Posted on by Fraser Cain

Giotto Met Halley 20 Years Ago

An artist’s impression of Giotto’s brief encounter with comet Halley. Image credit: ESA Click to enlarge
This week the European Space Agency celebrated the 20-year anniversary of the Giotto spacecraft’s encounter with Comet Halley. This was ESA’s first deep space mission, which launched on board an Ariane 1 rocket. Giotto flew for 8 months, traveling almost 150 million kilometres. It swept past the comet on March 13, 1986, getting as close as 596 km (370 miles), and delivered the best pictures ever seen of a comet’s nucleus.

Twenty years ago, in the night between 13 and 14 March 1986, ESA’s Giotto spacecraft encountered Comet Halley. It was ESA’s first deep space mission, and part of an ambitious international effort to solve the riddles surrounding this mysterious object.

The adventure began when Giotto was launched by an Ariane 1 rocket (flight V14) on 2 July 1985. After three revolutions around the Earth, the on-board motor was fired to inject it into an interplanetary orbit.

After a cruise of eight months and almost 150 million kilometres, the spacecraft’s instruments first detected hydrogen ions from Halley at a distance of 7.8 million kilometres from the comet on 12 March 1986.

Giotto encountered Comet Halley about one day later, when it crossed the bow shock of the solar wind (the region where a shock wave is created as the supersonic solar particles slow to subsonic speed). When Giotto entered the densest part of the dusty coma, the camera began tracking the brightest object (the nucleus) in its field of view.

Excitement rose at the European Space Operations Centre in Darmstadt, Germany, as the first fuzzy images and data came in. The ten experiment teams scrutinised the latest information and struggled to come up with a preliminary analysis.

The first of 12 000 dust impacts was recorded 122 minutes before closest approach. Images were transmitted as Giotto closed in to within a distance of approximately 2000 kilometres, as the rate of dust impacts rose sharply and the spacecraft passed through a jet of material that streamed away from the nucleus.

The spacecraft was travelling at a speed of 68 kilometres per second relative to the comet. At 7.6 seconds before closest approach, the spacecraft was sent spinning by an impact from a ‘large’ (one gram) particle. Monitor screens went blank as contact with Earth was temporarily lost.

TV audiences and anxious Giotto team members feared the worst but, to everyone’s amazement, occasional bursts of information began to come through. Giotto was still alive.

Over the next 32 minutes, the sturdy spacecraft’s thrusters stabilised its motion and contact was fully restored. By then, Giotto had passed within 596 kilometres of the nucleus and was heading back into interplanetary space.

The remarkably resilient little spacecraft continued to return scientific data for another 24 hours on the outward journey. The last dust impact was detected 49 minutes after closest approach. The historic encounter ended 15 March when Giotto’s experiments were turned off.

Original Source: ESA Portal

Posted on by Fraser Cain

Satellites Can Track Epidemics

Dust storms are being mapped for the ESA-led Epidemio project. Image credit: ESA Click to enlarge
All those eyes in the sky are coming in handy for purposes scientists never imagined. Now researchers from ESA are using Envisat data to track places on Earth where disease epidemics could get started. The team was able to link the outbreak of diseases in Africa with dryness and drought. So far they’ve been able to track regions which are dry, which contribute to the spread of meningitis. Aid workers can then target these regions to give vaccinations and provide early warnings.

The amount of data acquired by satellites is increasing at an exponential rate, and researchers are learning about the value of this data in fighting epidemic outbreaks as a result of the ESA’s Epidemio project.

“I was negative about the role satellites could play in addressing epidemics, but now I am positive,” Penelope Vernatsou of the Swiss Tropical Institute in Switzerland said.

The ESA-funded Epidemio project was developed in January 2004 to illustrate the benefits of remote-sensing data for studying, monitoring and predicting epidemic outbreaks.

By using data which focuses on a region’s landscape ? rainfall, vegetation, water bodies, elevation, dust mapping and temperature ? researchers are able to pinpoint climatic conditions which are favourable for harbouring various epidemic hosts, indicating where people are at greatest risk.

As the project draws to completion, epidemiologists and data users gathered in Frascati, Italy, at the ‘Earth Observation in Epidemiology Workshop’, on 8-10 March 2006, to report on how Earth observation (EO) has benefited the field of epidemiology.

Ghislain Moussavou of the Gabon-based International Centre for Medical Research (CIRMF) began studying Ebola haemorrhagic fever, which can cause runaway internal and external bleeding in humans and apes, in Congo and Gabon in the hope of spotting particular environmental characteristics associated with infected sites.

Combining ESA Envisat satellite data, under the Epidemio project, on water bodies, forest cover and digital elevation models (DEMs) with field results, Moussavou and his team were able to link the epidemic with dryness and drought.

Moussavou said determining these factors will allow officials to tell the villagers in the area that current conditions for transmission are high, and that they need to take extra precautions. “Because there are no medicines to prevent or cure Ebola, predictions and prevention are necessary.”

Dry conditions are also favourable for the spread of meningitis, an inflammation of the brain and spinal cord lining. Epidemics nearly always start in the early part of the dry season when it is hot and dusty. For this reason, ESA has been providing dust maps for high-risk areas to aid in implementing early warning systems.

Christelle Barbey of Silogic, in France, is currently involved in an Epidemio project to provide wind blown dust maps for Africa. Although her final results are still coming in, she was able to detect 100 percent of known dust events, using MeteoSat data, and determine that dust maps do correspond to a user need to contribute to meningitis prevention.

The Epidemio project – funded by the Data User Element of the ESA Earth Observation Envelope Programme – concludes its two-year mission in April 2006, but the groundwork it has laid will aid users in the continuance of their research and allow new projects to be undertaken.

Giuseppe Ottavianelli and Aude de Clercq of the HISTAR Solutions in the Netherlands are currently working on a project, backed by ESA business incubator financing, to confirm the onset of malaria epidemics in Africa, as predicted by remote sensing data.

