cafecuriosity

Cosmic Ghost in the Machine

Astronomy has long held a 'special' relationship with amateurs. While other professions have derided amateurs as dilettantes and retreated behind tall walls offered by formal qualifications, astronomy has burbled along happily. Comets and super nova are frequently spotted by dedicated enthusiasts and astronomers for their part have learned to tap the power of social networks. Projects such as Astronomy Zoo enable the public (150,000 participated, classifying 1 million images) to participate in online astronomical research. Hanny van Arkel a Dutch school teacher found an astonishing nugget in the online catalogue of galaxy images - discovering a new class of celestial object in the process. The image had been sitting quietly in the archives for decades until Henny came across it. That object (Voorwerp in Dutch) proved to be over 16,000 light years across and astronomers have no idea how it formed - some 'ghost'!   http://opa.yale.edu/news/article.aspx?id=5934   Image: Hanny's Voorwerp and IC2497, Dan Smith, Peter Herbert, Matt Jarvis & the ING

What's In A Label?

Two years ago was a time of loss for advocates of Pluto, as the International Astronomical Union (IAU) stripped Pluto of its planetary status. Last week the same IAU accepted the recommendation of the Committee on Small Body Nomenclature for a new label to be applied to transneptunian dwarf planets like Pluto and Erin. What was their undoubtedly inspired choice you ask? After due deliberation, the best they could come up with as 'plutoid' - yep, plutoid. I only hope the committee didn't pay good money for that insight into the bleeding obvious! Still, those quietly grieving for Pluto's ravaged status can take some small (transneptunian) solace!

http://www.iau.org/public_press/news/release/iau0804/   Image:Pluto and Erin, IAU, NASA/ESA Hubble Space Telescope, H. Weaver (JHU/APL), A. Stern (SwRI), the HST Pluto Companion Search Team and M. Brown

Unknown Unknowns On Mars

Unknown unknowns describe situations that we not predicted or believed possible by an individual, team or organization at a given point in time. As an individual or team's cumulative knowledge expands, the horizon for unknown unknowns shifts. Essentially, it establishes that decisions can only be arrived at using information currently available. This poses potentially significant unknown risks or hazards to a project. By definition, any outcome that can be conceived of will usually be incorporated into the decision makers frame of reference. What constitutes an unknown unknown is highly dependent on both a time and the perspective of the observer. To see this in real life (and almost real time), we only have to visit the time line for the Mars Phoenix Lander. The impact of unknown unknowns (made famous by Donald Rumsfeld) can be attested by the project team managing the Mars Phoenix Lander:

June 8: NASA's Phoenix Mars Lander gently drops a sample of Martian soil for analysis onto its laboratory instrument. Project team discovers to their horror that the Martian soil is clumpy and has clogged the protective screen on the Thermal and Evolved-Gas Analyzer  (TEGA)! TEGA has 8 ovens, each the width of a pencil lead. Each oven is equipped with a screen to stop lumps of soil clogging the narrow chute down to the oven. "There's something very special very unusual about this soil," opinions University of Arizona's Principal Investigator Peter Smith in a neat summary of the bleeding obvious. "We're interested in learning what sort of chemical and mineral activity has caused the particles to clump." Right!

June 9: Mechanical shakers inside the Thermal and Evolved-Gas Analyzer attempt to breakup the Martial soil sample trapped on TEGA's screen by vibrating it for 20 minutes. Programmers map the underside of the Lander and discover the descent thrusters have cleared the soil from a patch of rock or ice. Project team name the site "Snow Queen" mainly to confuse normal humans! Programme robotic arm to dig another sample trench named "Baby Bear". Where do they get their inspiration?

June 10: Engineers devise a new and very, very cunning plan to drop soil samples into the Thermal and Evolved-Gas Analyzer. This involves holding the mechanical arm at an angle to the screen while the sample is vibrated over the screen, hopefully sprinkling a light sample onto the screen and on down the chute.

June 11: The oven on NASA's Phoenix Mars Lander mysteriously fills with soil. The oven took 10 seconds to fill once sample eventually shifted after sitting on the screen for 4 days! Scientists have no idea why but as usual are fully equipped to speculate and don't stop to question gift horse. Proceed with plans to sprinkle a soil sample on the Optical Microscope for study and to widen the area photographed by the Lander's high resolution colour panorama camera Programmers adopt a determined look.

June 13: Joy! The robotic arm delivers a light dusting of soil over the Optical Microscope. This sample is called "Mama Bear", the sample delivered to TEGA's #4 oven is "Baby Bear" and both samples came from a trench named "Goldilocks". Observers conclude project team needs to get out more! Fuelled by their triumph, the team plan to command the robotic arm to dig deeper into "Goldilocks" and another trench "Dodo" to see how deep the underlying layer of rock or ice is.

http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080607.html   http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080608.html   http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080609.html   http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080611.html   http://www.nasa.gov/mission_pages/phoenix/news/phoenix-20080612.html   Image: 1. Robotic arm of NASA's Phoenix Mars Lander drops soil sample into screen, NASA/JPL-Caltech/University of Arizona/Max Planck Institute, 2. Image of landing site, NASA/JPL-Caltech/University of Arizona, 3. Trenches dug by Phoenix's robotic arm, NASA/JPL-Caltech/University of Arizona, Texas A&M University, 4. Robotic arm with soil sample poised, NASA/JPL-Caltech/University of Arizona, Texas A&M University. 

