Autonomous Space Capture Challenge

TopCoder®, Inc., the world’s largest competitive Community of digital creators and MIT, today announced registration has opened for the Autonomous Space Capture Challenge, an algorithm competition from Zero Robotics which seeks computationally efficient code solutions for a hypothetical mission scenario which models autonomous docking or satellite servicing procedures. The online challenge is open to all eligible participants but especially teams from high schools and colleges. Four winning submissions will be tested aboard the International Space Station (ISS) in the recently established SPHERES national laboratory by astronauts. Successful teams will be invited to watch the event live onsite at the Massachusetts Institute of Technology or via webcast feed remotely. Register at http://www.zerorobotics.org.

Competitors in the Autonomous Space Capture Challenge will be tasked with programming an active satellite or “Tender” to synchronize its motion with and capture a tumbling, passive space object or “POD”. The tournament will have four week-long rounds, during which teams will test their solutions and submit them for scoring and publication on the leader board. At the end of each week the best submission will be published on the Zero Robotics website for public reference and use in the next round. The winner from each week will be included in a demonstration aboard the ISS in late May with the best performing finalist being awarded an additional commendation.

Competition Dates

  • March 28 – competition begins
  • April 4 – submission 1 closes
  • April 11 – submission 2 closes
  • April 18 – submission 3 closes
  • April 25 – submission 4 closes

How to register

“Robots are not just very cool, they represent a rapidly growing and increasingly critical field of education and business,” said Rob Hughes, president and COO of TopCoder, Inc. “From defense to manufacturing, agriculture to pharmaceutical as well as ongoing space exploration, the study and application of robotics has a very bright future.”

Sponsored by DARPA and NASA, and run by the MIT Space Systems Laboratory, TopCoder and Aurora Flight Sciences, Zero Robotics is a programming tournament that opens the SPHERES satellite research platform to the general public. Originally developed to engage U.S. middle and high school students in science, technology, engineering and mathematics (STEM), Zero Robotics includes a web-based development environment to create programs for the SPHERES satellites and run simulations to evaluate resulting performance. For more information visit: http://www.zerorobotics.org.

About TopCoder, Inc.

TopCoder is the world’s largest competitive community of digital creators with nearly 400,000 members representing algorithmists, software developers and creative artists from over 200 countries. The TopCoder Community creates digital assets including analytics, software and creative designs and solutions for a wide-ranging client base through a competitive, rigorous, standards based methodology. Combined with our extremely talented community this groundbreaking methodology results in superior outcomes for our clients. For more information about sponsoring TopCoder events and utilizing TopCoder’s software services and platforms, visit www.topcoder.com.

TopCoder is a registered trademark of TopCoder, Inc. in the United States and other countries. All other product and company names herein may be trademarks of their respective owners.

Source: TopCoder, Inc.

STEM News: Robots in the Classroom

How cool is this!?

Sixth-graders in Cheney will run tests on the community water supply and present their findings to city officials. Students at Rainier Beach High School in Seattlewill travel to the Olympic Peninsula to work on the Elwha Dam removal project. And middle school girls in the Spokane area will build a programmable robot to learn practical applications for math.

The projects are among 14 around the state chosen to receive the third wave of Entrepreneur Award grants from Washington STEM, a nonprofit dedicated to advancing science, technology, engineering, and math (STEM) education across the state. With this round of investments, Washington STEM is now impacting more than 500 teachers and 16,000 students across the state.

“I had a D in science and didn’t do much studying, but working with my high school partner helped me work harder,” said Everett Greene-Maddelena, an eighth-grader at Markishtum Middle School in Neah Baywho was involved in a 2011 Washington-STEM project. “We also got to go on a research ship and learn about cool stuff, like the tribe’s work cleaning sand with mushrooms. I now have a B in science and think I am ready for high school.” Growing student success and enthusiasm for STEM has already helpedNeah Bay students win $70,000 in a national Samsung Solve for Tomorrow contest . The students have a chance to win more in the contest’s final round.

While Washington ranks first in the nation in the concentration of STEM jobs, too few of its students are prepared to pursue STEM degrees and take the jobs our state generates. This disparity stretches back to our elementary schools, where Washington kids typically receive two hours or less of science instruction a week.

