Posted on by Ken Kremer

Dawn Exceeds Wildest Expectations as First Ever Spacecraft to Orbit a Protoplanet – Vesta

Enhanced Image of Vesta Captured by Dawn on July 9, 2011. NASA's Dawn spacecraft entered orbit around Vesta on July 16, 2011. Dawn obtained the raw image of Vesta with its framing camera on July 9, 2011 - which has been enhanced and annotated. It was taken from a distance of about 26,000 miles (41,000 kilometers) away from the protoplanet Vesta. Each pixel in the image corresponds to roughly 2.4 miles (3.8 kilometers). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA. Enhanced and annotated by Ken Kremer

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NASA’s super exciting Dawn mission to the Asteroid Belt marked a major milestone in human history by becoming the first ever spacecraft from Planet Earth to achieve orbit around a Protoplanet – Vesta – on July 16. Dawn was launched in September 2007 and was 117 million miles (188 million km) distant from Earth as it was captured by Asteroid Vesta.

Dawn’s achievements thus far have already exceeded the wildest expectations of the science and engineering teams, and the adventure has only just begun ! – so say Dawn’s Science Principal Investigator Prof. Chris Russell, Chief Engineer Dr. Marc Rayman (think Scotty !) and NASA’s Planetary Science Director Jim Green in exclusive new interviews with Universe Today.

As you read these words, Dawn is steadily unveiling new Vesta vistas never before seen by a human being – and in ever higher resolution. And it’s only made possible via the revolutionary and exotic ion propulsion thrusters propelling Dawn through space (think Star Trek !). That’s what NASA, science and space exploration are all about.

“Dawn is in orbit, remains in good health and is continuing to perform all of its functions,” Marc Rayman of the Jet Propulsion Laboratory, Pasadena, Calif., told me. “Indeed, that is how we know it achieved orbit. The confirmation received in a routine communications session that it has continued thrusting is all we needed.”

Image of Vesta Captured by Dawn on July 9, 2011. NASA's Dawn spacecraft obtained this image with its framing camera on July 9, 2011. It was taken from a distance of about 26,000 miles (41,000 kilometers) away from the protoplanet Vesta. Each pixel in the image corresponds to roughly 2.4 miles (3.8 kilometers). Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Dawn entered orbit at about 9900 miles (16000 km) altitude after a nearly 4 year journey of 1.73 billion miles.

Over the next few weeks, the spacecrafts primary task is to gradually spiral down to its initial science operations orbit, approximately 1700 miles above the pock marked surface.

Vesta is the second most massive object in the main Asteroid Belt between Mars and Jupiter. Dawn is the first probe to orbit an object in the Asteroid Belt.

I asked Principal Investigator Chris Russell from UCLA for a status update on Dawn and to describe what the team can conclude from the images and data collected thus far.

“The Dawn team is really, really excited right now,” Russell replied.

“This is what we have been planning now for over a decade and to finally be in orbit around our first ‘protoplanet’ is fantastic.”

“The images exceed my wildest dreams. The terrain both shows the stress on the Vestan surface exerted by 4.5 billion years of collisions while preserving evidence [it seems] of what may be internal processes. The result is a complex surface that is very interesting and should be very scientifically productive.”

NASA's Dawn spacecraft, illustrated in this artist's concept, is propelled by ion engines to Protoplanets Vesta and Ceres. Credit: NASA/JPL

“The team is looking at our low resolution images and trying to make preliminary assessments but the final answers await the higher resolution data that is still to come.”

Russell praised the team and described how well the spacecraft was operating.

“The flight team has been great on this project and deserves a lot of credit for getting us to Vesta EARLY and giving us much more observation time than we had planned,” Russell told me.

“And they have kept the spacecraft healthy and the instruments safe. Now we are ready to work in earnest on our science observations.”

Dawn will remain in orbit at Vesta for one year. Then it will fire its ion thrusters and head for the Dwarf Planet Ceres – the largest object in the Asteroid Belt. Dawn will then achieve another major milestone and become the first spacecraft ever to orbit two celestial objects.

