Extreme Life Archives

October 2, 2015December 23, 2015 by Paul Patton

Is There a Kraken in Kraken Mare? What Kind of Life Would We Find on Titan?

The left image shows a mosaic of images of Titan taken by the Cassini spacecraft in near infrared light. Titan’s polar seas are visible as sunlight glints off of them. The right image is a radar image of Kraken Mare. Credit: NASA Jet Propulsion Laboratory.

Could there be life on Saturn’s large moon Titan? Asking the question forces astrobiologists and chemists to think carefully and creatively about the chemistry of life, and how it might be different on other worlds than it is on Earth. In February, a team of researchers from Cornell University, including chemical engineering graduate student James Stevenson, planetary scientist Jonathan Lunine, and chemical engineer Paulette Clancy, published a pioneering study arguing that cell membranes could form under the exotic chemical conditions present on this remarkable moon.

In many ways, Titan is Earth’s twin. It’s the second largest moon in the solar system and bigger than the planet Mercury. Like Earth, it has a substantial atmosphere, with a surface atmospheric pressure a bit higher than Earth’s. Besides Earth, Titan is the only object in our solar system known to have accumulations of liquid on its surface. NASA’s Cassini space probe discovered abundant lakes and even rivers in Titan’s polar regions. The largest lake, or sea, called Kraken Mare, is larger than Earth’s Caspian Sea. Researchers know from both spacecraft observations and laboratory experiments that Titan’s atmosphere is rich in complex organic molecules, which are the building blocks of life.

All these features might make it seem as though Titan is tantalizingly suitable for life. The name ‘Kraken’, which refers to a legendary sea monster, fancifully reflects the eager hopes of astrobiologists. But, Titan is Earth’s alien twin. Being almost ten times further from the sun than Earth is, its surface temperature is a frigid -180 degrees Celsius. Liquid water is vital to life as we know it, but on Titan’s surface all water is frozen solid. Water ice takes on the role that silicon-containing rock does on Earth, making up the outer layers of the crust.

The liquid that fills Titan’s lakes and rivers is not water, but liquid methane, probably mixed with other substances like liquid ethane, all of which are gases here on Earth. If there is life in Titan’s seas, it is not life as we know it. It must be an alien form of life, with organic molecules dissolved in liquid methane instead of liquid water. Is such a thing even possible?

The Cornell team took up one key part of this challenging question by investigating whether cell membranes can exist in liquid methane. Every living cell is, essentially, a self-sustaining network of chemical reactions, contained within bounding membranes. Scientists think that cell membranes emerged very early in the history of life on Earth, and their formation might even have been the first step in the origin of life.

Here on Earth, cell membranes are as familiar as high school biology class. They are made of large molecules called phospholipids. Each phospholipid molecule has a ‘head’ and a ‘tail’. The head contains a phosphate group, with a phosphorus atom linked to several oxygen atoms. The tail consists of one or more strings of carbon atoms, typically 15 to 20 atoms long, with hydrogen atoms linked on each side. The head, due to the negative charge of its phosphate group, has an unequal distribution of electrical charge, and we say that it is polar. The tail, on the other hand, is electrically neutral.

phospholipid membrane — Here on Earth, cell membranes are composed of phospholipid molecules dissolved in liquid water. A phospholipid has a backbone of carbon atoms (gray), and also contains hydrogen (sky blue), phosphorus (yellow), oxygen (red), and nitrogen (blue). Due to the positive charge associated with the nitrogen containing choline group, and the negative charge associated with the phosphate group, the head is polar, and attracts water. It is therefore hydrophilic. The hydrocarbon tail is electrically neutral and hydrophobic. The structure of a cell membrane is due these electrical properties of phospholipids and water. The molecules form a double layer, with the hydrophilic heads facing outward, towards water, and the hydrophobic tails facing inward, towards one another. Credit: Ties van Brussel

These electrical properties determine how phospholipid molecules will behave when they are dissolved in water. Electrically speaking, water is a polar molecule. The electrons in the water molecule are more strongly attracted to its oxygen atom than to its two hydrogen atoms. So, the side of the molecule where the two hydrogen atoms are has a slight positive charge, and the oxygen side has a small negative charge. These polar properties of water cause it to attract the polar head of the phospholipid molecule, which is said to be hydrophilic, and repel its nonpolar tail, which is said to be hydrophobic.

When phospholipid molecules are dissolved in water, the electrical properties of the two substances work together to cause the phospholipid molecules to organize themselves into a membrane. The membrane closes onto itself into a little sphere called a liposome. The phospholipid molecules form a bilayer two molecules thick. The polar hydrophilic heads face outward towards the water on both the inner and outer surface of the membrane. The hydrophobic tails are sandwiched between, facing each other. While the phospholipid molecules remain fixed in their layer, with their heads facing out and their tails facing in, they can still move around with respect to each other, giving the membrane the fluid flexibility needed for life.

Phospholipid bilayer membranes are the basis of all terrestrial cell membranes. Even on its own, a liposome can grow, reproduce and aid certain chemical reactions important to life, which is why some biochemists think that the formation of liposomes might have been the first step towards life. At any rate, the formation of cell membranes must surely been an early step in life’s emergence on Earth.

water and methane — At the left, water, consisting of hydrogen (H) and oxygen (O), is a polar solvent. Oxygen attracts electrons more strongly than hydrogen does, giving the hydrogen side of the molecule a net positive charge and the oxygen side a net negative charge. The delta symbol ( ) indicates that the charge is partial, that is less than a full unit of positive or negative charge. At right, methane is a non-polar solvent, due to the symmetrical distribution of hydrogen atoms (H) around a central carbon atom (C). Credit: Jynto as modified by Paul Patton.

If some form of life exists on Titan, whether sea monster or (more likely) microbe, it would almost certainly need to have a cell membrane, just like every living thing on Earth does. Could phospholipid bilayer membranes form in liquid methane on Titan? The answer is no. Unlike water, the methane molecule has an even distribution of electrical charges. It lacks water’s polar qualities, and so couldn’t attract the polar heads of phospholipid molecule. This attraction is needed for the phospholipids to form an Earth-style cell membrane.

Experiments have been conducted where phospholipids are dissolved in non-polar liquids at Earthly room temperature. Under these conditions, the phospholipids form an ‘inside-out’ two layer membrane. The polar heads of the phospholipid molecules are at the center, attracted to one another by their electrical charges. The non-polar tails face outward on each side of the inside-out membrane, facing the non-polar solvent.

membranes in polar and non-polar solvents — At left, phospholipids are dissolved in water, a polar solvent. They form a bilayer membrane, with their polar, hydrophilic heads facing outward towards water, and their hydrophobic tails facing each other. At right, when phospholipids are dissolved in a non-polar solvent at Earthly room temperature, they form an inside-out membrane, with the polar heads attracting one another, and the non-polar tails facing outwards towards the non-polar solvent. Based on figure 2 from Stevenson, Lunine, and Clancy (2015). Credit: Paul Patton

Could Titanian life have an inside out phospholipid membrane? The Cornell team concluded that this wouldn’t work, for two reasons. The first is that at the cryogenic temperatures of liquid methane, the tails of phospholipids become rigid, depriving any inside-out membrane that might form of the fluid flexibility needed for life. The second is that two key ingredients of phospholipids; phosphorus and oxygen, are probably unavailable in the methane lakes of Titan. In their search for Titanian cell membranes, the Cornell team needed to probe beyond the familiar realm of high school biology.

