Spare Telescope Parts Could be Used for Homeland Security

The life of NASA’s Compton Gamma Ray Observatory (CGRO) ended in 2000 when the spacecraft’s remains splashed down in the Pacific Ocean after a planned deorbit. But the space telescope’s spare parts live on, and they may have a new job. Instead of searching the universe for radioactive emissions, they could help military personnel search for dirty bombs and other radioactive materials. “If we can detect radioactive aluminum-26 on the other side of the galaxy we can find other radioactive materials like cesium-137 or cobalt-60 inside a building or on the other side of the street by the same method,” said Dr. James Ryan from the University of New Hampshire.

Ryan was a member of the research team that helped build and operate the gamma-ray imaging COMPTEL telescope onboard the CRGO, a 1991-2000 NASA mission. One of the key findings of COMPTEL was its map of radioactive aluminum from dying stars throughout the Galaxy.

Identical flight spares of all the telescope components were built, just in case any of the parts failed. While the spares were never launched, they haven’t been collecting dust on a shelf. At different times, Ryan told Universe Today, the flight spares were assembled into a working telescope, sometimes as a student exercise and once for the benefit of the US Army as a test for probing the interior of buildings based on the background gamma radiation being emitted from the contents of the building.

“It is a sensitive instrument and it required no great thought to envision this use for it,” Ryan said of his idea to use the parts to pinpoint the location of dirty bombs. He was motivated by witnessing a National Guard drill to search for and clean up radioactive material left over by “terrorists.”

“It was clear that we would be able to sense the presence and approximate location of the radioactive material without entering the building with this device,” he said.

The device, known as GRETA, short for the Gamma-ray Experimental Telescope Assembly, could potentially be loaded on a truck and used for homeland security work such as scanning shipping containers or buildings for radioactive materials.

GRETA can accurately determine the direction from which a radioactive source is being emitted by creating an image, unlike current technology used by the military, such as Geiger counters or spectrometers that can only determine that radiation in is the vicinity.

“They might detect the presence of cesium-137 but they won’t know where it is unless they get right up close to it, they would have to fish around inside the building,” said Ryan, which would be a safety issue for military personnel.

Other media outlets report that some scientists doubt the applicability of this technology, saying GRETA’s “older” design has its limitations. But Ryan told Universe Today that current technology has changed very little from what COMPTEL, and GRETA, employ.

“Few, if any, scintillator detectors today will perform better than what is in GRETA,” he said. “There are newer designs for gamma-ray telescopes under development, but they are far from a deployable state. All are expensive, far more than a GRETA-type instrument. In fact, one could argue that GRETA is optimized for this application, because it provides the sensitivity necessary for the imaging and spectroscopy, while still remaining affordable and deployable on a short time scale.”

While GRETA is a prototype, the blueprints for the detectors, electronics and operation software still exist and can be used, with little modification, to build up a commercial unit for a real field test.

Ryan said there could be several potential “customers” or users for this device. “The National Guard is an obvious one, because they are charged with the clean up and disposal problem if, and when, a terrorist cell is uprooted. The US Border Patrol, various branches of the military and different port authorities could all find this useful,” Ryan said.

More information about CGRO.

Closer to the Heart – 47 Tucanae

47 Tucanae by Don Goldman

Those huge, gravitationally bound balls of stars know as globular clusters aren’t without a heart. Containing a thick concentration of 10,000 to more than a million stars in a region spanning just 10 to 30 light-years, globular clusters are more akin to seething masses of suns where the lightweights head for the outer edges while the giants collect in the core. What causes this process? Do globular clusters really have a way of getting some stars closer to the heart?

What you see here is 47 Tucanae, the second largest globular cluster in the Milky Way’s busy galactic halo. As its name “47 Tucanae” implies, its core was first cataloged as a star and numbered the 47th in Tucana the Toucan – but not for long. On September 14, 1751 a French astronomer named Nicholas Louis de Lacaille was the first to discover its true nature with a half inch diameter spy glass and cataloged it as nebulous object. Next to observe and catalog it were James Dunlop in 1826, and John Herschel in 1834 when it became New General Catalog (NGC) 104.

At home some 13,400 to 16,000 light years away from our Earth, this inconceivably dense concentration of at least a million stars spans 120 light years at the outside, yet at its heart is more than 15,000 individual stars that are packed so densely that you couldn’t fit our solar system between them. Believed to have all been born about the same time from the same cloud of gas, globular clusters like 47 Tucanae are a wonderful study of how stars evolve and interact.

