Posted on by Fraser Cain

The Value of Space Exploration

The International Space Station. Image Credit: NASA

Read any debate about space exploration, and this question will invariably come up. “Why should we be spending money exploring space when there are so many problems here on Earth that we need to solve first?” It’s a tricky one. I’ve got a simple answer; space exploration is awesome. Come on, think of space ships traveling to other worlds – that’s really cool.

Okay, perhaps I’ve got too simplistic an argument, so I turned to the astrosphere and posed the question to other space bloggers. Here’s what they had to say…

Alun Salt – Archeoastronomy

Historical materials suggest that there wasn’t such sharp division between earth and sky in the ancient world. Instead there was one cosmos. Space exploration reveals that while there isn’t a divine link between the heavens and the earth, it is true that what happens up there can affect what happens down here. It would be useful to know about the cosmos, rather than just be a victim of it.

Mark Whittington – Curmudgeons Corner

What is the value of space exploration? Inherent in exploration of all types is the opportunities that it opens up to the people doing the exploring. For some it is the opportunity to gain new knowledge. For others it is the opportunity to create wealth and expand commerce. For still others the opportunity lies is trancendence, to grow spirtually and to gain a greater appreciation of the universe.

Alan Boyle – MSNBC Cosmic Log

I’ve been getting a healthy dose of the American revolution lately, between watching HBO’s “John Adams” miniseries and reading David McCullough’s “1776,” and that may be the reason I’m thinking of this in terms of pledging “our lives, our fortunes and our sacred honor” rather than just thinking in terms of paying taxes. I like to think of the reasons for making that pledge, in terms of the push to outer space, as the five E’s (plus examples): exploration (to the moon and Mars), entertainment (cool Hubble pictures), energy (space solar power and asteroid mines), empire building (defending the high frontier) and extinction avoidance (fending off space rocks, and getting off this rock). Check out the log item for more.

Steinn Sigurdsson – Dynamics of Cats

Because: we look out, and wonder, and explore;

and we do what little we can on the margin of our busy lives to explore the bigger universe, today;

and that is one of the things that makes life worth living,

and gives us hope that the future can be better, for us and for future generations.

Ethan Siegel – Starts With a Bang

This is like asking why we should spend money on making our city better when there are so many problems here in our own homes. Or why we should spend money on understanding our whole world when there are so many problems here in our own country. Space is something that we are not only a part of, but that encompasses and affects all of us. Learning about the grandest scales of our lives — about the things that are larger than us and will go on relatively unaffected by whatever we do — that has value! And it might not have a value that I can put a price tag on, but in terms of unifying everyone, from people in my city to people in a foreign country to people or intelligences on other planets or in other galaxies, space exploration is something that is the great equalizer. And the knowledge, beauty, and understanding that we get from it is something that one person, group, or nation doesn’t get to keep to itself; what we learn about the Universe can be, should be, and if we do our jobs right, will be equally available to everyone, everywhere. This is where our entire world came from, and this is the abyss our entire world will eventually return to. And learning about that, exploring that, and gaining even a small understanding of that, has the ability to give us a perspective that we can never gain just by looking insularly around our little blue rock.

Bill Dunford – Riding with Robots on the High Frontier

Why should we worry about what’s going on outside the cave? We have so many problems here inside in the cave.

Why should we waste time trying to figure out agriculture? We have so much work to do hunting and gathering.

Why should we spend so much effort messing about in boats? We have so many issues here on the land.

Why should we fiddle with those computers? There is so much calculating that still needs to be done with these pencils.

Why should we explore space? We have so many problems here on Earth.

The answer to all these questions is the same: reaching for new heights often creates new solutions, new opportunity and elevated hope back on the ground.

We should NOT spend indiscriminately in space. But moderately-funded space exploration — as one small part of an overall program of basic scientific research — has blessed lives in many ways over the years, from satellites measuring drought conditions to new imaging techniques in hospitals to global communication.

Brian Wang – Next Big Future

Lack of a space program will not solve anything else faster and a well planned program [not what we have been doing] can deliver massive benefits. History shows the logical flaw.