Although not composed of phospholipids, the scientists reasoned that any Titanian cell membrane would nevertheless be like the inside-out phospholipid membranes created in the lab. It would consist of polar molecules clinging together electrically in a solution of non-polar liquid methane. What molecules might those be? For answers the researchers looked to data from the Cassini spacecraft and from laboratory experiments that reproduced the chemistry of Titan’s atmosphere.

Titan’s atmosphere is known to have a very complex chemistry. It is made mostly of nitrogen and methane gas. When the Cassini spacecraft analyzed its composition using spectroscopy it found traces of a variety of compounds of carbon, nitrogen, and hydrogen, called nitriles and amines. Researchers have simulated the chemistry of Titan’s atmosphere in the lab by exposing mixtures of nitrogen and methane to sources of energy simulating sunlight on Titan. A stew of organic molecules called ‘tholins’ is formed. It consists of compounds of hydrogen and carbon, called hydrocarbons, as well as nitriles and amines.

The Cornell investigators saw nitriles and amines as potential candidates for their Titanian cell membranes. Both are polar molecules that might stick together to form a membrane in non-polar liquid methane due to the polarity of nitrogen containing groups found in both of them. They reasoned that candidate molecules must be much smaller than phospholipids, so that they could form fluid membranes at liquid methane temperatures. They considered nitriles and amines containing strings of between three and six carbon atoms. Nitrogen containing groups are called ‘azoto’ –groups, so the team named their hypothetical Titanian counterpart to the liposome the ‘azotosome’.

Synthesizing azotosomes for experimental study would have been difficult and expensive, because the experiments would need to be conducted at the cryogenic temperatures of liquid methane. But since the candidate molecules have been studied extensively for other reasons, the Cornell researchers felt justified in turning to the tools of computational chemistry to determine whether their candidate molecules could cohere as a flexible membrane in liquid methane. Computational models have been used successfully to study conventional phospholipid cell membranes.

acrylonitrile — Acrylonitrile has been identified as a possible basis for cell membranes in liquid methane on Titan. It is known to be present in Titan’s atmosphere at a concentration of 10 parts per million and has been produced in laboratory simulations of the effects of energy sources on Titan’s nitrogen-methane atmosphere. As a small polar molecule capable of dissolving in liquid methane, it is a candidate substance for the formation of cell membranes in an alternative biochemistry on Titan. Light blue: carbon atoms, dark blue: nitrogen atom, white: hydrogen atoms. Credit: Ben Mills as modified by Paul Patton.

acrylonitrile membrane — Polar acrylonitrile molecules align ‘head’ to ‘tail’ to form a membrane in non-polar liquid methane. Light blue: carbon atoms, dark blue: nitrogen atoms, white: hydrogen atoms. Credit: James Stevenson.

The group’s computational simulations showed that some candidate substances could be ruled out because they would not cohere as a membrane, would be too rigid, or would form a solid. Nevertheless, the simulations also showed that a number of substances would form membranes with suitable properties. One suitable substance is acrylonitrile, which Cassini showed is present in Titan’s atmosphere at 10 parts per million concentration. Despite the huge difference in temperature between cryogenic azotozomes and room temperature liposomes, the simulations showed them to exhibit strikingly similar properties of stability and response to mechanical stress. Cell membranes, then, are possible for life in liquid methane.

Computational chemistry simulations show that acrylonitrile and some other small polar nitrogen containing organic molecules are capable of forming ‘azotosomes’ when they are dissolved on liquid methane. Azotosomes are small membrane bounded spherules like the liposomes formed by phospholipids when they are dissolved in water. The simulations show that acrylonitrile azotosomes would be both stable and flexible in cryogenically cold liquid methane, giving them the properties they need to function as cell membranes for hypothetical Titanian life, or for life on any world with liquid methane on its surface. The azotosome shown is 9 nanometers in size, about the size of a virus. Light blue: carbon atoms, dark blue: nitrogen atoms, white: hydrogen atoms. Credit: James Stevenson.

The scientists from Cornell view their findings as nothing more than a first step towards showing that life in liquid methane is possible, and towards developing the methods that future spacecraft will need to search for it on Titan. If life is possible in liquid methane, the implications ultimately extend far beyond Titan.

When seeking conditions suitable for life in the galaxy, astronomers typically search for exoplanets within a star’s habitable zone, defined as the narrow range of distances over which a planet with an Earth-like atmosphere would have a surface temperature suitable for liquid water. If methane life is possible, then stars would also have a methane habitable zone, a region where methane could exist as a liquid on a planet or moon, making methane life possible. The number of habitable worlds in the galaxy would be greatly increased. Perhaps, on some worlds, methane life evolves into complex forms that we can scarcely imagine. Maybe some of them are even a bit like sea monsters.

References and Further Reading:

N. Atkinson (2010) Alien Life on Titan? Hang on Just a Minute, Universe Today.

N. Atkinson (2010) Life on Titan Could be Smelly and Explosive, Universe Today.

M. L. Cable, S. M. Horst, R. Hodyss, P. M. Beauchamp, M. A. Smith, P. A. Willis, (2012) Titan tholins: Simulating Titan organic chemistry in the Cassini-Huygens era, Chemical Reviews, 112:1882-1909.

E. Howell (2014) Titan’s Majestic Mirror-Like Lakes Will Come Under Cassini’s Scrutiny This Week, Universe Today.

J. Major (2013) Titan’s North Pole is Loaded With Lakes, Universe Today.

C. P. McKay, H. D. Smith, (2005) Possibilities for methanogenic life in liquid methane on the surface of Titan, Icarus 178: 274-276.

J. Stevenson, J. Lunine, P. Clancy, (2015) Membrane alternatives in worlds without oxygen: Creation of an azotosome, Science Advances 1(1):e1400067.

S. Oleson (2014) Titan submarine: Exploring the depths of Kraken, NASA Glenn Research Center, Press release.

Cassini Solstice Mission, NASA Jet Propulsion Laboratory

NASA and ESA celebrate 10 years since Titan landing, NASA 2015

January 27, 2015December 23, 2015 by Nancy Atkinson

Oldest Planetary System Discovered, Improving the Chances for Intelligent Life Everywhere

An artist rendition of Kepler-444 planetary system, which hosts five planets, all smaller than Earth. Credit: Tiago Campante, University of Birmingham, UK.

