Tag: star

News from Space: “Life” Molecules Detected in Space!

SagitariusB2The secret to the creation to life in our universe appears to be seeding – the proper elements in the right mix in the right places to form the right kind of molecules. Only then can these molecules evolve chemically into more and more complex structures, thus following a general pathway toward biology. The pathway for life as we know it starts with carbon, but one which is specific organized and structured.

Recently, a team of astronomers  at the ALMA Observatory reported the discovery of this very element while probing distant galaxies. What they found was not just interstellar carbon, but a form of carbon with a branched structure. The discovery was made in the gaseous-star forming region known as Sagittarius B2 – a giant molecular cloud of gas and dust that is located about 390 light years from the center of the Milky Way.

radio-wave-dishesSimple carbon chains aren’t particularly unusual in the cosmos, but complex carbon is a different matter. It is what the researchers, based at Cornell University and the Max Planck Institute, describe as finding a molecular needle in a cosmic haystack. The actual molecule in question is isopropyl cyanide, and it was discerned thanks to the miracle known as radio astronomy.

Within clouds of interstellar dust and gas, elements find themselves shielded from the harsh radiation of open space and are, thus, free to form into more complex arrangements. These molecules don’t just sit there, but instead move around within their cloud-homes and bump into each other. The result of this activity are radio signals which can be detected light-years away – in this case, by radio telescopes here on Earth.

MaxPlanckIns_radiowavepulseEvery molecule has a different radio signal, so it’s possible to pick apart the contents of interstellar junk by examining a cloud’s frequency spectra. NASA, via the Ames Research Center, even maintains a radio-emission frequency database to aid in the tracking of polycyclic aromatic hydrocarbons, a form of molecule thought to contain much of the universe’s carbon stockpiles.

The branching carbon structure of isopropyle cyanide is of particular interest because it’s thought that this arrangement is a step on the way to the production of amino acids, the building blocks of proteins, and hence organic life. The discovery gives weight to the increasingly popular notion that life, or at least many of the key steps leading toward life, actually occurs off-planet.

alien-worldLife on Earth may have been well on its way while the planet was still just space dust waiting to come together into our rock-home. What’s more, the molecules discovered by the ALMA team probably aren’t alone.  As the authors, led by astronomer Arnaud Belloche, wrote:

[Isopropyle cyanide’s] detection therefore bodes well for the presence in the [interstellar medium] (ISM) of amino acids, for which such side-chain structure is a key characteristic… This detection suggests that branched carbon-chain molecules may be generally abundant in the [interstellar medium].

The discovery follows a general progression in recent years adding more and more life-ingredients to our picture of the ISM. A 2011 study revealed that complex organic matter should be created in large volumes from stars, while a 2012 report study found that conditions within the ISM are uniquely suited to the creation of increasingly complex molecules, “step[s] along the path toward amino acids and nucleotides, the raw materials of proteins and DNA, respectively.”

sugar-in-space-molecules_58724_990x742Also in 2012, astronomers working for ALMA found basic sugar molecules hanging out in the gas cloud around IRAS 16293-2422 – a young star located some 400 light-years from Earth. The particular form, glycoaldehyde, is thought to be a key component of the reaction behind the creation of DNA. Indeed, more and more, the universe is looking less and less like a harsh environment in which life must struggle to emerge, to a life factory.

Source: motherboard.vice.com

News from Space: First Earth-Sized Exoplanet Found!

kepler78bFor the past three and a half years, the Kepler space telescope has been hurtling through space and searching the Milky Way for signs of of other planets orbiting distant stars. In that time, Kepler has identified many Earth-like exoplanets, many of which reside within our own stellar neighborhood. However, it has found only one planet in recent months that is Earth-sized.

That planet is known as Kepler-78b, the existence of of which was recently verified by NASA scientists at Cape Canaveral. Of all the planets discovered beyond our Solar System, this one is both rocky in composition and weighs in at roughly 1.2 times Earth’s mass. Beyond that, however, the similarities between this planet and our own end.

kepler78b2In addition to having an orbital period of 8.5 hours, the planet also rotates around its parent star at a distance of about 1.5 million kilometers (approx. 93205 miles). Basically, this means that Kepler-78b is thirty to forty-five times closer to its Sun than Mercury is to ours, and experiences a full year in under nine days. This makes Kepler 78b an extremely hostile environment, unsuitable for life as we know it.

Andrew Howard, of the University of Hawaii at Manoa’s Institute for Astronomy and the lead author on one of two papers published in Nature magazine about the discovery of the new planet, said in recent webcast:

We’ve been hearing about the sungrazing Comet ISON that will go very close to the Sun next month. Comet ISON will approach the Sun about the same distance that Kepler-78b orbits its star, so this planet spends its entire life as a sungrazer.

Kepler78b1A handful of planets the size or mass of Earth have been discovered, but Kepler-78b is the first to have both a measured mass and size. At 1.2 times the size of Earth with a diameter of 14,800 km (9,200 miles), astronomers say it has a density similar to Earth’s, which suggests an Earth-like composition of iron and rock. Its star is slightly smaller and less massive than the sun and is located about 400 light-years from Earth in the constellation Cygnus.

Verification of the planet’s existence and characteristics was made by two independent research teams that used ground-based telescopes for follow-up observations. The team led by Howard used the W. M. Keck Observatory atop Mauna Kea in Hawaii. The other team led by Francesco Pepe from the University of Geneva, Switzerland, did their ground-based work at the Roque de los Muchachos Observatory on La Palma in the Canary Islands.

exoplanet_hotAnd while the discovery is exciting, the close proximity of Kepler-78b to its star poses a challenge to theorists. According to current theories of planet formation, it couldn’t have formed so close to its star, nor could it have moved there. Given that its star would have surely been larger when the system was in formation, Kepler-78b’s orbit would have put in inside the swollen star. Hence, the planet’s existence is an enigma.

To make matters worse, Kepler-78b is a doomed world. Gravitational tides will continue to pull Kepler-78b even closer to its star, and eventually it will move so close that the star’s gravity will rip the world apart. Theorists predict that the planet will vanish within three billion years. And while this may sounds like an eternity to us, in astronomical terms it represents a life cut short.

Source: universetoday.com, nature.com