“STEM isn’t just for scientists and engineers, it’s the best ticket to a good job in today’s market and virtually the only ticket to a good job in the economy of the future,” said Carolyn Landel, Chief Program Officer at Washington STEM. “Entrepreneur Awards celebrate the commitment and innovative spirit ofWashington educators who strive to ensure that all kids are prepared to succeed.”

Washington STEM Entrepreneur Award grants support breakthrough ideas and promising approaches in STEM education. The one-year investments encourage teachers to take risks, pilot new ideas, and generate promising practices that can be used around the state. Applications for the next round of Entrepreneur Award investments are due May 3.

For those interested in pursuing multi-year STEM projects that develop or expand innovative interventions in STEM, Washington STEM is also opening applications for its second round of Portfolio Awards with letters of inquiry due March 23. To learn more about Entrepreneur and Portfolio Awards, go to www.washingtonstem.org/grantee-application.asp

“My female students use to think that building robots was just for boys,” said, Dave Neale, a seventh-grade science and automation and robotics teacher and lead of the Team GEAR Heads, an all-girl robotics club at Mountainside Middle School in Colbert that will be supported by an Entrepreneur Award. “Our club makes it cool for girls to be into math and science.”

A complete list of Washington STEM’s round three Entrepreneur Award investments can be found online at www.washingtonstem.org/investments.asp

About Washington STEM: Washington STEM is a statewide nonprofit dedicated to advancing innovation, equity, and excellence in science, technology, engineering, and math (STEM) education. Launched in March 2011, Washington STEM partners with education, business, and community leaders to bridge opportunities in education and economy that reimagine STEM education for all students, starting with those most underserved and underrepresented in STEM fields. Learn more atwww.washingtonstem.org , join the conversation at Facebook , or follow STEM on Twitter @washingtonstem.

Image Credit: The Journal
Source: Washington STEM

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New Book: Lights of Mankind Shows Beauty of Earth from Space

As far as we know, Earth is the only planet in the universe that lights up at night. Now comes the first full-planet study of Earth after dark. Lights of Mankind: The Earth at Night As Seen From Space shares the awe-inspiring views that have caught the imagination of millions, showcasing more than 250 incredible photographs taken by astronauts on the International Space Station.

Recently released by Lyons Press, this stunning illustrated book documents the entire globe, featuring over 100 world-class cities and 70-plus regional panoramic images that show in striking detail the interplay of geography, man, and science. Covering every major city — from Paris to Milan, New York City to San Francisco, Rio de Janeiro to Rome — this is a photographic reference of the Earth at night, as seen from space.

Five astronauts — Clay Anderson, Sandra Mangus, Don Pettit, Mario Runco Jr., and Doug Wheelock — eloquently share their own perspectives on Earth at night, infusing this beautiful and informative book with eyewitness testimony. As Wheelock describes, “Earth presents itself as this raging explosion of light in a black, empty sea.”

At night our cities glow in patterns of light that speak volumes about how we inhabit this planet. The human story, including political conflicts and cultural proclivities, is highlighted from this perspective:

  • Powerful images of the Korean Peninsula underscore in a glance the literal and metaphorical differences between democracy and a totalitarian state.
  • Lights delineate the seemingly harmonious line of Gaza, Israel, Lebanon, and Jordan perched on a narrow strip of land along the eastern shore of the Mediterranean.
  • Water as the lifeblood of civilization is clearly seen worldwide as the lights of major cities line sheltered harbors and navigable rivers.

Keeney’s picks for the “Seven Wonders of the Nighttime World” show truly awe-inducing panoramic images of population centers around the globe in all their glittering glory. His playful selection on “The Unintentional Artwork of Man” offers a counterpoint to the zodiac creatures of the ancient astronomers.

The book itself is a testament to new technology, very human sharing without face-to-face contact: inspired by an astronaut’s tweet, filled with digital images, refined via Twitter consultation, facilitated by interviews on FreeConferenceCall.com, and transmitted by YouSendIt.