They have designed a prototype of a sensor located in a box that detects mosquitoes as they fly overhead. The data collected by the sensor is then processed by a program inside the box, which will be placed in hat hutches in high-risk African villages, and indicates the species and numbers of the mosquitoes detected.

Malaria is transferred by the female mosquito of the species Anopheles, so if the sensor detects her presence in high numbers, public officials will be alerted so that preventive measures can be put into place.

Original Source: ESA Portal

Posted on by Fraser Cain

Mars Orbiter Survives Its Journey to the Red Planet

Artist’s concept of MRO in orbit at Mars. Image credit: NASA/JPL Click to enlarge
Data transmitted back to Earth by NASA’s Mars Reconnaissance Orbiter indicates that the spacecraft successfully inserted itself into orbit around the Red Planet. It fired its main thrusters long enough to slow down its speed so Mars could capture it a wide orbit. The spacecraft will spend the next half-year aerobraking to lower down into a nearly circular orbit. Its instruments will be capable of resolving the Martian surface better than any spacecraft currently orbiting Mars.

With a crucially timed firing of its main engines today, NASA’s new mission to Mars successfully put itself into orbit around the red planet.

The spacecraft, Mars Reconnaissance Orbiter, will provide more science data than all previous Mars missions combined.

Signals received from the spacecraft at 2:16 p.m. Pacific Time after it emerged from its first pass behind Mars set off cheers and applause in control rooms at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., and at Lockheed Martin Space Systems, Denver.

“This is a great milestone to have accomplished, but it’s just one of many milestones before we can open the champagne,” said Colleen Hartman, deputy associate administrator for NASA’s Science Mission Directorate. “Once we are in the prime science orbit, the spacecraft will perform observations of the atmosphere, surface, and subsurface of Mars in unprecedented detail.”

The spacecraft traveled about 500 million kilometers (310 million miles) to reach Mars after its launch from Florida on Aug. 12, 2005. It needed to use its main thrusters as it neared the planet in order to slow itself enough for Mars’ gravity to capture it. The thruster firing began while the spacecraft was still in radio contact with Earth, but needed to end during a tense half hour of radio silence while the spacecraft flew behind Mars.

“Our spacecraft has finally become an orbiter,” said JPL’s Jim Graf, project manager for the mission. “The celebration feels great, but it will be very brief because before we start our main science phase, we still have six months of challenging work to adjust the orbit to the right size and shape.”

For the next half-year, the mission will use hundreds of carefully calculated dips into Mars’ atmosphere in a process called “aerobraking.” This will shrink its orbit from the elongated ellipse it is now flying, to a nearly circular two-hour orbit. For the mission’s principal science phase, scheduled to begin in November, the desired orbit is a nearly circular loop ranging from 320 kilometers (199 miles) to 255 kilometers (158 miles) in altitude, lower than any previous Mars orbiter. To go directly into such an orbit instead of using aerobraking, the mission would have needed to carry about 70 percent more fuel when it launched.

The instruments on Mars Reconnaissance Orbiter will examine the planet from this low-altitude orbit. A spectrometer will map water-related minerals in patches as small as a baseball infield. A radar instrument will probe for underground layers of rock and water. One telescopic camera will resolve features as small as a card table. Another will put the highest-resolution images into broader context. A color camera will monitor the entire planet daily for changes in weather. A radiometer will check each layer of the atmosphere for variations in temperature, water vapor and dust.

“The missions currently at Mars have each advanced what we know about the presence and history of water on Mars, and one of the main goals for Mars Reconnaissance Orbiter is to decipher when water was on the surface and where it is now,” said JPL’s Dr. Richard Zurek, project scientist for the mission. “Water is essential for life, so that will help focus future studies of whether Mars has ever supported life.”

The orbiter can radio data to Earth at up to 10 times the rate of any previous Mars mission. Besides sending home the pictures and other information from its own investigations, it will relay data from surface missions, including NASA’s Phoenix Mars Scout scheduled for launch in 2007 and Mars Science Laboratory in development for 2009.

Additional information about Mars Reconnaissance Orbiter is available online at:

http://www.nasa.gov/mro

The mission is managed by JPL, a division of the California Institute of Technology, Pasadena, for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft.

Original Source: NASA News Release

Posted on by Fraser Cain

Next Solar Max Will Be a Big One

Illustration of the “conveyor belt” on the Sun. Image credit: NASA. Click to enlarge.
We’ve now reached the Sun’s solar minimum; there’s not a sunspot anywhere across the surface of our closest star. Give it a few years, though, and it should be anything but quiet. Solar researchers think they understand the long term cycles of solar activity, and they’re predicting that the next Solar Maximum – expected to arrive between 2010 and 2012 – will be the strongest in 50 years.

It’s official: Solar minimum has arrived. Sunspots have all but vanished. Solar flares are nonexistent. The sun is utterly quiet.

Like the quiet before a storm.

This week researchers announced that a storm is coming–the most intense solar maximum in fifty years. The prediction comes from a team led by Mausumi Dikpati of the National Center for Atmospheric Research (NCAR). “The next sunspot cycle will be 30% to 50% stronger than the previous one,” she says. If correct, the years ahead could produce a burst of solar activity second only to the historic Solar Max of 1958.

That was a solar maximum. The Space Age was just beginning: Sputnik was launched in Oct. 1957 and Explorer 1 (the first US satellite) in Jan. 1958. In 1958 you couldn’t tell that a solar storm was underway by looking at the bars on your cell phone; cell phones didn’t exist. Even so, people knew something big was happening when Northern Lights were sighted three times in Mexico. A similar maximum now would be noticed by its effect on cell phones, GPS, weather satellites and many other modern technologies.