Using data from the Kepler space telescope, an international group of astronomers has discovered the oldest known planetary system in the galaxy – an 11 billion-year-old system of five rocky planets that are all smaller than Earth. The team says this discovery suggests that Earth-size planets have formed throughout most of the Universe’s 13.8-billion-year history, increasing the possibility for the existence of ancient life – and potentially advanced intelligent life — in our galaxy.

“The fact that rocky planets were already forming in the galaxy 11 billion years ago suggests that habitable Earth-like planets have probably been around for a very long time, much longer than the age of our Solar System,” said Dr. Travis Metcalfe, Senior Research Scientist Space Science Institute, who was part of the team that used the unique method of asteroseismology to determine the age of the star.

The star, named Kepler-444, is about 25 percent smaller than our Sun and is 117 light-years from Earth. The system of five known planets is very compact, and all five planets orbit the parent star in less than 10 days, or within 0:08 AU, roughly one-fifth the size of Mercury’s orbit.

“The star is slightly cooler than the Sun (around 5000 K at the surface, compared to 5800 K),” Metcalfe told Universe Today, “but the planets in this system are still expected to be highly irradiated and inhospitable to life,” with little to no atmospheres.

The team wrote in their paper that the system’s habitable zone lies 0:47 AU from the parent star and so all planets orbit well interior to the inner edge of Kepler-444’s ‘Goldilocks zone.’

The team was led by Tiago Campante, a research fellow at the University of Birmingham in the UK.

The planets were found by analyzing four years of Kepler data, as the spacecraft had nearly continuous observations of Kepler-444 during Kepler’s active mission. The space telescope took high-precision measurements of changes in brightness in stars in its field of view. There are tiny changes in brightness when planets pass in front of their stars.

Transit signals indicated five planets orbiting Kepler-444, although this star has a binary companion, an M-dwarf, and it was a tedious process to tease out all the data to determine what were planets and not other stars, as well as which star the planets were orbiting.

An image of the Kepler-444 star system using the NIRC2 near-infrared imager on the Keck II telescope. Credit: Tiago Campante et al.

Metcalfe said the the job of “validating” the planets by ruling out all of the other possible “false positive” scenarios is always a big challenge for Kepler targets.

But asteroseismology was used to directly measure the precise age of the star. Asteroseismology, or stellar seismology is basically listening to a star by measuring sound waves. The sound waves travel into the star and bring information back up to the surface. The waves cause oscillations that Kepler observes as a rapid flickering of the star’s brightness.

How can this help determine a star’s age?

“As a star ages, it converts hydrogen into helium in the core,” Metcalfe said via email. “This changes the mean density of the star over time, and asteroseismology provides a very precise measure of the mean density (from the regular spacing of the individual oscillation frequencies).”

Metcalfe said that in this case, the uncertainty on the age of the star (and thus the planets, which formed essentially at the same time) is only 9%, compared to a typical uncertainty of 30-50% from other methods based on rotation (gyrochronology) or other properties of the star.

The team also noted in their paper that this finding may also help to pinpoint the beginning of the era of planet formation.

“I think this system has a lot to teach us about planet formation and the long-term evolution of planetary systems,” said Darin Ragozzine, a professor at Florida Institute of Technology and a a member of the discovery team, who specializes in multi-transiting systems. “With an age of 11.2 billion years, it means that this system formed near the beginning of the age of the Universe.”

The team wrote that this finding implies that small, Earth-size, planets may have readily formed at early epochs in the Universe’s history, even when metals were more scarce.

“By the time Earth formed, this star and its planetary system were already older than our planet is today,” Ragozzine told Universe Today. “We don’t know for sure if this system has stayed the same the whole time, but it is amazing to think that the little inner planet has gone around the star about a trillion times!”

To find out more about asteroseismology, check out a website called the Pale Blue Dot Project. Metcalfe launched a non-profit organization to help raise research funds for the Kepler Asteroseismic Science Consortium. The Pale Blue Dot Project allows people to adopt a star to support asteroseismology, since there is no NASA funding for asteroseismology.

“Much of the expertise for this exists in Europe and not in the US, so as a cost saving measure NASA outsourced this particular research for the Kepler mission,” said Metcalfe, “and NASA can’t fund researchers in other countries.”

Metcalfe added that the “adopt a star” program supported the asteroseismic analysis of Kepler-444, “determining the precise age that makes this ancient planetary system so interesting… This private funding from citizens around the world has been an invaluable resource to facilitate our research and fuel amazing discoveries like this one.”

You can help this research by adopting one of the Kepler stars or planetary systems.

This research was published today in the Astrophysical Journal.

The team’s paper is titled, “An Ancient Extrasolar System with Five Sub-Earth-Size Planets.”

December 3, 2014December 23, 2015 by Elizabeth Howell

Europa Life: Could ‘Extreme Shrimp’ Point To Microbes On That Moon?

This is a type of shrimp that lives in hydrothermal vents (areas of hot water) in the Caribbean. NASA is studying Rimicaris hybisae and other "extreme shrimp" to learn more about lifeforms that could survive on other worlds. Credit: Chris German, WHOI/NSF, NASA/ROV Jason C: 2012 Woods

For all of the talk about aliens that we see in science fiction, the reality is in our Solar System, any extraterrestrial life is likely to be microbial. The lucky thing for us is there are an abundance of places that we can search for them — not least Europa, an icy moon of Jupiter believed to harbor a global ocean and that NASA wants to visit fairly soon. What lurks in those waters?

To gain a better understanding of the extremes of life, scientists regularly look at bacteria and other lifeforms here on Earth that can make their living in hazardous spots. One recent line of research involves shrimp that live in almost the same area as bacteria that survive in vents of up to 750 degrees Fahrenheit (400 degrees Celsius) — way beyond the boiling point, but still hospitable to life.

Far from sunlight, the bacteria receive their energy from chemical combinations (specifically, hydrogen sulfide). While the shrimp certainly don’t live in these hostile areas, they perch just at the edge — about an inch away. The shrimp feed on the bacteria, which in turn feed on the hydrogen sulfide (which is toxic to larger organisms if there is enough of it.) Oh, and by the way, some of the shrimps are likely cannibals!

One species called Rimicaris hybisae, according to the evidence, likely feeds on each other. This happens in areas where the bacteria are not as abundant and the organisms need to find some food to survive. To be sure, nobody saw the shrimps munching on each other, but scientists did find small crustaceans inside them — and there are few other types of crustaceans in the area.

But how likely, really, are these organisms on Europa? Bacteria might be plausible, but something larger and more complicated? The researchers say this all depends on how much energy the ecosystems have to offer. And in order to see up close, we’d have to get underwater somehow and do some exploring.

In a recent Universe Today interview with Mike Brown, a professor of planetary science at the California Institute of Technology, the renowned dwarf-planet hunter talked about how a submarine could do some neat work.

