Stars & Astronomy

Three Earth-like Planets Found

The Homunculus Nebula

European astronomers have discovered three Earth-like planets” which circle a star and another two solar systems, along with several other small orbiting planets. The results strengthen the argument that the Earth (and possibly life) is not unique. “Each single star could have its planets. The star is 42 light-years away from the Doroto and Pictor constellations. The planets are bigger than Earth (respectively 4.2, 6.7 and 9.4 times) and they orbit their sun in respectively 4, 10 and 20 days, against the 365 days of our planet. Over 270 planets have been discovered outside our own solar system and in most cases they are giant planets, the size of Jupiter and Saturn. The smaller planets, like Earth, are harder to find. “These planets are just the tip of the iceberg. The data of all star systems show that around a third of the stars are similar to Sol and have super-Earths or satellites with a revolution of less than 50 days”.

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Phoenix on Mars

Ice exposed by the Mars lander

The Phoenix lander bakes a soil sample as it digs deeper into the martian surface.

One of the ovens on NASA’s Phoenix Mars Lander continued baking its first sample of martian soil over the weekend, while the Robotic Arm dug deeper into the soil to learn more about white material first revealed on June 3.

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Phoenix Lands on Mars

The Mars lander Phoenix has finally landed on the red planet and used its robotic arm to test the soil for the building blocks of life. The 2.3m-long titanium extension will dig through the Martian topsoil and into the water-ice which lies just beneath. The next step will be to test the arm’s four joints to be sure it is in working order before digging into the soil.

After a check that tests the robotic appendage at a range of warmer and colder temperatures, a camera on the arm will be used to look under the spacecraft to assess the terrain and underside of the lander. The robotic arm will later dig into the icy layers of Mars’ northern polar region and deliver samples of soil and ice to instruments on the lander’s deck for analysis.Phoenix is set to investigate the planet’s geological history and search for the chemical building blocks which could support life. The spacecraft has also transmitted a 360-degree panorama of its frigid Martian environment.

Phoenix is an apt name for the current mission, as it rose from the ashes of two previous failures. In September 1999, the Mars Climate Orbiter spacecraft crashed into the red planet following a navigation error caused when technicians mixed up imperial and metric units. A few months later, another Nasa spacecraft, the Mars Polar Lander was lost near the planet’s South Pole.Phoenix uses hardware from an identical twin of MPL, the Mars Surveyor 2001 Lander, which was cancelled following the two consecutive failures. The probe was launched on 4 August 2007 on a Delta II rocket from Cape Canaveral Air Force Station in Florida.

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Organic Molecule Found in Sagittarius

Since 1965 more than 140 molecular species have been detected in space, in interstellar clouds. A large fraction of these molecules is organic or carbon-based. A lot of attention is given to the quest for so-called bio-molecules, especially interstellar amino acids. Amino acids, the building blocks of proteins and therefore key ingredients for the origin of life, have been found in meteorites on Earth, but not yet in interstellar space.

Now scientists have detected a new molecule in space closely related to an amino acid: amino acetonitrile. The organic molecule was found with a 30-meter radio telescope in Spain and two radio interferometers in France and Australia in the Large Molecule Heimat, a giant gas cloud near the galactic center in the constellation Sagittarius. In this source of only 0.3 light-year diameter, which is heated by a deeply embedded newly formed star, most of the interstellar molecules known to date have been found, including the most complex ones such as ethyl alcohol, formaldehyde, formic acid, acetic acid, glycol aldehyde and ethylene glycol.

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Earthshine can be seen on the Moon

The other day I looked out my window and I could see the ‘dark side’ of the moon really well. The Moon was a whopper, swollen by the well-known illusion that makes moons near the horizon seem big. But that wasn’t what grabbed my attention. The wonderful thing was the way the “dark” part of the Moon was faintly glowing. The phase of the Earth changes reciprocally with the moon, so the illumination is greater for thin crescent moons; and specular reflection off the oceans increases the brightness of a near-full Earth in the moon’s sky. The brightness of the sky also has an effect: it can easily drown out the subtle illumination of earthshine. So for thin crescents, there’s a trade-off with the position of the sun below the horizon.