Dikpati’s prediction is unprecedented. In nearly-two centuries since the 11-year sunspot cycle was discovered, scientists have struggled to predict the size of future maxima—and failed. Solar maxima can be intense, as in 1958, or barely detectable, as in 1805, obeying no obvious pattern.

The key to the mystery, Dikpati realized years ago, is a conveyor belt on the sun.

We have something similar here on Earth—the Great Ocean Conveyor Belt, popularized in the sci-fi movie The Day After Tomorrow. It is a network of currents that carry water and heat from ocean to ocean–see the diagram below. In the movie, the Conveyor Belt stopped and threw the world’s weather into chaos.

The sun’s conveyor belt is a current, not of water, but of electrically-conducting gas. It flows in a loop from the sun’s equator to the poles and back again. Just as the Great Ocean Conveyor Belt controls weather on Earth, this solar conveyor belt controls weather on the sun. Specifically, it controls the sunspot cycle.

Solar physicist David Hathaway of the National Space Science & Technology Center (NSSTC) explains: “First, remember what sunspots are–tangled knots of magnetism generated by the sun’s inner dynamo. A typical sunspot exists for just a few weeks. Then it decays, leaving behind a ‘corpse’ of weak magnetic fields.”

Enter the conveyor belt.

“The top of the conveyor belt skims the surface of the sun, sweeping up the magnetic fields of old, dead sunspots. The ‘corpses’ are dragged down at the poles to a depth of 200,000 km where the sun’s magnetic dynamo can amplify them. Once the corpses (magnetic knots) are reincarnated (amplified), they become buoyant and float back to the surface.” Presto—new sunspots!

All this happens with massive slowness. “It takes about 40 years for the belt to complete one loop,” says Hathaway. The speed varies “anywhere from a 50-year pace (slow) to a 30-year pace (fast).”

When the belt is turning “fast,” it means that lots of magnetic fields are being swept up, and that a future sunspot cycle is going to be intense. This is a basis for forecasting: “The belt was turning fast in 1986-1996,” says Hathaway. “Old magnetic fields swept up then should re-appear as big sunspots in 2010-2011.”

Like most experts in the field, Hathaway has confidence in the conveyor belt model and agrees with Dikpati that the next solar maximum should be a doozy. But he disagrees with one point. Dikpati’s forecast puts Solar Max at 2012. Hathaway believes it will arrive sooner, in 2010 or 2011.

“History shows that big sunspot cycles ‘ramp up’ faster than small ones,” he says. “I expect to see the first sunspots of the next cycle appear in late 2006 or 2007—and Solar Max to be underway by 2010 or 2011.”

Who’s right? Time will tell. Either way, a storm is coming.

Original Source: Science@NASA

Posted on by Fraser Cain

Fly Through of a Martian Canyon

Flight through Mariner Valley. Image credit: NASA/JPL. Click to enlarge.
NASA researchers have created a virtual fly through of Valles Marineris on Mars. This video was created by stitching together images taken by the Thermal Emission Imaging System multi-band camera on NASA’s Mars Odyssey spacecraft. The images showed details as small as 300 meters (1,000 feet) across, and were taken during in infrared during the Martian daytime. The final images were coloured on computer to approximate how the landscape would look to the human eye.

A new view of the biggest canyon in the solar system, merging hundreds of photos from NASA’s Mars Odyssey orbiter, offers scientists and the public an online resource for exploring the entire canyon in detail.

This canyon system on Mars, named Valles Marineris, stretches as far as the distance from California to New York. Steep walls nearly as high as Mount Everest give way to numerous side canyons, possibly carved by water. In places, walls have shed massive landslides spilling far out onto the canyon floor.

A simulated fly-through using the newly assembled imagery is available online. The fly-through plus tools for wandering across and zooming into the large image are also available.

“We picked Valles Marineris to make this first mosaic because it’s probably the most complex, interesting feature on the entire planet,” said Dr. Phil Christensen of Arizona State University, Tempe. He is the principal investigator for Mars Odyssey’s versatile camera, the Thermal Emission Imaging System. “To understand many of the processes on Mars — erosion, landsliding and the effects of water — you really need to have a big-picture view but still be able to see the details.”

Small parts of the canyon have been seen at higher resolution, but at 100 meters (328 feet) per pixel, the new view has sharper resolution than any previous imaging of the entire canyon.

In addition to the completed mosaic of Valles Marineris images, the camera team has also prepared an online data set of nearly the entire planet of Mars at 232 meters (760 feet) per pixel, the most detailed global view of the red planet. The team plans to post 100-meter-resolution mosaics of other regions of Mars in coming months.

Odyssey reached Mars in 2001. The Thermal Emission Imaging System began observing the planet systematically in February 2002 both in visible wavelengths and in infrared wavelengths, which are better for seeing surface details through Mars’ atmospheric dust. As the spacecraft passes over an area, the camera records images of swaths 32 kilometers wide (20 miles wide). More than three years of observations made at infrared wavelengths during Martian daytime are combined into the assembled view of Valles Marineris and the global image data set.

Mars Odyssey is managed by NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology, Pasadena, for NASA’s Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The orbiter began an extended mission in August 2004 after successfully completing its primary mission.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Super Earths Might Be Common

Artist illustration of a super Earth. Image credit: CfA. Click to enlarge.
Nearly all the extrasolar planets discovered have been Jupiter-sized or larger. But astronomers from the Harvard-Smithsonian Center for Astrophysics think that super-earths – rocky planets several times larger that our planet – might actually be much more common. Based on the recent discovery of a super-earth around a red dwarf star 9,000 light-years away, the research team calculated that there are probably 3 times as many of these planets than the larger gas giants.

Astronomers have discovered a new “super-Earth” orbiting a red dwarf star located about 9,000 light-years away. This newfound world weighs about 13 times the mass of the Earth and is probably a mixture of rock and ice, with a diameter several times that of Earth. It orbits its star at about the distance of the asteroid belt in our solar system, 250 million miles out. Its distant location chills it to -330 degrees Fahrenheit, suggesting that although this world is similar in structure to the Earth, it is too cold for liquid water or life.