Dawn launch on September 27, 2007 by a Delta II rocket from Cape Canaveral Air Force Station, Florida. Credit: Ken Kremer

Jim Green, Director of Planetary Science for the Science Mission Directorate (SMD) at NASA HQ in Washington, DC, summed up his feelings about Dawn in this way;

“Getting Dawn into orbit is an amazing achievement,” Green told me.

“Instead of the ‘fire the thrusters full blast’ we just sort of slid into orbit letting gravity grab the spacecraft with a light tug. This gives us great confidence that the big challenge down the road of getting into orbit around Ceres can also be accomplished just as easily.”

Sharper new images from Vesta will be published by NASA in the next day or so.

“We did take a few navigation images in this last sequence and when they get through processing they should be put on the web this week,” Russell informed. “These images are from a similar angle to the last set and with somewhat better resolution and will not reveal much new.”

However, since Dawn is now orbiting Vesta our upcoming view of the protoplanet will be quite different from what we’ve seen in the approach images thus far.

“We will be changing views in the future as the spacecraft begins to climb into its science orbit,” stated Russell.

“This may reveal new features on the surface as well as giving us better resolution. So stay tuned.”

Marc Rayman explained how and why Dawn’s trajectory is changing from equatorial to polar:

“Now that we are close enough to Vesta for its gravity to cause a significant curvature in the trajectory, our view is beginning to change,” said Rayman. “That will be evident in the pictures taken now and in the near future, as the spacecraft arcs north over the dark side and then orbits back to the south over the illuminated side.”

“The sun is over the southern hemisphere right now,” added Russell. “When we leave we are hoping to see it shine in the north.”

Dawn is an international mission with significant participation from Germany and Italy. The navigation images were taken by Dawn’s framing cameras which were built in Germany.

Exploring Vesta is like studying a fossil from the distant past that will immeasurably increase our knowledge of the beginnings of our solar system and how it evolved over time.

Dawn Infographic Poster - click to enlarge. Credit: NASA

Vesta suffered a cosmic collision at the south pole in the distant past that Dawn can now study at close range.

“For now we are viewing a fantastic asteroid, seeing it up close as we zero in on its southern hemisphere, looking at the huge central peak, and wondering how it got there,” explained Jim Green

“We know Vesta was nearly spherical at one time. Then a collision in its southern hemisphere occurred blowing off an enormous amount of material where a central peak now remains.”

That intriguing peak is now obvious in the latest Dawn images from Vesta. But what does it mean and reveal ?

“We wonder what is that peak? replied Green. “Is it part of the core exposed?

“Was it formed as a result of the impact or did it arise from volcanic action?”

“The Dawn team hopes to answer these questions. I can’t wait!” Green told me.

As a result of that ancient south pole collision, about 5% of all the meteorites found on Earth actually originate from Vesta.

Keep your eyes glued to Dawn as mysterious Vesta’s alluring secrets are unveiled.

Dawn Trajectory and Current Location in orbit at Vesta on July 18, 2011. Credit: NASA/JPL

Read my prior features about Dawn
Dawn Closing in on Asteroid Vesta as Views Exceed Hubble
Revolutionary Dawn Closing in on Asteroid Vesta with Opened Eyes

Posted on by Matt Williams

What are Active Optics?

Active Optics
Keck Telescope

For astronomers and physicists alike, the depths of space are a treasure trove that may provide us with the answers to some of the most profound questions of existence. Where we come from, how we came to be, how it all began, etc. However, observing deep space presents its share of challenges, not the least of which is visual accuracy.

In this case, scientists use what is known as Active Optics in order to compensate for external influences. The technique was first developed during the 1980s and relied on actively shaping a telescope’s mirrors to prevent deformation. This is necessary with telescopes that are in excess of 8 meters in diameter and have segmented mirrors.

Definition:

The name Active Optics refers to a system that keeps a mirror (usually the primary) in its optimal shape against all environmental factors. The technique corrects for distortion factors, such as gravity (at different telescope inclinations), wind, temperature changes, telescope axis deformation, and others.

The twin Keck telescopes shooting their laser guide stars into the heart of the Milky Way on a beautifully clear night on the summit on Mauna Kea. Credit: keckobservatory.org/Ethan Tweedie
The twin Keck telescopes shooting their laser guide stars into the heart of the Milky Way on a beautifully clear night on the summit on Mauna Kea. Credit: keckobservatory.org/Ethan

Adaptive Optics actively shapes a telescope’s mirrors to prevent deformation due to external influences (like wind, temperature, and mechanical stress) while keeping the telescope actively still and in its optimal shape. The technique has allowed for the construction of 8-meter telescopes and those with segmented mirrors.

