Posted on by Fraser Cain

Pinpointing Huygens

The area marked in yellow is the region imaged by Huygens as it landed. Image credit: NASA/JPL/SSI. Click to enlarge.
The Cassini spacecraft carried the European Space Agency’s Huygens probe to Saturn and released it in December 2004. The probe landed on Titan Jan. 14, 2005, acquiring a set of images using the descent imager/spectral radiometer camera as it parachuted to the surface.

As Cassini continued to orbit Saturn, its imaging science subsystem and visual and infrared mapping spectrometer mapped the region where the Huygens probe landed. On Friday, Oct. 28, 2005, Cassini’s radar instrument provided the highest resolution orbital data yet of this area.

The two images shown here tell the story. On the left, in color, is a composite of the imaging camera and infrared data (red areas are brighter and blue darker, as seen in infrared). On the right is the synthetic aperture radar image. The Huygens descent images are shown inset on the left image and outlined in yellow on the right. The magenta cross in both images shows the best estimate of the actual Huygens landing site. This is a preliminary result, based on the best information available at the present time.

In the left image, the brighter areas seen by the Huygens camera correspond to the large area depicted in red and yellow. On closer inspection, bright features within the Huygens mosaic seem to correspond to smaller features in the map composed of data from the visual and infrared spectrometer and imaging camera. On the right, the correspondence is less clear. In radar images bright features are usually rougher, so one would not necessarily expect an obvious connection.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, 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 radar instrument team is based at JPL, working with team members from the United States and several European countries. The visual and infrared mapping spectrometer team is based at the University of Arizona. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov.

Original Source: NASA/JPL/SSI News Release

Posted on by Fraser Cain

Massive Star Has a Hot Partner

Eta Carinae. Image credit: Hubble. Click to enlarge.
Scientists using NASA’s Far Ultraviolet Spectroscopic Explorer satellite made the first direct detection of a companion star of Eta Carinae. Eta Carinae is one of the most massive and unusual stars in the Milky Way galaxy. The detection was made possible by the high temperature of the companion star and the unique sensitivity of the satellite at the shortest ultraviolet wavelengths.

Eta Carinae is an unstable star thought to be rapidly approaching the final stage of its life. It is clearly visible from the southern hemisphere and has been the subject of intense studies for decades. This mysterious star is located about 7,500 light-years from Earth in the constellation Carina. Scientists thought a companion star in orbit around Eta Carinae might explain some of its strange properties, but researchers lacked direct evidence a companion star existed.

“Until now, Eta Carinae’s partner has evaded direct detection,” said Dr. Rosina Iping, a research scientist at Catholic University of America in Washington. “This discovery significantly advances our understanding of the enigmatic star.”

Evidence that Eta Carinae might be a double star system was inferred from a repeating pattern of changes in visual, X-ray, radio and infrared light over approximately 5.5 years. Astronomers thought a second star in a 5.5 year orbit around Eta Carinae might cause the repeated changes in its light. The strongest indirect evidence supporting the double star theory is that once every 5.5 years, the X-rays coming from the system disappear for about three months. Eta Carinae is too cool to generate X-rays, but it continuously blasts a flow of gas into space as a stellar wind at about 300 miles per second.

If its companion has a similar wind, their stellar winds would collide with enough force to generate the X-rays. This collision region must lie somewhere between the two stars.

As Eta Carinae moves in its orbit, it passes in front of the region where the winds collide, as viewed from Earth. When this occurs, Eta Carinae eclipses the X-rays once every 5.5 years, causing them to disappear. The last X-ray eclipse began on June 29, 2003. The 5.5 year orbit places the companion star only about 10 times farther from Eta Carinae than Earth is from the sun. Eta Carinae is too far away for telescopes to distinguish two stars in such a close orbit.

Another way to find evidence of a double-star system would be to detect the light of the second star, which in this case is much fainter than Eta Carinae. Several scientists searched for light from Eta Carinae’s companion using ground-based telescopes, but none succeeded. Because the companion is thought to be much hotter than Eta Carinae, astronomers reasoned it should be brighter at shorter wavelengths like ultraviolet light. However, it still escaped detection when it was searched for using the ultraviolet capabilities of the Hubble Space Telescope.