Orbiting almost as far out as Jupiter does in our solar system, this “super-Earth” likely never accumulated enough gas to grow to giant proportions. Instead, the disk of material from which it formed dissipated, starving it of the raw materials it needed to thrive.

“This is a solar system that ran out of gas,” says Harvard astronomer Scott Gaudi of the Harvard-Smithsonian Center for Astrophysics (CfA), a member of the MicroFUN collaboration that spotted the planet.

The discovery is being reported today in a paper posted online at http://arxiv.org/abs/astro-ph/0603276 and submitted to The Astrophysical Journal Letters for publication.

Gaudi performed extensive data analysis that confirmed the existence of the planet. Further analysis simultaneously ruled out the presence of any Jupiter-sized world in the distant solar system.

“This icy super-Earth dominates the region around its star that, in our solar system, is populated by the gas giant planets,” said first author Andrew Gould (Ohio State University), who leads MicroFUN.

The team also calculates that about one-third of all main sequence stars may have similar icy super-Earths. Theory predicts that smaller planets should be easier to form than larger ones around low-mass stars. Since most Milky Way stars are red dwarfs, solar systems dominated by super-Earths may be more common in the Galaxy than those with giant Jupiters.

This discovery sheds new light on the process of solar system formation. Material orbiting a low-mass star accumulates into planets gradually, leaving more time for the gas in the protoplanetary disk to dissipate before large planets have formed. Low-mass stars also tend to have less massive disks, offering fewer raw materials for planet formation.

“Our discovery suggests that different types of solar systems form around different types of stars,” explains Gaudi. “Sun-like stars form Jupiters, while red dwarf stars only form super-Earths. Larger A-type stars may even form brown dwarfs in their disks.”

Astronomers found the planet using a technique called microlensing, an Einsteinian effect in which the gravity of a foreground star magnifies the light of a more distant star. If the foreground star possesses a planet, the planet’s gravity can distort the light further, thereby signaling its presence. The precise alignment required for the effect means that each microlensing event lasts for only a brief time. Astronomers must monitor many stars closely to detect such events.

Microlensing is sensitive to less massive planets than the more common planet-finding methods of radial velocity and transit searches.

“Microlensing is the only way to detect Earth-mass planets from the ground with current technology,” says Gaudi. “If there had been an Earth-mass planet in the same region as this super-Earth, and if the alignment had been just right, we could have detected it. By adding one more two-meter telescope to our arsenal, we may be able to find up to a dozen Earth-mass planets every year.”

The OGLE (Optical Gravitational Lensing Experiment) collaboration initially discovered the microlensed star in April 2005 while peering in the direction of the galactic center, where both foreground and background stars are widespread. OGLE identifies several hundred microlensing events per year, however only a small fraction of those events yield planets. Gaudi estimates that with one or two additional telescopes located in the southern hemisphere to monitor the galactic center, the planet count could jump drastically.

The discovery was made by 36 astronomers, including members of the MicroFUN, OGLE, and Robonet collaborations. The name of the planet is OGLE-2005-BLG-169Lb. OGLE-2005-BLG-169 refers to the 169th microlensing event discovered by the OGLE Collaboration toward the Galactic bulge in 2005, and “Lb” refers to a planetary mass companion to the lens star.

Crucial roles in the discovery were played by OGLE team leader Andrzej Udalski of Warsaw University Observatory and graduate students Deokkeun An of Ohio State and Ai-ying Zhou of Missouri State University. Udalski noticed that this microlensing event was reaching a very high magnification on May 1, and he quickly alerted the MicroFUN group to this fact, since high magnification events are known to be very favorable for planet detection. MicroFUN’s regular telescopes were unable to get many images, so MicroFUN leader Gould called the MDM Observatory in Arizona where An and Zhou were observing. Gould asked An and Zhou to obtain a few measurements of the star’s brightness over the course of the night, but instead An and Zhou made more than 1000 measurements. This large number of MDM measurements was crucial for the determination the observed signal must really be due to a planet.

Original Source: CfA News Release

Posted on by Fraser Cain

Pluto and Its Moons Were Born Together

Pluto and its three moons. Image credit: Hubble. Click to enlarge.
New photographs from the Hubble Space Telescope provide evidence that Pluto and its three moons probably formed at the same time, out of the same material. Scientists believe that the 4 objects were created when two Pluto-sized Kuiper Belt objects collided together. Hubble revealed that that Pluto and its moons have identical colours; exactly what you’d expect from this kind of an origin.

Using new Hubble Space Telescope observations, a research team led by Dr. Hal Weaver of the Johns Hopkins University Applied Physics Laboratory and Dr. Alan Stern of Southwest Research Institute has found that Pluto’s three moons are essentially the same color – boosting the theory that the Pluto system formed in a single, giant collision.

Publishing their findings in an International Astronomical Union Circular (No. 8686), the team determined that Pluto’s two “new” satellites, discovered in May 2005 and provisionally called S/2005 P 1 and S/2005 P 2, have identical colors to one another and are essentially the same, neutral color as Charon, Pluto’s large moon discovered in 1978.

All three satellites have surfaces that reflect sunlight with equal efficiency at all wavelengths, which means they have the same color as the Sun or Earth’s moon. In contrast, Pluto has more of a reddish hue.

The new observations were obtained March 2 with the high-resolution channel of the Hubble’s Advanced Camera for Surveys. The team determined the bodies’ colors by comparing the brightness of Pluto and each moon in images taken through a blue filter with those taken through a green/red filter. The images are available on the Hubble Web site at http://hubblesite.org/newscenter/newsdesk/archive/releases/2006/15/image/.

“The high quality of the new data leaves little doubt that the hemispheres of P1 and P2 that we observed have essentially identical, neutral colors,” says Weaver.