Use in Astronomy:

Historically, a telescope’s mirrors have had to be very thick to hold their shape and to ensure accurate observations as they searched across the sky. However, this soon became unfeasible as the size and weight requirements became impractical. New generations of telescopes built since the 1980s have relied on very thin mirrors instead.

But since these were too thin to keep themselves in the correct shape, two methods were introduced to compensate. One was the use of actuators which would hold the mirrors rigid and in an optimal shape, the other was the use of small, segmented mirrors which would prevent most of the gravitational distortion that occur in large, thick mirrors.

This technique is used by the largest telescopes that have been built in the last decade. This includes the Keck Telescopes (Hawaii), the Nordic Optical Telescope (Canary Islands), the New Technology Telescope (Chile), and the Telescopio Nazionale Galileo (Canary Islands), among others.

The New Technology Telescope (NTT) pioneered the Active Optics. Credit: ESO/C.Madsen. Bacon
The New Technology Telescope (NTT) pioneered the Active Optics. Credit: ESO/C.Madsen. Bacon

Other Applications:

In addition to astronomy, Active Optics is used for a number of other purposes as well. These include laser set-ups, where lenses and mirrors are used to steer the course of a focused beam. Interferometers, devices which are used to emit interfering electromagnetic waves, also relies on Active Optics.

These interferometers are used for the purposes of astronomy, quantum mechanics, nuclear physics, fiber optics, and other fields of scientific research. Active optics are also being investigated for use in X-ray imaging, where actively deformable grazing incidence mirrors would be employed.

Adaptive Optics:

Active Optics are not to be confused with Adaptive Optics, a technique that operates on a much shorter timescale to compensate for atmospheric effects. The influences that active optics compensate for (temperature, gravity) are intrinsically slower and have a larger amplitude in aberration.

. Credit: ESO/L. Calçada/N. Risinger
Artist’s impression of the European Extremly Large Telescope deploying lasers for adaptive optics. Credit: ESO/L. Calçada/N. Risinger

On the other hand, Adaptive Optics corrects for atmospheric distortions that affect the image. These corrections need to be much faster, but also have smaller amplitude. Because of this, adaptive optics uses smaller corrective mirrors (often the second, third or fourth mirror in a telescope).

We have written many articles about optics for Universe Today. Here’s The Photon Sieve Could Revolutionize Optics, What did Galileo Invent?, What did Isaac Newton Invent?, What are the Biggest Telescopes in the World?

We’ve also recorded an entire episode of Astronomy Cast all about Adaptive Optics. Listen here, Episode 89: Adaptive Optics, Episode 133: Optical Astronomy, and Episode 380: The Limits of Optics.

Sources:

Posted on by Tammy Plotner

Catch A Pulsar By The Tail

A pulsar located about 1,600 light years from Earth.

Originally discovered by the Fermi Gamma Ray Space Telescope in 2009, Pulsar PSR J0357 had a bit of a surprise for astronomers when NASA’s Chandra X-ray Observatory turned an eye its way. Even though it might be 1,600 light years from Earth and half a million years old, it would appear this object has a cosmic sense of humor. Stretching across 4.2 light years is an enormous tail…

Viewable only at X-ray wavelengths, this incredible cosmic contrail is the longest ever associated with a so-called “rotation- powered” pulsar. Unlike other pulsars, J0357 gets its power from energy depletion as the spin rate decreases. But where did the plumage come from? According to the Chandra data, it may be an emission from energetic particles in the pulsar wind produced while turning around magnetic field lines. While artifacts of this type have been noted before, they’re classed as bow-shocks generated by the supersonic motion of pulsars through space. From there, the wind pulls the particles along behind it as the pulsar passes through interstellar gas.

But Pulsar PSR J0357 isn’t exactly fitting into a neat a tidy category…

According to data taken from Fermi, J0357 is only losing a small amount of energy as its spin rate slows. This means it shouldn’t be producing a particle wind of such proportions. Another anachronism is the placement of the bright portions of the tail – not anywhere near where bow-shocks are associated with pulsars.