Weird Ring Serendipitously Stumbled Upon

Quote of the week surely goes to NASA Spitzer Science Center's Stefanie Wachter when she observed, "The universe is a big place and weird things can happen." Wachter was referring to her serendipitous discovery of a ring of material surrounding the magnetic corpse of a massive dead star (magnetar) seductively named SGR-1900+14. Trawling through Spitzer's archived data - a dull job at any time, Wachter happened to notice the odd ring formation around the magnetar. Believed to have formed in 1998, when the surface of the magnetar cracked, emitting an energy blast that blew out a nearby dust cloud, creating a cavity around SGR-1900+14 which was subsequently lit up by a surrounding cluster of stars. This type of ring has never been seen before but as Wachter's theory goes, if there is one out there, there might be more and someone has to find them! 

http://www.jpl.nasa.gov/news/news.cfm?release=2008-086   Image: Ghostly ring 7 light years across around a massive dead star, NASA/JPL-Caltech

More On the Universe's Missing Matter

Last week the European Space Station announced they had found the location of the Universe's missing matter. Apparently, it was messing about in the spider web structure that links galaxies. This week, the University of Colorado at Boulder went one better and found about half the Universe's missing matter (called baryons) in that same cosmic web that spans the gaps between galaxies. Using the Hubble telescope and NASA's Far Ultraviolet Spectroscopic Explorer (try saying that quickly!), astronomers found highly ionized oxygen and other elements - hinting at vast reservoirs of unseen hot ionized hydrogen - too hot to be seen in visible light, yet too cool to show up as x-rays. The team is now seeking to map the structure of the cosmic web, measure the heavy metals inside it and get a fix on its temperature in order to understand how galaxies form.

http://www.colorado.edu/news/r/81c6b13ada69601e23e0def24a37bdd6.html   Image: Illustration of how the Hubble Space telescope searches for missing ordinary matter by looking at the light from quasars several billion light-years away, Space Telescope Science Institute, NASA

The Universe's Missing Matter Found

One of the most intriguing mysteries in science is the hunt for the Universe's missing matter. According to current cosmic theory, only about 5% of matter is the usual suspects - protons, neutrons and electrons. Around 23% is the shy and retiring 'dark matter', while 'dark energy' accounts for the rest. By present estimations, around half the normal matter is missing. A decade ago, scientists reckoned the missing normal stuff was lurking in the vast spaces between galaxies. Scientists predicted its existence as a very hot gas which would emit low-energy x-rays. Unfortunately, the gas' low-density would also make it tricky to detect - until now! Thanks to the ESA's orbiting X-ray observatory XMM Newton, astronomers have observed a bridge of hot gas connecting the Abell 222 and Abell 223 clusters of galaxies. This hot gas is presumed to form over half of the normal matter in the Universe. Now scientists know where (and what) to look for, the next step is to scrounge funding for a dedicated probe to explore the cosmic web. In the interim, we can sit back, comforted with the knowledge that our missing matter is no longer missing!

http://www.esa.int/esaCP/SEMQLPZXUFF_index_0.html   Image: 1. Composite optical & x-ray image of galaxy clusters Abell 222 and 223, ESA/XMM-Newton/EPIC/ESO, J. Dietrich/SRON, N. Werner/MPE, A Finoguenov, 2. Cosmic web, Springer et al, Virgo Consortium

Behold the Earth's Mighty Magnetotail

For decades, we've become accustomed to viewing the Moon as a dead world where nothing much has happened for millennia. Now astronomers have discovered that something weird happens to the Moon every month when the Earth's magnetic tail sweeps across it. Each month three days before the full moon, the moon enters the earth's magnetotail. Six days later it pops out the other side. What happens during those six days is kind of cool. Massive sheets of hot charged particles lash the moon's surface. On the cold dark side, these electrons accumulate producing surface voltages of hundreds, even thousands of volts. Fine particles of moon dust may float into the air, repulsed by this electrostatic charge. The plasma may even generate a soft lunar wind with dust particles drawn from the strongly-positive dark side to the weakly-negative day side. Interesting, no one has ever witnessed the phenomenon. None of the Apollo missions landed during a full moon. The next generation of NASA astronauts may fill in this gap is NASA manages to fund its ambitious plans for a permanent moon base.