There has been no historical example of any group “solving all of their problems before embarking on exploration/expansion/major project”. The solve all problems locally before advancing has not been shown to be a successful strategy. There has been major examples where the imperfect/highly flawed expander had major advantages over the non-expander (who was also flawed). The biggest one is China had the largest ocean going fleet in 1400’s. Then the emperor destroyed that fleet. The Western nations came a few hundred years later and forced China to give up Hong Kong and Macau for 99 years. The Europeans colonized North America and expanded economies because of those policies. The world has about a 60 trillion/year economy. There is not a shortage of resources in money or people to target problems. Well funded, well planned and well executed efforts can be directed at all of the problems simultaneously. Just putting ten times, a hundred times or a million times more money does not convert a failing plan, project against hunger, poverty, corruption into a successful plan. We better plans and better thinking.

Space exploration and development has had a lot of waste and a lack of purpose and a good plan. A strong case can be made that the overall purpose of the space programs have been one aspect of political pork with minimal space efforts and the name space program. Clearly the space shuttle and the space station have vastly under delivered for the money spent on them.

Strategies for successful space development: Focus on lowering the cost and the purpose of colonization and industrialization and
commerce (tourism etc…)

– If lowering the cost is best down with more robots then use robots first or mainly. do not force the manned program until costs go down.

– fuel depots in space (bring the costs down closer to the cost of LEO $2000/kg)

– More nuclear propulsion and non-chemical systems (mirrored laser arrays for launches).

Ian O’Neill – Astroengine

Being an astrophysicist and space colonization advocate, my natural, basic and very quick answer is: to explore the undiscovered. It is a very basic human trait to want to explore, why limit our horizons to the surface of the Earth when there are infinite possibilities for development of the human race amongst the stars? We could be on the verge of realising that this step into the cosmos is a very natural progression for us. To borrow a quote from Stephen Hawking:

“We once thought we were at the centre of the Universe. Then we thought the sun was. Eventually, we realised we were just on the edge of one of billions of galaxies. Soon we may have to humbly accept that our 3D universe is just one of many multi-dimensional worlds.” (ref)

Looking back on the 21st century, when we have established a presence throughout the solar system, future generations will view our “proto-space” selves much like how we look upon the pioneers and explorers of the 16th century who colonized the strange but fruitful lands of the Americas. Back then, the Earth was flat. Like then, the going will be tough and the rewards of “leaving the nest” will not be fully realised until we make that bold push into a new era of discovery. Space exploration is as natural as colonizing the continents; it may look costly from the outset, but in the end we’ll all benefit and evolve.

John Benac – Action For Space

Mankind’s expansion to the Moon and Mars will serve as a shocking and unifying symbol that lifts the even the poorest soul’s belief in what they, as a human, can accomplish. 7 billion people each raise their belief in what man, individually and in groups, can accomplish, and the collective change in positive self-confidence provides a new ability and impetus to solve all other problems on Earth.

Phil Plait – Bad Astronomy

First, the question of why spend money there when we have problems here is a false dichotomy. We have enough money to work on problems here and in space! We just don’t seem to choose to, which is maddening. $12 million an hour is spent in Iraq; the US government chose to do that instead of fix many problems that could have been solved with that money. NASA is less than 1% of the US budget, so it’s best to pick your fights wisely here.

Second, space exploration is necessary. We learn so much from it! Early attempts discovered the van Allen radiation belts (with America’s first satellite!). Later satellites found the ozone hole, letting us know we were damaging our ecosystem. Weather prediction via satellites is another obvious example, as well as global communication, TV, GPS, and much more.

If you want to narrow it down to exploring other planets and the Universe around us, again we can give the practical answer that the more we learn about our space environment, the more we learn about the Earth itself. Examining the Sun led us to understand that its magnetic field connects with ours, sometimes with disastrous results… yet we can fortify ourselves against the danger, should we so choose. Space exploration may yet save us from an asteroid impact, too. Spreading our seed to other worlds may eventually save the human race.