L. Douglas Keeney is the author of eleven books on military or American history. He is a cofounder of The Military Channel, and has visited many of the cities in this book. He lives in Louisville, Kentucky.

Source: Globe Pequot Press

Venus – Beautiful, Deadly, Strange or Fascinating?

Venus symbolizes femininity, beauty, and love. It is the twin planet to Earth, our world of vast green forests, deep blue seas, and majestic snow-capped mountains. Venus was formed at about the same time as Earth of the same type of material. It’s almost the same size as Earth and it is the planet closest to Earth. It is the second planet from the sun, the third brightest object in our sky after the Sun and the moon. Shining brightly near the horizon, it dazzles stargazers and inspires poets.

Close-up and personal, Venus must be heavenly – right? Not exactly. Hot and dry with an atmosphere that would choke an earthling to death – that’s Venus.  The atmosphere is made up of carbon dioxide, dioxide, nitrogen, water vapor, argon, carbon monoxide, neon, and sulfur dioxide. Carbon dioxide is the largest component of the atmosphere. Sulfuric acid is the largest component of the thick clouds that cover the planet so well that not even the largest earthbound telescope can gaze upon its surface. While keeping prying eyes out, the clouds keep the heat in. Temperatures reach 870 degrees Fahrenheit, which is enough to melt lead. Venus’ intolerable heat also discourages visitors by vaporizing them. Venera 13, a Russian Lander, holds the record as the surface visitor to last the longest. It operated for 127 minutes before being vaporized by the inhospitable planet.
Many other attempts have been made to investigate Venus in the form of unmanned spacecraft that journeyed to our sister planet. As mentioned, those that dared land on the planet met a quick demise. Venera 13 transmitted the first color pictures of the surface of Venus before it ceased functioning.  NASA’s Magellan Spacecraft orbited Venus from 1990 to 1994 using radar imaging to map 98% of its surface. The European Space Agency’s Venus Express arrived in orbit around the planet in 2006, and is currently studying its atmosphere and surface characteristics (this led to a recent discovery mentioned below).

Vast smooth plains cover about 65% of the surface. There are thousands of volcanoes ranging in all sizes from an extremely small half mile across to an extremely large 150 miles across. Of the six mountainous ranges, the highest range is Maxwell, which is seven miles high and 540 miles long. There are also circular structures called coronae or crowns that were formed when hot material from inside the planet bubbled up to the surface. The diameter of a crown varies from 95 to 365 miles.

And get this. According to a recent report in National Geographic, Venus is spinning even slower than astronomers originally thought, according to new data from a European space probe. In the early 1990s scientists with NASA’s Magellan mission calculated that a single rotation of Venus takes 243.015 Earth days, based on the speed of surface features passing beneath the orbiting spacecraft. If you’re paying attention and you do the math, you will see that a day on Venus is longer than a year on Venus! However, while Venus slowly spins, it manages to make a pretty quick trip around the Sun. Earth makes its yearly trip around the Sun in 365 days; Venus does it in only 224 earth days.

Anyhow, scientists now mapping Venus’s surface with the European Space Agency’s Venus Express orbiter were surprised to find the same features up to 12.4 miles (20 kilometers) from where they were expected to be, based on the previous measurements. According to the new data, Venus is rotating 6.5 minutes slower than it was 16 years ago, a result that’s been found to correlate with long-term radar observations taken from Earth.

Another point to think about. Venus may now resemble what Earth will become in millions of years time. When our Sun expands thereby heating the Earth, all of its surface water will be turned into a vapor thus trapping sunlight and heat in the atmosphere. The result will include suffocating conditions like those found on Venus today.

So now you’re probably saying to yourself, “Venus is strange.” And you would be right. It gets stranger. Venus is a contrary planet, no doubt about it. If you were to awaken on Venus in time to enjoy the sunrise over the barren lava plains to the east, you would be out of luck. However, if you were facing west, you would see the sun rise. Yes, that’s right. Old contrary Venus spins from west to east – the opposite direction of earth and the other planets in our solar system. This is called retrograde rotation.