Iping and her collaborators used the satellite to detect the companion, because it can see even shorter ultraviolet wavelengths than Hubble. The team observed the far-ultraviolet light from Eta Carinae with the satellite on June 10, 17 and 27, 2003, right before the expected X-ray eclipse. While the far ultraviolet light from Eta Carinae was seen in the observations from June 10 and 17, it vanished on the 27, two days before the X-ray eclipse.

The disappearance of far ultraviolet light so close to the X-ray eclipse implies when Eta Carinae eclipsed the X-rays, it also eclipsed the companion star. The far-ultraviolet light observed prior to the eclipse was from the hotter companion, because Eta Carinae is too cool to emit much far-ultraviolet light.

“This far ultraviolet light comes directly from Eta Carinae’s companion star, the first direct evidence that it exists,” said Dr. George Sonneborn. He is Far Ultraviolet Spectroscopic Explorer Project Scientist at NASA’s Goddard Space Flight Center, Greenbelt, Md. “The companion star is much hotter than Eta Carinae, settling a long-standing mystery about this important star.”

This discovery will be published today in the Astrophysical Journal Letters. Authors include Iping, Sonneborn and Ted Gull of Goddard; Derck Massa of SGT Inc., Greenbelt, Md.; and John Hiller of the University of Pittsburgh. The project is a NASA Explorer mission developed in cooperation with the French and Canadian space agencies by Johns Hopkins University, Baltimore, University of Colorado, Boulder, and University of California, Berkeley. Goddard manages the program for NASA’s Science Mission Directorate. For images and information about the project on the Web, visit:

Original Source: NASA News Release

Posted on by Fraser Cain

What If We Burn Everything?

This map represents global temperature anomalies averaged from 2008 through 2012. Credit: NASA Goddard Institute for Space Studies/NASA Goddard's Scientific Visualization Studio.

If humans continue to use fossil fuels in a business-as-usual manner for the next few centuries, the polar ice caps will be depleted, ocean sea levels will rise by seven meters and median air temperatures will soar to 14.5 degrees warmer than current day.

These are the stunning results of climate and carbon cycle model simulations conducted by scientists at Lawrence Livermore National Laboratory. By using a coupled climate and carbon cycle model to look at global climate and carbon cycle changes, the scientists found that the earth would warm by 8 degrees Celsius (14.5 degrees Fahrenheit) if humans use the entire planet’s available fossil fuels by the year 2300.

The jump in temperature would have alarming consequences for the polar ice caps and the ocean, said lead author Govindasamy Bala of the Laboratory’s Energy and Environment Directorate.

In the polar regions alone, the temperature would spike more than 20 degrees Celsius, forcing the land in the region to change from ice and tundra to boreal forests.

“The temperature estimate is actually conservative because the model didn’t take into consideration changing land use such as deforestation and build-out of cities into outlying wilderness areas,” Bala said.

Today’s level of atmospheric carbon dioxide is 380 parts per million (ppm). By the year 2300, the model predicts that amount would nearly quadruple to 1,423 ppm.

In the simulations, soil and living biomass are net carbon sinks, which would extract a significant amount of carbon dioxide that otherwise would remain in the atmosphere from the burning of fossil fuels. The real scenario, however, might be a bit different.

“The land ecosystem would not take up as much carbon dioxide as the model assumes,” Bala said. “In fact in the model, it takes up much more carbon than it would in the real world because the model did not have nitrogen/nutrient limitations to uptake. We also didn’t take into account land use changes, such as the clearing of forests.”

The model shows that ocean uptake of CO² begins to decrease in the 22nd and 23rd centuries due to the warming of the ocean surface that drives CO² fluctuations out of the ocean. It takes longer for the ocean to absorb CO² than biomass and soil.

By the year 2300, about 38 percent and 17 percent of the carbon dioxide released from the burning of all fossil fuels are taken up by land and the ocean, respectively. The remaining 45 percent stays in the atmosphere.

Whether carbon dioxide is released in the atmosphere or the ocean, eventually about 80 percent of CO² will end up in the ocean in a form that will make the ocean more acidic. While the carbon dioxide is in the atmosphere, it could produce adverse climate change. When it enters the ocean, the acidification could be harmful to marine life.

The models predict quite a drastic change not only in the temperature of the oceans but also in its acidity content, which would become especially harmful for marine organisms with shells and skeletal material made out of calcium carbonate.

