Stephen Hawking: 'Humankind Belongs in Space'

Technological advancements that took place over the past few decades have made the world a very dangerous place to live in. Nuclear missiles are just the tip of the iceberg when it comes to methods that humankind can employ to destroy itself. Global warming and chemical weapons are also high on the list, as are other natural factors. Famed physicist and scientist Stephen Hawking believes that the world needs to look at the stars for inspiration, and leave Earth before it's too late.

The famed expert believes that it's wrong for humankind to keep all of its eggs in a single basket, so to speak. “I believe that the long-term future of the human race must be in space. It will be difficult enough to avoid disaster on planet Earth in the next hundred years, let alone the next thousand, or million. The human race shouldn't have all its eggs in one basket, or on one planet. Let's hope we can avoid dropping the basket until we have spread the load,” Hawking tells Big Think.

He also mentions the fact that the world's resources are currently being depleted at a massively-high rate, far beyond what can be replenished naturally or artificially. Greed and the quest for profits is making large corporations hinder innovation in fields of science investigation alternative energy sources, and this will soon manifest its effects on the planet. Hawking believes that we wouldn't want to be here when that happens. Plus, he adds, the Sun will only take a few billion years before it expands to envelop Earth, so we shouldn't be here at that time.

Speaking about situations such as the Cuban Missile Crisis, which almost saw the onset of global nuclear war between the US and the Soviet Union, Hawking says that “the frequency of such occasions is likely to increase in the future. We shall need great care and judgment to negotiate them all successfully.” Even if we are successful in doing so, the Sun will kill all life on Earth over a period of time. When it begins to swell, global warming will increase its effects, until all water is evaporated. Without the precious liquid, life as we know it will disappear.

“Life on Earth will have disappeared long before 7.6 billion years. Scientists have shown that the Sun's slow expansion will cause the temperature at the surface of the Earth to rise. Oceans will evaporate, and the atmosphere will become laden with water vapor, which (like carbon dioxide) is a very effective greenhouse gas. Eventually, the oceans will boil dry and the water vapor will escape into space. In a billion years from now the Earth will be a very hot, dry and uninhabitable ball,” says Dr. Robert Smith, an astrophysicist at the University of Sussex.

How Binary Star Systems Form

For many years, we have been taught to believe that most stars are similar to our Sun, in the sense that they form the sole core of their systems. This picture now appears to be dismantled piece-by-piece by new scientific evidence, which shows that a great number of cosmic fireballs are in fact members of binary systems. In these setups, two stars spin around each other, bound together by the mutual gravitational pulls they exert on each other. The mechanisms through which these binaries form have fascinated and puzzled astronomers for a long time, and now new data comes to clarify the mystery.

One of the main questions related to their development is whether the two components of the binary develop in separate molecular clouds, or if maybe they are born in the same one. Commonly, experts say that systems featuring stars that are fairly distant from each other appeared when two nearby clouds of gas and dust collapsed. When the stars orbit each other at a close distance, researchers believe that a single cloud was the source for both fireballs. But astronomers were in the dark about how a single source could produce two stars.

Experts at the University of Michigan in Ann Arbor decided to investigate the phenomenon, and used the American space agency's Spitzer Space Telescope, which surveys the sky in infrared wavelengths. Data collected with the sensitive observatory determined the existence of asymmetrical gas and dust envelopes around forming stars. These blob-like structures may promote the development of irregularities inside the clouds, which may in turn lead to the emergence of binary systems. Details of the new work appear in a recent issue of the esteemed publication Astrophysical Journal.

University of Michigan in Ann Arbor expert John Tobin, who is also the lead author of the paper, says that “we see asymmetries in the dense material around these proto-stars on scales only a few times larger than the size of the solar system. This means that the disks around them will be fed unevenly, possibly enhancing fragmentation of the disk and triggering binary star formation. We were really surprised by the prevalence of asymmetrical envelope structures. And because we know that most stars are binary, these asymmetries could be indicative of how they form,” Spitzer is managed by experts at the NASA Jet Propulsion Laboratory (JPL) in Pasadena, California.

New Evidence for Ancient Life on Mars

Scientists from the NASA Johnson Space Center (JSC) recently announced that a new study they conducted on a famous Martian meteorite found in 1996 lends further credence to the fact that ancient life existed at one point on Mars. The space rock has been a cause for discord in the international scientific community since it was first discovered, and many groups have argued either for or against it containing sings of past Martian life. Using modern techniques, the JSC team determined that early life remains the most plausible explanation for the structures identified in the rocks, ScienceDaily reports.

