A team of astronomers who had been creating a survey of stars at the Max-Planck Institute for Astronomy in Heidlberg, Germany have detected a planetary system – 375 light-years away in the constellation Cetus – that is nearly as old as the universe.

The star in the system, designated HIP 11952, is estimated to be 12.8 billion years old, having formed just a billion years after the Big Bang. Our system, by comparison, is only 4.6 billion years old. Two gas giant planets, HIP 11952b and HIP 11952c, each the size of Jupiter, orbit HIP 11952 and have an orbital period of seven days and nine and a half months, respectively.

The age of this system is certainly stunning, but the composition of the HIP 11952 and its planets are what baffles astronomers: they lack the presence of heavy elements (carbon, oxygen, and iron, for example), contradicting a major aspect of the Accretion theory.

Basically, the Accretion theory describes how solar systems are born and develop, but it also states that planets need a high concentration of heavy elements to form. Many planets that astronomers have studied before the discovery of the HIP 11952 system have all been made of many heavy elements. Even the gas giants in our own solar system contain them – mostly metals in their cores, which need these elements in order to form.

However, shortly after the Big Bang, the lighter elements (hydrogen and helium) dominated the universe. Stars were just beginning to form. Only when these first stars went nova did heavy elements exist, but this must have occurred billions of years following the Big Bang, considering the average lifespan of stars.

Despite the contradiction brought forth by the HIP 11952 system, the Accretion theory is still backed-up by evidence of other planets – largely detected by the NASA spacecraft Kepler – that are composed of heavier elements. These planets and their parent stars, however, are young in comparison with the universe’s age.

Nonetheless, the fact that HIP 11952b, and HIP 11952c exist proves that planets are able to form without the presence of heavy elements and, therefore, have astronomers considering new possibilities of how planets come into being. To solve the Accretion theory issue, they would need to further find and study older and metal-poor planets.

“We would like to discover and study more planetary systems of this kind,” Anna Pasquali tells Huffington Post. Pasquali is a co-author of the team’s paper and is from the Center for Astronomy at Heidelberg University (ZAH). “That would allow us to refine our theories of planet formation. The discovery of the planets of HIP 11952 shows that planets have been forming throughout the life of our Universe.”

According to their paper, the team accounts for the lack of heavy elements and HIP 11952’s long age by surmising that HIP 11952 is a dwarf star, a type of star that has low metallicity and a long lifespan.

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On March 17th, NASA’s spacecraft MESSENGER revealed surprising details about Mercury’s interior and topography, changing astronomers’ understanding of the small planet and how it was formed.

MESSENGER (MErcury Space Surface ENvironment, GEochemistry, and Ranging) is the first spacecraft sent to orbit and study Mercury, which orbits the Sun a mere 36 million miles away. It’s the innermost and hottest planet in our solar system. MESSENGER was launched in August 2004. Before traveling to Mercury, it made a series of flybys around the Earth (once) and Venus (twice).

MESSENGER finally arrived at Mercury on March 18, 2011 and went around three times. Using radio signals, the spacecraft studied Mercury’s gravitational field, magnetic field, topography, internal geological structure, and chemical composition. Because the results of MESSENGER’S flybys around Mercury were so valuable, its mission was extended to last for another year in November 2011.

Mercury’s topography has changed many times since Mercury was fully formed, meaning that there has been a considerable amount of geological activity. For that reason, before studying any of the planet’s internal structure and history, MESSENGER first produced an accurate map of Mercury’s gravitational field using information derived from the planet’s topography and spin state.

Thereafter, two studies were conducted simultaneously, examining Mercury’s internal structure and geography. In one study, the researchers involved with MESSENGER discovered that the planet’s core was much larger than previously thought: it takes up 85 percent of the planet’s radius. Furthermore, it is liquid instead of solid. Previously, scientists assumed that Mercury would have been cooled enough by now for the core to be solid.

Above the core lies an unusual layer that is composed of solid sulphur and iron – a layer not found in the other rocky planets in the Solar System. The outer layers of the internal structure consist of a solid silicate crust and mantle. It is thought that inside the larger liquid core lies a smaller solid core composed of sulphur and iron.

The other study of Mercury’s topography produced other surprising discoveries. When MESSENGER’s Mercury Laser Altimeter (MLA) produced a topographic model of the northern hemisphere and areas in the mid-latitude range, researchers learned that the elevation spread is smaller than similar regions on the Moon and Mars. The area that sticks out the most is lowlands that contain the northern volcanic plains.

