Toxic Universe

STS-135 Crew Portrait, Source: NASA

Space is truly the final frontier — at least for NASA’s space shuttle program, which ends on July 8, 2011. When Commander Craig Ferguson, Pilot Doug Hurley, and Mission Specialists Rex Walheim and Sandy Magnus board STS-135 Atlantis, carrying cargo to the International Space Station (ISS) the dramatic countdown of “Ten, nine, eight…” read at launch will fade quietly into history. The future without shuttles is sharply emphasized by cargo being hauled by the Atlantis, which includes a system to investigate the potential for robotically refueling spacecraft.

Shuttles -– humanity’s first reusable spacecraft -– came not from a cubicle at NASA headquarters, but from the U.S. Air Force, where a “winged” space vehicle, or “shuttle,” was first imagined in 1962. Prototypes were tried and discarded, but when NASA became involved in the 1960s space race, officials had a sky-high budget — to be the first among nations — never seen since. Still, after six exciting and manned Apollo Moon landings riveted the public, global and national politics changed. Space travel was no longer a priority, and money that flowed into engineering dried up, forcing NASA to cancel three more trips to the Moon, among other projects.

In 1974, six shuttles were built, with the idea of making space voyages a more-efficient alternative to other means. The first shuttle -– the Enterprise — so named by then-President Gerald Ford because of a huge outpouring of support from “Star Trek” fans, was constructed to be the first American orbiter. But it never orbited, it never shuttled, and it never went to space. The 130-ton Enterprise, in fact, had no engines. Instead, it was designed to piggyback on the back of a Boeing 747 jet, to test its gliding abilities. The first free flight in 1977 lasted 5.5 minutes from an altitude of 4.5 miles over California, with two astronauts steering it into Edwards Air Force Base. To this day, many people are unaware that shuttles are not similar to airplanes when they return home, but are instead, the largest gliders in the world.

Flying Through the Years

The excitement of watching shuttle flights dimmed considerably in 1986, when STS-51L (later renamed STS-25), killed seven astronauts when the Challenger exploded just 73 seconds after launch, in front of millions of viewers. Despite the tragedy, public outcry and emotion supported allocating federal funds to one replacement orbiter. In the following years, men and women commanded more shuttles while conducting experiments, re-defining science, and beaming never-imagined photos to Earth-bound residents thanks to sophisticated new imaging technology. In 2003, another setback hurt the shuttle program when the STS-107 Columbia was lost during re-entry, with 16 minutes until touchdown. Another seven astronauts were lost, and the world again mourned the heroes, while wondering if the risks were worth the results. Yet, when the opportunity to explore arose, the shuttles flew again, arranging transport to and from the ISS, among other missions.

Mission Accomplished?

Though the shuttle program will end, other forms of travel are scheduled for launch, some including private enterprise, some including NASA’s efforts, and some including the talents of both. Though the Atlantis signals an end of one era, the unmanned Messenger orbiter recently sent back high-resolution photos of Mercury, answering scientific questions about its impact craters and volcanic activity. In addition, the robot probe “New Horizons” is currently headed to Pluto, the only major planet (or dwarf planet, a controversial designation by the International Astronomical Union), never visited in our solar system. Estimated arrival time: 2015.

So though the Atlantis crew’s 12-day mission will finish a decades-long program, the record-setting travel — which pushed the bounds of exploration -– will continue to affect daily life through many of its discoveries.

When the last shuttle returns, a generation of scientists, astronomers and everyday people will miss the exciting sights and sounds on the launch pad. But though the shuttles will stay Earth-bound, their end will signal a new voyage — one that will send back information unknown to mankind, ensuring that the dream to understand the universe will live on.

References

Space Today Online
NASA
Space News

Map of Superclusters, Source: NASA

A new study of galactic superclusters published on June 13, 2011 by Shaun A. Thomas, Filipe B. Abdalla and Ofer Lahav of University College London (UCL) indicates that some superclusters may stretch on for more than 3 billion light years and vary in density. This variation in density is more than double that of the maximum variation in currently accepted astronomical theory.

What are Superclusters?

Superclusters, also known as hyperclusters, are the largest astronomical configurations in the universe. Superclusters are composed of around one dozen galactic clusters, which are groups of galaxies located near each other. To go on down the scale, galaxies are composed of star systems, around which planets revolve, and moons revolve around some planets.

Earth itself is included in a supercluster. This supercluster is officially named the Virgo Supercluster but is often referred to as the local supercluster. The Virgo supercluster gets its name because it is centered on the Virgo cluster, a large cluster of approximately 2000 galaxies. The cluster to which the Milky Way galaxy belongs is known as the Local Group. It consists of just over 30 galaxies spread out over 10 million light years and is 65 million light years from the Virgo cluster.