What's interesting about this new work is that it did not focus directly on studying the ancient meteorites. Instead, the group analyzed the studies that proposed the structures found in the space rocks were not signs of life. Their results are very clear – other origins than lifeforms are not plausible for these particular samples. The investigation comes 14 years after another JSC team, led by scientists David McKay, Everett Gibson and Kathie Thomas-Keprta, published a paper in the highly-regarded journal Science, claiming the discovery of biogenic evidence in the meteorite known as ALH84001.

The recent paper, entitled “Origin of Magnetite Nanocrystals in Martian Meteorite ALH84001,” again revisits the same old hypothesis, but adds additional data to support the claims. Details of the data appear in the November issue of the journal Geochimica et Cosmochimica Acta of The Geochemical Society and The Meteoritical Society, and is authored by Thomas-Keprta. Coauthors include experts Simon Clemett, McKay, Gibson and Susan Wentworth, who are all based at the JSC Astromaterials Research and Exploration Science Directorate.

“In this study, we interpret our results to suggest that the in situ inorganic hypotheses are inconsistent with the data, and thus infer that the biogenic hypothesis is still a viable explanation,” reveals Thomas-Keprta, who was the lead author of the investigation. He is also a JSC senior scientist for Barrios Technology. “We believe that the biogenic hypothesis is stronger now than when we first proposed it 13 years ago,” adds Gibson, who is a senior scientist at the American space agency.

“The evidence supporting the possibility of past life on Mars has been slowly building up during the past decade. This evidence includes signs of past surface water including remains of rivers, lakes and possibly oceans, signs of current water near or at the surface, water-derived deposits of clay minerals and carbonates in old terrain, and the recent release of methane into the Martian atmosphere, a finding that may have several explanations, including the presence of microbial life, the main source of methane on Earth,” says McKay, who is the JSC chief scientist for exploration and astrobiology.

New Hubble pictures suggest Milky Way fell together

New infrared images of the Milky Way globular cluster 47 Tucanae (this one recorded at a wavelength of 1.6 micrometers), reveal that both the cluster and the Milky Way's central bulge are 11 billion to 12 billion years old and may have formed simultaneously with the Milky Way’s halo.

BALTIMORE — A preliminary analysis of elderly stars in the Milky Way appears to strike a blow against the prevailing theory of galaxy formation. The study suggests that several large and seemingly disparate chunks of the Milky Way galaxy formed at the same time from the collapse of a single blob of gas and dust.

That’s in direct contrast to the leading galaxy-formation scenario, which holds that the Milky Way and other galaxies began small and grew bit by bit for the most part, gravitationally acquiring intergalactic gas and dust and merging with galaxies in their immediate neighborhood.

The new evidence, which astronomers emphasize is only tentative, comes from a new, ongoing study of a familiar globular cluster — a dense, elderly grouping of more than a million Milky Way stars collectively known as 47 Tucanae. Earlier this year, Harvey Richer of the University of British Columbia in Canada and his colleagues began examining 47 Tucanae with two Hubble Space Telescope cameras — the newly installed Wide Field Camera 3 and the Advanced Camera for Surveys, which stopped working early in 2007 but was revived by astronauts during the servicing mission last year.

The cluster lies near but not inside the Milky Way’s bulge, a massive concentration of stars that surrounds the galaxy’s core. But because the cluster shares several properties with the bulge, such as chemical composition and orbital motion, astronomers consider the age of 47 Tucanae a good proxy for that of the bulge.

An analysis of the Hubble portrait, which includes one of the deepest infrared views ever recorded, reveals that 47 Tucanae, and therefore the Milky Way’s bulge, formed between 11 billion and 12 billion years ago, Richer reported May 4 at a symposium on stellar evolution at the Space Telescope Science Institute in Baltimore. He said previous age estimates that did not use the new Hubble camera and put the cluster at a more youthful 9 billion years old are simply not correct.

“This is not a young cluster. That’s definitive,” Richer said. But he cautioned that both the analysis and observations of 47 Tucanae are ongoing, so the precise age determination is still “very preliminary.”

The new age determination places the bulge at roughly the same vintage as the halo of the Milky Way, a vast spherical region that extends to the outskirts of the galaxy and envelops the flattened disk containing the Milky Way’s signature spiral arms,.

Researchers had previously determined the halo’s age by studying several globular clusters that lie within it. The similarity in age of 47 Tucanae and the galactic halo suggests that the two structures may have formed simultaneously, in one giant monolithic gravitational collapse of material, Richer said. “It may have been that major components of the galaxy pretty much formed everywhere at the same time very early on and other bits and pieces came along later,” he noted.

