Astronomy

The Lunar Reconnaissance Orbiter (LRO) mission is the first step in NASA’s plans to return humans to the moon by 2020, and your name can reach there first. Cool, isn’t it?

NASA invite everyone to participate in the lunar adventure and place their names in orbit around the moon for years to come. Participants can submit their information at the project’s website, print a certificate and have their name entered into a database. The database will be placed on a microchip that will be integrated onto the spacecraft and travel along with it. The deadline for submitting names is June 27, 2008.

The LRO orbiter, comprised of six instruments and one technology demonstration, will provide the most comprehensive data set ever returned from the moon. The mission will focus on the selection of safe landing sites and identification of lunar resources. It also will study how the lunar radiation environment could affect humans.

The mission will also create a comprehensive atlas of the moon’s features and resources that will be needed as NASA designs and builds a planned lunar outpost. The mission will support future human exploration while providing a foundation for upcoming science missions. LRO is scheduled for launch in late 2008.

So, hurry up. Sign in the website and have your name traveling into orbit!

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Most of the matter and energy in the Universe is of unknown nature, so they are called “dark matter” and “dark energy”. Dark energy accounts for 72% of the total energy in the Universe, while some 23% of the total amount of matter/energy is made of this so-called “dark matter”, which is composed of heavy particles still waiting to be discovered by particle physicists. The remaining 5% of the Universe is made of ordinary matter, the one we know on Earth that constitutes stars and planets. It consists of protons and neutrons – called baryons – and of electrons, all the building blocks of the atoms. But part of this 5% of “baryonic” matter is also missing. Stars, galaxies, and gas that astronomers observed in the Universe account for less than half of the baryonic matter.

Studies of the Big Bang and the fluctuations of cosmic background radiation yield quite exact figures on the existence of baryons in the Universe. So from the calculations astronomers knew for a long time that the vanished pieces of the cosmological puzzle must be hidden somewhere. To trace and apprehend this solely observable component in the Universe is the precondition to learn more about the web of Dark Material and to test the quality of different cosmological models.

Scientists from SRON Netherlands Institute for Space Research using the X-ray space observatory XMM-Newton to observe the two clusters of galaxies Abell 222 and Abell 223 which are connected by a filament. The newly-detected bridge would be part of this missing baryonic matter.

A bridge of hot gas connects two clusters of galaxies (Image credits: ESA/XMM-Newton/ EPIC/ ESO [J. Dietrich]/ SRON [N. Werner]/ MPE [A. Finoguenov]).

The Universe is constructed like an oversized spider web. All visible material is arranged along the filamentary structure of the dark matter. On its threads and knots, this web holds gigantic chunks of baryonic matter, which are made of quarks and leptons. For 10 years, astronomers suspected that the missing baryonic matter is hot gas at very low density permeating the filamentary structure of the cosmic web. Because of its low density, detecting this hot gas was a very challenging task. The hot gas they found there is probably the hottest and densest part of the diffuse gas which constitutes half of the missing baryons in the Universe. The properties of the gas, for example its density and temperature, are consistent with the results of simulations. This is the first time that scientists see the bridge of gas connecting two clusters of galaxies in X-rays.

This discovery was made possible because of the very fortunate geometry of the two clusters. As seen from the Earth, the filament connecting the two clusters is aligned along our line-of-sight, so that the entire emission from the filament is concentrated in a small region of the sky, thereby making its detection possible. Previous observations, at a lower sensitivity level, only allowed astronomers to detect the clusters and some groups of galaxies, the dense knots of the web. The high-sensitivity level now achieved with in-depth XMM-Newton observations makes it possible to observe the connecting wires of the cosmic web.

The study, which has been published on May 2008 issue of Astronomy & Astrophysics Letters, is considered as a step toward understanding the distribution of the matter within the large-scale structure of the Universe. The distribution and composition of the baryonic matter gives information about what happened after the Big Bang and which forces are dominating the Universe today and in the future.

Source: MPE Press Release

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On May 10th we will celebrate Astronomy Day. It is an astronomical PR event that helps highlight ways the general public can get involved with astronomy - or at least get some of their questions about astronomy answered. At the day, hundreds of astronomy clubs, science museums, observatories, universities, planetariums, laboratories, libraries, and nature centers host special events and activities to acquaint their population with local astronomical resources and facilities.

Astronomy Day was born in California in 1973. Doug Berger, then president of the Astronomical Association of Northern California, decided that rather than try to entice people to travel long distances to visit observatory open houses, they would set up telescopes closer to where the people were - busy locations - urban locations like street corners, shopping malls, parks, etc.