The new results further strengthen the hypothesis that Pluto and its satellites formed after a collision between two Pluto-sized objects nearly 4.6 billion years ago. “Everything now makes even more sense,” says Stern. “If all three satellites presumably formed from the same material lofted into orbit around Pluto from a giant impact, you might well expect the surfaces of all three satellites to have similar colors.”

The researchers hope to make additional Hubble color observations, in several more filters, to see if the similarity among the satellites persists to longer (redder) wavelengths. They have proposed to obtain compositional information on the new satellites by observing them at near-infrared wavelengths, where various ice and mineral absorptions are located. The researchers also hope to better refine the orbits of P1 and P2 and measure the moons’ shapes and rotational periods.

The Hubble observations were made in support of NASA’s New Horizons mission to Pluto and the Kuiper Belt. New Horizons launched on Jan. 19, 2006, and will fly through the Pluto system in July 2015, providing the first close-up look at the ninth planet and its moons. Stern leads the mission and science team as principal investigator; Weaver serves as the mission’s project scientist. The Johns Hopkins University Applied Physics Laboratory, Laurel, Md., manages the mission for NASA’s Science Mission Directorate and operates the New Horizons spacecraft. For more information on the mission, visit http://pluto.jhuapl.edu.

The other members of the Hubble Space Telescope-Pluto satellite observing team include Max Mutchler of the Space Telescope Science Institute, Baltimore; Drs. William Merline, John Spencer, Andrew Steffl, Elliot Young and Leslie Young of Southwest Research Institute, Boulder, Colo.; and Dr. Marc Buie of Lowell Observatory, Flagstaff, Ariz.

Original Source: JHUAPL News Release

Update: Pluto is not a planet.

Posted on by Fraser Cain

What’s Up This Week – March 13 – March 19, 2006

What's Up 2006

Download our free “What’s Up 2006” ebook, with entries like this for every day of the year.


Greetings, fellow SkyWatchers! Although the Moon is back “en force”, this will still be an exciting week filled with events such as an eclipse, meteor shower and bright, beautiful star clusters.

Here’s what’s up!

Archival image of Percival Lowell. Click to enlarge.
Monday, March 13 – On this day in 1781, Uranus was discovered by William Herschel. 74 years later, in 1855, Percival Lowell was born.

Originally named “the Georgium Sidus,” Uranus was previously catalogued as a faint 6th magnitude star by John Flamsteed in 1690 and designated as 34 Tauri. Herschel came upon this same “star” – then located in the constellation Gemini – while doing a double star search using a homemade 6″ speculum-mirrored reflector. Imagine his surprise when the “star” revealed itself as a small greenish globe!

Percival Lowell was born to a distinguished Boston family with ties to Harvard University. Lowell graduated with honors in mathematics from that same institution in 1876. After traveling throughout the Far East, Lowell’s imagination was set on fire by Giovanni Schiaparelli’s observation of “canali” on Mars. In 1894, Lowell moved to Flagstaff, Arizona and established the Lowell Observatory. Over the next 15 years, he observed Mars with a passion few astronomers could ever hope to match for any single study. During this period, Lowell wrote several books developing the idea of an extinct race of Martians responsible for various artificial features he thought he had observed on the planet’s surface.

Tonight the great Grimaldi, found in the central region of the moon near the terminator is the best lunar feature for binoculars. If you would like to see how well you have mastered your telescopic skills, then let’s start there. About one Grimaldi length south, you’ll see a narrow black ellipse with a bright rim. This is Rocca. Go the same distance again (and a bit east) to spot a small, shallow crater with a dark floor. This is Cruger, and its lava-filled interior is very similar to another study – Billy. Now look between them. Can you see a couple of tiny dark markings? Believe it or not, this is called Mare Aestatis. It’s not even large enough to be considered a medium-sized crater, but is a mare!

Tuesday, March 14 – Today is the birthday of Albert Einstein. Born in 1879, Einstein was later hailed as one of the finest scientific minds of our times. In 1921, Einstein won the Physics Nobel Prize based on work completed 15 years earlier associated with the photoelectric effect – a natural phenomenon now regularly used to accumulate light to image the most distant things in the Universe. Even more significantly, Einstein developed a theory of gravity based on the curvature of space and time caused by the distribution of matter and another theory (of mass-energy conversion) which accounted for the prodigious and sustainable energy output of the stars.

Tonight is the Full Moon. In many cultures, it is known as the “Worm Moon.” As ground temperatures begin to warm and produce a thaw in the northern hemisphere, earthworms return and encourage the return of robins. For the Indians of the far north, this was also considered the “Crow Moon.” The return of the black bird signaled the end of winter. Sometimes it has been called the “Crust Moon” because warmer temperatures melt existing snow during the day, leaving it to freeze at night. Perhaps you may have also heard it referred to as the “Sap Moon.” This marks the time of tapping maple trees to make syrup. To early American settlers, it was called the “Lenten Moon” and was considered to be the last full Moon of winter. For those of us in northern climes, let’s hope so!

But for viewers almost the world over, tonight’s Moon will hold a far greater significance as it passes through a portion of the Earth’s shadow known as the penumbra. Eclipse time? You bet. For viewers in Asia, India and the western portion of Australia, you’ll get to see the Moon pass through this shadow just as it sets for your local time. For Europe and Africa? You’re in luck as the entire event can be seen from your area. For the majority of both North and South America, the eclipse will be underway as the Moon rises, but you can watch it slide out of the shadow long before it sets. Unfortunately, the western-most portion of the Americas will not see anything.

While a penumbral eclipse is not known to be particularly exciting – this one is deep. The edge of the Moon will just graze the inner umbral shadow. As a rule of thumb, remember that the Moon moves about its own diameter each hour, so the very beginning of a penumbral eclipse will be difficult to notice. Slowly and steadily, the coloration will begin to change and even inexperienced SkyWatchers will notice that something is different. It’s a very relaxing experience and we wish you clear skies!