With such busy conditions, it only stands to reason that stellar collisions have occurred at one time or another and 47 Tucanae is no exception. In the core, 23 unusually hot and bright stars called blue stragglers have been identified – the double massive result of two stars bumping into one another. Due to the associated gravitational pull, heavier stars slow down and sink to the cluster’s core, while lighter stars pick up speed and head for the outer edges. The more often collisions happen the more dramatic the results – pushing the smaller stars ever faster towards the periphery and creating exotic objects.

What no earthly photo can ever show is that 47 Tucanae contains at least twenty millisecond pulsars – better known as neutron stars. Can you imagine a sun that rotates on its axis a few hundreds to one thousand times a second? Just imagine the power. According to scientists, such peculiar objects are generally thought to have a companion from which they receive matter. Close interacting binaries and bright cataclysmic binaries… dwarf novae and nova-like variable candidates…. They all make their home here closer to the heart.

This incredible image of 47 Tucanae was done by Don Goldman of Macedon Ranges Obervatory

Podcast: Adaptive Optics

Since the dawn of humanity, astronomers have wished to destroy the atmosphere. Oh sure, it’s what we breathe and all, but that stupid atmosphere is always getting in the way. Since destroying the atmosphere is out of the question, astronomers have figured out how to work with it. To distort the mirror of the telescope itself though the magic of adaptive optics.

Click here to download the episode

Adaptive Optics – Show notes and transcript

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

No Doomsday in 2012

Apparently, the world is going to end on December 21st, 2012. Yes, you read correctly, in some way, shape or form, the Earth (or at least a large portion of humans on the planet) will cease to exist. Stop planning your careers, don’t bother buying a house, and be sure to spend the last years of your life doing something you always wanted to do but never had the time. Now you have the time, four years of time, to enjoy yourselves before… the end.

So what is all this crazy talk? We’ve all heard these doomsday predictions before, we’re still here, and the planet is still here, why is 2012 so important? Well, the Mayan calendar stops at the end of the year 2012, churning up all sorts of religious, scientific, astrological and historic reasons why this calendar foretells the end of life as we know it. The Mayan Prophecy is gaining strength and appears to be worrying people in all areas of society. Forget Nostradamus, forget the Y2K bug, forget the credit crunch, this event is predicted to be huge and many wholeheartedly believe this is going to happen for real. Planet X could even be making a comeback.

Related 2012 articles:

For all those 2012 Mayan Prophecy believers out there, I have bad news. There is going to be no doomsday event in 2012, and here’s why…

The extent of the Mayan empire

The Mayan Calendar
So what is the Mayan Calendar? The calendar was constructed by an advanced civilization called the Mayans around 250-900 AD. Evidence for the Maya empire stretches around most parts of the southern states of Mexico and reaches down to the current geological locations of Guatemala, Belize, El Salvador and some of Honduras. The people living in Mayan society exhibited very advanced written skills and had an amazing ability when constructing cities and urban planning. The Mayans are probably most famous for their pyramids and other intricate and grand buildings. The people of Maya had a huge impact on Central American culture, not just within their civilization, but with other indigenous populations in the region. Significant numbers of Mayans still live today, continuing their age-old traditions.

The Mayans used many different calendars and viewed time as a meshing of spiritual cycles. While the calendars had practical uses, such as social, agricultural, commercial and administrative tasks, there was a very heavy religious element. Each day had a patron spirit, signifying that each day had specific use. This contrasts greatly with our modern Gregorian calendar which primarily sets the administrative, social and economic dates.

Venus Express observation of Venus (ESA)

Most of the Mayan calendars were short. The Tzolk’in calendar lasted for 260 days and the Haab’ approximated the solar year of 365 days. The Mayans then combined both the Tzolk’in and the Haab’ to form the “Calendar Round”, a cycle lasting 52 Haab’s (around 52 years, or the approximate length of a generation). Within the Calendar Round were the trecena (13 day cycle) and the veintena (20 day cycle). Obviously, this system would only be of use when considering the 18,980 unique days over the course of 52 years. In addition to these systems, the Mayans also had the “Venus Cycle”. Being keen and highly accurate astronomers they formed a calendar based on the location of Venus in the night sky. It’s also possible they did the same with the other planets in the Solar System.

