), which involved looking at archival X-ray images of very bright objects. They then followed up by studying these objects using the Magellan Telescope, an optical observatory in Chile.

If the Magellan observations revealed more galaxies than expected surrounding the bright object, they then observed the point source using the space-based Chandra X-ray Observatory.

“Some 90 percent of these sources turned out not to be clusters,” McDonald said.

The CHiPS survey did find one new galaxy cluster obscured by a very bright supermassive black hole.

Findings of the study have been published in the Astrophysical Journal.


Merging neutron stars likely created a black hole

Though that alone made the merger worthy of study, it was also significant because it may have created the lowest mass black hole ever found.

The merging of two neutron stars may have created one of the most interesting black holes ever recorded, according to recent research published in the Astrophysical Journal Letters.

Last year, the U.S.-based Laser Interferometer Gravitational-Wave Observatory (LIGO) and the Europe-based Virgo detector detected a collision between two neutron stars that was so strong it generated gravitational waves.

Such an event had never been witnessed before. Though that alone made the merger worthy of study, it was also significant because it may have created the lowest mass black hole ever found.

In the study, scientists from Trinity University analyzed data from NASA’s Chandra X-ray Observatory taken before the technology noticed the gravitational waves in August 2017.

Matching that against data taken from LIGO, the team estimated the mass of the object created by the star merger has roughly 2.7 times the solar mass. That suggests it is either the lowest mass black hole or the highest mass neutron star ever recorded.

However, as a heavy neutron star would have produced both a strong magnetic field and X-rays — neither of which the team detected during their research — it is likely the collision led to a black hole.

“Astronomers have long suspected that neutron star mergers would form a black hole and produce bursts of radiation, but we lacked a strong case for it until now,” said study co-author Pawan Kumar, a researcher at the University of Texas, in a statement.

Though this study is compelling, it does not give definitive evidence that the merger created a neutron star. More research needs to be done on the event, including both X-ray and radio observations, before any hard conclusions can be reached.

“If the remnant is a rapidly rotating magnetized neutron star, the total energy in the external shock should rise by a factor ~102 (to ~1052 erg) after a few years; therefore, Chandra observations over the next year or two that do not show substantial brightening will rule out such a remnant,” the team wrote in their study, according to Tech Times.

NASA project could help search for extraterrestrial life

A new project headed by NASA could help astronomers get a better picture of what to search for when looking for extraterrestrial life.

A new NASA-headed project known as the Nexus for Exoplanet Systems Science (NExSS) may help scientists better detect life on distant planets, according to six new papers published in the journal Astrobiology.

There are currently over 3,500 exoplanets known to science. However, researchers are not quite sure how to find signs of life on those worlds.

To fix that, the team behind the new study outlined different ways researchers could find extraterrestrial “biosignatures” with modern technology, as well the best way to sort through that data.

The scientists believe the new method could help detect distant biosignatures by the year 2030.

This new research comes from two years of work that spans various universities and institutions across the world. The idea behind it is to gather a fully comprehensive overview of what humans know about life and then use that information to search for it throughout the cosmos.

However, that is not an easy task.

“For life to be detectable on a distant world it needs to strongly modify its planet in a way that we can detect,” explained one of the study-authors Victoria Meadows, an astronomer at the University of Washington, according to Gizmodo. “But for us to correctly recognize life’s impact, we also need to understand the planet and star—that environmental context is key.”

In one of the papers, scientists concluded that they should look for both atmospheric gases that are produced by life and any light reflected by life. In another, researchers discussed any potential false positives or negatives that might arise during a search.

The other papers detail what scientists understand about life on Earth, a framework to evaluate biosignatures on other planets, and a full evaluation of potential life-carrying worlds, as well as future ones.

Those aspects are all important, and the better they are understood the closer scientists will come to figuring out if life does exist in space.