His strategy paid off. Not only did Astronomy Day go over with a bang, not only did the public find out about the astronomy club, they found out about future observatory open houses. Since the public got a chance to look through a portable telescope, they were hooked. Then wanted to see what went on at the bigger telescopes, so they turned out in droves at the next observatory open house.

Astronomy Day occurs on a Saturday between mid-April and mid-May, and is scheduled so as to occur at or just before the first quarter Moon. This means that the event happens on a different date each year, rather than a set calendar date.

Thus, happy Astronomy Day everyone!

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Astronomy textbooks typically present galaxies as staid, solitary, and majestic island worlds of glittering stars. But galaxies also have a dynamical side. They have close encounters that sometimes end in grand mergers and overflowing sites of new star birth as the colliding galaxies morph into wondrous new shapes.

Celebrating 18th launch anniversary of the Hubble Space Telescope, NASA publishing 59 views of colliding galaxies constitute the largest collection of Hubble images ever released to the public. This new Hubble atlas dramatically illustrates how galaxy collisions produce a remarkable variety of intricate structures in never-before-seen detail.

Most of the 59 new Hubble images are part of a large investigation of luminous and ultra- luminous infrared galaxies called the GOALS project (Great Observatories All-sky LIRG Survey). This survey combines observations from Hubble, NASA’s Spitzer Space Telescope, NASA’s Chandra X-ray Observatory, and NASA’s Galaxy Evolution Explorer. The majority of the Hubble observations are led by Aaron S. Evans of the University of Virginia, Charlottesville, the National Radio Astronomy Observatory, and Stony Brook University.

The complete image can be seen on the Hubble Space Telescope official site. Enjoy!

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A blazar is a very compact and highly variable energy source associated with a supermassive black hole. It is also characterized by a relativistic jet that is pointing in the general direction of the Earth. Blazars are among the most violent phenomena in the universe and are an important topic in extragalactic astronomy. Now, for the first time, astronomers have observed a blazar in action, substantiating a prevailing theory about how these luminous and energetic galactic cores work.

Two University of Michigan astronomers contributed to the research, which was led by Alan Marscher of the Institute for Astrophysical Research at Boston University. A paper on the observations is published in the April 24 issue of Nature.

Competing theoretical models currently sought to explain how this phenomenon occurs. One model predicted that the jets were propelled by magnetic fields that were twisted by the gravity of the black hole and the materials falling into it. This is the behavior the astronomers detected.

The scientists has observed the mechanism by which the acceleration of relativistic particles in the emanating jets occurs. Knowing that mechanism enhances our understand of the physics that goes into the acceleration process. Relativistic particles are particles traveling close to the speed of light. Though, it’s been difficult to catch these outbursts when they occur.

Scientists from across the globe aimed a variety of telescopes at the blazar BL Lacertae, about 950 million light-years away from Earth. Optical, X-ray and radio telescopes monitored the galaxy at different electromagnetic wavelengths periodically for several years. University of Michigan’s team successfully recorded radio light curves at the Radio Astronomy Observatory at Peach Mountain in Dexter. This is the first observational evidence that really fits with the picture that the theoreticians have had. Key factor of this evidence is a very fine sampling of a large number of instruments, including the Michigan radio telescopes.

Scientists hope to get a closer look at blazar jets when NASA launches its Gamma-ray Large Area Space Telescope (GLAST) satellite observatory in May.

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On December 20th, 2007, United Nations has declares 2009 as the International Year of Astronomy. The event marks the 400th anniversary of Galileo’s use of a telescope for astronomical observations. This is a momentous event that initiated 400 years of astronomical discoveries and triggered a scientific revolution which profoundly affected our worldview.

The vision of the International Year of Astronomy 2009 (IYA 2009) is to help the citizens of the world rediscover their place in the Universe through the day- and night time sky, and thereby engage a personal sense of wonder and discovery. All humans should realize the impact of astronomy and basic sciences on our daily lives, and understand better how scientific knowledge can contribute to a more equitable and peaceful society.

For several millennia, astronomers have worked together across all boundaries including geographic, gender, age, culture and race, in line with the principles of the UN Charter. In that sense, astronomy is a classic example of how science can contribute towards furthering international cooperation.

The IYA2009 is, first and foremost, an activity for the citizens of planet Earth. It aims to convey the excitement of personal discovery, the pleasure of sharing fundamental knowledge about the Universe and our place in it, and the merits of the scientific method. So far 99 nations and 14 organisations have signed up to participate in the IYA2009 – an unprecedented network of committed communicators and educators in astronomy.

For more information on the International Year of Astronomy 2009 please visit the website at http://www.astronomy2009.org/.