“Further observations with Chandra could help test this bow-shock interpretation.” says the Chandra team. “If the pulsar is seen moving in the opposite direction from that of the tail, this would support the bow-shock idea.”

Original News Source: Chandra News.

Posted on by Jon Voisey

Another Kepler Planet Confirmed

Artist's concept of Kepler in action. NASA/Kepler mission/Wendy Stenzel.

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The Kepler mission, launched in 2009, is looking to greatly improve our understanding of planets. Since beginning operation, the planet hunting spacecraft has made tentative identifications of over 1,200 planets, having spotted them as they transited their parent stars. However, these planets need confirmation from a more robust method, specifically the spectroscopically detected wobbles, before they’re added to the official list of extrasolar planets.

Thus far, confirmations have been slow to come; only 16 of the planets have been detected using other methods. But recently, astronomers using the Hobby-Eberly Telescope (HET), operated by the University of Texas, Austin have confirmed another.

The planet, Kepler-15b, is the first confirmed by this unique telescope. As opposed to most observatories, the mirror at the HET does not track the stars. Instead, the mirror remains stationary and the detecting instruments are moved along the focal plane to track the object in question. While this doesn’t allow for the object to track the entire night, it does let astronomers get continuous observation of the target for up to 2 hours. This unusual configuration was estimated to reduce the construction costs by as much as 80%.

From the Kepler observations, the tentative planet was expected to have an orbital period of just under 5 days and would transit the parent star for 3.5 hours, dimming the star’s light by about 1.2%. Using this information, the expectation was that the planet should have a radius of 1.4 times that of Jupiter, putting it in the class of “hot-Jupiters”.

The observations by the HET were taken from March until November of 2010. The team used the telescope’s spectrometer to search for the signs of variation between 2 and 100 days. When analyzed for periodicity, the team independently confirmed a strong signal with a period of 4.94 days.

Using the new spectroscopic data, the team estimates the new planet has a mass of 0.66 Jupiter masses, and reduces the estimated radius to 0.96 times that of Jupiter, giving a mean density of ~.9 grams per cubic centimeter. The parent star contains high amounts of heavy elements and is tied with Kepler-6 for the most metal rich parent star of the Kepler findings. If the planet, being formed from the same interstellar cloud, has similar metallicity, then it could be expected that the presence of these additional heavy elements could help to shrink the planet.

The team also reports that they have observed other purported Kepler planets and intends to include the findings in an upcoming publication. Additionally, the HET is scheduled for a major upgrade starting later this year. This will include upgrades to the tracking assembly, as well as the fiber optics used in the spectroscope. Currently, this instrument is only capable of performing confirmations for Jovian massed planets, but once upgrades are complete, the team expects to be able to use the system to search for lower mass candidates in the mass range of Neptune and those in the “Super-Earth” category.

Posted on by Tammy Plotner

New Kids On The Block – The Brown Dwarfs

False-colour images of the two brown dwarf discoveries WISE J0254+0223 and WISE J1741+2553. (Credit: AIP, NASA/IPAC Infrared Science Archive)

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When it comes to being close to “home”, there are not a lot of stars out there in our general neighborhood. Proxima Centauri is 4.2 light years away and Rigil Kentaurus is 4.3. There’s Barnard’s Star, Wolf 359, Lalande 21185, Luyten 726-8A and B and big, bright Sirius A and B. But what about a celestial neighbor that’s not quite so prominent? Try a pair of newly discovered brown dwarfs.

Scientists from the Leibniz Institute for Astrophysics Potsdam (AIP) using the NASA satellite WISE (Wide-field Infrared Survey Explorer) have discovered this unlikely duo just 15 and 18 light years from our solar system. “We have used the preliminary data release from WISE, selected bright candidates with colours typical of late-T dwarfs, tried to match them with faint 2MASS and SDSS objects, to determine their proper motions, and to follow-up them spectroscopically.” says RD Scholz, et al.