Calcium carbonate organisms, such as coral, serve as climate stabilizers. When the organisms die, their carbonate shells and skeletons settle to the ocean floor, where some dissolve and some are buried in sediments. These deposits help regulate the chemistry of the ocean and the amount of carbon dioxide in the atmosphere. Earlier Livermore research, however, found that unrestrained release of fossil-fuel carbon dioxide to the atmosphere could threaten extinction for these climate-stabilizing marine organisms.

“The doubled-CO² climate that scientists have warned about for decades is beginning to look like a goal we might attain if we work hard to limit CO² emissions, rather than the terrible outcome that might occur if we do nothing,” said Ken Caldeira of the Department of Global Ecology at the Carnegie Institution and one of the other authors.

Bala said the most drastic changes during the 300-year period would be during the 22nd century, when precipitation change, an increase in atmospheric precipitable water and a decrease in sea ice size are the largest and when emissions rates are the highest. According to the model, sea ice cover disappears almost completely in the northern hemisphere by the year 2150 during northern hemisphere summers.

“We took a very holistic view,” Bala said. “What if we burn everything? It will be a wake-up call in climate change.”

As for global warming skeptics, Bala said the proof is already evident.

“Even if people don’t believe in it today, the evidence will be there in 20 years,” he said. “These are long-term problems.”

He pointed to the 2003 European heat wave and the 2005 Atlantic hurricane season as examples of extreme climate change.

“We definitely know we are going to warm over the next 300 years,” he said. “In reality, we may be worse off than we predict.”

Other Livermore authors include Arthur Mirin and Michael Wickett, along with Christine Delire of ISE-M at the Université Montepellier II.

The research appears in the Nov. 1 issue of the American Meteorological Society’s Journal of Climate.

Founded in 1952, Lawrence Livermore National Laboratory has a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by the University of California for the U.S. Department of Energy’s National Nuclear Security Administration.

Original Source: LLNL News Release

Posted on by Fraser Cain

Canyons on Dione

Saturn’s moon Dione taken by Cassini. Image credit: NASA/JPL/SSI. Click to enlarge.
The Cassini spacecraft views the far-off wispy canyons of Saturn’s moon Dione and sees an interesting dichotomy between the bright wisps and the bright south polar region at the bottom.

The view looks toward the trailing hemisphere on Dione. North is up. Dione’s diameter is 1,126 kilometers (700 miles).

The image was taken with the Cassini spacecraft’s narrow-angle camera on Sept. 20, 2005, through a filter combination sensitive to polarized green light. The image was acquired at a distance of approximately 2.1 million kilometers (1.3 million miles) from Dione and at a Sun-Dione-spacecraft, or phase, angle of 64 degrees. Resolution in the original image was 12 kilometers (8 miles) per pixel. The image has been magnified by a factor of two to aid visibility.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, 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 and its two onboard cameras were designed, developed and assembled at JPL. The imaging operations center is based at the Space Science Institute in Boulder, Colo.

For more information about the Cassini-Huygens mission visit http://saturn.jpl.nasa.gov . The Cassini imaging team homepage is at http://ciclops.org .

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Two New Moons for Pluto?

Pluto and its possible new moons. Image credit: Hubble. Click to enlarge.
Using NASA’s Hubble Space Telescope to probe the ninth planet in our solar system, astronomers discovered that Pluto may have not one, but three moons.

If confirmed, the discovery of the two new moons could offer insights into the nature and evolution of the Pluto system, Kuiper Belt Objects with satellite systems, and the early Kuiper Belt. The Kuiper Belt is a vast region of icy, rocky bodies beyond Neptune’s orbit.

“If, as our new Hubble images indicate, Pluto has not one, but two or three moons, it will become the first body in the Kuiper Belt known to have more than one satellite,” said Hal Weaver of the Johns Hopkins Applied Physics Laboratory, Laurel, Md. He is co-leader of the team that made the discovery.

Pluto was discovered in 1930. Charon, Pluto’s only confirmed moon, was discovered by ground-based observers in 1978. The planet resides 3 billion miles from the sun in the heart of the Kuiper Belt.

“Our result suggests that other bodies in the Kuiper Belt may have more than one moon. It also means that planetary scientists will have to take these new moons into account when modeling the formation of the Pluto system,” said Alan Stern of the Southwest Research Institute in Boulder, Colo. Stern is co-leader of the research team.