But I’m with Fraser. These are all good reasons, and there are many, many more. But it is the very nature of humans to explore! We could do nothing in our daily lives but look no farther than the ends of our noses. We could labor away in a gray, listless, dull world.

Or we can look up, look out to the skies, see what wonders are there, marvel at exploding stars, majestic galaxies, ringed worlds, and perhaps planets like our own. That gives us beauty and joy in our world, and adds a depth and dimension that we might otherwise miss.

Space exploration is cheap. Not exploring is always very, very expensive.

Astroprof – Astroprof’s Page

Space exploration is important BECAUSE we have problems here on Earth. We need to expand and grow as a species. Our planet has limited resources, and we need the resources availible in the Solar System as a whole if we are to use them to solve our problems here. The technological advances developed for space exploration also go to solving other problems on Earth. And, on top of all that, Earth is a planet. Understanding planets helps us understand our own planet. And, Earth is affected and influenced by external forces. Understanding those things also helps us to understand our planet, and allows us to adapt to changes that occur naturally or that we create.

Robert Pearlman – collectSPACE

Many of the problems we have on Earth are rooted in a our need for new ideas. From medical advancements to political diplomacy, it often takes a new perspective to find the answer. Space exploration offers the rare opportunity to look inwards while pushing out. The photographs sent back of the Earth as a “fragile blue marble”, a whole sphere for the first time, gave birth to the environmental movement. Astronauts, regardless of their home nation, have returned to Earth with a new world view, without borders. But the perspective isn’t limited to those who leave the planet. When Neil Armstrong and Buzz Aldrin walked on the Moon, “mankind” took on a new appreciation for all of humanity. It was “we” who went, even if “we” were not living in the United States. That sense of unity was recognized by the Apollo 11 crew upon their return to the planet: Buzz turned to Neil and commented, “We missed the whole thing…”

Robert Simpson – Orbiting Frog

The value of knowing about things is not quantifiable. We can qualitatively say that as we have become more knowledgeable, we have become better prepared for the things that come our way. We are more able to grow and to make progress by knowing more about the world we live in. Our planet is just one of many in a solar system that is also just one of many.

The cost of human exploration, and the risks involved, are often discussed. However everyone would seem to agree that until a human being had set foot on the Moon, we had not really been there. Likewise, it will not be until humans stand on Mars, that we have really visited the planet. Science can be done by robots and probes, but experience can still only be obtained by human beings.

Ryan Anderson – The Martian Chronicles

The List:
1. Perspective
2. Protecting and Understanding our World
3. Inspiration
4. The Economy
5. Exploration
6. New Technology
7. Answering the Big Questions
8. International Collaboration
9. Long-Term Survival
Click here to read the full version.

Of course, that’s just our opinion. What’s yours? Feel free to comment below and continue the discussion.

Posted on by Nancy Atkinson

Phoenix Spacecraft Maneuvers for Mars Landing

Looking towards a May 25 landing for the Phoenix Mars Lander, the navigation team for mission adjusted the flight path for the spacecraft on April 10. “This is our first trajectory maneuver targeting a specific location in the northern polar region of Mars,” said Brian Portock, chief of the Phoenix navigation team at the Jet Propulsion Laboratory. The mission’s two prior trajectory maneuvers, made last August and October, put the spacecraft on target to just intersect with Mars. But this recent maneuver put it on course to land at a site called “Green Valley,” a broad, flat valley in Mars north polar region. NASA announced they have “conditionally” approved this site, but a final decision has yet to be made. And why, you ask, hasn’t a final decision been made on a landing site at this late date?

Phoenix mission managers are still looking for a safe, yet exciting place to land. The proposed landing area is an ellipse about 62 miles by about 12 miles (100 kilometers by 20 kilometers). In looking at high resolution images of this area, researchers have mapped more than five million rocks in and around that ellipse, each big enough to end the mission if hit by the spacecraft during landing. “The environmental risks at landing — rocks and slopes — represent the most significant threat to a successful mission. There’s always a chance that we’ll roll snake eyes, but we have identified an area that is very flat and relatively free of large boulders,” said JPL’s David Spencer, Phoenix deputy project manager and co-chair of the landing site working group.