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On April 24th, eighteen years ago, astronauts aboard the Space Shuttle Discovery deployed the Hubble Space Telescope. This marks beginning of the new era of the space research. Hubble’s discoveries have transformed the way scientists look at the universe. Its ability to show the universe in unprecedented detail has turned astronomical conjectures into concrete certainties. It has winnowed down the collection of theories about the universe even as it sparked new ones, clarifying the path for future astronomers.

Among its many discoveries, Hubble has revealed the age of the universe to be about 13 to 14 billion years, much more accurate than the old range of anywhere from 10 to 20 billion years. Hubble played a key role in the discovery of dark energy, a mysterious force that causes the expansion of the universe to accelerate.

Hubble has shown scientists galaxies in all stages of evolution, including toddler galaxies that were around when the universe was still young, helping them understand how galaxies form. It found protoplanetary disks, clumps of gas and dust around young stars that likely function as birthing grounds for new planets. It discovered that gamma-ray bursts — strange, incredibly powerful explosions of energy — occur in far-distant galaxies when massive stars collapse. And these are only a handful of its many contributions to astronomy.

Eventually, Hubble’s time will end. After more than 18 years in orbit, Hubble’s components will slowly degrade to the point at which the telescope stops working. The next service mission for the telescope will be carried out by Atlantis space shuttle mission, scheduled for launch on August 28, 2008. The mission will replace batteries, replace all gyroscopes, and install Wide Field Camera 3 and the Cosmic Origins Spectrograph. This should extend Hubble’s life into at least 2013, until it replaced by its successor, a brand-new generation of space telescope, named James Webb Space Telescope.

Happy birthday Hubble!

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Pictured here is a Hubble Space Telescope image on Stingray Nebula. Located in constellation Ara (The Altar) at the distance of 18.000 light years, this beautiful object considered as the youngest planetary nebula ever observed!

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An international team led by French and Canadian astronomers has just discovered the coldest brown dwarf ever observed. Their results has been on April 10th issue of Astronomy & Astrophysics.

The brown dwarf is named CFBDS J005910.83-011401.3 (it will be called CFBDS0059 in the following). Its temperature is about 350°C and its mass about 15-30 times the mass of Jupiter, the largest planet of our solar system. Located about 40 light years from our solar system, it is an isolated object, meaning that it doesn’t orbit another star.

This new finding made possible by the framework of the Canada-France Brown-Dwarfs survey. The object was first identified in pictures from the wide-field camera Megacam installed on the CFHT (Canada France Hawaii Telescope). Infrared pictures were then obtained with the NTT telescope (La Silla, ESO, Chile) and confirmed the low temperature of the object. Finally, the spectrum showing the presence of ammonia was obtained using the Gemini North Telescope (Hawaii).

Picture of the brown dwarf CFBDS0059 (small red dot on the top of the picture) and its near-infrared spectrum (lowest curve) illustrating the presence of ammonia.

To date, two classes of brown dwarfs have been known: the L dwarfs (temperature of 1200-2000°C), which have clouds of dust and aerosols in their high atmosphere; and the T dwarfs (temperature lower than 1200°C), which have a very different spectrum because of methane forming in their atmospheres. Because it contains ammonia and has a much lower temperature than do L and T dwarfs, CFBDS0059 might be the prototype of a new class of brown dwarfs to be called the Y dwarfs. This new class would then become the missing link in the sequence from the hottest stars to giant planets of less than -100°C, by filling the gap now left in the midrange.

This discovery also has important implications in the study of extrasolar planets. The atmosphere of brown dwarfs looks very much like that of giant planets, therefore the same models are used to reproduce their physical conditions. Such modeling needs to be tested against observations. Observing the atmospheres of extrasolar planets is indeed very hard because the light from the planets is embedded in the much stronger light from their parent stars. Because brown dwarfs are isolated bodies, they are much easier to observe. Thus, looking to brown dwarfs with a temperature close to that of the giant planets will help in testing the models of extrasolar planets’ atmospheres.

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This Chandra X-ray Observatory image shows the debris of a massive star explosion in the Large Magellanic Cloud, a small galaxy about 160,000 light years from Earth. The supernova remnant (SNR) shown here, N132D, is the brightest in the Magellanic clouds, and belongs to a rare class of oxygen-rich remnants. Most of the oxygen that we breathe on Earth is thought to have come from explosions similar to this one.

The colors in this image show low energy X-rays (red), intermediate energy X-rays (green) and high energy X-rays (blue). Substantial amounts of oxygen are detected in this image, particularly in the green regions near the center of the image. The origin of this shell is unknown, but it might have been created by a `nickel bubble’ shortly after the supernova explosion, caused by radioactive energy input from nickel that was created by the explosion. The existence of such bubbles is predicted by theoretical work.

Image credits: NASA/CXC/NCSU/K.J.Borkowski et al.

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