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Planet X Found?

The researchers at Kobe University in western Japan said calculations using computer simulations led them to conclude it was only a matter of time before the mysterious “Planet X” was found.

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Dark Galaxies

In the year 2001 Davis Disnes and his colligues detected VIRG0H121 in the virgo culster about 5 million light years away – an invisible galaxy made almost entirely of dark matter – the first ever detected. A dark galaxy is an area in the universe containing a large amount of mass that rotates like a galaxy, but contains no stars. Without any stars to give light, it could only be found using radio telescopes. The big Question is does a Dark Galaxy really exist? Devoid of light and gas? The question is associated with understanding how the universe bloosomed from the big bang as we consider. According to increasingly refined story 85% of the matter in the universe is not ordinary baryonic matter-that makes up galaxies and stars and planets. Rather it is dark matter. As the universe grew from its infancy, the dark matter condensed in to enormous filaments like tubes, clumps and haloes. These weighty objects pooled in hydrogen gas which formed the galaxies and stars. Simulations show that dark matter should have myriad clumps between 1/1000 and 1/1000,000 as massive as our milky way galaxy. At first these small haloes should have accumulated gas and lit up as small dwarf galaxies thousands of which should whiz around Milky Way. So far astronomy could have few near by. Various factors kept the small halos dark. So space should have many dark galaxies.

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Hundreds of Worlds in the Milky Way

Rocky planets, possibly with conditions suitable for life, may be more common than previously thought in our galaxy, a study has found. New evidence suggests more than half the Sun-like stars in the Milky Way could have similar planetary systems. There may also be hundreds of undiscovered worlds in outer parts of our Solar System, astronomers believe. If there are hundreds of planets and dwarf planets waiting to be discovered in the outer reaches of our own solar system, untold billions in the rest of the milky way.

http://news.bbc.co.uk/1/hi/sci/tech/7249884.stm

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The Web of Dark Matter

Astronomers using the Hubble Space Telescope are examining one of the largest structures in the universe as part of a quest to understand the violent lives of galaxies. Hubble is providing evidence of unseen dark matter tugging on galaxies in the crowded, rough-and-tumble environment of a massive supercluster of hundreds of galaxies. Dark matter is an invisible form of matter that accounts for most of the universe’s mass. Hubble’s Advanced Camera for Surveys has mapped the invisible dark matter scaffolding superclusters as well as the detailed structure of individual galaxies embedded in it.

The dark matter map was constructed by measuring the distorted shapes of over 60,000 faraway galaxies. To reach Earth, the galaxies’ light traveled through the dark matter that surrounds the supercluster galaxies and was bent by the massive gravitational field. Heymans used the observed, subtle distortion of the galaxies’ shapes to reconstruct the dark matter distribution in the supercluster using a method called weak gravitational lensing. The dark matter map is 2.5 times sharper than a previous ground-based survey of the supercluster.

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Supernovas are a Threat to Human Life

Supernova explosions pose a threat to human life, however small. When a star explodes, most of its energy will be absorbed in the vast emptiness of space. Cosmic rays would be diffused by magnetic fields, and most of the damaging light would not affect life on Earth. But it is believed long-term exposure to blue-enhanced light could interfere with life. Those who study chronobiology, or the effects of biological timing, have found that low levels of blue light can strongly affect the endocrine systems of mammals by causing physiological and alerting responses. Blue-enhanced light is associated with reduced levels of melatonin production and affects circadian rhythms. For these reasons, it is sometimes prescribed to counteract seasonal affective disorder (SAD) or winter depression. Blue light can increase insomnia, reduce resistance to infection and is being studied as a possible risk of cancer.

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