MRO’s High Resolution Imaging Science Experiment (HiRISE) camera has taken more than three dozen images of the area. Analysis of those images prompted the Phoenix team to shift the center of the landing target 13 kilometers (8 miles) southeastward, away from slightly rockier patches to the northwest. Navigators used that new center for planning the recent trajectory correction maneuver.

“Our landing area has the largest concentration of ice on Mars outside of the polar caps. If you want to search for a habitable zone in the arctic permafrost, then this is the place to go,” said Peter Smith, principal investigator for the mission, at the University of Arizona , Tucson .

When Phoenix lands, it will dig to an ice-rich layer expected to lie within arm’s reach of the surface. It will analyze the water and soil for evidence about climate cycles and investigate whether the environment there has been favorable for microbial life.

The April 10 trajectory adjustment began by pivoting Phoenix 145 degrees to orient and then fire spacecraft thrusters for about 35 seconds, then pivoting Phoenix back to point its main antenna toward Earth. The mission has three more planned opportunities for maneuvers before May 25 to further refine the trajectory for a safe landing at the desired location.

In the final seven minutes of its flight on May 25, Phoenix must perform a challenging series of actions to safely decelerate from nearly 21,000 kilometers per hour (13,000 mph). The spacecraft will release a parachute and then use pulse thrusters at approximately 914 meters (3,000 feet) from the surface to slow to about 8 kilometers per hour (5 mph) and land on three legs.

For more information about Phoenix , visit NASA’s site, and ASU’s site

Posted on by Nancy Atkinson

Space Debris Illustrated: The Problem in Pictures

Trackable objects in Earth ORbit. Image Credit: ESA

Space junk, space debris, space waste — call it what you want, but just as junk and waste cause problems here on Earth, in space spent booster stages, nuts and bolts from ISS construction, various accidental discards such as spacesuit gloves and cameras, and fragments from exploded spacecraft could turn into a serious problem for the future of spaceflight if actions to mitigate the threat are not taken now. The European Space Operations Centre has put together some startling images highlighting this issue. Above is a depiction of the trackable objects in orbit around Earth in low Earth orbit (LEO–the fuzzy cloud around Earth), geostationary Earth orbit (GEO — farther out, approximately 35,786 km (22,240 miles) above Earth) and all points in between.

Trackable objects in Low Earth Orbit. Image Credit: ESA
Between the launch of Sputnik on 4 October 1957 and 1 January 2008, approximately 4600 launches have placed some 6000 satellites into orbit; about 400 are now travelling beyond Earth on interplanetary trajectories, but of the remaining 5600 only about 800 satellites are operational – roughly 45 percent of these are both in LEO and GEO. Space debris comprise the ever-increasing amount of inactive space hardware in orbit around the Earth as well as fragments of spacecraft that have broken up, exploded or otherwise become abandoned. About 50 percent of all trackable objects are due to in-orbit explosion events (about 200) or collision events (less than 10).
Impact from space debris on shuttle window
Officials from the space shuttle program have said the shuttle regularly takes hits from space debris, and over 80 windows had to be replaced over the years. The ISS occasionally has to take evasive maneuvers to avoid collisions with space junk. And of course, this debris is not just sitting stationary: in orbit, relative velocities can be quite large, ranging in the tens of thousands of kilometers per hour.

For the Envisat satellite, for example, the ESA says the most probable relative velocity between the satellite and a debris object is 52,000 kilometers per hour. If a debris objects hits a satellite, the ISS or the Shuttle, at those speeds it could cause severe damage or catastrophe.