Formation of Superclusters

Science shows that soon after the birth of the universe in the Big Bang, matter was distributed close to evenly throughout the universe, as it existed at the time. We know this by measurements taken of the cosmic microwave background radiation (CMB) that began to be emitted about 370,000 years after the universe’s birth event.

As the force of gravity began to play on the expanding universe, the density of matter in the universe began to vary. These gravitational variations are what formed the galaxies, galactic clusters and superclusters.

The variation in the density of matter on smaller scales is readily apparent. The existence of star groups, galaxies, clusters and even superclusters cannot be argued. However, current theory suggests that on the scale of superclusters, very little variation should be seen because the force from the expansion of the universe is greater than that of gravity. To be more accurate, variations in the density of matter in the universe should be infinitesimally small beyond a few hundred million light years.

The variations in the density of superclusters as large as 3 billion light years across, as found in the UCL study, would not be possible under current theory. Astronomers are now scrambling to come up with a new theory that will support the new findings or to find a flaw in the study that would account for the never-before-seen variations.

Redshift Measurements

As the basis of the UCL study, Thomas, Felipe and Lahav used a giant catalog of galaxies compiled with the Apache Point, New Mexico telescope. This catalog is called the Sloan Digital Sky Survey. Although the catalog plots galaxies in a full quarter of the sky, they are only plotted two-dimensionally.

Thomas said that he first noticed the large structures by viewing much larger areas of the survey than are usually viewed. However, he also knew that a 2D survey alone would never be accepted as proof in his study. As additional proof, he plotted a new 3D survey using the redshift measurements of known galaxies.

The redshift is a phenomenon that allows astronomers to measure the distance of faraway interstellar objects. To complete the study, approximate distances were calculated for 700,000 objects in the Sloan Digital Sky Survey.

Explanations

Astronomers are beginning to look for explanations for the data in the UCL study. Some say the presence of dark energy could account for the variation. Thomas says that a new general theory of relativity may be in order.

Other scientists are taking another tack. David Spergel of Princeton University says that using colors and redshift to measure distances has some flaws that could be skewing the data in the study. Thomas admits that this is a possibility.

References:

Battersby, Stephen. “Largest cosmic structures ‘too big’ for theories.” New Scientist.
“The Nearest Superclusters.” NASA High Energy Astrophysics Science Archive Research Center.
Thomas, Shaun A.; Abdalla, Filipe B.; Lahav, Ofer. “Excess Clustering on Large Scales in the MegaZ DR7 Photometric Redshift Survey.” American Physical Society.

Betelgeuse Nebula, Source: Physorg

Betelgeuse is one of the brightest stars in the night sky. A red supergiant, its radius is at least 3.1 AU (Astronomical Units), or 3.1 times the approximate distance from the Earth to the sun. Because of its enormous size, Betelgeuse burns through its fuel at an incredible pace, and there’s a possibility of it going supernova within the next several thousand years once it has used up most of its fuel.

Rebirth Before Death

All of this has been known for a number of years now, but for the first time, astrophysicists are able to see what’s going on around the star. The Very Large Telescope in Chile has delivered high resolution images of Betelgeuse and its immediate region, displaying a nebula about 400 AU across.

Red supergiants are large enough that they constantly spew matter into space. What scientists now know about Betelgeuse is that over the past 10,000 years, a split second in the life of any star, Betelgeuse has lost an amount of matter equal to our own sun. What astrophysicists could only guess at before is now evidenced by its surrounding nebula, the result of its continuous material loss.

Insight Into Our Solar System

Most of the stars that we can observe are millions of light years away, but Betelgeuse is thought to be only 640 light years from Earth. Any light we receive from the star is only 640 years old, making it incredibly clear and bright for telescopes to study. In cosmic terms, what we’re witnessing in Betelgeuse occurred just a moment ago.

Once it goes supernova, Betelgeuse will provide years of fireworks for scientists to study, but it will obliterate the infantile nebula surrounding it, casting it out into the farthest reaches of space. It’s important to study that nebula right now because it may help explain how the Earth and other rocky planets were formed.

According to Physorg.com, “At some time in the distant past, the silicates of the Earth were formed by a massive (and now extinct) star similar to Betelgeuse.” Silicates, one form of silicon, form a large part of the Earth’s crust and are used in manufacturing, forming semiconductors, glass, and cement.

Betelgeuse is so bright that the nebula is only visible in infrared, since the visible light from the star completely overwhelms any light emitted from the surrounding gas.

Betelgeuse’s Final Years

With most of its fuel already consumed, Betelgeuse does not have long to live, at least in its current form. Once the hydrogen is fused into helium, the helium will begin fusing into an iron core. Everything outside the core will explode in a type II supernova, but it’s not large enough to form a black hole. Instead, Betelgeuse will probably form an incredibly dense neutron star about 20 kilometers across, about half the length of a typical marathon.