You probably want to know why. Here are the four answers proffered by astronomers today. Take your pick:

A) Venus was hit by a very large object that changed the direction of its spin;

B) The Sun’s gravitational pull messed with the heavy clouds of Venus. Eventually, this caused the entire planet to flip over on its axis. Therefore, it is still spinning in the same direction as the other planets. It appears to be spinning in the opposite direction because it is upside down;

C) The Sun’s gravitational pull messed with the heavy clouds of Venus. However, it didn’t turn it upside down; it just reversed its spin;

D) Or my personal favorite – no one really knows!

Here again is the question posed by the title: Venus – beautiful, deadly, strange or fascinating? The answer: Absolutely!

Image Credit: European Space Agency.

Reference:

A. Moullet, E. Lellouch, R. Moreno, M. Gurwell, & H. Sagawa (2012). Wind mapping in Venus’ upper mesosphere with the IRAM-Plateau de Bure interferometer Astronomy & Astrophysics DOI: arXiv:1202.5279v1

Costantino Sigismondi (2012). Solar diameter with 2012 Venus transit Fourth French-Chinese meeting on Solar Physics Understanding Solar Activity: Advances and Challenges DOI: arXiv:1201.4011v1

Major, J. (2012, February 14). Venus Spinning Slower Than Thought-Scientists Stumped. National Geographic. Retrieved February 25, 2012, from http://news.nationalgeographic.com/news/2012/02/120214-venus-planets-slower-spin-esa-space-science/

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Wanna Check Out the Webb Telescope? Here’s How You Can…

NASA’s Goddard Space Flight Center Visitor Center in Greenbelt, MD will host this month’s Sunday Experiment on Sunday, March 18 from1:00 to 3:00 p.m. EDT. It’s a free afternoon for children of all ages and their families with a look at how NASA’s most powerful space telescope will look at the universe and see further back in time than ever before.

The James Webb Space Telescope will examine every phase of our history including the first galaxies to form after the Big Bang. Through a variety of hands-on activities, visitors will model the life cycle of a star, explore how the Webb telescope will “see” the universe in infrared light, and see how its hardware pieces will fit together.

Children will partake in hands-on activities, and will be able to see what they look like in an infrared camera, similar to the one that will fly on the Webb telescope. By creating special bookmarks with multi-colored beads, children will learn about the difference between stars in the universe.

“The Sunday Experiment is a great way for the general public to meet and interact with some of our scientists and engineers while learning about our latest projects,” said Lynn Chandler, Communications Officer for the Webb Telescope at Goddard. “It is great fun for the entire family.”

As always, the Visitor Center’s Science on a Sphere theater will offer insight to Goddard’s cutting edge science and research.

The Sunday Experiment, held on the third Sunday of each month, spotlights Goddard’s world-renowned science and engineering research and technological developments. Families leave inspired by the activities, wowed by the scientists and engineers, and excited about Goddard’s revolutionary research and technology. In addition to celebrating all things science, technology, engineering, and mathematics, the Sunday Experiment celebrates major science missions that are managed by NASA Goddard and set to launch in the near future.

For more information on the Sunday Experiment, visit Goddard’s Visitor Center Web page:

http://www.nasa.gov/centers/goddard/visitor/events/index.html

For more information and directions to the NASA Goddard Visitor’s Center, visit:

http://www.nasa.gov/centers/goddard/visitor/home/faq.html

http://www.nasa.gov/centers/goddard/visitor/directions/index.html

Source: NASA

Image: Artist’s impression of the James Webb Space Telecope.
Credit: ESA

Let’s Explore the States of Matter

Our universe is actually constructed of a small number of building blocks that interact in a small number of well defined ways. This is physics in a nut-shell for all intents and purposes. One of the fundamental building blocks of the universe as you likely know is matter. And matter in all its’ glory may exist in various states

Let’s start with learning 7 states of matter. I know, I know, we’re all taught in grade school that there are only 3 or 4 states right? There of course are solids, liquids, and gases. For instance, in the case of H20, it can take the form of:

  • Solid – Ice
  • Liquid – Water
  • Gas – Steam

But get this. There are a few other states of matter that may exist as well. I’m going to discuss four states beyond the classical states in this post however there are other aspects of this subject that you may research if interested. Understanding them all fully can be a rather complex exercise, so let’s just start with the basics for now.