“In the proposed missions that I’ve heard, and in the only one that seems semi-viable, you land on the surface with basically a big nuclear pile, and you melt your way down through the ice and eventually you get down into the water,” he said. “Then you set your robotic submarine free and it goes around and swims with the big Europa whales.” You can see the rest of that interview here.

Source: Jet Propulsion Laboratory

The puzzling, fascinating surface of Jupiter's icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA's Galileo spacecraft in the late 1990s. Image credit: NASA/JPL-Caltech/SETI Institute — The puzzling, fascinating surface of Jupiter’s icy moon Europa looms large in this newly-reprocessed color view, made from images taken by NASA’s Galileo spacecraft in the late 1990s. Image credit: NASA/JPL-Caltech/SETI Institute

October 3, 2014December 23, 2015 by Elizabeth Howell

How Do Aliens Think? We Need To Learn About Their Biology First, Analyst Argues

TORONTO, CANADA – Should E.T. finally give Earth a ring, it’s not only important to understand what the message says but why it is being sent, a speaker at a talk about extraterrestrials urged this week. This requires understanding about alien social behavior, also known as sociology.

“We keep complaining about the fact that we know so little about extraterrestrials in general, and even though sociology is mentioned in the Drake Equation, it is generally agreed that is the most difficult aspect to address,” said Morris Jones, an Australian who describes himself as an independent space analyst.

The Drake Equation is a set of variables proposed by astronomer Frank Drake that estimates how many intelligent, communicating civilizations there are in the universe. While speaking at the International Astronautical Congress Wednesday (Oct. 1), Jones pointed out that most talk about alien communications focuses on the basics – how they transmit, and where to search, and whether we can hear them. But to fully understand the message, we have to understand how their society works.

Extraterrestrials in the 1979 movie "Close Encounters of the Third King." Credit: Columbia Pictures / Alien Wiki — Extraterrestrials in the 1979 movie “Close Encounters of the Third Kind.” Credit: Columbia Pictures / Alien Wiki

How a society functions is partly a function of biology, Jones argued. So if humans decided to incorporate machine intelligence in their bodies, it would be reasonable to assume that society would change because of that. “Machine society is an entirely different sociology, and that we cannot predict,” Jones said. An extraterrestrial civilization could use machines, drugs, genetic engineering or surgery to alter their basic nature (something that is used also with humans.)

Class systems could also be in place that are similar to the animal kingdom. Herd and hive sociology covers how animals behave. Pigeons, for example, flock together for mutual protection. In the insect world, beings such as ants tend to be born in specific physiological roles that prepare them for different functions — such as the queen ant that is the mother of other ants in the colony.

These are societies that we could predict, perhaps, but more intriguing are those that are difficult to extrapolate from human experience or observation. Jones is particularly interested in cryptosociology. That’s the concept that because we can’t predict yet how alien civilizations will behave, we can speculate what they are capable of.

SETI's Allen Telescope Array monitor the stars for signs of intelligent life (SETI.org) — SETI’s Allen Telescope Array monitors the stars for signs of intelligent life (SETI.org)

Here’s where the danger lies, Jones said: it’s possible to make unfounded assumptions that cannot be tested through science. “If our thinking is too wild it could degenerate into dragons and unicorns, and become a pseduo science. At some point it has to be a framework of … reason and evidence,” he said.

Here, Jones urges using systems theories that would make each system consistent with itself. On Earth, if a system contradicts itself it disappears — such as with ancient civilizations that failed.

While he didn’t detail what these systems could be — predicting them would be difficult, he said — Jones argued it would be tough to really know the true sociology of extraterrestrial civilizations when we not only are ignorant about their biology, but aspects of our own sociology.

August 1, 2014December 23, 2015 by Elizabeth Howell

Companion Planet Could Keep Alien Earths Warm In Old Age: Study

An artist's concept of a rocky world orbiting a red dwarf star. (Credit: NASA/D. Aguilar/Harvard-Smithsonian center for Astrophysics).

People are generally social creatures, and in the case of planets that generally is the case as well. Many of these alien worlds we have discovered are in groups of two or more around their parent star or stars. A new study, however, goes a step further and says that a companion planet could actually save another planet in its old age.

“Planets cool as they age. Over time their molten cores solidify and inner heat-generating activity dwindles, becoming less able to keep the world habitable by regulating carbon dioxide to prevent runaway heating or cooling,” the University of Washington stated.

“But astronomers … have found that for certain planets about the size of our own, the gravitational pull of an outer companion planet could generate enough heat — through a process called tidal heating — to effectively prevent that internal cooling, and extend the inner world’s chance at hosting life.”

The researchers ran computer models finding that tidal heating, which is known to happen on Jupiter’s moons Europa and Io, can also happen in planets the size of Earth that are in non-circular orbits around dwarf stars. An outer planet would keep the orbit from stabilizing in a circle, generating tidal heating and keeping conditions potentially warm enough for life.

The study, led by the University of Arizona’s Christa Van Laerhoven, will be available in the Monthly Notices of the Royal Astronomical Society and is available now in preprint version on Arxiv.

June 24, 2014December 23, 2015 by Ken Kremer

Curiosity Marks Milestone Anniversary – 1 Martian Year On Mars!

NASA's Mars Curiosity Rover captures a selfie to mark a full Martian year -- 687 Earth days -- spent exploring the Red Planet. Curiosity Self-Portrait was taken at the 'Windjana' Drilling Site in April and May 2014 using the Mars Hand Lens Imager (MAHLI) camera at the end of the roboic arm. Credit: NASA/JPL-Caltech/MSSS

NASA’s Curiosity rover celebrated a milestone anniversary today, June 24 – 1 Martian Year on Mars!

A Martian year is equivalent to 687 Earth days, or nearly two Earth years.

NASA marked the illustrious achievement with the release of a new ‘selfie’ captured recently while drilling deep into the Red Planet to unlock the secrets of Mars hidden past eons ago when the planet was far warmer and wetter and more conducive to the origin of life.

Curiosity’s new self-portrait was taken at the ‘Windjana’ Drilling Site in April and May 2014 using the Mars Hand Lens Imager (MAHLI) camera at the end of the robotic arm.

As of today the 1 ton rover has been exploring the alien surface for a full Martian year since her nail biting touchdown inside Gale Crater on Aug. 5, 2012 – using the unprecedented sky crane maneuver which culminated in a rocket assisted touchdown astride a humongous mountain named Mount Sharp.

Mount Sharp dominates the center of Gale Crater and reaches 3.4 miles (5.5 km) into the Martian sky – taller than Mount Rainier.

During Mars Year 1 on Mars, Earth’s metallic emissary has already accomplished her primary objective of discovering a habitable zone on the Red Planet that contains the chemical ingredients necessary to support microbial life in the ancient past.