Moreover, according to the Carnegie Institute for Science’s press release,

“… the interior plains of Caloris impact basin — 1,550 kilometers (960 miles) in diameter — have been modified so that part of the basin floor now stands higher than the rim. The elevated portion appears to be part of a quasi-linear rise that extends for approximately half the planetary circumference at mid-latitudes. These features imply that large-scale changes to Mercury’s topography occurred after the era of impact basin formation and large-scale emplacement of volcanic plains had ended.”

This new knowledge of Mercury’s internal structure and topography gives insight as to how Mercury formed thermally and how the planet’s magnetic field is generated. Details of the findings of each study from MESSENGER’s mission will appear in two separate papers, which will appear on March 23 in the journal Science.

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On February 2, a team of astronomers detected an exoplanet (short for extrasolar planet) located in the habitable zone, a slim area in which a planet must be located, so that it is not too close nor too far away from the star it orbits, thus having a surface temperature that can sustain liquid. This newly discovered exoplanet may be able to sustain water and even life.

Using data from the European Southern Observatory, the W.M. Keck Observatory in Hawaii, and the Carnegie Planet Finder Spectograph at the Magellan II Telescope in Chile, the astronomers – from the University of California in Santa Cruz and the private research organization Carnegie Institution for Science in Washington, DC – found the exoplanet through discerning the gravitational tug it and its parent star impose on each other. The system lies 22 light-years away in the constellation Scorpius.

“This is basically our next-door neighbor,” Steven Vogt tells Space.com. Vogt, one of the members of the team, is an astronomer at the University of California. “It’s very nearby. There are only about 100 stars closer to us than this one.”

“We’ve been explicitly focusing on very nearby stars,” he adds, “because with today’s technology, we could send a robotic probe out there, and within a few hundred years, it could be sending back picture postcards.”

The star, dubbed GJ 667C, is a part of a triple star system. Unlike its companion stars, which are orange K dwarfs, GJ 667C is an M-class dwarf: it is much smaller and less luminous than the Sun and emits infrared light, which is less intense in light and temperature. GJ 667C’s composition is very different from that of the Sun’s, lacking elements heavier than hydrogen and helium such as carbon, iron, and silicon that are needed to form planets.

“We shouldn’t have really expected this star to be a likely case for harboring planets,” says Vogt.

The exoplanet, named GJ 667Cc, is a super-Earth, roughly 4.5 times the size of the Earth. Because of the absence of heavy elements, much of GJ 667Cc’s mass comes from ice and gas. The orbital period of GJ 667Cc measures 28 days, which would seem dauntingly close to us compared to the Earth’s orbital period.

A planet that takes the same amount of time to orbit the Sun (for instance) would roast; however, GJ 667C’s weak temperature and light, and the fact that GJ 667Cc receives 10 percent of the light the Earth receives from the Sun, counterbalance the closeness of the exoplanet, creating a comfortable region in which to dwell.

Furthermore, GJ 667Cc is in the right spot to absorb the same amount of energy that the Earth absorbs from the Sun to have an atmosphere. In the Carnegie Institution for Science press release, Guillem Anglada-Escudé – co-leader of the study and lead writer of the team’s paper that will soon be published in The Astrophysical Journal Letters – states, “This planet is the new best candidate to support liquid water and, perhaps, life as we know it.”

GJ 667Cc has a sibling, GJ 667Cb, which is around the size of the Earth. Unlike GJ 667Cc, GJ 667Cb has a much smaller orbital period. Hence, it is too close and has too high a temperature to sustain liquid.

Only one other exoplanet located in the habitable zone has been discovered before, Kepler-22b, which was detected by the NASA spacecraft Kepler on December 5, 2011. Astronomers believe that Kepler-22b, which is 2.4 times the Earth’s size, may also maintain water and life.

Image Courtesy of  http://www.esa.int

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Astronomers part of the international collaboration Probing Lensing Anomalies NETwork (PLANET) calculated the approximate number of planets based on statistical analyses from multiple surveys gathered from observatories, institutions, and ground-based telescopes, including NASA’s spacecraft Kepler, the European Southern Observatory (ESO), the Niels Bohr Institute, the Optical Gravitational Lensing Experiment (OGLE), and the Microlensing Observations in Astrophysics (MOA).