The fourth state of matter, after gas, is plasma. Most people are familiar with plasma primarily due to its prevalence in plasma screen TV’s. Plasma is, essentially, an ionized gas. This means that plasma is gas that has become so hot that some electrons have become separated and have joined other nuclei. Plasma can act in bizarre, unpredictable ways, and is therefore a somewhat dangerous form of matter.

The next state of matter, after plasma, is the beam state. This is a somewhat difficult state of matter to understand, and is debated within the scientific community regarding its’ validity. Essentially, what’s important to understand about beam matter is that its particle makeup acts much differently than that of solids, liquids, gases, or plasmas. In all of those other states of matter, the constituent particles act in seemingly random patterns. In the beam state, however, the particles all act in a sort of synchronized harmony, all working towards the same end. Hence the term “beam.” Beam is also different because it is not a heat-exchange form of matter. In other words, all the other states involve an exchange of heat energy, but the beam state does not.

The sixth state of matter, which is actually much lower on the scale than any of the previously discussed five, is called Bose-Einstein condensate. This is also called the zero state of matter. It takes place when matter is frozen to a temperature that is so low that it almost reaches absolute zero. In this state the matter almost ceases to be, and the nuclei pile on top of each-other.

The final state of matter I want to mention, the seventh, is by far the most ethereal concept. It is the thought wave state of matter. The thought wave moves more quickly and is more efficient than even beam matter. It is an idea that is far too complex to deal with in this post and is generally not accepted by the scientific community. I encourage you to research it more if this is of interest to you.

The study of matter is important in the field of astronomy. By understanding the basics, we can increase our understanding of more complex concepts dealing with dark matter, particle/astro physics, neutrinos, and more. I’ll continue to write and expand on this subject as my own understanding grows. Feel free to chime in with any input, thoughts, etc. as always.

Interactive Matter Simulator (kinda cool)

States of Matter

Click to Run

Watch different types of molecules form a solid, liquid, or gas. Add or remove heat and watch the phase change. Change the temperature or volume of a container and see a pressure-temperature diagram respond in real time. Relate the interaction potential to the forces between molecules.

Reference:

CERN – European Organization for Nuclear Research – Press Office. (n.d.). CERN Press Release – New State of Matter Created at CERN. Retrieved February 25, 2012, from http://press.web.cern.ch/press/PressReleases/Releases2000/PR01.00EQuarkGluonMatter.html

Nikolay Prokof’ev, & Boris Svistunov (2005). On the Supersolid State of Matter American Physical Society arXiv: cond-mat/0409472v2

Zhang, S. (2008). Topological states of quantum matter Physics, 1 DOI: 10.1103/Physics.1.6

Image Credit: Center for Cosmological Physics/U Chicago; MSU.

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Richard Dawkins – A Short Introduction

Richard Dawkins is considered by many to be ‘Darwin’s Bulldog’ of the modern day, the title given to Thomas Huxley for his strong advocacy of Darwin’s theory of natural selection. Clinton Richard Dawkins was born in Nairobi, Kenya in 1941 and moved to England at the age of eight. His early childhood experiences of the bare natural life of Kenya were potent in his choosing the career of a biologist. Read More →

Cassini Detects Hint of Fresh Air at Dione

NASA’s Cassini spacecraft has “sniffed” molecular oxygen ions around Saturn’s icy moon Dione for the first time, confirming the presence of a very tenuous atmosphere. The oxygen ions are quite sparse – one for every 0.67 cubic inches of space (one for every 11 cubic centimeters of space) or about 2,550 per cubic foot (90,000 per cubic meter) – show that Dione has an extremely thin neutral atmosphere.

At the Dione surface, this atmosphere would only be as dense as Earth’s atmosphere 300 miles (480 kilometers) above the surface. The detection of this faint atmosphere, known as an exosphere, is described in a recent issue of the journal Geophysical Research Letters.