Named WISE J0254+0223 and WISE J1741+2553, the pair drew attention to themselves by their very disparity – one very bright in infrared and the other very faint in optical light. Even more attractive was the speed at which they’re moving – the proper motion changing drastically between observations. “The very large proper motions are a first hint that these objects should be very close to the Sun. Both objects are only detected in the SDSS z-band which is typical of nearby late-T dwarfs.” says Scholz.

Because the pair were optically visible at the time of the discovery, the team employed the Large Binocular Telescope (LBT) in Arizona to determine their spectral type and home in more accurately on their distance. They wanted to know more about the coolest representatives of T-type brown dwarf – the ultra-cool ones. Better known as failed stars because they lacked the mass to ignite nuclear fusion, the duo required study because their magnitude decreases sharply with time. Because they fade so quickly, there’s a strong possibility of a brown dwarf being much closer than we realize.

Like maybe next door…

Original News Source: Leibniz Institute for Astrophysics Potsdam News. For further reading: Cornell University Library – Two very nearby (d ~ 5 pc) ultracool brown dwarfs detected by their large proper motions from WISE, 2MASS, and SDSS data.

Posted on by Tammy Plotner

Are The Galaxies In Our Universe More Right-Handed… Or Left-Handed?

A new study found an excess of counter-clockwise rotating or "left-handed" spiral galaxies like this one, compared to their right-handed counterparts. This provides evidence that the universe does not have mirror symmetry. Credit: NASA, ESA

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It’s called mirror symmetry and it has everything to do with a recent study done by physics professor Michael Longo and a team of five undergraduates from the University of Michigan. Their work encompasses the rotation direction of tens of thousands of spiral galaxies cataloged by the Sloan Digital Sky Survey. What they’re looking for is the shape of the Big Bang… and what they found is much more elaborate than they thought.

By utilizing SDSS images, the team began looking for mirror symmetry and evidence the early universe spun on an axis. “The mirror image of a counter-clockwise rotating galaxy would have clockwise rotation. More of one type than the other would be evidence for a breakdown of symmetry, or, in physics speak, a parity violation on cosmic scales.” Longo said. However, there seems to be a certain “spin preference” when it comes to spiral galaxies toward the north pole of the Milky Way. Here they found an abundance of left-handed, or counter-clockwise rotating, spirals – an effect which extended beyond an additional 600 million light years.

“The excess is small, about 7 percent, but the chance that it could be a cosmic accident is something like one in a million,” Longo said. “These results are extremely important because they appear to contradict the almost universally accepted notion that on sufficiently large scales the universe is isotropic, with no special direction.”

On the other hand, be it left or right, Galaxy Zoo has done some very interesting research into mirror symmetry as well. In conjunction with the Sloan Digital Sky Survey, the team also involved the public for their input – a total of 36 million classifications for 893,212 galaxies from 85,276 users. The GZ study is absolutely fascinating and took every variable into account.

“We wish to establish the large scale statistical properties of the galaxy spins. Although there is some level of uncertainty in the overall number counts, it is still possible to look for a dipole, for example, in the spin distributions.” says Kate Land, et al. “Curiously, the dipoles from these two analyses are in completely opposite directions. The samples cover different amounts and parts of the sky, with SDSS mainly in the Northern hemisphere and the sample of Sugai & Iye (1995) predominantly in the Southern hemisphere. In both cases the dipoles tend to point away from the majority of the data but neither analysis fits for a monopole or takes account of their partial sky coverage in assessing the dipole. With incomplete sky coverage the spherical harmonic decomposition is no longer orthogonal and for a sample covering less than half of the sky it is hard to tell the difference between a monopole (an excess of one type over the other) and a dipole (an asymmetry in the distribution).”

So what’s the end result? Well, chances are good that our universe was born spinning… but like any family, there isn’t much evidence one way or another that says most members have to be right – or left – handed. It’s more about how we, as humans, perceive them…

Original Story Source: University of Michigan New Service. For further information, read Galaxy Zoo: The large-scale spin statistics of spiral galaxies in the Sloan Digital Sky Survey.