Wednesday, March 15 – Today celebrates the birth of Nicolas Lacaille. Born in 1713, Lacaille’s measurements confirmed the Earth’s equatorial bulge. He also named the fifteen southern constellations, and a lunar feature honors his life’s work. Although the Moon will be bright, we can still have a look at the crater named for Lacaille. Start by heading towards the lunar south central region. Dominating the scene will be brilliant crater Tycho. From there, it’s north to the eastern shores of Mare Nubium, where you will see the bright ring of Thebit. Shallow Lacaille resides to the east and will be a challenge to make out under the low contrast conditions.

While skies remain bright all night, we can still have a look at an open cluster easily located in northeastern Orion. This 5.9 magnitude scattered group of stars may have been first observed by Giovanni Batista Hodierna in the mid-17th century. While bright enough to have been a Messier object, William Herschel added it to his log of discoveries on October 15, 1784, as H VIII.24. Of the 30 known stars associated with this 3,600 light-year distant group, the brightest is 50 million years old. Despite lunar interference, a half-dozen of the cluster’s very brightest members can be seen in small scopes at mid-range powers. Look for NGC 2169 slightly less than a fist width north-northeast of Betelguese and slightly south of Xi and Nu Orionis.

Thursday, March 16 – On this day in 1926, Robert Goddard launched the first liquid-fuel rocket. He first showed his potential in 1907 when a cloud of smoke rose from a powder rocket fired off in the basement of the physics building in Worcester Polytechnic Institute. Needless to say, the school took an immediate interest in the work of this student! Thankfully Robert was not expelled and a lifetime career in rocketry followed. Goddard was also the first person to realize the full spectrum of possibilities associated with missiles and space flight, and his life was completely dedicated to bringing his visions to realization. While most of Goddard’s achievements went unrecognized for many years, tonight we celebrate his name and passion for the space sciences. His first flight may have only gone 12 meters, but forty years later on this same date the Gemini 8 performed the first orbital docking – a maneuver that could have never happened without Goddard’s work!

Tonight, let’s have a look at an ancient walled plain – Gauss. Located north of Mare Crisium, this oblong crater should be divided by the terminator for most viewers tonight. Its east wall will be quite bright and the west wall outlined by a black arc. It is a very old crater, and if you up the magnification, you will see its ruined, cracked floor riddled with numerous small craterlets.

While out, be on watch for the Corona-Australids meteor shower. While the fall rate is low, about 5 to 7 per hour, our friends in the southern hemisphere stand the best chance with this one.

While we’re out, let’s have a look at another fine study on Messier’s list – M50. Described as “heart-shaped” by some observers, those with larger telescopes will see enough members of this 5.9 magnitude open cluster to note two main “petals” of stars arcing outward to the north and southeast. Several tenth magnitude stars congregate toward the center of this 3,200 light-year distant cluster while numerous 11th and 12th magnitude members dance around them in chains and arcs. Look for at least one luminous red giant and a half dozen yellow giants among this 80 million year-old, 20 light-year diameter study.

Friday, March 17 – On this day in 1958, the first solar-powered spacecraft was launched. Christened Vanguard 1, it was an engineering test satellite. From its orbital position, the data taken from its transmissions helped to refine the true shape of the Earth.

While out observing, turn a scope towards Saturn and see if you can begin to make out faint structure in the ring system. On a fine night of “seeing,” you should easily be able to make out the shadow of the planet’s globe cast the planet casts against its posterior ring plane. Look for the shadow of the ring itself softening the view of the planet’s northern equatorial region.

As the Moon rises tonight, look for bright Spica to accompany it. For some lucky viewers, this will be an occultation! Please check with IOTA for details in your area.

Saturday, March 18 – Today in 1965, the first spacewalk was performed by Alexei Leonov onboard the Soviet Voskhod spacecraft. The “walk” lasted around 20 minutes and Alexei had problems re-entering the spacecraft because his space suit had inflated. Imagine his fear as he let air leak out of his suit in order to squeeze back inside. Later when the crew of two landed off target in the heavily forested Ural Mountains, the pair had to spend the night in the woods surrounded by wolves. It took over twenty-four hours before they were located, then workers had to chop their way through the forest to recover them on skis. Brave men on the frontiers of human exploration of space!

Tonight let’s honor their courage by going after something really tough – but certainly not dangerous. Start with Castor and head 3 degrees north-northeast to center on 4.9 magnitude Omicron Geminorum. Now move north another 4 degrees to locate a widely spaced east-west oriented pair of 8th magnitude stars in the constellation Lynx. Look nearby for the faint whisper of luminosity associated with one of the most fascinating studies in the heavens – 10.4 magnitude globular cluster NGC 2419 – the famed “Intergalactic Wanderer.”

First discovered by William Herschel on New Year’s Eve 1788, the Intergalactic Wanderer may or may not just be “passing through” the Milky Way region. – Even as a member of our galaxy’s entourage of clusters and satellite dwarf galaxies, it is one of the most distant. Outside of our own galaxy at around 300,000 light-years!

Small scopists take heart. NGC 2419 can be seen on dark sky occasions in instruments as small as a spotting scope – although you will need to avert your vision to see it. How is that possible? NGC 2419 is intrinsically one of the brightest globular clusters we know of. Be sure to catch this one before moonrise!

Sunday, March 19 – With time to spare before Luna lights up the night, let’s go south and locate a fine reflecting nebula – NGC 2467 – in northern Puppis. Sometimes referred to as the “skull and crossbones nebula,” this billowing cloud of gas and dust is easily found less than a finger-width south-southeast of 3.5 magnitude Xi Puppis. Even a small telescope will find this expansive, star-studded emission nebula a real beauty! Those with larger apertures should look for neighboring splotches of nebulosity illuminated by small groupings of stars – some of which are part of a newly forming open cluster.