“We now know that Dione, in addition to Saturn’s rings and the moon Rhea, is a source of oxygen molecules,” said Robert Tokar, a Cassini team member based at Los Alamos National Laboratory, Los Alamos, N.M., and the lead author of the paper. “This shows that molecular oxygen is actually common in the Saturn system and reinforces that it can come from a process that doesn’t involve life.”

Dione’s oxygen appears to derive from either solar photons or energetic particles from space bombarding the moon’s water ice surface and liberating oxygen molecules, Tokar said. But scientists will be looking for other processes, including geological ones, that could also explain the oxygen.

“Scientists weren’t even sure Dione would be big enough to hang on to an exosphere, but this new research shows that Dione is even more interesting than we previously thought,” said Amanda Hendrix, Cassini deputy project scientist at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., who was not directly involved in the study. “Scientists are now digging through Cassini data on Dione to look at this moon in more detail.”

Several solid solar system bodies – including Earth, Venus, Mars and Saturn’s largest moon Titan – have atmospheres. But they tend to be typically much denser than what has been found around Dione. However, Cassini scientists did detect a thin exosphere around Saturn’s moon Rhea in 2010, very similar to Dione. The density of oxygen at the surfaces of Dione and Rhea is around 5 trillion times less dense than that at Earth’s surface.

Tokar said scientists suspected molecular oxygen would exist at Dione because NASA’s Hubble Space Telescope detected ozone. But they didn’t know for sure until Cassini was able to measure ionized molecular oxygen on its second flyby of Dione on April 7, 2010 with the Cassini plasma spectrometer. On that flyby, the spacecraft flew within about 313 miles (503 kilometers) of the moon’s surface.

Cassini scientists are also analyzing data from Cassini’s ion and neutral mass spectrometer from a very close flyby on Dec. 12, 2011. The ion and neutral mass spectrometer made the detection of Rhea’s thin atmosphere, so scientists will be able to compare Cassini data from the two moons and see if there are other molecules in Dione’s exosphere.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency, and the Italian Space Agency. NASA’s Jet Propulsion Laboratory, Pasadena, Calif., a division of the California Institute of Technology in Pasadena, manages the mission for NASA’s Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL. The Cassini plasma spectrometer team and the ion and neutral mass spectrometer team are based at Southwest Research Institute, San Antonio.

For more information about the Cassini mission, visit: http://www.nasa.gov/cassini andhttp://saturn.jpl.nasa.gov .

Image Credit: NASA/JPL/Space Science Institute

Source: JPL/NASA

Dark Matter Core Defies Explanation in NASA Hubble Image

Astronomers using data from NASA’s Hubble Telescope have observed what appears to be a clump of dark matter left behind from a wreck between massive clusters of galaxies. The result could challenge current theories about dark matter that predict galaxies should be anchored to the invisible substance even during the shock of a collision.

Abell 520 is a gigantic merger of galaxy clusters located 2.4 billion light-years away. Dark matter is not visible, although its presence and distribution is found indirectly through its effects. Dark matter can act like a magnifying glass, bending and distorting light from galaxies and clusters behind it. Astronomers can use this effect, called gravitational lensing, to infer the presence of dark matter in massive galaxy clusters.

This technique revealed the dark matter in Abell 520 had collected into a “dark core,” containing far fewer galaxies than would be expected if the dark matter and galaxies were anchored together. Most of the galaxies apparently have sailed far away from the collision.

“This result is a puzzle,” said astronomer James Jee of the University of California in Davis, lead author of paper about the results available online in The Astrophysical Journal. “Dark matter is not behaving as predicted, and it’s not obviously clear what is going on. It is difficult to explain this Hubble observation with the current theories of galaxy formation and dark matter.”

Initial detections of dark matter in the cluster, made in 2007, were so unusual that astronomers shrugged them off as unreal, because of poor data. New results from NASA’s Hubble Space Telescope confirm that dark matter and galaxies separated in Abell 520.

One way to study the overall properties of dark matter is by analyzing collisions between galaxy clusters, the largest structures in the universe. When galaxy clusters crash, astronomers expect galaxies to tag along with the dark matter, like a dog on a leash. Clouds of hot, X-ray emitting intergalactic gas, however, plow into one another, slow down, and lag behind the impact.