“We’re moving from theorizing about life elsewhere in our galaxy to a robust science that will eventually give us the answer we seek to that profound question: Are we alone?” said author of one of the studies Martin Still, an exoplanet scientist at NASA Headquarters, Washington, according to Phys.org.

3D visualization of star-forming cloud helps scientists understand formation of our solar system

Vibrating gas cloud is at very early stage of star and planet formation.

The creation of a 3D visualization of a star-forming cloud is helping scientists understand the formation process of our own solar system and the birth of stars and planets.

Led by Aris Tritsis of the Australian National University (ANU) Research School of Astronomy and Astrophysics, a team of scientists from ANU and from the University of Crete in Greece created the 3D visualization as part of their study of Musca, a needle-shaped star-forming cloud in the southern sky located several hundred light years from Earth.

Composed mostly of molecular hydrogen and dust, Musca extends about 27 light years across the plane of the sky. Its depth is approximately 20 light years while its width is just a fraction of a single light year.

“We were able to reconstruct the 3D structure of a gas cloud in its very early stages of making new stars and planets, which will ultimately take millions of years to form,” Tritsis said.

“Knowledge of the 3D shape of clouds will greatly improve our understanding of these nurseries of stars and the birth of our own solar system.”

To create the visualization, the researchers used data collected by the European Space Agency’s (ESA) Herschel space telescope.

Having visualized Musca’s 3D shape, the scientists now know the gas cloud is an active, complex structure surrounded by hair-like features known as striations. The latter are caused by trapped waves of gas and dust produced by the cloud’s vibrations.

“With its 3D shape now determined, Musca can be used as a laboratory for testing star formation, astrochemical, and dust-formation theories,” Tritsis stated.

Studying the model will also give scientists insight into the formation of molecules in gas clouds.

According to Konstantinos Tassis of the University of Crete, Musca was chosen for the study because it is the largest vibrating whole structure in the galaxy.

By analyzing the frequency of these vibrations, the researchers were able to convert them into songs or ringing tones and thereby determine Musca’s shape.

“This is a cloud in space that is singing to us–all we had to do was listen. It’s actually quite awesome,” said Tritsis.

A paper on the study will be published in the journal Science.

Models estimate size of neutron stars

Researchers have discovered how big neutron stars are able to grow.

New models could help researchers estimate the size of neutron stars, according to a recent study published in the journal Physical Review Letters.

These simulations — which come from scientists at Goethe University — use data collected on gravitational waves. By analyzing such information, astronomers may be able to get a more precise idea of how big neutron stars can grow.

Neutron stars are incredibly dense. So dense that they have a mass greater than our sun stuffed into the size of a large city. However, though scientists have had a rough idea of their size, nobody has managed to get their precise dimensions.

To fix that, the team behind the new study developed a formula that estimates the size of neutron stars by analyzing the gravitational waves produced by merging neutron stars.

They came up with the method after comparing the predictions of two billion theoretical models of neutron stars and then constraining their models with parameters observed in the gravitational waves created by a neutron star merger known as GW170817.

“By exploring the results for all possible values of the parameters, we can effectively reduce our uncertainties,” said study co-author Luciano Rezzolla, a researcher at Goethe University, according to UPI.

The new findings revealed that neutron stars have a diameter that sits between 7.4 and 8.4 miles. However, that measurement is not completely definitive because there are several ways neutron stars can exist.

“However, there is a twist to all this, as neutron stars can have twin solutions,” said study co-author Jürgen Schaffner-Bielich, a researcher at Goethe University, according to Phys.org.

While there is no proof such solutions exist, the team took them into account in their findings. That then revealed twin stars are statistically rare and are unlikely to be deformed during a merger. As a result, scientists may be able to rule out their existence in future calculations.

Interstellar ‘Oumuamua now believed to be a comet

Material ejected via outgassing is causing object to travel faster than expected through the solar system.

‘Oumuamua, the interstellar object racing through the solar system, is now believed to be a comet rather than an asteroid.