Keep in mind while observing NGC 2467 that we are seeing it from a great distance. At 17,000 light-years, this expansive region of star formation is some 10 times farther away than the Great Nebula in Orion. If it were the same distance away, NGC 2467 would dwarf M42!

May all your journeys be at light speed… ~Tammy Plotner. Additional writing by Jeff Barbour @ astro.geekjoy.com.

Posted on by R. Jay Gabany

Astrophoto: The Vela Supernova Remnant by Loke Kun Tan

The Vela Supernova Remnant by Loke Kun Tan
About 11,000 years ago, around the dawn of human history, a fantastic stellar explosion took place relatively nearby our place in the galaxy. It left an aftermath covering nearly 40 degrees of the sky (the Moon and Sun extend only 1/2 a degree, for comparison), an aftermath captured by astrophotographer Loke Kun Tan.

The brilliance of this supernova explosion would have rivaled the quarter moon. According to an article in Science Digest, defects in the human cornea would have given this explosion the appearance of a dancing fire, hung low in the heavens if viewed from a location near the Mediterranean, shooting sparks of intense color in every direction like a fountain about the size of the full moon. The landscape would have been flooded with bands of shadows and pulsing illumination. It would have both awed and terrified any observer in antiquity.

Today, we can still see the remains of the conflagration as the Vela Supernova Remnant. It is located within the Gum Nebula, itself the result of an earlier star detonation. The remnant is in the southern constellation of Vela, about 1,300 light years distant – more than three times closer than the famous supernova seen by the Chinese in 1054, which, today, is marked by the Crab Nebula. This is a picture of the remnant’s central region; a growing shell of gas and dust that has enlarged to over 1,000 light years in diameter putting its leading edge only about 300 or 400 lights years from Earth and still expanding in all directions.

As the fast moving energy thrown off in the explosion slams into much slower moving gas and dust that occurs naturally throughout the space between the stars, it creates these beautiful shock wave fronts which glow like sinuous threads. Another view shows an extension of the upper part.

At the heart of the remnant glows a pulsar, the core of the star that exploded. It spins at over ten times per second and is the source of intense X-ray radiation.

Loke Kun Tan recently produced this image from thirty three separate shots that were digitally combined to create the equivalent of a six hour exposure. It was taken during a 2004 trip to La Frontera in Alcohuaz, Chile and was captured through a 4-inch refractor, designed specifically for wide field astrophotography, with an eleven mega-pixel astronomical camera.

Do you have photos you’d like to share? Post them to the Universe Today astrophotography forum or email them, and we might feature one in Universe Today.

Written by R. Jay GaBany

Posted on by Nancy Atkinson

The NASA Science Missions Getting Cut

Artist illustration of the Dawn mission, now cancelled. Image credit: NASA/JPL. Click to enlarge.
With the release NASA’s 2007 budget request, it was clear that the productive science programs will be paying the price for the new Vision for Space Exploration, returning humans to the Moon and then sending them on to Mars. Many programs will be affected. We review the missions, what they were supposed to accomplish, and what the cuts will bring. It’s not a pretty picture.

Scientists, space interest groups, and even members of Congress have expressed so much concern about NASA’s $16.79 billion budget request for Fiscal Year 2007 that the Associate Administrator of NASA’s Science Directorate has reportedly agreed to review the proposed cuts in science and solar system exploration programs. According to the American Association for the Advancement of Science and their magazine Science, NASA will re-evaluate the missions and programs that are under threat of being cancelled or delayed.

The outcry over the budget proposal began immediately after it was released on February 6. At first glance, the 2007 budget would be an overall increase of 3.2% over the FY06 appropriation, or a 1.5% increase when including Katrina funding in Fiscal Year 2006. But while the proposed budget will support the space shuttle and space stations programs in addition to the emerging costs of the Vision for Space Exploration, it does so while slashing the funds needed to sustain the current and anticipated programs in science and exploration.

Central to the problems of this budget is that the space shuttle program has a projected $3 – 5 billion shortfall for the planned 17 missions before the shuttle is to be retired in approximately 2010. To alleviate that shortage, NASA is planning to shift $3 billion from planetary exploration and science over the next four years to pay for the manned missions.

The Planetary Society has said that what NASA is doing is essentially transferring funds from a popular and highly productive program (science) to one that is scheduled for termination (the space shuttle).

“I am extremely uneasy about this budget,” said U.S. House Science Committee Chairman Sherwood Boehlert from New York. “This budget is bad for space science, worse for earth science, perhaps worse still for aeronautics. It basically cuts or deemphasizes every forward looking, truly futuristic program of the agency to fund operational and development programs to enable us to do what we are already doing or have done before.”

Senator Pete Domenici from New Mexico and 59 other senators have introduced a bill to authorize a 10 percent increase per year in NASA’s science budget from now through 2013.

But Louis Friedman, Executive Director of the Planetary Society doesn’t anticipate any big changes in what Congress will approve for NASA. “I think it is unlikely that NASA will get very much of an increase in budget, but I do anticipate some give and take and perhaps some restoration of science funding,” he said. “We will be trying very hard for a major restoration of funding, but it will be a difficult fight.”

The budget shows a 1.5% increase in science funding for this year, and 1% increase for each of the following two years, before inflation is taken into consideration. But even with that increase, there will actually be $2 billion less for space science and $1.5 billion less for exploration that what was previously planned, and needed, for all of the missions to continue.

Following are some of the areas that would be affected:
– Research and analysis: 15% across-the-board cuts in grants for research, ($350 to $400 million over the next five years) with some retroactive to 2006. An official at NASA Headquarters said he wasn’t aware that any notices of specific research cuts have been issued at this time.
– Astrobiology research alone will have 50% of funding slashed.
– Astronomy and astrophysics at NASA cut by 20% over 5 years
– Aeronautics: cut by 18.1%, down to $724.4 million

In a press conference, NASA Administrator Mike Griffin acknowledged that “science and exploration are each paying to help complete our pre-existing obligations to the space station and the space shuttle, and when those obligations are completed the other major pieces of our portfolio will be able to do better.” In his congressional testimony, Griffin said, “I truly wish that it could be otherwise, but there is only so much money.”