PS. The Earth's magnetic field stretches out into space, far beyond the moon. When Earth's magnetic field encounters the solar wind it streams downwind in a spectacular 'magnetotail'

http://www.nasa.gov/topics/moonmars/features/magnetotail_080416.html   Image: 1. The Moon, NASA, 2. Conceptual image of the Earth's magnetic field responding to the solar wind, NASA/Goddard Space Flight Center

Fire in the Sky

I came across an interesting shop when I was Abu Dhabi at the end of March. Its the closest thing I've seen to an antique shop since I arrived in the Gulf. It had some nice 18th Century figurines some antiquities (possibly made in a workshop just down the road, who can tell?) and in one corner a collection of fossils and meteorites. Meteorites were big news in March. The University of Western Ontario captured footage of a meteorite on video as it plunged to Earth. The group tracked the fireball down to altitude about 24 kilometers before losing it. At least one or more asteroids were likely to have made it safely to Earth.

On the other side of the world, Peru went one better when a stony meteorite smashed into a dry riverbed, creating a 49' crater and scattering debris over a respectably wide area. Thought to be a stony meteorite, these babies are generally fragile things, often breaking up as they enter the Earth's atmosphere. When they impact, they usually leave just a small pit in their wake, not a major crater. Analysis of the 'shocked sand grains' indicated the meteorite was traveling at 15,000 miles per hour at impact, much faster than it should have been going if existing theories are correct. Moreover, it emerged basically intact. Naturally scientists responded they way they do when an unexplained event defies conventional wisdom - they thought it was a fake! However, one scientist has posed a new theory about these meteorites that could upend the long-establish belief that stony meteorites disintegrate before impact. if true, the theory could rearrange scientists views about the size and composition of eons of impact strikes the Earth has experienced over millennia.

PS. Researchers from the Natural History Museum of Denmark suggests that life exploded in the oceans after an intense meteorite bombardment of up to 100 meteorites! Their theory indicates that for the Baltic region at least, a explosion of life forms emerged following a cataclysmic event. Does diversity follow mass extinctions as organism adapt to occupy vacant niches? Do meteorite impacts seed life and are there links between meteorites found in the Baltic and those found as far away as southern China and the USA?

http://communications.uwo.ca/com/media_newsroom/media_newsroom_stories/western_astronomers_on_hunt_for_meteor_20080307441590/  http://www.brown.edu/Administration/News_Bureau/2007-08/07-113.html   http://www.ku.dk/english/news/   Image: 1. Meteor Falling To Earth, University of Western Ontario, 2. Caracas fireball, Peter Schultz, Brown University, 3. Alpha-Monocerotid meteorite outburst, 1995, NASA

Finding the Source of the Solar Wind

The Royal Astronomical Society has been busy this month with a couple of firsts. The twin STEREO spacecraft captured the first images of a solar tsunami traveling at a million+ kph through the layers of the solar atmosphere and lasting for 35 minutes. Putting our energy woes in perspective, the solar tsunami consumed two billion times the world's energy consumption in a fraction of a second! Amusingly the four cameras used to record the tsunami were set to different shutter speeds, making it hard to compare individual image frames. Hence, observers still don't know what causes the tsunamis or how they are able to maintain their speed through the varying thickness of the solar atmosphere!

Further out, the Hinode observation platform provided the clues that lead to the discovery of the particles comprising the solar wind. Pinpointing the source of the solar wind is akin to finding the legendary source of the Nile. Generated by powerful magnetic fields bridging the gap between localised regions of eruptions (some up to 500,000 km apart!), hot gas escapes, flowing out as the solar wind. The solar wind's electrically charged particles zip along at 200 km per second wrecking havoc with terrestrial power grids and satellites. Mind you, anyone who has witnessed the southern aurora or northern 'lights' won't begrudge the solar wind a little fun!

http://www.ras.org.uk/index.php?option=com_content&task=view&id=1432&Itemid=2   http://www.ras.org.uk/index.php?option=com_content&task=view&id=1440&Itemid=2   Image: 1. X-Ray image of the Sun, NASA, 2. Image of Solar Tsunami, University of Dublin

Serendipity Taking the Hiss

One of my earliest examples of serendipity relates to the discovery of the Van Allen radiation belts, so I was intrigued when yet another serendipitous discovery relating to their mysterious ways was published in the journal 'Nature' back in March. There have been many mostly unsuccessful attempts to explain the hiss in the Earth's upper atmosphere in the 40 years since their existence was confirmed by Explorer 1 in 1958. try as they might, scientists just could not account for all the odd properties in the upper atmosphere. Researcher Jacob Bortnik was studying a type of electromagnetic wave called 'chorus waves' (ah, nerdish humour!) when he realised the intense low frequency radio waves that pervade the Earth's upper atmosphere were not generated by lightning, wave-particle interactions, turbulence or plasma as previously thought, but by his 'chorus waves'. As it turns out, Bortnik had every right to be surprised. Naturally, the 'chorus waves' had previously been thought to be totally unrelated to the hiss!

http://www.newsroom.ucla.edu/portal/ucla/scientists-identify-origin-of-46690.aspx   Image: Earth's Van Allen Radiation belts, NASA