If we’re lucky, we’ll be able to catch the beginning stages of Betelgeuse’s spectacular supernova, a process which will take months. It’s theorized that a supernova could have caused the Ordovician Extinction 440 million years ago; luckily, Betelgeuse is not large enough to pose any such threat to Earth.

References:

Physorg – “The Flames of Betelgeuse: New Image Reveals Vast Nebula Around Famous Supergiant Star.”
Kaler, Jim. “Betelgeuse.”

Solar Storm

There are a lot of rumors in the news about the upcoming solar storm in 2012, which many people believe is the beginning of the end of the world. According to many believers of the Bible, the Rapture is coming and Earth will be soon consumed in fire and brimstone. Others believe that devastating solar storms are just a natural occurrence and have nothing to do with religion.

Some of you may recall that from August 28 to September 2, 1959 there were major solar flares and sunspots observed in the sun. It was on September 1 when a British astronomer named Richard Carrington observed the largest flare that triggered a massive coronal mass ejection (CME) traveling 18 hours directly towards Earth. It was indeed a remarkable event as the solar eruption triggered electrical currents that created dramatic displays of northern lights in Hawaii and Cuba, and also caused telegraph offices to catch fire.

This incident was recalled by prominent scientists and officials from different organizations who gathered around in Washington, DC to find out if this phenomenon will happen again. One solar physicist based at NASA headquarters said that it is inevitable that it will happen again, and the effects will be more devastating especially since solar flares will affect the technology that we have today. These high-tech systems that will be affected include satellite communications, cellular phones, radio communications, smart power grids and GPS systems which are vulnerable to solar flares.

So what exactly is a Solar Storm?

Solar storms occur when there is a large explosion in the sun’s atmosphere. The sun’s surface ejects clouds of atoms, ions, and electrons through its corona and out into space. The clouds usually reach the earth in a day or two after it has been observed on the sun’s surface. These flares usually occur in active regions around sunspots. Intense magnetic fields infiltrate the photosphere to link the corona to the solar interior. The sudden release of magnetic energy stored in the corona is what powers the solar flares. This is similar to the energy produced by coronal mass ejections (CME) and its relation to solar flares still needs further research in order to link the two phenomena together.

When the sun is active, minor solar flares occur several times per day. These minor flares are hardly noticeable on Earth, as these flares rarely travel far enough to affect us. When the sun is quiet, solar flares happen less than once a week.

Major solar flares have the potential to create a devastating impact on the Earth’s magnetosphere, which may result in radiation hazards to spacecrafts and cosmonauts that are in the path of the flare. It is also predicted that in the event of a massive solar flare, radiation will scorch the earth and all of its inhabitants.

Ultraviolet radiation and x-rays emitted by solar flares can also affect the earth’s ionosphere. This can disrupt radars, short wave radio communications, long-radio communications and other devices operating at the same type of frequencies.

The so-called radiation poses risk to manned mission to the moon, Mars, and other planets. The human body may absorb the radiation’s protons, which cause biochemical damage that is extremely harmful to astronauts during interplanetary travel. To protect such occurrences, astronauts and cosmonauts must wear physical or magnetic shields to defend themselves against this radiation risk.

Preparing for the Solar Storm of 2012

Scientists and researchers now have technologies that assist them in the forecasting and tracking of solar storms more accurately than ever. These systems were designed to essentially prepare humanity before a devastating solar flare occurs. Solar storms can now be tracked in three dimensions as the storm approaches Earth. This gives experts time to create weather alerts and to make the necessary arrangements to preserve high tech assets and other power grids during these extreme periods of solar activity.

Computer software has created 3-D models for the sun’s activity to predict when sun activity will occur, the direction of the solar storm, how intense it will be and it will also give us a better idea of which planets and spacecraft will be affected. Electrical currents from solar storms reaching the earth’s surface must be determined through specially designed computers. These currents will also damage power transformers, so having good models may help to prevent a worldwide blackout if the necessary preparations are made before the storm reaches Earth.

It is a widely known fact that the Sun will approach its “solar maximum” in 2012, which is the peak of its 11-year cycle. This means that the solar activity will increase and there will be more of a chance that it will have some effect on Earth. The last solar maximum occurred in 2002-2003 when record-breaking X-class flares were noticed by many solar physicists. No effects were noted on Earth, but nevertheless, it is a serious problem to worry about. Thankfully, with our advances in technology, we may be able to prevent (or at least hide from) the future effects of major solar flares.

References

Nasa: Storm Warning
Big think
Universe Today: No Killer Solar Flare