A younger age for the bulge would have indicated that the galaxy grew more gradually and from the outside in, with the halo forming first and the central bulge arising a few billion years later.

But if the age estimate holds up, it would appear to be in conflict with the prescription for galaxy formation dictated by the cold dark matter theory, which holds that galaxies began as small fry that built themselves up by stealing gas and stars from their neighbors.

Evidence that the halo and the bulge of the Milky Way formed together could be seen either as a cosmic coincidence or a finding that suggests some previously unknown episode of violence early in the galaxy’s history, commented Rosie Wyse of Johns Hopkins University in Baltimore, who was not a collaborator on the study.

One possibility, she notes, is that the Milky Way suffered a major collision not long after its birth that drove material from the halo into the central part of the galaxy, forming the bulge. That could also explain why the mass of stars in the bulge is about 10 times heavier than that in the halo, she said.

The finding does not rule out the possibility that parts of the Milky Way grew by accreting, or gravitationally accumulating material, from neighbors, Richer said. Indeed, the Milky Way today continues to grow by pulling in small neighboring galaxies, such as the Sagittarius dwarf galaxy.

New Martian Views From Orbiting Camera Show Diversity

New images from more than 750 recent observations of Mars by an orbiting telescopic camera testify to the diversity of landscapes there.

The images from the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter are now available on NASA's Planetary Data System and on the camera team's website. The features visible in the images range from oddly sculpted terrain inside a giant crater to frosted dunes, deformed craters, old gullies and pits strung along fractured ground.

This new batch brings the tally from the high-resolution camera to more than 1.4 million image products derived from more than 14,200 observations. Each observation can reveal features as small as desks in areas covering several square miles.

The camera is one of six instruments on NASA's Mars Reconnaissance Orbiter, which reached Mars in 2006. For more information about the mission, see http://www.nasa.gov/mro.

First All-Sky Infrared Catalogs Released After 25 Years

All-sky surveys represent one of the most important tools in astronomy today. They allow experts to set reference points for their studies, and also to compare various celestial objects between themselves, and with newly discovered ones. For the first time in more than a quarter of a century, a new series of infrared all-sky surveys, covering in excess of 1.3 million light sources, has been made available, under the name of the AKARI All-Sky Catalogs. The information is available here and here, ScienceDaily reports.

“The release of the catalogs is very timely. Many of the objects detected by AKARI and contained in these catalogs will be prime candidates for future investigation at far-infrared and submillimeter wavelengths with Herschel. These catalogs will be very useful for astronomers preparing for the next opportunity, in May, to propose observations with Herschel,” the AKARI project scientist for the European Space Agency (EAS), Alberto Salama, explains. He shares that the new datasets could be used to derive more information on subjects such as the traits of nearby stars, on how planetary systems form around new stars, or on how stars started forming very early in the history of the Universe.

Launched in February 2006, the AKARI spacecraft was Japan's first infrared astronomical satellite. Its mission ran between May 2006 and August 2007, during which time it did a full sweep of the visible sky, imaging all the targets that eventually ended up forming the catalogs. Its two main instruments were the Infrared Camera (IRC), which worked in the 9- and 18-micrometer bands, and the Far-Infrared Surveyor (FIS), which looked at the sky in the 65-, 90-, 140-, and 160-micrometer bands. IRC holds the record for most infrared sources discovered, at 70,000 objects, with FIS trailing some distance away, with only about 430,000 objects identified.

Each of the two catalogs features data from one of these two instruments. As such, rather than producing a single, large dataset, experts decided to split the information into the AKARI-IRC Point Source Catalog and the AKARI-FIS Bright Source Catalog. Behind this ambitious project was the Japanese Aerospace Exploration Agency (JAXA), which managed the AKARI mission in collaboration with ESA. Scientists from the Seoul National University, in South Korea, have also contributed to developing the satellite and its instruments. Survey-data processing took place at the ESA European Space Astronomy Center (ESAC) near Madrid, Spain.

New ESO Image Shows Thousands of Galaxies

Astronomers at the European Southern Observatory (ESO) have just released a new spectacular, wide-field image of a very crowded portion of the sky. The photograph covered several thousands of very distant galaxies, according to the team behind the study, as well as a significant group of such structures that are included in the massive Abell 315 galaxy cluster. But the scientists warn that the visible portion of this particular cluster is only the tip of the iceberg. The entire structure is several times more massive, given that much of its content is made up of dark matter.