PLANET has taken 16 years to find planets, and six to make a statistical hypothesis (from 2002 to 2007). It is estimated that there are at least 100 billion stars in the Milky Way and that each one has 1.6 planets in orbit on average, coming to a total of 160 billion hypothetical planets. This number is much, much higher than the number originally predicted.

Astronomers use three methods to search for planets. The first one is called transiting, in which one observes a stars’ level of brightness. If the level slightly drops, the dip acts as a signal that a planet is crossing the star during its orbit. The second method is the radial-velocity method. When planets orbit a star, the star does not remain stationary.

Rather, it moves in a small circular motion, causing the planet’s gravitational pull. Lastly, the third method is gravitational microlensing. In relation to an observer on Earth, two stars, one in front of the other, seem to form a straight line. The foreground star causes light from the background star to curve, thus magnifying the latter. If there is a slight temporary difference in the light curve from the foreground star, a planet is orbiting the star.

With the former two methods, astronomers can only find low-mass planets closely orbiting stars. They are what the Kepler spacecraft uses to hunt for planets. The third one, on the other hand, is more sensitive: astronomers can find planets of all sizes (from Mercury-sized to Jupiter-sized) and those that are near and far from their parent stars. In addition, planets’ masses can be determined.

“Together,” Uffe Gråe Jørgensen states in the Niels Bohr Institute press release, “the three methods are, for the first time, able to say something about how common our own solar system is.” Jørgensen is the head of the Astrophysics and Planetary Science research group at the Niels Bohr Institute at the University of Copenhagen.

Based on the collected data, astronomers predict that Earth-like planets (small and rocky) are much more common in the galaxy than gas giants like Jupiter. According to Stephen Kane – who is a part of NASA’s Exoplanet Science Institute at the California Institute of Technology in Pasadena, California – in the HubbleSite press release, “This is encouraging news for investigations into habitable planets.”

Ultimately, this new hypothesis significantly increases the probability of the existence of extraterrestrial life, even sentient life.

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Working with the Palomar Observatory near San Diego and the W.M. Keck Observatory in Hawaii and using NASA’s spacecraft Kepler, astronomers from the California Institute of Technology have found three teeny, rocky, extrasolar planets (otherwise known as exoplanets, which lie beyond our solar system).

NASA launched Kepler in 2009 to search for Earth-like planets that orbit stars in the habitable zone, a region colloquially called the “Goldilocks Zone”, in which a planet must not be too close or too far from a star, so that its temperature would be just right to be habitable for life. Kepler uses a method called transiting to accomplish its mission: it sees if any stars have slight dips in brightness caused by a planet, which eventually eclipses its parent star sometime during its orbit.

The freshly discovered planetary system’s star is named KOI-961 (KOI is an acronym for Kepler Object in Question). Approximately 130 light-years from the Earth, KOI-961 is a red dwarf – a pipsqueak of a star compared to the Sun, which is six times larger. KOI-961 is similar to a nearby star, Barnard’s Star, which is also a red dwarf. Astronomers used information about Barnard’s Star to determine KOI-961′s characteristics, which were then used to calculate its companion planets’ sizes.

The planets’ names are KOI-961.01, KOI-961.02, and KOI-961.03 and have the radii of 0.78, 0.73, and 0.57 times that of the Earth, respectively. The smallest, KOI-961.03, is about the size of Mars, and the other two are about the size of Venus. All three do not lie in habitable zones; they orbit their parent star too closely, and one year equals two days.

Due to their incredibly close orbits, they are too hot to form liquid, let alone for life to thrive. Temperatures are hundreds of degrees, with the closest, KOI-961.01, having a surface temperature of nearly 1,000 degrees Fahrenheit (500°C).

This planetary system is the tiniest known to astronomers. John Johnson, assistant professor of astronomy at Caltech and co-author of the team’s paper, states in the Caltech press release, “It’s actually more similar to Jupiter and its moons in scale than any other planetary system. The discovery is further proof of the diversity of planetary systems in our galaxy.”

Red dwarfs are the most common type of star in our home galaxy, the Milky Way, making up eight out of every ten stars. Because of their ubiquity, Kepler may find more planetary systems with red dwarfs as parent stars. “That boosts the chances of other life being in the universe – that’s the ultimate result here,” Johnson says.