Space Debris in polar orbit. Image Credit: ESA

Above is a depiction of debris in polar orbit around Earth. From the image below, it’s evident how explosions of spacecraft causes even more scattered debris. Even after the end of the mission, batteries and pressurised systems as well as fuel tanks explode. This generates debris objects, which contribute to the growing population of materials in orbit, ranging from less than a micrometer to 10 centimeters or more in size.
An upper stage of a spacecraft exploding. Image Credit: ESA

About 40% of ground-trackable space debris come from explosions, now running at four to five per year. In 1961, the first explosion tripled the amount of trackable space debris. In the past decade, most operators have started employing on-board passive measures to eliminate latent sources of energy related to batteries, fuel tanks, propulsion systems and pyrotechnics. But this alone is insufficient. At present rates, in 20 or 30 years, collisions would exceed explosions as a source of new debris.

2112 future simulation. Image credit: ESA
The ESA says it is crucial to start immediately to implement mitigation measures. This image shows a simulation of the the 2112 GEO environment in the case when no measures are taken. In the top panel, with mitigation measures, a much cleaner space environment can be observed if the number of explosions is reduced drastically and if no mission-related objects are ejected. The bottom panel shows the “business-as-usual” scenario, without any mitigation measures taken. However, to stop the ever-increasing amount of debris, more ambitious mitigation measures must be taken. Most importantly, spacecraft and rocket stages have to de-orbited and returned to Earth after the completion of their mission.

They’ll burn up in the atmosphere, or splash down in uninhabited ocean areas. In the case of telecommunication and other satellites operating in the commercially valuable geostationary zone, they should boost their satellites to a safe disposal orbit, as shown below.
Graveyard orbit. Image credit: ESA

There are other measures, like reducing the number of mission-related objects and controlling the risk for reentry, but these are the basics. The issue is that such mitigation measures cost fuel and operational time, and therefore they increase cost. In the commercial world, this may competitiveness, unless there is an international consensus to accept such costs.

Original News Source: ESA

Posted on by Tammy Plotner

What’s Up – The Weekend SkyWatcher’s Forecast

Theophilus - Credit: Wes Higgins

Greetings, fellow SkyWatchers! If we’ve explored the Moon in “Astronomy For Kids”, then by all means let’s explore the Moon in Astronomy for BIG kids! This weekend would be an great opportunity to dust off your telescopes or binoculars and do a little moongazing, because… Here’s what’s up!

Friday, April 11 – Tonight we’ll begin our SkyWatcher’s Weekend by heading toward the lunar surface to view a very fine old crater on the northwest shore of Mare Nectaris – Theophilus. Slightly south of midpoint on the terminator, this crater contains an unusually large multiple-peaked central mountain which can be spotted in binoculars. Theophilus is an odd crater: it’s shaped like a parabola – with no area on the floor being flat. It stretches across a distance of 100 kilometers and dives down 440 meters below the surface. Viewable in binoculars, Theophilus tonight it will appear dark, shadowed by its massive west wall, but if you’re using a telescope, look for sunrise on its 1400 meter summit!

Wes HigginsSaturday, April 12 – Today marks the 1851 birth of Edward Maunder – a bank teller turned assistant Royal Astronomer. Assigned to photographing and cataloging sunspots, Maunder was the first to discover solar minimum times and equate these with climate change. Maunder was also the first to suggest that Mars had no “canals,” only delicate changes in surface features. Smart man!

On Saturday night, Mars will play a very important role in observing as it will be slightly more than a degree away from the Moon’s limb for many observers. As grand as observing can be when the planet is near, it doesn’t even come close to the details that can be seen on the Moon. An outstanding feature visible tonight will be crater Maurolycus just southwest of the three rings of Theophilus, Cyrillus and Catharina. This Lunar Club challenge spans 114 kilometers and goes below the lunar surface by 4730 meters. Be sure to look for Gemma Frisius just to its north.

Wes HigginsSunday, April 13 – Tonight, let’s have a look at the Moon as challenge craters Cassini and Cassini A have now come into view just south of the black slash of the Alpine Valley. For more advanced lunar observers, head a bit further south to the Haemus Mountains to look for the bright punctuation of a small crater. You’ll find it right on the southwest shore of Mare Serenitatis! Now power up and look for a curious feature with an even more curious name…Rima Sulpicius Gallus. It is nothing more than a lunar wrinkle which accompanies the crater of the same name – a long-gone Roman counselor. Can you trace its 90 kilometer length?