The candidate moons, provisionally designated S/2005 P1 and S/2005 P2, were observed to be approximately 27,000 miles (44,000 kilometers) away from Pluto. The objects are roughly two to three times as far from Pluto as Charon.

The team plans to make follow-up Hubble observations in February to confirm that the newly discovered objects are truly Pluto’s moons. Only after confirmation will the International Astronomical Union consider names for S/2005 P1 and S/2005 P2.

The Hubble telescope’s Advanced Camera for Surveys observed the two new candidate moons on May 15, 2005. “The new satellite candidates are roughly 5,000 times fainter than Pluto, but they really stood out in these Hubble images,” said Max Mutchler of the Space Telescope Science Institute and the first team member to identify the satellites. Three days later, Hubble looked at Pluto again. The two objects were still there and appeared to be moving in orbit around Pluto.

“A re-examination of Hubble images taken on June 14, 2002 has essentially confirmed the presence of both P1 and P2 near the predicted locations based on the 2005 Hubble observations,” said Marc Buie of Lowell Observatory, Flagstaff, Ariz., another member of the research team.

The team looked long and hard for other potential moons around Pluto. “These Hubble images represent the most sensitive search yet for objects around Pluto,” said team member Andrew Steffl of the Southwest Research Institute, “and it is unlikely that there are any other moons larger than about 10 miles across in the Pluto system.”

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. The Space Telescope Science Institute in Baltimore conducts Hubble science operations. The Institute is operated for NASA by the Association of Universities for Research in Astronomy, Inc., Washington, under contract with Goddard.

The other team members for this observation are: William J. Merline, John R. Spencer, Eliot Y. Young, and Leslie A. Young, Southwest Research Institute.

Original Source: Hubble News Release

Update: Why isn’t Pluto a planet?

Posted on by Mark Mortimer

Book Review: Strange Angel

Jack Parsons, born John Whiteside Parsons, grew up in Pasadena, California. Though his family had substantial assets, the depression hit them hard. His life went from being a sole child in a rich family to being just one more member of a shrinking family with quickly disappearing money. An early fascination with space travel from the likes of Jules Verne gave Parsons a great desire to journey off the planet. In pursuing this quest, Parsons took what was then known of black powder and experimented. He varied constituent ingredients, relative compositions and manufacturing techniques. Yet, seldom did he get far from a glorified firecracker. Nevertheless, through trial and error, he was able to manufacture rockets that convinced the military of their usefulness in assisting take-offs (the JATO’s). Not long after, his group launched the first aeroplane flight powered solely by rockets.

With Parsons leading in such a captivating field, a biography would seem likely to focus primarily on accomplishments. Yet Pendle’s work delivers a much broader perspective. Apparently, as much as Parsons wanted to physically fly into the heavens on a rocket machine, he also wanted to journey mentally into other realms. Pendle provides all the details of how Parsons took over the local chapter of religious group, the Thelemas. Free love was in vogue as was much alcohol and the occasional ritual midnight mass. With their leader’s directive being, ‘Do what thou wilt’, there seemed little to inhibit participants’ actions.

These are the two main venues that appear in this book. Rockets and religion. Pendle steps through Parsons’ life from one main event to another. He describes each step in great detail. Housing architecture, real estate deals, and city officials on the take are all background for Parsons’ first appearance in court as an expert witness. Or there’s the Arroyo Seco range with its dry, still air occasionally broken by the blast from experimental rocket engines, swept clean by a deluge of rain, or enjoyed by youths of the area. By giving such a complete view of events and surroundings, Pendle places the reader directly into the times and moments of Parson’s life.

In keeping with this broad view, Pendle expands upon these background notes. There’s a rendition of the life of the Church of Thelema’s leader, Aleister Crowley. Time and again we get portrayals of the residents and architecture of Orange Grove, the street in Pasadena where Parsons spent much of his life. Pendle also shows a good view of some members of Caltech. Tie-ins with local and national science fiction authors abound. Many came to see Parsons or vice versa. There’s even a perception that L. Ron Hubbard’s definitions of Scientology originally came from Hubbard’s association with Parsons.