This is visible when looking at the shape of the galaxies behind it, which appear to be slightly bent. The ESO team also adds that the most of the stars we see in this new image are almost never visible from Earth with the unaided eye. Most of the bright dots we see in the evening sky are actually stars from our own galaxy, the Milky Way, plus a few extra-bright ones from neighboring galaxies such as Andromeda. Other star “collections” emit very small amounts of visible light, and are therefore too dim to be perceived by the human eye.

One interesting thing to note is that, if we were to become capable of seeing this dim light, the radiation coming from distant galaxies would basically cover the sky. Since we don't have that ability, astronomers rely on devices such as the Wide Field Imager instrument. This is located on the MPG/ESO 2.2-meter telescope facility, which is based at the ESO La Silla Observatory, high in the Chilean Andes. For the new image, scientists used three different filters and long exposure times. The composite photography that resulted from this is of both the wide-field and long-exposure kind. The WFI covered an area of the sky about 34x33 arcminutes across.

“Beginning in the center of the image and extending below and to the left, a concentration of about a hundred yellowish galaxies identifies a massive galaxy cluster, designated with the number 315 in the catalog compiled by the American astronomer George Abell in 1958. The cluster is located between the faint, red and blue galaxies and the Earth, about two billion light-years away from us. It lies in the constellation of Cetus (the Whale),” ESO scientists explain in a press release.

“The presence of dark matter is revealed through its gravitational effect: the enormous mass of a galaxy cluster acts on the light from galaxies behind the cluster like a cosmic magnifying glass, bending the trajectory of the light and thus making the galaxies appear slightly distorted. By observing and analyzing the twisted shapes of these background galaxies, astronomers can infer the total mass of the cluster responsible for the distortion, even when this mass is mostly invisible. However, this effect is usually tiny, and it is necessary to measure it over a huge number of galaxies to obtain significant results,” the astronomers add.

Deep Space as Seen by the Chandra X-Ray Observatory

This new image from the Solar Dynamics Observatory's Atmospheric Imaging Assembly (AIA) shows in great detail a solar prominence taken from a March 30, 2010 eruption. The twisting motion of the material is the most noticeable feature.

(Photo: NASA/CXC/SAO)

New images from the Chandra X-ray Observatory, NASA's flagship mission for X-ray astronomy.

Read the whole article on CBSNews - Science

Mars Odyssey THEMIS images - April 26-30, 2010

The following new images taken by the Thermal Emission Imaging System (THEMIS) on the Mars Odyssey spacecraft are now available:

• Auqakuh Vallis (Released 26 April 2010)
  This VIS image shows a small portion of Auqakuh Vallis.
• Daedalia Planum (Released 27 April 2010)
  Some of the youngest volcanic flows on Mars are from Arsia Mons.
• Ascraeus Mons (Released 28 April 2010)
  This VIS image shows part of the northeastern flank of Ascraeus Mons, one of the large Tharsis volcanoes.
• Juventae Chasma (Released 29 April 2010)
  Baetis Chasma is a chasmata near Valles Marineris.
• Galaxias Fossae (Released 30 April 2010)
  The fracture system in this VIS image is part of Galaxias Fossae, a series of fractures on the northern part of the Elysium Mons volcanic complex.

Cassini ISS images - April 26-30, 2010

The following new images taken by the Imaging Science Subsystem (ISS) on the Cassini spacecraft are now available:

• Hyperion's South (Released 26 April 2010)
  Myriad shadows cover the pitted surface of Saturn's small moon Hyperion in this Cassini spacecraft image, which shows the moon's south pole on the right.
• Woven Shadow (Released 27 April 2010)
  Part of the shadow of Saturn's moon Epimetheus appears as if it has been woven through the planet's rings in this Cassini image taken about a month and a half before the planet's August 2009 equinox.
• West of the Probe (Released 28 April 2010)
  The Cassini spacecraft peers through Titan's atmosphere at the region called Adiri, west of the landing site of the Huygens probe on the anti-Saturn side of the moon.
• Shadows from the Waves (Released 29 April 2010)
  Shadows are cast by Daphnis and the moon's attendant edge waves in this Cassini spacecraft image taken about a month and a half before the Saturn's August 2009 equinox.
• Crescent at Equinox (Released 30 April 2010)
  The Cassini spacecraft looks down and pictures Saturn wrapped in a pencil-thin shadow of the rings just days after the planet's August 2009 equinox.