Wishing you clear skies!

This week’s awesome lunar images belong to noneother than Wes Higgins. Many thanks!

Posted on by Mark Mortimer

Book Review: Woman Astronomers – Reaching for the Stars

Perhaps it is time for a female president. If nothing else, this would continue the laborious road to equality. Mabel Armstrong shows some of the steps already taken along this road in her book Woman Astronomers: Reaching for the Stars. In it, we see that, from a long time ago until as recently as the previous generation, many ladies have been unable to achieve the desires of their hearts and minds. However, some have persevered and become pioneers for many others to follow.

Whether being refused access to telescopes or being denied entry to university programs, Armstrong shows that woman have had many barriers in their path. Perhaps this is old news, but Armstrong writes that as recently as 1975, universities like Princeton would not accept women into graduate programs. Nevertheless, her book is all about accomplishments in spite of roadblocks. Following a chronological trend, she begins with a Babylonian priestess, Enheduanna, who used the night sky to portend the future. Then, age by age, she presents one great achiever after another who advanced humanity’s knowledge in spite of the restrictions of the day. There’s Caroline Herschel who had to overcome many travails at home before joining her brother in England. And Cecilia Payne Gaposchkin who rebelled against tradition to study science and receive Harvard’s first ever astronomy PhD. Jill Cornell Tarter’s work on discerning extraterrestrial intelligence concludes the main sections on individuals, though Armstrong adds a few pages of rising stars. All these serve to symbolize the capability and vitality of some very impressive women.


Armstrong’s book may just be the necessary incentive for a young lady to choose a challenging career. From its writing style and content, it’s obviously aimed at the young adult audience. The well laid out chapters contain short sections where each section provides a concise biography of a woman astronomer. Across the bottom of every page, a timeline provides dates and significant events, such as ‘1786 Caroline Herschel discovers her first comet’. Pictures of each of the astronomers and many other relevant photographs and sketches brighten up the pages. And, a few in-depth features captured in side bars such as ‘Cepheid Variables and Stellar Distances’ ensure the reader has the technical background to understand the significant of the astronomer’s discoveries. Altogether, the book’s informative and succinct. Its obvious summary is that women are as capable an astronomer as any man.

Certainly, this warm tribute to women astronomers would encourage young ladies to take up tasks far beyond the traditional role of child nurturer. However, the book does have a tendency to make the mentioned women appear to have been the solely responsible for most accomplishments. Perhaps this is only fair, as so often only one person, usually a man, would get the accolades. But, now, astronomers and researchers work in teams and rely upon many others. Hence, though this book provides great encouragement, the reader may need to temper their enthusiasm while still maintaining a fierce, single-minded determination.

Baseless discriminations keep falling to the wayside. Whether entering research fields once only the domain of men or forcing clubs and institutes to accept women and men equally, much progress has been made. Mabel Armstrong’s book Woman Astronomers: Reaching for the Stars shows that women astronomers can and have added to humanity’s knowledge and that their contributions have been as worthwhile as men’s.

Read more reviews, or purchase a copy online from Amazon.com.

Posted on by Fraser Cain

Podcast: Wave Particle Duality

Have you ever heard that photons behave like both a particle and a wave and wondered what that meant? It’s true. Sometimes light acts like a wave, and other times it behaves like a little particle. It’s both. This week we discuss the experiments that demonstrate this, explain how scientists figured it all out in the first place. What does wave/particle duality have to do with astronomy? Well, everything, since light is the only way astronomers can see out into the Universe.

Click here to download the episode

Wave Particle Duality – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

Posted on by Fraser Cain

Carnival of Space #49

Wolf Rayet Star

Another new host for the Carnival of Space. This week we’re at the home of science journalist Will Gater. Read about the largest stars, gamma ray bursts, black hole interactions, Hubble science and more.