Perhaps what does get challenging is that these side issues take up so much of the book. There’s California’s culture, Caltech’s inception and growth, the military’s disfavour with rockets and lists of Crowley’s writings. All of these are interesting, some even fascinating, but it’s not always easy to associate with the biography. Further, though there might have been a tight science fiction community at the time, the description of magazine editors and their many stories and editorials makes one think that Pendle had more information than he knew where to insert. As my interest is in the rocketry aspect, I would have preferred more on this topic and less on the other people marginally involved with Parsons.

As well, the missing element in this writing is the lack of conjecture about Parsons himself. There are allusions to a final suicide, or was it an industrial accident? What was it like always being an outsider of Caltech or Aerojet? Why did magick hold such a spell over Parson? With no formal university training, but an encyclopaedic knowledge of chemistry and explosives, why couldn’t or wouldn’t Parsons integrate into research and development groups? These questions arose in my mind, but I kept having more questions and few answers.

Jack Parsons devoted most of his working life to proving and bettering rocket propulsion. His personal life was equally devoted, but to magick and philosophy. George Pendle in his biography Strange Angel colourfully portrays Parsons’ life and the exciting and mystical events that surrounded him. Some people were just never meant to be normal, and the rocket industry can thank Parsons for being one of those people.

Review by Mark Mortimer

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

Posted on by Fraser Cain

What’s Up This Week – October 31 – November 6, 2005

The Pleiades. Image credit: David Malin
Monday, October 31 – Happy Halloween! Tonight’s astronomical adventure will be about exploring an ancient and well renowned star cluster associated with this holiday that we’ve kept track of all week — the Pleiades! Easily found from a modestly dark site with the unaided eye, the Pleiades can be spotted well above the north-eastern horizon within a couple of hours of nightfall. To average skies, many of the 7 bright components will resolve easily without the use of optical aid, but to telescopes and binoculars? The M45 is stunning…

First let’s explore a bit of history. The recognition of the Pleiades dates back to antiquity and it’s known by many names in many cultures. The Greeks and Romans referred to them as the “Starry Seven”, the “Net of Stars”, “The Seven Virgins”, “The Daughters of Pleione” and even “The Children of Atlas”. The Egytians referred to them as “The Stars of Athyr”, the Germans as “Siebengestiren” (the Seven Stars), the Russians as “Baba” after Baba Yaga, the witch who flew through the skies on her fiery broom. The Japanese call them “Suburu”, Norsemen saw them as packs of dogs and the Tonganese as “Matarii” (the Little Eyes). American Indians viewed the Pleiades as seven maidens placed high upon a tower to protect them from the claws of giant bears, and even Tolkien immortalized the stargroup in the “Hobbit” as “Remmirath”. The Pleiades have even been mentioned in the Bible! So, you see, no matter where we look in our “starry” history, this cluster of seven bright stars has been part of it.

But let’s have some Halloween fun!

The date of the Pleiades culmination (its highest point in the sky) has been celebrated through its rich history by being marked with various festivals and ancient rites — but there is one particular rite that really fits this occasion! What could be more spooky on this date than to imagination a bunch of Druids celebrating the Pleiades midnight “high” with Black Sabbath? This night of “unholy revelry” is still observed in the modern world as “All Hallow’s Eve” or more commonly as “Halloween”. Although the actual date of the Pleiades midnight culmination is now on November 21 instead of October 31, why break with tradition? Thanks to its nebulous regions the M45 looks wonderfully like a “ghost” haunting the starry skies.

Treat yourself and your loved ones to the “scariest” object in the night. Binoculars give an incredible view of the entire region, revealing far more stars than are visible with the naked eye. Small telescopes at lowest power will enjoy the M45’s rich, icy-blue stars and fog-like nebulae. Larger telescopes and higher power reveal many pairs of double stars buried within its silver folds. No matter what you chose, the Pleiades definitely rocks!

Tuesday, November 1 – On this day in 1977, Charles Kowa made a wild discovery – Charon. This represented the first of a multitude of tiny, icy bodies that lay in the outer reach of our solar system.

While we have your icy body outside on the night of New Moon and “All Souls Day”, let’s try looking for one – asteroid Psyche – the personification of the soul.

While Psyche will not be easy, if you’ve found the Pleiades you are not far. Located around 2 degrees southwest of Zeta Taurii, you’ll find this tiny asteroid moving slowly past star 115 to the south. Don’t let her steal you away….