Using the Calendar Round is great if you simply wanted to remember the date of your birthday or significant religious periods, but what about recording history? There was no way to record a date older than 52 years.

The end of the Long Count = the end of the Earth?
The Mayans had a solution. Using an innovative method, they were able to expand on the 52 year Calendar Round. Up to this point, the Mayan Calendar may have sounded a little archaic – after all, it was possibly based on religious belief, the menstrual cycle, mathematical calculations using the numbers 13 and 20 as the base units and a heavy mix of astrological myth. The only principal correlation with the modern calendar is the Haab’ that recognised there were 365 days in one solar year (it’s not clear whether the Mayans accounted for leap years). The answer to a longer calendar could be found in the “Long Count”, a calendar lasting 5126 years.

I’m personally very impressed with this dating system. For starters, it is numerically predictable and it can accurately pinpoint historical dates. However, it depends on a base unit of 20 (where modern calendars use a base unit of 10). So how does this work?

The base year for the Mayan Long Count starts at “0.0.0.0.0”. Each zero goes from 0-19 and each represent a tally of Mayan days. So, for example, the first day in the Long Count is denoted as 0.0.0.0.1. On the 19th day we’ll have 0.0.0.0.19, on the 20th day it goes up one level and we’ll have 0.0.0.1.0. This count continues until 0.0.1.0.0 (about one year), 0.1.0.0.0 (about 20 years) and 1.0.0.0.0 (about 400 years). Therefore, if I pick an arbitrary date of 2.10.12.7.1, this represents the Mayan date of approximately 1012 years, 7 months and 1 day.

This is all very interesting, but what has this got to do with the end of the world? The Mayan Prophecy is wholly based on the assumption that something bad is going to happen when the Mayan Long Count calendar runs out. Experts are divided as to when the Long Count ends, but as the Maya used the numbers of 13 and 20 at the root of their numerical systems, the last day could occur on 13.0.0.0.0. When does this happen? Well, 13.0.0.0.0 represents 5126 years and the Long Count started on 0.0.0.0.0, which corresponds to the modern date of August 11th 3114 BC. Have you seen the problem yet? The Mayan Long Count ends 5126 years later on December 21st, 2012.

Doomsday
When something ends (even something as innocent as an ancient calendar), people seem to think up the most extreme possibilities for the end of civilization as we know it. A brief scan of the internet will pull up the most popular to some very weird ways that we will, with little logical thought, be wiped off the face of the planet. Archaeologists and mythologists on the other hand believe that the Mayans predicted an age of enlightenment when 13.0.0.0.0 comes around; there isn’t actually much evidence to suggest doomsday will strike. If anything, the Mayans predict a religious miracle, not anything sinister.

Myths are abound and seem to be fuelling movie storylines. It looks like the new Indiana Jones and the Kingdom of the Crystal Skull is even based around the Mayan myth that 13 crystal skulls can save humanity from certain doom. This myth says that if the 13 ancient skulls are not brought together at the right time, the Earth will be knocked off its axis. This might be a great plotline for blockbuster movies, but it also highlights the hype that can be stirred, lighting up religious, scientific and not-so-scientific ideas that the world is doomed.

Could an asteroid wipe out the Earth? (NASA)

Some of the most popular space-based threats to the Earth and mankind focus on Planet X wiping most life off the planet, meteorite impacts, black holes, killer solar flares, Gamma Ray Bursts from star systems, a rapid ice age and a polar (magnetic) shift. There is so much evidence against these things happening in 2012, it’s shocking just how much of a following they have generated. Each of the above “threats” needs their own devoted article as to why there is no hard evidence to support the hype.

But the fact remains, the Mayan Doomsday Prophecy is purely based on a calendar which we believe hasn’t been designed to calculate dates beyond 2012. Mayan archaeo-astronomers are even in debate as to whether the Long Count is designed to be reset to 0.0.0.0.0 after 13.0.0.0.0, or whether the calendar simply continues to 20.0.0.0.0 (approximately 8000 AD) and then reset. As Karl Kruszelnicki brilliantly writes:

…when a calendar comes to the end of a cycle, it just rolls over into the next cycle. In our Western society, every year 31 December is followed, not by the End of the World, but by 1 January. So 13.0.0.0.0 in the Mayan calendar will be followed by 0.0.0.0.1 – or good-ol’ 22 December 2012, with only a few shopping days left to Christmas.” – Excerpt from Dr Karl’s “Great Moments in Science“.