That theory was supported by visible-light and X-ray observations of a colossal collision between two galaxy clusters called the Bullet Cluster. The galactic grouping has become an example of how dark matter should behave.

Studies of Abell 520 showed that dark matter’s behavior may not be so simple. Using the original observations, astronomers found the system’s core was rich in dark matter and hot gas, but contained no luminous galaxies, which normally would be seen in the same location as the dark matter. NASA’s Chandra X-ray Observatory was used to detect the hot gas. Astronomers used the Canada-France-Hawaii Telescope and Subaru Telescope atop Mauna Kea to infer the location of dark matter by measuring the gravitationally lensed light from more distant background galaxies.

The astronomers then turned to the Hubble’s Wide Field Planetary Camera 2, which can detect subtle distortions in the images of background galaxies and use this information to map dark matter. To astronomers’ surprise, the Hubble observations helped confirm the 2007 findings.

“We know of maybe six examples of high-speed galaxy cluster collisions where the dark matter has been mapped,” Jee said. “But the Bullet Cluster and Abell 520 are the two that show the clearest evidence of recent mergers, and they are inconsistent with each other. No single theory explains the different behavior of dark matter in those two collisions. We need more examples.”

The team proposed numerous explanations for the findings, but each is unsettling for astronomers. In one scenario, which would have staggering implications, some dark matter may be what astronomers call “sticky.” Like two snowballs smashing together, normal matter slams together during a collision and slows down. However, dark matter blobs are thought to pass through each other during an encounter without slowing down. This scenario proposes that some dark matter interacts with itself and stays behind during an encounter.

Another possible explanation for the discrepancy is that Abell 520 has resulted from a more complicated interaction than the Bullet Cluster encounter. Abell 520 may have formed from a collision between three galaxy clusters, instead of just two colliding systems in the case of the Bullet Cluster.

A third possibility is that the core contained many galaxies, but they were too dim to be seen, even by Hubble. Those galaxies would have to have formed dramatically fewer stars than other normal galaxies. Armed with the Hubble data, the group will try to create a computer simulation to reconstruct the collision and see if it yields some answers to dark matter’s weird behavior.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Md., manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Md., conducts Hubble science operations. STScI is operated by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

For more information about Hubble visit: http://www.nasa.gov/hubble

Image Credit: NASAESA, CFHT, CXO, M.J. Jee (University of California, Davis), and A. Mahdavi (San Francisco State University)

Source: NASA

Meet I Zw 18: A Dwarf Galaxy

The Center of Astrophysics of the University of Porto recently came up with an analysis that seriously calls into question the current model of galactic formation. Polychronis Papaderos represented the CAUP, and with his Swedish colleague Göran Östlin, Papderos examined data from the Hubble Space Telescope to better understand the I Zw 18 dwarf galaxy. That particular object has received a lot of attention, and it is one of the few places where star-forming activity can be readily observed.

I Zw 18 region. (Credit: Image courtesy of Centro de Astrofísica da

For a long time, astrophysicists have simply assumed that stars were emitting light from gas structures. These structures occupied the same region as the stars that were emitting the light. The research suggests that galaxies that undergo active starbursts don’t follow this rule. Instead, nebula gases might actually be emitting around half of the total light in question. Since star mass is often calculated from the galaxy’s total luminosity, the idea that nebular emissions account for so much light means that many of these calculations could be totally off. One could also surmise that since I Zw 18 is young, the galaxy is acting the way many objects did shortly after the Big Bang. Many of the stars there have been around for less than 1 billion years. It will be interesting to watch this galaxy in the years ahead.

Reference:

Papaderos, P., & Östlin, G. (2012). I Zw 18 as morphological paradigm for rapidly assembling high-galaxies Astronomy & Astrophysics, 537 DOI: 10.1051/0004-6361/201117551

Izotov, Y., Chaffee, F., Foltz, C., Thuan, T., Green, R., Papaderos, P., Fricke, K., & Guseva, N. (2001). A Spectroscopic Study of Component C and the Extended Emission around I Zw 18 The Astrophysical Journal, 560 (1), 222-235 DOI: 10.1086/322494

Image Credit: Hubble

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