In the past, Kepler has found numerous gas giants around the sizes of Jupiter and Neptune. Its most recent discoveries occurred in December 2011, when it detected Kepler-22b, the first planet discovered to orbit in the habitable zone, and Kepler-20e and Kepler-20f, the first Earth-sized exoplanets detected.

The more planets Kepler detects nowadays, the more they become smaller and rockier, it seems. Kepler’s last two discoveries increases the probability that there may be more rocky exoplanets than astronomers thought, thereby, boosting the chance of the existence of extraterrestrial life.

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In early January, researchers at the California Institute of California (Caltech) created a computer model that reproduces Titan’s atmosphere and methane cycle, solving Titan’s weather phenomena that were once inexplicable.

Having a surface temperature of approximately -300°F (-183°C), Titan is one of Saturn’s largest moons. It has a thick atmosphere of methane, a gas deadly for humans. Titan, the only other planetary body in the solar system that has large bodies of liquid on the surface, contains lakes and precipitation of liquid methane. For nearly a decade, researchers at Caltech have noticed bizarre geographical settings and meteorological occurrences.

The first was noticed in 2009 by Odel Aharonson, leader of planetary science at Caltech. He noted that the lakes tended to cluster around Titan’s poles, more so in the northern pole than in the southern. This leaves areas around the equator very dry, lacking in clouds, precipitation, and bodies of liquid.

But in 2005, the space probe Huygens observed a presence of deep channels which look carved out by running liquid. Lastly, regions in the middle and around high altitudes contain clouds that cluster during Titan’s summer in the southern hemisphere.

Previously, scientists have created computer models to account for these meteorological mysteries, though none of them were successful. The newer model, which is three dimensional and simulates Titan’s atmosphere for the past 135 Titan years (equivalent to 3000 Earth years), manages to explain the phenomena by reproducing the distribution of clouds and lakes.

According to the newest model, more lakes exist in the northern hemisphere because Titan is farther from the Sun during the summer due to Saturn’s elliptical orbit, and since Titan is at the far end of Saturn’s orbit the, summer is longer in the northern pole. As Tapio Schneider explains in the Caltech press release, “Methane tends to collect in lakes around the poles because the sunlight there is weaker on average.”

Schneider is a co-author of the paper about the simulation’s findings published in the January 5th issue of Nature and is the Frank J. Gilloon Professor of Environmental Science and Engineering. Hence, without much heat from the Sun, the methane is unable to exist in the gaseous state at the north pole and remains in the liquid state.

To account for the second oddity, the model shows that Titan is closer to the Sun during the moon’s southern summer. Consequently, the rains are more intense here than in the northern hemisphere; however, the model further shows that more lakes exist in the north because storms occur more frequently than they do in the south.

This newer model also explains the presence of liquid-carved channels in the parched equator by producing a simulation that shows rain occurring during the vernal and autumnal equinoxes. Even though these rains are rare, they are quite intense: at the time of the equinoxes, Titan’s poles reverse, causing unstable weather patterns.

“The results for the first time give us a unified picture of how Titan’s methane cycle works,” Schneider tells Space.com. “What I find most satisfying is that many seemingly disparate observations – clouds, lakes, dry river beds – can be explained within one sparse and coherent framework.”

In addition to simulating its atmosphere and methane cycle, the model can also predict Titan’s weather several years in advance, similar to how we are able to predict Earth’s. For instance, the researchers have determined that lake levels will rise in the northern hemisphere for the next fifteen years, and over the next two years, more clouds will form at the north pole.

“This is just the beginning,” Scheinder adds. “We now have a tool to do new science with, and there’s a lot we can do and will do.”

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An international research team of astronomers and astrophysicists were originally trying to find and study pulsars with the Kepler space telescope and the Kitt Peak Earth observatory in Arizona. However, the team got more than they bargained for. Later last week, they detected a star with a unusual pulsating rate: intervallic modulations, which occurred every 5.76 and 8.23 hours, caused the star to faintly flicker. Upon further studying, the team found out that these modulations were not produced by the star, and that is when they discovered two earth-sized exoplanets rotating around a red giant star well within its outer envelopes of gas.

“Having migrated so close, they probably plunged deep into the star’s envelope during the red giant phase, but survived,” says Stéphane Charpinet, who is the leader of the team and an astronomer at the University of Toulouse in France.