During 2013, Curiosity conducted the first two drill campaigns at the ‘John Klein’ and ‘Cumberland’ outcrop targets inside Yellowknife Bay. They were both mudstone rock outcrops and the interiors were markedly different in color and much lighter compared to the new drill site at ‘Windjana’ into a slab of red, sandstone rock.

The fresh bore hole was drilled into the “Windjana” rock outcrop on May 5, 2014, Sol 621, at the base of Mount Remarkable at a science stopping point called “The Kimberley Waypoint.”

It was 0.63 inch (1.6 centimeters) in diameter and about 2.6 inches (6.5 centimeters) deep and resulted in a mound of dark grey colored drill tailings piled around.

Windjana lies some 2.5 miles (4 kilometers) southwest of Yellowknife Bay.

Curiosity has successfully delivered pulverized and sieved samples from all three drill sites to the pair of onboard miniaturized chemistry labs; the Chemistry and Mineralogy instrument (CheMin) and the Sample Analysis at Mars instrument (SAM) – for chemical and compositional analysis.

Composite photo mosaic shows deployment of NASA Curiosity rovers robotic arm and two holes after drilling into ‘Windjana’ sandstone rock on May 5, 2014, Sol 621, at Mount Remarkable as missions third drill target for sample analysis by rover’s chemistry labs. The navcam raw images were stitched together from several Martian days up to Sol 621, May 5, 2014 and colorized. Credit: NASA/JPL-Caltech/Ken Kremer - kenkremer.com/Marco Di Lorenzo — Composite photo mosaic shows deployment of NASA Curiosity rovers robotic arm and two holes after drilling into ‘Windjana’ sandstone rock on May 5, 2014, Sol 621, at Mount Remarkable as missions third drill target for sample analysis by rover’s chemistry labs. The navcam raw images were stitched together from several Martian days up to Sol 621, May 5, 2014 and colorized. Credit: NASA/JPL-Caltech/Ken Kremer – kenkremer.com/Marco Di Lorenzo

It was through the results of the SAM and CheMin analysis and the discovery of clay minerals that the science team was able to determine that this area on the floor of Gale Crater is a habitable zone.

“Windjana has more magnetite than previous samples we’ve analyzed,” said David Blake, principal investigator for Curiosity’s Chemistry and Mineralogy (CheMin) instrument at NASA’s Ames Research Center, Moffett Field, California, in a statement.

“A key question is whether this magnetite is a component of the original basalt or resulted from later processes, such as would happen in water-soaked basaltic sediments. The answer is important to our understanding of habitability and the nature of the early-Mars environment.”

Chemical analysis and further sample deliveries are in progress as NASA’s rover is ‘on the go’ to simultaneously maximize movement and research activities.

Curiosity’s Panoramic view of Mount Remarkable at ‘The Kimberley Waypoint’ where rover conducted 3rd drilling campaign inside Gale Crater on Mars. The navcam raw images were taken on Sol 603, April 17, 2014, stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer – kenkremer.com/Marco Di Lorenzo. Featured on APOD - Astronomy Picture of the Day on May 7, 2014 — Curiosity’s Panoramic view of Mount Remarkable at ‘The Kimberley Waypoint’ where rover conducted 3rd drilling campaign inside Gale Crater on Mars. The navcam raw images were taken on Sol 603, April 17, 2014, stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer – kenkremer.com/Marco Di Lorenzo
Featured on APOD – Astronomy Picture of the Day on May 7, 2014

The lower reaches of Mount Sharp are the rovers ultimate goal because the sedimentary layers are believed to hold caches of water altered minerals based on high resolution measurements obtained by the CRISM spectrometer aboard NASA’s powerful Martian ‘Spysat’ – the Mars Reconnaissance Orbiter (MRO) – soaring overhead.

Curiosity still has about another 2.4 miles (3.9 kilometers) to go to reach the entry way at a gap in the dunes at the foothills of Mount Sharp sometime later this year.

Curiosity snaps selfie at Kimberley waypoint with towering Mount Sharp backdrop on April 27, 2014 (Sol 613). Inset shows MAHLI camera image of rovers mini-drill test operation on April 29, 2014 (Sol 615) into “Windjama” rock target at Mount Remarkable butte. MAHLI color photo mosaic assembled from raw images snapped on Sol 613, April 27, 2014. Credit: NASA/JPL/MSSS/Marco Di Lorenzo/Ken Kremer - kenkremer.com — Curiosity snaps selfie at Kimberley waypoint with towering Mount Sharp backdrop on April 27, 2014 (Sol 613). Inset shows MAHLI camera image of rovers mini-drill test operation on April 29, 2014 (Sol 615) into “Windjama” rock target at Mount Remarkable butte. MAHLI color photo mosaic assembled from raw images snapped on Sol 613, April 27, 2014. Credit: NASA/JPL/MSSS/Marco Di Lorenzo/Ken Kremer – kenkremer.com

To date, Curiosity’s odometer totals over 4.9 miles (7.9 kilometers) since landing inside Gale Crater on Mars in August 2012. She has taken over 159,000 images.

This map shows in red the route driven by NASA's Curiosity Mars rover from the "Bradbury Landing" location where it landed in August 2012 (blue star at upper right) to nearly the completion of its first Martian year. The white line shows the planned route ahead. Image Credit: NASA/JPL — This map shows in red the route driven by NASA’s Curiosity Mars rover from the “Bradbury Landing” location where it landed in August 2012 (blue star at upper right) to nearly the completion of its first Martian year. The white line shows the planned route ahead. Image Credit: NASA/JPL

Stay tuned here for Ken’s continuing Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, commercial space, MAVEN, MOM, Mars and more planetary and human spaceflight news.

Ken Kremer
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Learn more about NASA’s Mars missions, upcoming sounding rocket and Orbital Sciences Antares ISS launch from NASA Wallops, VA in July and more about SpaceX, Boeing and commercial space and more at Ken’s upcoming presentations.

June 25: “Antares/Cygnus ISS Launch (July 10) and Suborbital Rocket Launch (June 26) from Virginia” & “Space mission updates”; Rodeway Inn, Chincoteague, VA, evening

June 22, 2014December 23, 2015 by Ken Kremer

Driving, Driving, Driving – Curiosity’s Top Priority on the Road to Mysterious Mount Sharp

Driving, Driving, Driving – that’s the number one priority for NASA’s rover Curiosity as she traverses across the floor of Gale Crater towards towering Mount Sharp on an expedition in search of the chemical ingredients of life that could support Martian microbes if they ever existed.

See our photo mosaics above and below showing the 1 ton rover trundling across the alien terrain of Mars – our Solar Systems most Earth-like planet and leaving behind dramatic wheel tracks in her wake.

“The top priority for MSL continues to be the traverse toward the base of Mt. Sharp,” wrote science team member Ken Herkenhoff in a mission update.