Sources: Dr Karl’s Great Moments in Science, IHT, 2012 Wiki

Leading image credits: MIT (supernova simulation), WikiMedia (Mayan pyramid Chichen Itza). Effects and editing: myself.

Wow! Satellite Catches Bright Solar Flare From a Another Star

Artist's depiction of red-dwarf-flare. Image credit: Casey Reed/NASA

NASA’s Swift satellite picked up one of the brightest solar flares ever seen — not from our own sun, but a star 16 light-years away. This flare packed the power of thousands of solar flares combined, and a flare of this magnitude from our own sun would have stripped Earth’s atmosphere and sterilized the planet. Astronomers say the flare would have been visible to the naked eye on April 25, 2008 if the star had been easily observable in the night sky at the time. As it was, the flare’s brightness caused Swifts’ Ultraviolet/Optical Telescope to shut down for safety reasons. But Swift was able to study the flare for over 8 hours with its X-ray capabilities.

The Swift satellite normally searches for gamma ray bursts, and is surrounded with detectors that look for bursts of light. The spacecraft then “swiftly” and autonomously re-points itself to the location of the burst. However, this was no gamma ray burst, just a solar flare. But what a solar flare!

The star, EV Lacertae, is a basic red dwarf, the most common type of star in the universe. It shines with only one percent of the Sun’s light, and contains only a third of the Sun’s mass. It’s one of our closest stellar neighbors, but normally is not visible with the naked eye, as it holds a magnitude of -10.

“Here’s a small, cool star that shot off a monster flare. This star has a record of producing flares, but this one takes the cake,” says Rachel Osten, from NASA’s Goddard Space Flight Center. “Flares like this would deplete the atmospheres of life-bearing planets, sterilizing their surfaces.”

Astronomers say EV Lacertae is like an unruly child that throws frequent temper tantrums. It’s a relatively young star at a few hundred million years of age. But it’s a fast rotating star which generates a strong magnetic field, about 100 times as magnetically powerful as the Sun’s field. The energy stored in its magnetic field powers these giant flares.

The flare’s incredible brightness enabled Swift to make detailed measurements in X-ray, as the star remained bright in x-rays for about 8 hours. “This gives us a golden opportunity to study a stellar flare on a second-by-second basis to see how it evolved,” says Stephen Drake of NASA Goddard.

Flares release energy across the electromagnetic spectrum, but the extremely high gas temperatures produced by flares can only be studied with high-energy telescopes like those on Swift. Swift’s wide field and rapid repointing capabilities, designed to study gamma-ray bursts, make it ideal for studying stellar flares. Most other X-ray observatories have studied this star and others like it, but they have to be extremely lucky to catch and study powerful flares due to their much smaller fields of view.

Original News Source: NASA

There’s A lot of Dust Out There in the Universe

The whole point of putting telescopes in orbit is to avoid distortions caused by our murky atmosphere. But now astronomers say they have calculated only half the light of our universe reaches telescopes, even those in orbit, because of the amount of dust that permeates the universe. In essence, they say, the universe is twice as bright as previously thought. The lead author of a new paper detailing this discovery, Dr. Simon Driver from the University of St Andrews said, “For nearly two decades we’ve argued about whether the light that we see from distant galaxies tells the whole story or not. It doesn’t; in fact only half the energy produced by stars actually reaches our telescopes directly, the rest is blocked by dust grains.”

While astronomers knew the universe contains small grains of dust, they hadn’t realized the extent to which this is restricting the amount of light that we can see. The dust absorbs starlight and re-emits it, making it glow. They knew that existing models were flawed, because the energy output from glowing dust appeared to be greater than the total energy produced by the stars.

Dr. Driver said, “You can’t get more energy out than you put in so we knew something was very wrong. Even so, the scale of the dust problem has come as a shock – it appears that galaxies generate twice as much starlight as previously thought.”

The team used a new model of the dust distribution in galaxies from a catalogue of 10,000 galaxies to precisely calculate the fraction of starlight blocked by the dust. The team says dust blocks approximately half of the light that the Universe generates.

The Universe is currently generating energy, via nuclear fusion in the cores of stars, at a whopping rate of 5 quadrillion Watts per cubic light year, about 300 times the average energy consumption of the Earth’ population.