Posted on by Jon Voisey

More Images of HR 8799

HR 8799 system
One of the discovery images of the system obtained at the Keck II telescope using adaptive optics system and the NIRC2 Near-Infrared Imager. Image shows all four confirmed planets indicated as b, c, d and e in the labeled image. Planet "b" is a ~5 Jupiter-mass planet orbiting at about ~68 AU, while planets c, d, and e are ~7 Jupiter-mass companions orbiting the star at about 38, 24 and 14.5 AU. Credit: NRC-HIA, C. Marois & Keck Observatory

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Late last year, astronomers using the Keck II telescope released the first direct image of a planetary system including four planets. These planets orbited the star HR 8799 and were taken in the J and L bandpasses which are in the near-infrared portion of the spectrum. Since then the team has collected new data using the same telescope, extending the spectral range into the mid-infrared portion of the spectra.

The new images are important to astronomers because this provides a more complete understanding of the distribution of radiation that the planets are emitting. This can be compared to models of planetary formation, allowing these young planets to act as a test bed. Previous comparison to models have suggested that these planets have cool, dusty atmospheres without the presence of methane or other common absorbing molecules.

The team hopes that the new observations will help distinguish between the various models that explain this deficiency of methane. Unfortunately, getting good observations in this portion of the spectra is challenging. In particular, at the Keck telescope, the design of the telescope itself makes observations especially challenging due to portions of the instrument themselves emitting in the infrared, masking the faint signals from the planet.

To bring out the planets, the team developed a new technique to help clean the images of the unwanted noise. They estimate that their new technique is nine times more efficient than previously used techniques. To do this, they moved the telescope slightly between images, allowing the patterns of interference to change between exposures, thereby making them more apparent and easier to remove.

When the results were analyzed and compared to models, the team found that they were in good agreement with predictions of planetary evolution for planets c and d. However, for planet b, the models predicted a planet with a radius that would be too small to account for the observed luminosity. The observations could be brought into agreement with the models by increasing the metallicity of the model.

With additional future observations, the team hopes to constrain these models and further investigate the atmospheres of these planets.

NOTE: I Emailed the authors of the paper to ask permission to reproduce the new image here, but have not gotten a reply. The one used above is the K and L band images from last year. To see the new ones, feel free to go to the paper directly.

Posted on by Jon Voisey

New Planet Discovered In Trinary Star System

A planet 6 times the mass of Earth orbits around the star Gliese 667 C, which belongs to a triple system. Credit: ESO

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Until recently, astronomers were highly skeptical of whether or not planets should be possible in multiple star systems. It was expected that the constantly varying gravitational force would eventually tug the planet out of orbit. But despite doubts, astronomers have found several planets in just such star systems. Recently, astronomers announced another, this time in the trinary star HD 132563.

The detection of the new planet came as part of a larger study on the trinary star system spanning 10 years. The two main stars that comprise the system are both similar to the Sun in mass, although somewhat less prevalent in metals, and orbit each other at a distance of around 400 AU. The main star, HD 132563A is also itself, a binary. This fact was not previously recognized and also reported by the team, led by Silvano Desidera from the Astronomical Observatory in Padova, Italy.

The newly discovered planet orbits the secondary star in the system, HD 132563B. As with the binary component of the main star, the new planet was discovered spectroscopically. The planet is at least 1.3 times the mass of Jupiter, with an average distance from its parent star of 2.6 AU, and an moderately high eccentricity of 0.22.

The team also attempted to image the planet directly using adaptive optics from the Italian Telescopio Nazionale Galileo. While there was a hint in the glare of the star that may have been the planet in question, the team could not rule out that the detection was not an instrumental effect.

With the discovery of this new planet, the total number of discovered planets in multiple star systems lies at eight. while this is rather small numbers from which to draw firm conclusions, it appears that planets can be commonly found orbiting the more remote members of trinary star systems for good periods of time. On the shorter end, the stellar system is anticipated to be 1-3 billion years in aged, based on the amount of stellar activity and amount of lithium present in the star’s atmosphere (which decreases with time). However, fitting of the mass and luminosity onto isochrones suggest the stars may be as much as 5 billion years in age. In either situation, the planetary system is dynamically stable.

Also based on these eight systems, the team also suggests that planets existing around such far removed members of a multiple star system may be as common as planets around wide binaries, or even single stars.

