From Dust to Dust

A look into the Orion Nebula reveals the beginning of new stars and planets. Stars have life cycles; they are born, develope through different phases, and eventually die. Earth's sun was born about 4.6 billion years ago and will remain much as it is for another 5 billion years. How these massive bodies come to be, is feat that astonishes astronomers all over the world. What begins as a cloud of dust, through gravity and pressure, transforms into heavenly bodies circling their motherly star. The process--as shown on the video--that changes dust and gas into solar systems is believed to be the exact process that formed the solar system in which humanity thrives. Once stars become 5 times or more massive than earth's Sun, reaching the red giant phase, their core temperature increases as carbon atoms are formed from the fusion of helium atoms. As the cosmic process continues, the star begins growing, and consumes its adjacent planets and stars. The star continues eating until it begins secreting gases and dust, feeding the next generation of heavenly bodies.

source: nasa http://www.nasa.gov/multimedia/hd/index.html

Worlds a Way

There are over 300 known extra solar planets circling a number of nearby stars. Scientists, using multiple methods, have recently discovered a new earth like planet. A group of European astronomers discovered a planet estimated to be only twice the mass of Earth. It is by far the smallest world yet discovered orbiting a faraway star. Their data was presented in an article submitted to the journal Astronomy & Astrophysics. "The holy grail of current exoplanet research is the detection of a rocky, Earth-like planet in the 'habitable zone,'” said lead author Michel Mayor of the Geneva Observatory. Though this planet does not meet such requirements, it does give astronomers confidence that their techniques will soon pay off.
The newest planet, Gliese 581e, to be discovered is the fourth one found circling its parent star. A member of the discovery team, Xavier Bonfils of the Grenoble Observatory, believes that with a minimum mass of 1.9 Earths the planet is most likely a rocky world like our own. But as the innermost planet in the system it is extremely close to its star, completing each orbit in just over 3 days. Its surface is therefore far too hot to sustain liquid water or life as we know it. The red dwarf star, Gliese 581, has been a star of interest for astronomers for some time now. This particular star has a planet that is with in the habitual zone.

The astronomers used the European Southern Observatory's 3.6 meter telescope at La Silla, Chile. The two planets, Gliese 581d and Gliese 581e, were studied using HARPS spectrograph. Built specifically to search for exoplanets HARPS, through the radial velocity method, can detect the miniscule shifts in a star's spectrum as it rocks back and forth to the tug of an orbiting planet. HARPS is so sensitive, in fact, that it can register a star's motion towards the Earth or away from it, even if it is as slow as 1 meter per second -- about the speed of a leisurely stroll. It is thanks to this remarkable sensitivity that the spectrograph was able to discover a planet as small as Gliese 581e.

Click to enlarge > Credit: ESO

Gliese 581e’s larger neighbor, the planet Gliese 581d, whose minimum mass is seven times that of the Earth, is believed to be a good candidate for sustaining life. Since it is located in the habitable zone, a member of the team said, it "could even be covered by a large and deep ocean – it is the first serious 'water world' candidate."

Scientists discover Flabbergasting Gas Giant.