Before this finding, scientists in general assumed that planets engulfed by a red giant’s outer layers would be incinerated, and it is believed that this is to happen to the Earth since the Sun is fated to become a red giant. Now that these two exoplanets have been discovered, though, it seems that planets are able to endure stars’ transition to a red giant.

The star in question is named KIC 05807616 (also KOI 55, with “KOI” being the acronym for “Kepler Object of Interest”), formerly a main sequence star on the Hertzsprung-Russell Diagram, like our Sun. The two exoplanets, KOI 55-01 and KOI 55-02, revolve around KIC 05807616 less than approximately 900,000 kilometers and approximately one million kilometers, orbiting KIC 05807616 closer than Mercury orbits the Sun. They have the radii of .76 and .87 times the Earth’s respectively, making them the smallest exoplanets detected thus far.

According to another member of the team, Elizabeth ‘Betsy’ Green, an associate astronomer at the University of Arizona’s Steward Observatory, “The friction with the star’s envelope also strips the gaseous and liquid layers off the planet, leaving behind only some part of the solid core, scorched but still there.” This would account for KOI 55-01 and KOI 55-02′s small sizes.

The research team studied KIC 05807616 and found out that it had been transitioning to become a typical red giant, but since the nuclear reactions began occurring in the outer shells rather than in the core, it expanded, shedding its outer layers and jettisoning much of its mass. Due to the fact that KOI 55-01 and KOI 55-02 orbit KIC 05807616 closer than Mercury orbits the Sun, they may have may have helped KIC 05807616 with its transition, causing it to lose mass more rapidly by stripping its outer shells of gas.

The exoplanets ultimately affected KIC 05807616 enough to become a subdwarf B, which, entirely stripped of its outer layers, has the core of a red giant and the luminosity of a main sequence star, but smaller in mass. Upon finishing their research, the team concluded that planets can affect stellar evolution. “We think this is the first documented case of planets influencing a star’s evolution,” Charpinet states.

“We thought we had a pretty good understanding of what solar systems were like as long as we only knew one – ours,” says Green. “Now we are discovering a huge variety of solar systems that are nothing like ours, including, for the first time, remnant planets around a stellar core like this one.”

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In 2006, a group of scientists at the University of Hawaii detected a small asteroid circling the Earth, and kept track of it until it went out of orbit mid-2007. Later last week, these scientists – Mikael Granvik, Jeremie Vaubaillon, Robert Jedicke – published a paper stating that the Earth may have additional temporary moons at any given time. The paper, published in the science journal Icarus, also theoretically models the orbits of the secondary moons, and states that the research they did is consistent with the observations of the current secondary moon.

Another recent study at Cornell concludes that it is common for numerous small objects to enter the Earth’s orbit and become temporary moons at any given time. These objects are usually small asteroids, one to several meters in length.

“There are lots of asteroids in the solar system, so chances for the Earth to capture one at any time is, in a sense, not surprising,” explains Vauballion.

Sometimes, an asteroid on its way to the sun is “grabbed” by Earth’s gravitational pull. It orbits the Earth for nearly a year, and then it breaks out of its orbit and goes along its merry way. These objects are too small to do any damage to the Earth, though they do qualify as natural satellites like the Moon.

Although it may be reassuring that these asteroids can do no harm to our planet due to their miniscule sizes, scientists find it quite difficult to detect them for the same reason. Moreover, instruments cannot collect data because the secondary moons move too quickly when they come closer to Earth. There would not be enough time to send an observational satellite. Also, according to Granvik, “When coming closer in during their orbit, they are moving too fast to be detected, because the limited amount of photons is spread over too many pixels.”

Currently, the Large Synoptic Survey Telescope (LSST) is being constructed and will open in the northern mountains of Chile in 2005. The LSST will be able to detect these tiny moons and collect data.

Having astronauts visit asteroids and mine them of their assets is one of the astronomers’ ambitions. It may be possible to take further  advantage of these secondary temporary satellites so astronauts would be able to visit one of them and then transport it (it would not be too difficult, considering the asteroid’s size) back to Earth for analysis.

Says Granvik, “We certainly hope that a space mission to a natural Earth satellite would someday materialize and have actually already started a collaboration with experts in spacecraft orbital mechanics to find out how a mission from the Earth to a temporary satellite could be accomplished.”

He, Vaubaillon, and Jedicke conclude their paper stating: “The scientific potential of being able to first remotely characterize a meteoroid and then visit and bring it back to Earth would be unprecedented.”

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