Wednesday, November 2 – Today celebrates the birth of an astronomy legend – Harlow Shapely. Born in 1885, the American-born Shapley paved the way in determining distances to stars, clusters, and the center of our Milky Way galaxy. Among his many achievements, Shapely was also the Harvard College Observatory director for many years. Today in 1917 also represents the night first light was seen through the Mt. Wilson 100″ telescope.

Although we don’t have that much aperture to study with tonight, we can still get a very satisfactory look at M15 through any size binoculars or telescopes. You can find it easily just about two fingerwidths northwest of red Epsilon Pegasi (Enif). Shining brightly at magnitude 6.4, low power users will find it a delightfully tight ball of stars, but scope users will find it quite unique. As resolution begins, sharp-eyed observers will note the presence of a presence of planetary nebula – Pease 1. This famous X-ray source you have just seen with your eyes may have supernovae remnants buried deep inside…

Thursday, November 3 – On this day in 1955, one of the few documented case of a person being hit by a meteorite occurred. What are the odds on that? Better than average tonight…

1957 the Russian Space Program launched its first “live” astronaut into space – Laika. Carried on board Sputnik 2, our canine hero was the first living creature to reach orbit. The quickly developed Sputnik 2 was designed with sensors to transmit ambient pressure, breathing patterns and heartbeat of its passenger along with a television camera monitor. The craft also monitored ultraviolet and x-ray radiation as well to further study the impact of space flight upon human occupants. Unfortunately, the technology of the time offered no way to return Laika to Earth, so she perished in space. On April 14, 1958, Laika and Sputnik 2 returned to Earth in a fiery re-entry ending after 2,570 orbits.

Laika may be gone, but the cosmos let her a glowing “bone” in space. Tonight turn your telescopes just a breath above Phi Perseii to view planetary nebula – M76. It may be hell in the heavens, because its central star is one of the hottest known. We’ll be back to “dig up” more on this one later.

Friday, November 4 – This morning will be the peak of the Southern Taurid meteor shower. Already making headlines around the world for producing fireballs, the Taurids will be best visible in the early morning hours as soon as the Moon is far west.. The radiant for this shower is, of course, the constellation of Taurus and red giant Aldeberan, but did you know the Taurids are divided into two streams?

It is surmised that the original parent comet shattered as it passed our Sun around 20,000 to 30,000 years ago. The larger “chunk” continued orbiting and is known as periodic comet Encke. The remaining debris field turned into smaller asteroids, meteors and larger fragments that often pass through our atmosphere creating astounding “fireballs” known as bolides. Although the fall rate for this particular shower is rather low at 7 per hour, these slow traveling meteors (27km or 17 miles per second) are usually very bright and appear to almost “trundle” across the sky. With the chances high all week of seeing a bolide, this makes a bit of quiet contemplation under the stars a “frighteningly” good time.

Saturday, November 5 – What dark and creepy night would be complete without the sad tale of Andromeda and Perseus? Tonight let’s have a look at Beta Perseii – the most famous of all eclipsing variable stars. Now, identify Algol and we’ll learn about the “Demon Star”.

Ancient history has given this star many names. Associated with the mythological figure, Perseus, Beta was considered to be the head of Medusa the Gorgon, and was known to the Hebrews as Rosh ha Satan or “Satan’s Head”. 17th century maps labeled Beta as Caput Larvae, or the “Spectre’s Head”, but it is from the Arabic culture that the star was formally named. They knew it as Al Ra’s al Ghul, or the “Demon’s Head”, and we know it as Algol. Because these medieval astronomers and astrologers associated Algol with danger and misfortune, we are led to believe that Beta’s strange visual variable properties were noted throughout history.

Italian astronomer Geminiano Montanari was the first to note that Algol occasionally “faded” and its methodical timing was cataloged by John Goodricke in 1782, who surmised that it was being partially eclipsed by a dark companion orbiting it. Thus was born the theory of the “eclipsing binary” and it was proved spectroscopically in 1889 by H.C. Vogel. At 93 light years away, Algol is the nearest eclipsing binary of its kind and is treasured by the amateur astronomer for it requires no special equipment to easily follow its stages. Normally Beta Persii holds a magnitude of 2.1, but approximately every three days it dims to magnitude 3.4 and gradually brightens again. The entire eclipse only lasts about 10 hours!