Posted on by Jon Voisey

The Sun’s Heartbeat

Within our own lives, one of the most powerful forces is that of the Sun. Directly or indirectly, it provides all of the energy we use on a daily basis. Yet this mass of incandescent plasma is often a mere afterthought. But not to be forgotten, writer for Astronomy magazine, Bob Berman makes the Sun the focus of a new book, The Sun’s Heartheat which explores how our parent star affects our lives in ways more direct than we might expect. The book is due to be released July 13th, but I got a review copy to tell everyone about.

The book is a short read clocking in at a quick 20 chapters. Roughly the first third of them is a brief history of solar astronomy. Most of this is concentrated on the history of observations of sunspots. It goes through the initial discoveries, the waxing and waning of popularity of sunspots thanks to the Maunder minimum, and Schwabe’s discovery of the cycles.

Once that’s ironed out, we get to what I consider to be the main theme of the book: How does the Sun affect us here on Earth? The first topics addressed are rather germane: The sun brings life, but too much of it can kill you. But after that, the topics are a bit more interesting. There’s a fantastic chapter on the importance of getting adequate supplies of vitamin D which your body produces naturally from exposure to the Sun. Another chapter deals with the way the Sun doesn’t affect us: Astrologically. The book discusses our ability to see colors and the impressiveness of total solar eclipses and auroras.

The second to last chapter covers just how much peril we face from a large coronal mass ejection. I was familiar with nearly everything in the book, including this chapter, but I think this chapter was my favorite. Sadly, most people are disinterested in science, but more than any other, this one was tangible enough to be rather alarming.

It closes with a preview of the future Sun, describing how its slow increase in brightness will make life on Earth unfavorable in a billion years or so and how it will eventually expand into a red giant.

If you’re an experienced astronomy enthusiast, this book will likely offer little new information on the Sun itself, although it does have lots of good backstories on some of the discoveries and those involved. It is engaging thanks to a friendly tone, even if Berman does have an odd fascination with anachronisms (17th century HMO’s?). The book lacked several of the deeper topics that I feel could have been more inviting for advanced readers such as a more thorough description of our knowledge of the innards of the Sun thanks to helioseismology. I suspect this is because it didn’t relate strongly enough to the main thesis aside from a general, how the Sun works which doesn’t focus on how it affects us.

But if you know a young astronomer, or someone older just getting into the field, or someone that’s stared only at deep sky objects and never thought much about the closest star to home, this book would likely be of some interest.

Posted on by Nancy Atkinson

The Challenges — and Dangers — of Amateur Astronomy in Afghanistan

A local famer from Afghanistan looks at the night sky through a telescope. Credit: Saeid Aghaei.

Most amateur astronomers take for granted that they can just go outside and enjoy viewing the night sky without encountering many problems — aside from keeping mosquitoes at bay or fixing equipment malfunctions. But in order for amateur astronomers in Afghanistan to simply set up a telescope in a dark region, they have to deal with more serious complications, such as making sure the area is clear of land mines, not arousing the suspicions the Taliban or the local police, and watching out for potential bombing raids by the US/UK/Afghan military alliance. But amateur astronomers like Saeid Aghaei and Yunos Bakhshi take those risks in stride just so they can share the beauty of the night sky with the Afghani people.

Aghaei is an amateur astronomer and a science and technology columnist from Neyshabur, Iran. For several years, he has been translating Universe Today articles on space and astronomy and publishing them in his local newspaper in Iran. But he is now in Kabul, Afghanistan working with his Afghan friend Yunos Bakhshi, to help establish and nurture the Afghanistan Astronomy Association. Bakhshi is one of the founders and is currently head of the organization.

This organization was initiated during the International Year of Astronomy in 2009, but has faced difficulties; not only from the upheaval the country is experiencing but because of the limited scientific exposure the general public has in Afghanistan. Bakhshi said there is confusion between astronomy and astrology (which, unfortunately happens everywhere) and also, due to limited access to the internet and illiteracy among the majority of Afghanis, many don’t see the practical applications of studying the sciences.

But on their website, the Afghan Astronomy Association says they hope to help make it easier to learn more about astronomy for all Afghans with different levels of knowledge on the subject.