Having discovered all the planets in our own solar system astronomers are now interested in discovering planets in other systems. Georgi Mandushev, an astronomer from Lowell Observatory, is one of the leading astronomers on the prowl. He is part of a team working on the Transatlantic Exoplanet Survey (TrES).
Mandushev has always been interested in the mid-night sky. “When I was child, astronomy was hobby of mine,” Mandushev said, “as I grew up I realized I was also good at math and science so I decide to combine my passion with my knowhow, and an astronomer is what I became.
In 2003, scientists found their first transient planet.”It’s hard to find transient planets because in order for us to see them our line of site has to view the planet revolve horizontally around its host star,” Mandushev said. “If the planet revolves vertically our instruments will never detect it.” planetary transits are only observable for planets whose orbits happen to be perfectly aligned from astronomers' field of view. This leaves only about ten percent of all transits able to be detected.
For the last five years, Mandushev and other scientists have been pointing their equipment at far off stars in hopes of finding planets like the ones in Earth’s solar system. “It’s hard to find rocky planets because they’re too small, so all we have yet to find are gas giants,” Mandushev said. Through the use of a network of three 10cm telescopes in Arizona, California and the Canary Islands, scientists are charting far off galaxies in hopes of discovering new planets.
“TrES—4 is one of 20 transiting planets that have been discovered using the transiting method,” Mandushev said. “A transiting planet passes directly between the Earth and the star, blocking some of the star's light and causing a slight drop in its brightness.” The average drop in brightness is usually 2 percent. Once the transiting method is used to detect light differentials of the host star, scientists then use the radial-velocity method to determine the velocity of the planet. As the planet revolves around the star it slightly pulls the star, which can be detected on Earth through the Doppler Effect. An observed red shift due to the Doppler effect occurs whenever a light source moves away from the observer where as a blue shift happens when the light source moves towards the observer. Knowing how big a star is and how long it takes to revolve around the star gives scientist clues as to how fast the star moves.
TrES—4 is a gas giant that resembles Jupiter, but is 70 percent larger then Jupiter. The planet was discovered when astronomers pointed their equipment into the constellation of Hercules on Aug. 2, 2007. “Our equipment examines over 50 thousand stars in one view,” Mandushev said. “Of all those stars only about 150 of them are candidates, and most turn out to be duds.” Scientists determine if a star has a transiting planet by the fluctuation in light as the planet crosses in front of the star and the telescopes’ field of view. When astronomers are reviewing the data, they are looking at thousands of dots and zeroing in on a slight differense in brightness.
“TrES—4 is the biggest planet that we have found so far,” Mandushev said. “In fact its discovery may lead to new gas giant models.” The mostly hydrogen planet has the largest radius and lowest density of any of the known transiting planets. Mandushev has written in the Astrophysics Journal, Oct. 1, 2007, that some scientists propose that the planet is able to be big with a low density because it may be composed of different heat sources, or that the planet has an extended outer atmosphere caused by blow off of atmospheric material.
It is theorized that the planet leaves a comet like residue as it revolves around its host star once every 3.55 days. The composition and size of the planet leaves more questions than answers. Scientists hope that as long as they keep surveying the night skies that they will keep being astonished and amazed. After all, is that not what all great discoverers hope for?

The Origin and Evolution of Life throughout the Cosmos

Astrobiology is an interdisciplinary science that hopes to answer the age old question, where does life originate. Through the integration of astronomy, biology, geology and planetary science, Astrobiology Professor David Koerner, hopes to unravel that very mystery.
Koerner began his education early in the 1970s. He enrolled at California State University-Long Beach as geology major, but graduated with a degree in physics and minors in math and geology. Koerner chose his field of study so he could better understand when and where life originated.
In 1993, Koerner, along with fellow scientists, were the first to demonstrate that a gas disk was in a stable orbit around a young star named GM Aurigae, indicating that the disk could give rise to a new set of planets. The discovery of planets being born within an interstellar medium reaffirmed early theories that planet formation is one step in the evolution of life. His findings, along with countless others, have been published in The Astrophysical Journal.
To understand how long Earth has been circling its star, scientists must first investigate geological records. As geological records show, the Earth has been a stable planet for about 4.6 billion years. Earliest fossil cells date back to 3.5 billion years ago, and “circumstantial evidence dates life’s beginnings at 3.9 billion years ago.’ The question that astrobiologists hope to answer is what caused inorganic molecules like water and salt to suddenly change into amino acids, the building blocks of all organic life.
A gas disk around a protostar, or a solar nebula, is a precursor to a solar system. Koerner believes that through intense study of a solar system’s formation, scientists will one day have a better understanding of the mechanics of life. “What I really care about is not just the steps that lead to making the planets, but the habitability of the cosmos,” Koerner said.
Arguments in favor of life on other planets have become more viable in the last 10 years. Solar nebulas are full of polycyclic aromatic hydrocarbons, which are interstellar molecules that formed through a complicated network of chemical reactions inside the solar nebula. Koerner explains, “That’s like the goo on your grill after you do a hamburger.” More technically they are what scientists consider pre cursers to amino acids. The discoveries of these molecules, in conjunction with comet and meteorite studies, have made the speculation of extraterrestrial life more attractive to scientists around the world.
Koerner is now part of a research group that uses the Spitzer Space Telescope to identify how planets form, the frequency in which they form and what are the prospects for life on these planets. They use the telescope to investigate nearby stars in hopes of unraveling the cosmos’ mysteries. The Spitzer Space Telescope is a space-based infrared observatory, which is part of NASA's Great Observatories program.
Through NASA's scientific endeavor, Koerner’s research group have already identified close to four dozen solar nebulas within the Milky Way Galaxy. The group’s findings are incorporated with other researchers’ data from around the world, in order to compile a likely theory that will explain the creation of organic life throughout the cosmos. Koerner is a professor a Northern Arizona University. His articles and other scientific data can be accessed at http://www.astrobio.nau.edu/~koerner.