Although Algol is known to have two additional spectroscopic companions, the true beauty of watching this variable star is not telescopic – but visual. The constellation of Perseus is well placed this month for most observers and appears like a glittering chain of stars that lay between Cassiopeia and Andromeda. To help further assist you, locate Gamma Andromedae (Almach) east of Algol. Almach’s visual brightness is about the same as Algol’s at maxima.

Sunday, November 6 – On this night in 1572, the incomparable Tycho Brahe set to record a bright new star. Today we realize he was looking at a supernova! “Visible” now as a supernova event only at very long wavelengths in the constellation of Cassiopeia, if you are good with your finderscope under such bright conditions, you can still view it as a 7th magnitude star. Using Gamma, Alpha and Beta as your visual starting point, use binoculars to locate Kappa just north of this trio. Small Kappa will also be part of a configuration of stars which will look much like our starting point, only much dimmer. From Kappa, you will see a line of stars heading northwest. The very first in this series of 7th magnitude stars is SN1572.

Tomorrow Mars reaches opposition, but why wait to take on the “God of War”? The planet’s bloody red color, swift movement and changing brightness made the ancients fear it. For them, these times of changes in the sky spelled disaster for mortal man, but you’ll find this natural phenomena rather enlightening! Even if you do not use a telescope, look at how close it is to the Pleiades. Double disaster? Or double the pleasure.

Until next week? May all your journeys be at light speed… ~Tammy Plotner

Posted on by Fraser Cain

Power Problem with SSETI Express

SSETI Express in construction. Image credit: ESA. Click to enlarge.
Since Friday morning, the ground control station in Aalborg has not had any contact with SSETI Express. Thorough analysis over the weekend indicates that a failure in the electrical power system on board the spacecraft is preventing the batteries from charging, resulting in a shutdown of the satellite. There is a small but significant possibility of recovery, the likelihood of which is being ascertained by ongoing testing.

“Naturally, the SSETI teams are disappointed that we lost contact, but the mission has still been a success from both an educational and a technical standpoint”, says Project Manager Neil Melville. “The main goal of the mission was to educate students by having them involved hands-on in all the different aspects of a space mission, and now we really have experienced everything”.

On top of the educational purpose, several of the operational goals were met in the time the satellite operated. All evidence suggests that the three CubeSat passengers were successfully deployed into orbit by SSETI Express, and were hence able to begin their own independent missions.

The CubeSats Xi-V and UWE-1 are alive and well, the status of NCube-2 has yet to be confirmed. Stable two-way communications between the groundstation and SSETI Express was established and both the Aalborg University as well as many radio amateurs all over the world downloaded a significant amount of housekeeping data.

Currently, the student teams continue to investigate the situation and assess the chances of recovery. “Even if we don’t recover contact with SSETI Express, it was still a very worthwhile mission for everyone. We will take many lessons learned on to our next educational satellite project, SSETI ESEO”, says Roger Elaerts, ESA’s Head of Education Department.

Original Source: ESA News Release

Posted on by Fraser Cain

Anything That Can Go Wrong, Will… on Mars

Mars. Image credit: NASA/JPL.
The spacecraft door has just clanged shut behind you, locking you and your fellow astronauts into the small cabin that will be your home for the next half-year’s journey through interplanetary space–at the end of which you personally will be the first human to set foot on Mars.

As the countdown echoes in your ears and as you feel the boosters rumbling beneath you, you wonder … Are we ready?

According to Murphy’s Law, whatever can go wrong, will go wrong, and presumably this applies on Mars as well as Earth. So if things go wrong on Mars, are we ready for them? What do we need to know about Mars before we send people there?

That question is what NASA’s Mars Exploration Program Analysis Group (MEPAG for short) addressed in its report dated June 2, 2005, which bears the long mouthful of a title An Analysis of the Precursor Measurements of Mars Needed to Reduce the Risk of the First Human Mission to Mars.

The heart of MEPAG’s June report is a full-page table on p. 11 that lists 20 risks, “any one of which could take out a mission,” says David Beaty, Mars Program Science Manager at the Jet Propulsion Laboratory, and the report’s lead author.

Top among those risks:
* Martian dust–its corrosiveness, its grittiness, its effect on electrical systems such as computer boards;
* possible Martian “replicating biohazards”–organisms dangerous either to the astronauts or for return to Earth;
* the dynamics of the Martian atmosphere, including dust storms, that might affect landing and takeoff;
* potential sources of water, especially crucial if the first astronauts were to stay on the surface longer than a month.