“We believe, that astronomy can solve one of the background problems of Afghanistan; the struggle over the real ownership of this country, which lasts more than three decades. We try by wiping off the gun smoke from Afghanistan sky, to show the beauty and mysterious of Universe to all Afghans; so they will understand that this world, this blue planet and even this sun with its planets are just a tiny point in the Grand picture of Universe that no one is better than other; except by knowledge and moral values.”

Bakhshi said he and Aghaei are “committed to disseminate the astronomy knowledge among ordinary Afghans, mainly school children.” They are helping the cause by doing what they call “Adventure Astronomy” – basically braving dangerous situations to expose more Afghanis to astronomy.

The two shared their experiences from a recent night of skywatching in Afghanistan:

A view of the night sky about 20 km from Kabul, Afghanistan, with light pollution from the Bagram Military Base. Credit: Yunos Bakhshi.

At the end of last week, they traveled about 20 km from Kabul with a group of interested people. Even at that distance they experienced light pollution from the city and the American military base in Bagram. “Our observation site was a small farm not so far from the main highway,” Aghaei told Universe Today in an email. “It was a peaceful and calm place (based on local standards): all land mines are cleared or exploded, no sign of Taliban, because two days before they attacked Intercontinental Hotel in Kabul and based on our experiences and statistics (nonofficial), they would rest for one or two weeks. The only concern of us, even from the start of night was the battery charge (energy supply). But our presence with suspicious equipments triggered the local farmers’ concerns.”

After aligning the telescope, a car slowly approached, shining its lights on Aghaei and his friends, which included scientist Yunos Bakhshi and another amateur astronomer, and several Afghani people who were just interested in seeing the night sky.

“Suddenly we found ourselves surrounded by a group of gunmen,” Aghaei said. “We explained that we are astronomers, but the local police commander approached so to be sure that we are not terrorists and that our telescope had no military application and it is not a rocket launcher. We invited him to watch M4 Star Cluster, but he didn’t like it and said that his own binocular is more powerful. He told us were a group of half-witted and nothing else. One of the police registered our names and listed all our equipment.”

This frightened some of people who had joined the astronomers and many of them left.

“We explained that in most cases national and international forces do not mistake and target civilians, but we couldn’t assure them, and most of them (who for sure were saner than us) escaped and left us three astronomers alone,” Aghaei said.

Just when they finally had a chance to start observing and do some night sky photography, the sky was lit up from bright lights from the Bagram Military Airbase, one of the big bases of US forces in Afghanistan.

“We were sure that the American forces launched some kind of military training and that is why they simulated the daylight condition.” Aghaei said. “After one hour another issue halted our observation, saving our life: two military helicopters on their way to the Bagram military base, with no light crossed the sky over us. At first we were ready to risk our life but not turn off the telescope remote, because once again alignment could take a lot of time, but finally we preferred to stay alive. We heard that in many occasions by mistake pastors were attacked by these iron birds, and this issue forced us not to play Russian roulette.”

Aghaei quickly looked one last time at M27 and then turned off the telescope, lay down on the ground and didn’t move. The trio realized only later that the military could have had night vision cameras and the astronomers could have been spotted. Aghaei also said with this experience, he is going to propose to telescope companies that they invent a special button to switch off the remote control light in situations like this, at least for Afghan astronomers.

But their adventures weren’t over for the night. Next, a pack of dogs approached and began barking loudly. Aghaei said they dispersed the dogs by inventing a new application for green laser pointers.

Ultimately, the group was able to do what they hoped most, to take some astronomical images from their observations. Here is their image of M27:

Saeid Aghaei’s first experience of deep sky photography in Afghanistan, showing M27, the Dumbbell Nebula. Credit: Saeid Aghaei.

Aghaei and Bakhshi reflected on their experiences.

“Finally the night passed and close to dawn we arrived to the main entrance check point to Kabul city. We were thinking about our adventures and want to say that, no matter what kind of telescope or photography equipment you have, even it is not important you have got the first deep sky photo or TWAN-style (The World At Night) photo of this country (we had such experience that night), but it was important that we saved our life. We realized that for any next observation program, the main challenge is security concern and this factor will determine where ever we want to go for next our observation.”

But – no question — they will be going again, and Aghaei says, “Anyone who wants to experience such adventure we highly appreciate and welcome.”

Find out more about the Afghan Astronomy Association at www.kabulsky.com