First discovered in October 2017, ‘Oumuamua has been observed by both the Hubble Space Telescope (HST) and by ground-based telescopes moving faster through the solar system than scientists had predicted.

While its speed is being slowed by the Sun’s gravitational pull, this is occurring at a rate lower than that expected by calculations of celestial mechanics.

Marco Micheli of the European Space Agency (ESA), leader of a study on ‘Oumuamua’s movements published in the journal Nature, attributes its faster-than-expected movement to the object outgassing or venting material from its surface as a result of being heated by the Sun. He theorizes the small amount of ejected material is giving the object a slight push in its trajectory out of the solar system.

‘Oumuamua was traveling at a speed of 70,836 miles (114,000 km) per hour on June 1.

Outgassing is a feature of comets, not asteroids, and involves the ejection of gas and dust that form a coma or cloud around the objects as a result of solar heating.

In ‘Oumuamua’s case, scientists did not actually see development of a coma or tail but suspect the object is venting large, coarse dust grains, possibly due to its smaller dust grains having eroded during its journey through interstellar space. Hubble cannot detect clouds of large dust grains because they are not very bright.

“We think this is a tiny, weird comet. We can see in the data that its boost is getting smaller the farther away it travels from the Sun, which is typical for comets,” Micheli said.

When ‘Oumuamua was first detected last year, scientists were uncertain as to whether it should be classed as an asteroid or a comet.

The researchers’ initial reason for observing the object with Hubble was an effort to trace its path back to the star system from which it originated. Its unexpected increase in speed makes that a more difficult task, meaning scientists may never know its true origin.


Undetected asteroid explodes over Russia

Impact highlights gaps in ability to detect some potentially hazardous Near-Earth Objects.

Just days after NASA announced a 10-year plan to improve its capability to track potentially hazardous asteroids, an undetected asteroid exploded over Russia.

No injuries or damages were reported from the impact, which occurred on Thursday, June 21 at 1:15 Universal Time (UT) or 4:15 AM local time. Estimated to have been 13 feet (four meters) in diameter, the asteroid exploded in a fireball over the Russian city of Lipetsk southeast of Moscow.

Accompanied by a loud sonic boom, the fireball was seen by residents of the Russian cities of Kursk, Voronzeh, and Orel. It exploded around 16.7 miles (27 km) above Earth’s surface.

Traveling at an estimated 32,200 miles  per hour (52,000 km per hour), the asteroid was estimated to have the energy of 2.8 kilotons of TNT, much less than that of the one that impacted Chelyabinsk in February 2013, which was estimated to have had the power of 440 kilotons of TNT and injured close to 1,500 people.

Nine stations run by the International Meteor Organization (IMO), an international non-profit group of amateur meteor observers, detected the fireball produced by the asteroid, as did several weather satellites and NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

A local observer caught the explosion on video and uploaded the footage online.

Last week, NASA reported its detection systems do not always find asteroids coming towards Earth from its “day side.”

An 18-page report released by the White House Office of Science and Technology Policy this month outlines a 10-year plan to protect the planet from impacts by boosting tracking capabilities, enabling earlier detection of potential impactors.  Improved technology described in the report will help scientists more accurately predict the likelihood of particular asteroids hitting the Earth.

According to NASA planetary defense officer Lindley Johnson, scientists have detected 95 percent of all potentially hazardous asteroids and comets with diameters of two-thirds of a mile (one km) or larger.

All asteroids and comets orbiting within 30 million miles of Earth are considered Near-Earth Objects (NEOs).

The remaining five percent of asteroids that remain undetected, as well as smaller ones, could still pose significant threats to the planet.

Titled “The National Near-Earth Object Preparedness Strategy and Action Plan,” the report establishes five goals, including better detection and tracking methods, improved computer modeling, development of deflection technologies, more international cooperation on the issue, and establishing emergency procedures should a threat be discovered.