The group asked itself, “What would we need to learn by sending robotic missions to Mars to reduce each risk? And how much would that information lower the risk [e.g., if engineers could design the spacecraft differently to protect astronauts]?”

Loud and clear from the MEPAG report is that “Martian dust is a #1 risk,” says Jim Garvin, NASA chief scientist at the Goddard Space Flight Center. “We need to understand the dust in designing power systems, space suits and filtration systems. We need to mitigate it, keep it out, figure out how to live with it.”

According to MEPAG, a mission to gather and return samples of Martian soil and dust to Earth is crucial.

“Most scientists believe it’s not possible to evaluate biohazards without a sample return,” notes Beaty. In addition, a sample return could resolve controversies about just how gritty or how chemically toxic the Martian soil may be. Even though lunar dust proved to be a major problem for the Apollo astronauts, “lunar dust does not equal Martian dust,” Garvin cautions. Scientists and engineers simply need to get their hands on real Martian dirt. The significance of a sample even as small as 1 kilogram “should not be underestimated” for both its scientific and engineering value, Beaty adds.

The MEPAG report also gave high rank to measurements involving the release of probes with parachutes and balloons into the Martian atmosphere. “We could observe Martian wind speeds at different altitudes, which is vital both for targeting accuracy when a mission lands, and for reaching the right orbit when the mission departs,” Beaty says.

And then there’s water: MEPAG assigns high priority to robotic expeditions that could definitively find water, either as water ice or as deposits of hydrous minerals. Two versions of a first human expedition are being debated: a short stay of about a month, and a long stay of about a year and a half. While a short-stay mission might be able to carry all the water it needed with it–relying on closed-loop life-support systems to recycle waste-water–a long-stay mission would need to excavate fresh water and manufacture breathable oxygen from ice-filled Martian soils.

These are but a few of MEPAG’s recommendations. The full report may be read here.

MEPAG itself is something new.

“NASA is reinventing how it formally acquires advice,” explains Garvin. Until the last few years, NASA has relied either on commissioning formal recommendations from the National Academy of Sciences, or on constituting ad hoc working groups. But both “would go quiet” after completing a single report, so there was no mechanism for evaluating how such high-level recommendations translated into concrete specifications for engineering hardware, scientific experiments, and actual measurements.

In contrast, MEPAG is a permanent body of scientists and engineers, working rather like the former U.S. Congressional Office of Technology Assessment. Its sole purpose is to figure out how big-picture goals translate into specific design options for exploration.

“It’s worked so well that we’re seeking to use the MEPAG model to form similar groups devoted to analyzing mission approaches to the Moon, Venus, and the outer planets,” Garvin says.

Are we ready? Ask MEPAG.

Original Source: Science@NASA Story

Posted on by Fraser Cain

Spitzer Presents Black Widow Nebula for Halloween

Black widow nebula. Image credit: NASA/Spitzer. Click to enlarge.
Unsuspecting prey be warned! Hiding in the darkest corner of the constellation Circinus is a gigantic black widow spider waiting for its next meal. For decades, this galactic creepy crawler has remained largely invisible, cunningly escaping visible-light detection. At last, it has finally been caught by NASA’s Spitzer Space Telescope’s dust-piercing, infrared eyes.

The spider is actually a star-forming cloud of gas and dust. In this Halloween interactive image comparison, an hourglass-shaped insignia, typically found on the underbelly of a black widow spider, can be seen faintly in the visible-light image from Digital Sky Survey (DSS). As Spitzer’s infrared image fades in, the veil of galactic dust shrouding the rest of the spider is lifted to reveal a poisonous widow.

In the Spitzer image, the two opposing bubbles that make up the black widow’s body are being formed in opposite directions by the powerful outflows from massive groups of forming stars. The baby stars can be seen inside the widow’s “stomach” where the two bubbles meet.

When individual stars form from molecular clouds of gas and dust they produce intense radiation and very strong particle winds. Both the radiation and the stellar winds blow the dust outward from the star creating a cavity or, bubble.

In the case of the Black Widow Nebula, astronomers suspect that a large cloud of gas and dust condensed to create multiple clusters of massive star formation. The combined winds from these large stars probably blew out bubbles into the direction of least resistance, forming a double-bubble.

Original Source: Spitzer News Release