Click here to read the Carnival of Space #49

And if you’re interested in looking back, here’s an archive to all the past carnivals of space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, let me know if you can be a host, and I’ll schedule you into the calendar.

Finally, if you run a space-related blog, please post a link to the Carnival of Space. Help us get the word out.

Posted on by Nancy Atkinson

Evidence of Asteroid Impact For Sodom and Gomorrah?

Cuneiform clay tablet. Image Credit: Bristol University

A Cuneiform clay tablet that has puzzled researchers for over 150 years is now believed to describe an asteroid impact in 3123 BC in Austria. Researchers believe the tablet, which seemingly describes a cataclysmic event, may account for the biblical tale of Sodom and Gomorrah. No mention of pillars of salt however, on the clay tablet.

Geologists discovered evidence of a giant landslide centered at Köfels, Austria back in the 19th century. At 500 meters thick and five kilometers in diameter, this landslide mystified researchers trying to figure out why such an event occurred. Some researchers thought the landslide may have been caused by a meteorite impact, because of the evidence of crushing pressures and explosions. But there was no crater, so it didn’t look as an impact site should, and the impact theory fell out of favor. But researchers knew this wasn’t just an ordinary landslide.

But new research brings the impact theory back into play. It centers on another 19th century mystery, a Cuneiform tablet in the British Museum, known as “the Planisphere”. It was found in the remains of the library in the Royal Place at Nineveh, and was made by an Assyrian scribe around 700 BC. It is an astronomical work with drawings of constellations and the text has known constellation names. The clay tablet has attracted a lot of attention but until now no one has come up with a convincing explanation as to what it is.

Alan Bond and Mark Hempsell from Bristol University used computer programs to simulate trajectories and reconstruct the night sky thousands of years ago to establish what the Planisphere tablet refers to. It is a copy of the night notebook of a Sumerian astronomer as he records the events in the sky before dawn on the 29 June 3123 BC (Julian calendar). Half the tablet records planet positions and cloud cover, but the other half of the tablet records an object large enough for its shape to be noted even though it is still in space. The astronomer made an accurate note of its trajectory relative to the stars, which to an error better than one degree is consistent with an impact at Köfels.

The observation suggests the asteroid is over a kilometer in diameter and the original orbit about the Sun was an Aten type, a class of asteroid that orbits close to the earth, that is resonant with the Earth’s orbit. This trajectory explains why there is no crater at Köfels. The incoming angle was very low (six degrees) and means the asteroid clipped a mountain near the town of Längenfeld, 11 kilometers from Köfels, and this caused the asteroid to explode before it reached its final impact point. As it travelled down the valley it became a fireball, about five kilometers in diameter (the size of the landslide). When it hit Köfels it created enormous pressures that pulverized the rock and caused the landslide but because it was no longer a solid object it did not create a classic impact crater.

Mark Hempsell, hinting at the possible fate of Sodom and Gomorrah, added, “Another conclusion can be made from the trajectory. The back plume from the explosion (the mushroom cloud) would be bent over the Mediterranean Sea re-entering the atmosphere over the Levant, Sinai, and Northern Egypt. The ground heating though very short would be enough to ignite any flammable material – including human hair and clothes. It is probable more people died under the plume than in the Alps due to the impact blast.”

This evidence seems to coincide with the biblical story of the legendary dens of vice (“Then the Lord rained down burning sulfur on Sodom and Gomorrah – from the Lord out of the heavens” – Genesis 19:24) but it’s never been categorically proven that the towns actually existed in their suspected location close to the Dead Sea. And the story of Lot’s wife turning into a pillar of salt for turning around to witness the mayhem is just biblical legend as well.

The full translation of the tablet together with the analysis supporting these conclusions can be found in the book, “A Sumerian Observation of the Kofels’ Impact Event” by Bond and Hempsell.