Curiosity has been on the move since mid-May after successfully completing her 3rd Martian drill campaign at a science stopping point called “The Kimberley” where she bored a fresh hole into the ‘Windjama’ rock target on May 5, Sol 621 at the base of Mount Remarkable.

“Progress has been good since leaving The Kimberley,” Herkenhoff added.

Investigating mysterious Mount Sharp is why Gale Crater was chosen as the landing site because the mountain holds clues to the habitability of the Red Planet.

Mars was far wetter and warmer – and more conducive to the origin of life – billions of years ago.

The six-wheeled rover has been traveling with all deliberate speed to get to the mountain with minimal science along the way.

“[Curiosity conducted] a 129-meter drive on Sol 662 (June 17),” says Herkenhoff.

“We successfully planned a rapid traverse sol last week, in which scientific observations are limited in favor of maximizing drive distance.”

Curiosity is driving on a path towards the ‘Murray Buttes’ – which lies across the dark and potentially treacherous dunes on the right side of Mount Sharp as seen in our photo mosaic above from Sol 651.

She will eventually ascend the mountain at the ‘Murray Buttes’ after the team locates a spot to carefully cross the sand dunes.

The fresh hole drilled into “Windjana” was 0.63 inch (1.6 centimeters) in diameter and about 2.6 inches (6.5 centimeters) deep and resulted in a mound of dark grey colored drill tailings piled around. It looked different from the initial two holes drilled at Yellowknife Bay in the spring of 2013.

Windjana was a cold red slab of enticing bumpy textures of Martian sandstone located at the base of ‘Mount Remarkable’ within the “The Kimberley Waypoint” region.

The first two drill campaigns involved boring into mudstone outcrops at Yellowknife Bay.

Windjana lies some 2.5 miles (4 kilometers) southwest of Yellowknife Bay.

Curiosity then successfully delivered pulverized and sieved samples to the pair of onboard miniaturized chemistry labs; the Chemistry and Mineralogy instrument (CheMin) and the Sample Analysis at Mars instrument (SAM) – for chemical and compositional analysis.

Chemical analysis and further sample deliveries are in progress as NASA’s rover is ‘on the go’ to simultaneously maximize movement and research activities.

The science and engineering team has deliberately altered the robots path towards the foothills of Mount Sharp which reaches 3.4 miles (5.5 km) into the Martian sky – taller than Mount Ranier.

The team decided to follow a new path to the mountain with smoother terrain after sharp edged rocks caused significant damage in the form of dents and holes to the robots 20 inch wide aluminum wheels.

The wheel punctures happened faster than expected in 2013 and earlier this year.

Curiosity still has about another 2.4 miles (3.9 kilometers) to go to reach the entry way at a gap in the dunes at the foothills of Mount Sharp sometime later this year.

Curiosity’s panoramic view departing Mount Remarkable and ‘The Kimberley Waypoint’ where rover conducted 3rd drilling campaign inside Gale Crater on Mars. The navcam raw images were taken on Sol 630, May 15, 2014, stitched and colorized. Credit: NASA/JPL-Caltech/Ken Kremer – kenkremer.com/Marco Di Lorenzo

To date, Curiosity’s odometer totals over 7.9 kilometers (4.9 miles) since landing inside Gale Crater on Mars in August 2012. She has taken over 159,000 images.

Stay tuned here for Ken’s continuing Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, commercial space, MAVEN, MOM, Mars and more planetary and human spaceflight news.

Ken Kremer

…………….
Learn more about NASA’s Mars missions, upcoming sounding rocket and Orbital Sciences Antares ISS launch from NASA Wallops, VA in July and more about SpaceX, Boeing and commercial space and more at Ken’s upcoming presentations

June 25: “Antares/Cygnus ISS Launch (July 10) and Suborbital Rocket Launch (June 26) from Virginia” & “Space mission updates”; Rodeway Inn, Chincoteague, VA, evening

June 16, 2014December 23, 2015 by Ken Kremer

Opportunity Peers Out from ‘Pillinger Point’ – Honoring British Beagle 2 Mars Scientist Where Ancient Water Flowed

Opportunity Mars rover peers into vast Endeavour Crater from Pillinger Point mountain ridge named in honor of Colin Pillinger, the Principal Investigator for the British Beagle 2 lander built to search for life on Mars. Pillinger passed away from a brain hemorrhage on May 7, 2014. This navcam camera photo mosaic was assembled from images taken on June 5, 2014 (Sol 3684) and colorized. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer-kenkremer.com

NASA’s decade old Opportunity rover has reached a long sought after region of aluminum-rich clay mineral outcrops at a new Endeavour crater ridge now “named ‘Pillinger Point’ after Colin Pillinger the Principal Investigator for the [British] Beagle 2 Mars lander”, Prof. Ray Arvidson, Deputy Principal Investigator for the rover, told Universe Today exclusively. See above the spectacular panoramic view from ‘Pillinger Point’ – where ancient water once flowed billions of year ago.

The Beagle 2 lander was built to search for signs of life on Mars.

The Mars Exploration Rover (MER) team named the noteworthy ridge in honor of Prof. Colin Pillinger – a British planetary scientist at the Open University in Milton Keynes, who passed away at the age of 70 on May 7, 2014.

‘Pillinger Point’ is a scientifically bountiful place possessing both clay mineral outcrops and mineral veins where “waters came up through the cracks”, Arvidson explained to me.

Since water is a prerequisite for life as we know it, this is a truly fitting tribute to name Opportunity’s current exploration site ‘Pillinger Point’ after Prof. Pillinger.

See our new photo mosaic above captured by Opportunity peering out from ‘Pillinger Point’ ridge on June 5, 2014 (Sol 3684) and showing a panoramic view around the eroded mountain ridge and into vast Endeavour crater.

The gigantic crater spans 14 miles (22 kilometers) in diameter.

See below our Opportunity 10 Year traverse map showing the location of Pillinger Point along the segmented rim of Endeavour crater.

British planetary scientist Colin Pillinger with the Beagle 2 lander.

Pillinger Point is situated south of Solander Point and Murray Ridge along the western rim of Endeavour in a region with caches of clay minerals indicative of an ancient Martian habitable zone.

For the past several months, the six wheeled robot has been trekking southwards from Solander towards the exposures of aluminum-rich clays – now named Pillinger Point- detected from orbit by the CRISM spectrometer aboard NASA’s powerful Martian ‘Spysat’ – the Mars Reconnaissance Orbiter (MRO) – while gathering context data at rock outcrops along the winding way.

“We are about 3/5 of the way along the outcrops that show an Al-OH [aluminum-hydroxl] montmorillonite [clay mineral] signature at 2.2 micrometers from CRISM along track oversampled data,” Arvidson told me.

“We have another ~160 meters to go before reaching a break in the outcrops and a broad valley.”

The rover mission scientists ultimate goal is travel even further south to ‘Cape Tribulation’ which holds a motherlode of the ‘phyllosilicate’ clay minerals based on extensive CRISM measurements accomplished earlier at Arvidson’s direction.