NASA has 50 science and planetary missions currently operating, which includes missions from Voyager to the all of the Earth orbiting satellites to the recently launched New Horizons mission to Pluto. There are 22 missions that are in development, and 19 being studied for development. The budget maintains all of these missions, with the exception of some delays in launches to upgrade or replace existing Earth orbiting satellites. Following are missions that, if the current budget proposal is approved, will be cancelled or delayed:

Dawn: Cancelled.
The mission: Using an ion engine, the spacecraft would have traveled to the asteroid belt to study two dissimilar asteroids to help determine the role that size and water play in planetary evolution. It also would have helped determine the origin and evolution of our solar system. According to the NASA Watch website, 98% of Dawn’s hardware is complete, with a majority of it already integrated into the spacecraft. The shutdown costs for Dawn are $10 million, while it would take $40 million to complete the spacecraft and fly the mission.

In a statement, JPL Director Dr. Charles Elachi said, “During development a number of implementation and technical challenges led to a cost increase estimate of approximately 20% (from $373.2M to $446.5M.) Even though all the technical issues could be resolved, additional funding is still needed to complete and launch the mission by the spring of 2007. Of course we are disappointed, but the current tight budget environment has led to its cancellation.”

NASA has defended the cancellation not as a budget cut, but as a management decision due to developmental problems with the project. Louis Friedman says, “Indeed, (Dawn’s) cancellation was made separate from the budget submission and is not addressed in the Fiscal Year 2007 budget proposal. But the timing of the cancellation is suspicious – made immediately after the budget hearing in which testimony was unanimous that making mission cancellations in order to beef up research an analysis funding was an acceptable allocation of priorities.”

SOFIA (Stratospheric Observatory for Infrared Astronomy): Cancelled.
The mission: An airborne observatory consisting of a 2.5 meter reflecting infrared telescope. It would facilitate in developing observational techniques, new instrumentations, and in education of young scientists and teachers. The telescope is fully installed in a 747 aircraft and is functional. The first test flights for the observatory would have been done this year. SOFIA was being conducted in cooperation with the DLR, the German Aerospace Center, and was part of NASA’s Origins Program.

Mission to Europa: Cancelled.
Friedman said that the Europa mission was not yet an approved mission, but preliminary work had started and Congress had directed NASA to do that work in anticipation of a Fiscal Year 2007 new start for this mission. Instead NASA cancelled the existing work and ignored the request for a FY ’07 new start.

Last year, the Jupiter Icy Moon Orbiter was put down, which would have used a nuclear reactor to power an ion engine to send an orbiter to 3 of Jupiter’s moons. This year future missions to Europa have been tabled, even though the National Academy of Sciences and internal NASA advisory committees have endorsed the exploration of Europa as the next highest priority solar system objective after Mars.

Terrestrial Planet Finder: Cancelled.
The proposed mission: Terrestrial Planet Finder would have consisted of two complementary observatories: a visible-light coronagraph and a formation-flying infrared interferometer. It would study extra-solar planets, from their formation and development in disks of dust and gas around newly forming stars to studying features of planets and determining suitability for containing life.

TPF was not yet an approved mission, but preliminary development work had begun. NASA cancelled that work and removed TPF from the list of missions to be started in the next four years.

SIM Planet Quest: Delayed.
Formerly called the Space Interferometry Mission. As an optical interferometer in an Earth-trailing orbit, the spacecraft would survey approximately 100 of our closest stars and identify potential habitable planets. It would also survey thousands of other stars to help our general understanding of the formation and evolution of planetary systems. Also would help to answer questions in astrophysics concerning dark matter, black holes and the mass of the universe.

Mars Sample Return Mission: Delayed Indefinitely.
Not yet an approved mission, but preliminary development had begun. An exciting if not controversial mission to bring Martian soil to Earth.

Additional Programs Affected
Two Mars Scout missions planned for after 2011 were removed from the four year planning budget. These missions may have included airborne vehicles such as airplanes or balloons and small landers.

The Explorer Program, which launches small spacecraft to study areas such as Heliophysics and Astrophysics would be cut drastically with the earliest launch coming in 2014.

Beyond Einstein would be delayed indefinitely. These are missions such as Constellation -X and LISA that would attempt to answer questions about the Big Bang, Black Holes and Dark Matter.

The Associated Press has reported that a long list of satellites orbiting Earth are under threat of being delayed, downsized or cancelled. Scientists have warned that decreasing funding for these satellites will jeopardize the capability for forecasting weather and monitoring environmental issues.
The list includes:

Landsat: delay in launch of satellite to replace and upgrade Landsat 7, launched in 1999.

Earth Observing System: If cut, satellites such as Aqua (2002) and Terra (1999) would not be replaced when they fail.

Global Precipitation Measuring Mission: The launch of GPMM has been pushed back to 2012. GPMM will replace and upgrade the Tropical Rainfall Measuring Mission, which was supposed to be decommissioned in 2004.

Deep Space Climate Observatory: cancelled. An Earth observing satellite placed at the L-1 Point to determine cloud and radiation properties of the atmosphere. The spacecraft is already built, but would cost $60-100 million to launch and operate.

National Polar-Orbiting Operational Environmental Satellite System: Under review. Will monitor global environmental conditions, and collect and disseminate data related to weather, atmosphere, oceans and land, and is a cooperative effort between NASA, NOAA, the Department of Defense and the Department of Commerce.

The next round of Congressional hearings on the budget proposal are scheduled for March 30 at the House Appropriation Subcommittee on Science, State Justice and Commerce Hearing.

Written by Nancy Atkinson