Original News Sources: Bristol University and The Register

Posted on by Nancy Atkinson

Smallest Exo-planet Found

Ignasi Ribas with simulated picture of the new planet. Image Credit: REUTERS/Sergio Perez

We’re getting closer to finding an Earth-like planet out there in the universe. Spanish astronomers announced the discovery of the smallest exo-planet found to date, located 30 light years from earth. “I think we are very close, just a few years away, from detecting a planet like Earth,” team leader Ignasi Ribas said at a news conference on Wednesday April 9, 2008. The newest planet, “GJ 436T” was discovered by a team led by Ribas through its gravitational pull on other planets already discovered around the same star in the constellation of Leo.

The planet has a mass five times the size of Earth, which makes it the smallest extrasolar planet among the roughly 300 identified so far, Ribas said. The astronomers believe the planet could possibly be a rocky, Earth-like planet because of its size. Most of the planets found so far are gas giants like Jupiter.

But Ribas said the new planet is uninhabitable due to the close distance that it orbits its star, which is far less than that between the earth and the sun. Planet GJ 436 orbits close to its small, relatively cool star once every 5.2 Earth days and rotates every 4.2 Earth days.

This latest planet was found by analyzing distortions in the orbit of another, larger planet around the star GJ 436, a technique similar to that used more than 100 years ago to discover Neptune.

“Planets with a mass similar to Earth situated at a distance from their star which allows liquid water on the surface, in other words, a habitable planet, we’re probably a bit further from (discovering those), but we surely will in a decade,” said Ribas of Spain’s CSIC scientific research institute.

Original News Source: Reuters

Posted on by Ian O'Neill

What Happens When Three Black Holes Collide?

A computer simulation of two black holes colliding, what happens if three collide? (credit: EU Training Network)

The consequences of two black holes colliding may be huge, the energy produced by such a collision could even be detected by observatories here on Earth. Ripples in space-time will wash over the Universe as gravitational waves and are predicted to be detected as they pass through the Solar System. Taking this idea one step further, what would happen if three black holes collide? Sound like science fiction? Well it’s not, and there is observational evidence that three black holes can cluster together, possibly colliding after some highly complex orbits that can only be calculated by the most powerful computers available to researchers…

Caltech/EPFL)
Back in January 2007, a quasar triplet was observed over 10 billion light years away. Quasars are generated by the supermassive black holes eating away at the core of active galaxies. Using the powerful W. M. Keck Observatory, researchers from Caltech were able to peer back in time (10 billion years) to see a period in the Universe’s life when active galaxies and black hole mergers would have been fairly common events (when compared to the calmer Universe of today). They observed three tightly packed quasars, an unprecedented discovery.

Now, scientists Manuela Campanelli, Carlos Lousto and Yosef Zlochower, all working at Rochester Institute of Technology’s Center for Computational Relativity and Gravitation, have simulated the highly complex mechanisms behind three interacting and merging supermassive black holes, much like the situation observed by Keck in 2007. The same group have worked on calculating the collision of two black holes before and have written a code that is powerful enough to simulate the collision of up to 22 black holes. However, 22 black holes probably wouldn’t collide naturally, this simply demonstrates the stability of the code, “Twenty-two is not going to happen in reality, but three or four can happen,” says Yosef Zlochower, an assistant professor. “We realized that the code itself really didn’t care how many black holes there were. As long as we could specify where they were located – and had enough computer power – we could track them.”

These simulations are of paramount importance to the gravitational wave detectors such as the Laser Interferometer Gravitational-Wave Observatory (LIGO). So far there has been no firm evidence to come from these detectors, but more time is needed, the LIGO detector requires several years of “exposure time” to collect enough data and remove observational “noise”. But what do gravitational wave astronomers look for? This is the very reason many different cosmic scenarios are being simulated so the characteristics of events like two or three black holes mergers can be identified from their gravitational wave signature.

Gravitational wave astronomers “need to know what to look for in the data they acquire otherwise it will look like just noise. If you know what to look for you can confirm the existence of gravitational waves. That’s why they need all these theoretical predictions.” – Manuela Campanelli, director of RIT’s Center for Computational Relativity and Gravitation.

Source: RIT University News