“The idea is to characterize the outcrops as we go and then once we reach the valley travel quickly to Cape Tribulation and the smectite valley, which is still ~2 km to the south of the present rover location,” Arvidson explained.

Mars Express and Beagle 2 were launched in 2003, the same year as NASA’s twin rovers Spirit and Opportunity, on their interplanetary voyages to help unlock the mysteries of Mars potential for supporting microbial life forms.

Pillinger was the driving force behind the British built Beagle 2 lander which flew to the Red Planet piggybacked on ESA’s Mars Express orbiter. Unfortunately Beagle 2 vanished without a trace after being deployed from the orbiter on Dec. 19, 2003 with an expected air bag assisted landing on Christmas Day, Dec. 25, 2003.

In an obituary by the BBC, Dr David Parker, the chief executive of the UK Space Agency, said that Prof. Pillinger had played a critical role in raising the profile of the British space programme and had inspired “young people to dream big dreams”.

NASA’s Opportunity Mars rover captures sweeping panoramic vista near the ridgeline of 22 km (14 mi) wide Endeavour Crater’s western rim. The center is southeastward and also clearly shows the distant rim. See the complete panorama below. This navcam panorama was stitched from images taken on May 10, 2014 (Sol 3659) and colorized. Credit: NASA/JPL/Cornell/Marco Di Lorenzo/Ken Kremer-kenkremer.com

During his distinguished career Pillinger also analyzed lunar rock samples from NASA’s Apollo moon landing missions and worked on ESA’s Rosetta mission.

“It’s important to note that Colin’s contribution to planetary science goes back to working on Moon samples from Apollo, as well as his work on meteorites,” Dr Parker told the BBC.

Today, June 16, marks Opportunity’s 3696th Sol or Martian Day roving Mars – compared to a warranty of just 90 Sols.

So far she has snapped over 193,400 amazing images on the first overland expedition across the Red Planet.

Her total odometry stands at over 24.51 miles (39.44 kilometers) since touchdown on Jan. 24, 2004 at Meridiani Planum.

Meanwhile on the opposite side of Mars, Opportunity’s younger sister rover Curiosity is trekking towards gigantic Mount Sharp after drilling into her 3rd Red Planet rock at Kimberley.

Stay tuned here for Ken’s continuing Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, MAVEN, MOM, Mars and more planetary and human spaceflight news.

Ken Kremer

Traverse Map for NASA’s Opportunity rover from 2004 to 2014 - A Decade on Mars. This map shows the entire path the rover has driven during a decade on Mars and over 3692 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location along Pillinger Point ridge south of Solander Point summit at the western rim of Endeavour Crater and heading to clay minerals at Cape Tribulation. Opportunity discovered clay minerals at Esperance - indicative of a habitable zone. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer — Traverse Map for NASA’s Opportunity rover from 2004 to 2014 – A Decade on Mars
This map shows the entire path the rover has driven during a decade on Mars and over 3692 Sols, or Martian days, since landing inside Eagle Crater on Jan 24, 2004 to current location along Pillinger Point ridge south of Solander Point summit at the western rim of Endeavour Crater and heading to clay minerals at Cape Tribulation. Opportunity discovered clay minerals at Esperance – indicative of a habitable zone. Credit: NASA/JPL/Cornell/ASU/Marco Di Lorenzo/Ken Kremer

June 7, 2014December 23, 2015 by Ken Kremer

Curiosity Captures Stunning New Mount Sharp Panorama ‘On The Go’

Curiosity rover panorama of Mount Sharp captured on June 6, 2014 (Sol 651) during traverse inside Gale Crater. Note rover wheel tracks at left. She will eventually ascend the mountain at the ‘Murray Buttes’ at right later this year. Assembled from Mastcam color camera raw images and stitched by Marco Di Lorenzo and Ken Kremer. Credit: NASA/JPL/MSSS/Marco Di Lorenzo/Ken Kremer-kenkremer.com
Story updated[/caption]

Within the past Martian day on Friday, June 6, NASA’s rover Curiosity captured a stunning new panorama of towering Mount Sharp and the treacherous sand dunes below which she must safely traverse before reaching the mountains foothills – while ‘On The Go’ to her primary destination.

See our brand new Mount Sharp photo mosaic above – taken coincidentally by humanity’s emissary on Mars on the 70th anniversary of D-Day on Earth.

Basically she’s eating desiccated dirt while running a Martian marathon.

Having said ‘Goodbye Kimberley’ after drilling her third bore hole deep into a cold red slab of enticing bumpy textures of Martian sandstone in the name of science, our intrepid mega rover Curiosity is trundling along with all deliberate speed towards the inviting slopes of sedimentary rocks at the base of mysterious Mount Sharp which hold clues to the habitability of the Red Planet.

The sedimentary layers of Mount Sharp, which reaches 3.4 miles (5.5 km) into the Martian sky, is the six wheeled robots ultimate destination inside Gale Crater because it holds caches of water altered minerals.

Such minerals could possibly mark locations that sustained potential Martian microbial life forms, past or present, if they ever existed.

Mars was far wetter and warmer – and more conducive to the origin of life – billions of years ago.

The 1 ton robot is driving on a path towards the Murray Buttes which lies across the dunes on the right side of Mount Sharp as seen in our photo mosaic above, with wheel tracks on the left side.

She will eventually ascend the mountain at the ‘Murray Buttes’ after crossing the sand dunes.

Curiosity still has roughly another 4 kilometers of driving to go to reach the foothills of Mount Sharp sometime later this year.

Approximately four weeks ago, Curiosity successfully completed her 3rd drilling campaign since landing at the science waypoint region called “The Kimberley” on May 5, Sol 621, into the ‘Windjana’ rock target at the base of a 16 foot tall ( 5 Meter) hill called Mount Remarkable.

The fresh hole drilled into “Windjana” was 0.63 inch (1.6 centimeters) in diameter and about 2.6 inches (6.5 centimeters) deep and resulted in a mound of dark grey colored drill tailings piled around. It looked different from the initial holes drilled at Yellowknife Bay in the spring of 2013.

Windjana lies some 2.5 miles (4 kilometers) southwest of Yellowknife Bay.

Before departing, Curiosity blasted the hole multiple times with her million watt laser on the Mast mounted Chemistry and Camera (ChemCam) instrument , leaving no doubt of her capabilities or intentions.

And she completed an up close examination of the texture and composition of ‘Windjana’ with the MAHLI camera and spectrometers at the end of her 7-foot-long (2 meter) arm to glean every last drop of science before moving on.

“Windjana” is named after a gorge in Western Australia.

While ‘On the Go’ to Mount Sharp, the rover is keeping busy with science activities by investigating the newly cored Martian material.

“Inside Curiosity we continue to analyse the Kimberley samples with CheMin and SAM,” wrote mission team member John Bridges in an update.