After measuring the brightness of thousands of disc-shaped galaxies with different orientations, the astronomers matched their observations to computer models of dusty galaxies. From this they were able to calibrate the models and, for the first time, determine how much light is obscured when a galaxy has a face-on orientation. This then allowed them to determine the absolute fraction of light that escapes in each direction from a galaxy.

While modern instruments allow astronomers to see further into space, they can’t eliminate the obscuring effect from these tiny dust grains. “It is somewhat poetic that in order to discover the full glory of our Universe we first had to appreciate the very small” said Dr. Alister Graham from the Swinburne University of Technology.

The team consists of astronomers from the United Kingdom, Germany and Austrailia. Their research was published in the May 10 issue of Astrophysical Journal Letters.

Original News Source: Science and Technology Facilities Council

Fly Over the Columbia Hills at APOD

If you haven’t yet discovered Astronomy Picture of the Day, its an absolutely wonderful site that provides a different image every day of our universe, with explanations written by two professional astronomers, Robert Nemiroff and Jerry Bonnell. Today’s APOD post is not a picture, however, but a movie. Combining data taken from the Mars Reconnaissance Orbiter and the Mars Rover Spirit, Doug Ellison from UnmannedSpaceflight.com created a movie that simulates a fly-over of the Columbia Hills region on Mars. Of course, the Hills were named in memory of the astronauts who died in the Columbia space shuttle accident in February 2003.

In the movie you see the rippled sand on the sides of the Hills, the peak on Husband Hill where Spirit triumphantly climbed and surveyed the amazing view, and a white-colored area back on lower ground called Home Plate that Spirit has been studying for a couple of months now. Spirit herself makes a cameo in the video, too. It’s just great fun to watch.

Well, instead just reading about it, go visit APOD to watch the movie. And stay and browse awhile: APOD boasts the largest collection of annotated astronomical images on the internet.

Job Posting: Apply Today to Become an Astronaut

Looking for a new and exciting job that will take you places? Now is the time to take the leap, as everyone is looking for astronauts. Here’s how to become an astronaut. The European Space Agency today opened applications for talented individuals wishing to become an astronaut. There hasn’t been a call for new applicants for the European Astronaut Corps since 1992, and so the ESA says this is a rare opportunity to be at the forefront of Europe’s human spaceflight programs including future missions to the ISS, the Moon and beyond. Four European astronauts will be selected from the applicants. But if you’re not from Europe, don’t lose hope. NASA also has openings, as does Canada and Japan.

“As a former astronaut I have been looking forward to the start of the selection procedure with a great deal of anticipation”, says Michel Tognini, Head of the European Astronaut Center. “With the recent additions of ESA’s Columbus laboratory to the ISS and the Automated Transfer Vehicle serving as an ISS logistics spacecraft, European human spaceflight has now entered a new era with respect to science and operations. Building on the past 30 years of experience of ESA astronauts, we now need high-calibre people to spearhead ESA’s vision of ISS exploitation and future human exploration of our solar system.”

For the ESA astronaut positions, candidates from all 17 Member States (Austria, Belgium, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Luxembourg, the Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom) are welcome to apply.

Those Europeans interested can take the first step by filling out a preliminary application online.

NASA is accepting applications until July 1, 2008. Click here for more information.

Canada’s application process will open at the end of May 2008. More info.

And JAXA, the Japanese space agency, announced on April 1, 2008 they are looking for astronauts, too.

The usual procedure for astronaut selection goes something like this: Those making the first cut will go through a series of additional selection procedures such as psychological and professional aptitude evaluations, and a medical evaluation. At the end of that process, potential candidates are invited for interviews, after which the final selections are made.

To everyone with high aspirations: Go for it!

Original News Source: ESA Press Release

Venus’ Orbit Around the Sun

The orbit of Venus is the most circular in the entire Solar System. In mathematical terms, the eccentricity of Venus is less than 0.01. A year on Venus lasts 223 days.

As Venus travels around the Sun, it ranges in distance from 107 million km to 109 million km. The average distance is 108 million km. This is 72% the distance of Earth to the Sun.

Venus can get as close as 40 million km from the Earth. This is called an inferior conjunction every 584 days, on average.

One of the most unusual things about Venus is that it rotates backwards from the rest of the planets in the Solar System. Seen from above, all of the planets rotate counter-clockwise, but Venus turns clockwise. Of course, Venus orbits so slowly that its day is actually longer than its year. A day on Venus lasts 243 Earth days, while its year is 224.7 Earth days.