To date, Curiosity’s odometer totals 3.8 miles (6.1 kilometers) since landing inside Gale Crater on Mars in August 2012. She has taken over 154,000 images.

Stay tuned here for Ken’s continuing Curiosity, Opportunity, Orion, SpaceX, Boeing, Orbital Sciences, commercial space, MAVEN, MOM, Mars and more planetary and human spaceflight news.

Ken Kremer

The Mars Hand Lens Imager on NASA's Curiosity Mars rover provided this nighttime view of a hole produced by the rover's drill and, inside the hole, a line of scars produced by the rover's rock-zapping laser. The hole is 0.63 inch (1.6 centimeters) in diameter. The camera used its own white-light LEDs to illuminate the scene on May 13, 2014. Credit: NASA/JPL-Caltech/MSSS — The Mars Hand Lens Imager on NASA’s Curiosity Mars rover provided this nighttime view of a hole produced by the rover’s drill and, inside the hole, a line of scars produced by the rover’s rock-zapping laser. The hole is 0.63 inch (1.6 centimeters) in diameter. The camera used its own white-light LEDs to illuminate the scene on May 13, 2014. Credit: NASA/JPL-Caltech/MSSS

June 4, 2014December 23, 2015 by David Dickinson

Discovered: Two New Planets for Kapteyn’s Star

An artist's conception of the planets orbiting Kapteyn's Star (inset) and the stream of stars associated with an ancient galaxy merger. Credit: image courtesy of Victor Robles, James Bullock, and Miguel Rocha at University of California Irvine and Joel Primack at University of California Santa Cruz.

The exoplanet discoveries have been coming fast and furious this week, as astronomers announced a new set of curious worlds this past Monday at the ongoing American Astronomical Society’s 224th Meeting being held in Boston, Massachusetts.

Now, chalk up two more worlds for a famous red dwarf star in our own galactic neck of the woods. An international team of astronomers including five researchers from the Carnegie Institution announced the discovery this week of two exoplanets orbiting Kapteyn’s Star, about 13 light years distant. The discovery was made utilizing data from the HIRES spectrometer at the Keck Observatory in Hawaii, as well as the Planet Finding Spectrometer at the Magellan/Las Campanas Observatory and the European Southern Observatory’s La Silla facility, both located in Chile.

The Carnegie Institution astronomers involved in the discovery were Pamela Arriagada, Ian Thompson, Jeff Crane, Steve Shectman, and Paul Butler. The planets were discerned using radial velocity measurements, a planet-hunting technique which looks for tiny periodic changes in the motion of a star caused by the gravitational tugging of an unseen companion.

“That we can make such precise measurements of such subtle effects is a real technological marvel,” said Jeff Crane of the Carnegie Observatories.

Kapteyn’s Star (pronounced Kapt-I-ne’s Star) was discovered by Dutch astronomer Jacobus Kapteyn during a photographic survey of the southern hemisphere sky in 1898. At the time, it had the highest proper motion of any star known at over 8” arc seconds a year — Kapteyn’s Star moves the diameter of a Full Moon across the sky every 225 years — and held this distinction until the discovery of Barnard’s Star in 1916. About a third the mass of our Sun, Kapteyn’s Star is an M-type red dwarf and is the closest halo star to our own solar system. Such stars are thought to be remnants of an ancient elliptical galaxy that was shredded and subsequently absorbed by our own Milky Way galaxy early on in its history. Its high relative velocity and retrograde orbit identify Kapteyn’s Star as a member of a remnant moving group of stars, the core of which may have been the glorious Omega Centauri star cluster.

The worlds of Kapteyn’s Star are proving to be curious in their own right as well.

“We were surprised to find planets orbiting Kapteyn’s Star,” said lead author Dr. Guillem Anglada-Escude, a former Carnegie post-doc now with the Queen Mary University at London. “Previous data showed some irregular motion, so we were looking for very short period planets when the new signals showed up loud and clear.”

The location of Kapteyn's Star in teh constellation Pictor. Created using Stellarium. — The location of Kapteyn’s Star in the constellation Pictor. Created using Stellarium.

It’s curious that nearby stars such as Kapteyn’s, Teegarden’s and Barnard’s star, though the site of many early controversial claims of exoplanets pre-1990’s, have never joined the ranks of known worlds which currently sits at 1,794 and counting until the discoveries of Kapteyn B and C. Kapteyn’s star is the 25th closest to our own and is located in the southern constellation Pictor. And if the name sounds familiar, that’s because it made our recent list of red dwarf stars for backyard telescopes. Shining at magnitude +8.9, Kapteyn’s star is visible from latitude 40 degrees north southward.

Kapteyn B and C are both suspected to be rocky super-Earths, at a minimum mass of 4.5 and 7 times that of Earth respectively. Kapteyn B orbits its primary once every 48.6 days at 0.168 A.U.s distant (about 40% of Mercury’s distance from our Sun) and Kapteyn C orbits once every 122 days at 0.3 A.U.s distant.

This is really intriguing, as Kapteyn B sits in the habitable zone of its host star. Though cooler than our Sun, the habitable zone of a red dwarf sits much closer in than what we enjoy in our own solar system. And although such worlds may have to contend with world-sterilizing flares, recent studies suggest that atmospheric convection coupled with tidal locking may allow for liquid water to exist on such worlds inside the “snow line”.

And add to this the fact that Kapteyn’s Star is estimated to be 11.5 billion years old, compared with the age of the universe at 13.7 billion years and our own Sun at 4.6 billion years. Miserly red dwarfs measure their future life spans in the trillions of years, far older than the present age of the universe.

A comparison of habitable zones of Sol-like versus Red dwarf stars. Credit: Chewie/Ignacio Javier under a Wikimedia Commons 3.0 license). — A comparison of habitable zones of Sol-like versus red dwarf stars. Credit: Chewie/Ignacio Javier under a Wikimedia Commons 3.0 license).

“Finding a stable planetary system with a potentially habitable planet orbiting one of the very nearest stars in the sky is mind blowing,” said second author and Carnegie postdoctoral researcher Pamela Arriagada. “This is one more piece of evidence that nearly all stars have planets, and that potentially habitable planets in our galaxy are as common as grains of sand on the beach.”

Of course, radial velocity measurements only give you lower mass constraints, as we don’t know the inclination of the orbits of the planets with respect to our line of sight. Still, this exciting discovery could potentially rank as the oldest habitable super-Earth yet discovered, and would make a great follow-up target for the direct imaging efforts or the TESS space telescope set to launch in 2017.

“It does make you wonder what kind of life could have evolved on those planets over such a long time,” added Dr Anglada-Escude. And certainly, the worlds of Kapteyn’s Star have had a much longer span of time for evolution to have taken hold than Earth… an exciting prospect, indeed!

-Read author Alastair Reynolds’ short science fiction piece Sad Kapteyn accompanying this week’s announcement.