Cassini Gazes at Veiled Titan
NASA's Cassini spacecraft will swing high over Saturn's moon Titan on Friday, Sept. 24, taking a long, sustained look at the hazy moon. At closest approach, Cassini will fly within 8,175 kilometers (5,080 miles) above the hazy moon's surface. This flyby is the first in a series of high-altitude Titan flybys for Cassini over the next year and a half.
Cassini's composite infrared spectrometer instrument will be probing Titan's stratosphere to learn more about its vertical structure as the seasons change. Equinox, when the sun shone directly over the equator, occurred in August 2009, and the northern hemisphere is now in spring.
Another instrument, the visual and infrared mapping spectrometer, will be mapping an equatorial region known as Belet at a resolution of 5 kilometers (3 miles) per pixel. This mosaic will complement the mosaics that were obtained in earlier Titan flybys in January and April. This spectrometer will also look for clouds at northern mid-latitudes and near the poles.
Cassin's visible-light imaging cameras will also be taking images of Titan's trailing hemisphere, or the side that faces backward as Titan orbits around Saturn. If Titan cooperates and has a cloudy day, scientists plan to analyze the images for cloud patterns.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL, a division of the California Institute of Technology in Pasadena, manages the mission for NASA's Science Mission Directorate, Washington, D.C.
Spring on Titan Brings Sunshine and Patchy Clouds
The northern hemisphere of Saturn's moon Titan is set for mainly fine spring weather, with polar skies clearing since the equinox in August last year. The visual and infrared mapping spectrometer (VIMS) aboard NASA's Cassini spacecraft has been monitoring clouds on Titan regularly since the spacecraft entered orbit around Saturn in 2004. Now, a group led by Sébastien Rodriguez, a Cassini VIMS team collaborator based at Université Paris Diderot, France, has analyzed more than 2,000 VIMS images to create the first long-term study of Titan's weather using observational data that also includes the equinox. Equinox, when the sun shone directly over the equator, occurred in August 2009.
Rodriguez is presenting the results and new images at the European Planetary Science Congress in Rome on Sept. 22.
Though Titan's surface is far colder and lacks liquid water, this moon is a kind of "sister world" to Earth because it has a surface covered with organic material and an atmosphere whose chemical composition harkens back to an early Earth. Titan has a hydrological cycle similar to Earth's, though Titan's cycle depends on methane and ethane rather than water.
A season on Titan lasts about seven Earth years. Rodriguez and colleagues observed significant atmospheric changes between July 2004 April 2010. The images showed that cloud activity has recently decreased near both of Titan's poles. These regions had been heavily overcast during the late southern summer until 2008, a few months before the equinox.
Over the past six years, the scientists found that clouds clustered in three distinct latitude regions of Titan: large clouds at the north pole, patchy clouds at the south pole and a narrow belt around 40 degrees south. "However, we are now seeing evidence of a seasonal circulation turnover on Titan – the clouds at the south pole completely disappeared just before the equinox and the clouds in the north are thinning out," Rodriguez said. "This agrees with predictions from models and we are expecting to see cloud activity reverse from one hemisphere to another in the coming decade as southern winter approaches."
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. JPL manages the mission for NASA's Science Mission Directorate, Washington, D.C. The visual and infrared mapping spectrometer team is based at the University of Arizona, Tucson.
Mars Reconnaissance Orbiter Mission Status Report
NASA's Mars Reconnaissance Orbiter put itself into a precautionary standby mode after experiencing a spontaneous computer reboot on Sept. 15. The mission's ground team has begun restoring the spacecraft to full operations.
Initial analysis of telemetry from the orbiter indicates the "safe mode" status was triggered by a reboot similar to one experienced Aug. 26, 2009. That was the most recent time that the Mars Reconnaissance Orbiter put itself into safe mode. For 10 months prior to this latest reboot, the spacecraft operated normally, making science observations and returning data. During 2009, unplanned reboots put the spacecraft into safe mode four times.
The orbiter has normal power, fully charged batteries and safe temperatures. The team has increased the data-rate of communications and is taking additional steps to resume science observations soon.
The Mars Reconnaissance Orbiter, at Mars since 2006, has met the mission's science goals and returned more data than all other Mars missions combined. It completed its primary science phase of operations in November 2008, but continues to observe Mars both for science and for support of future landed missions.
The Mars Reconnaissance Orbiter mission is managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif. Caltech manages JPL for NASA.
Cosmic Ice Sculptures
Enjoying a frozen treat on a hot summer day can leave a sticky mess as it melts in the Sun and deforms. In the cold vacuum of space, there is no edible ice cream, but there is radiation from massive stars that is carving away at cold molecular clouds, creating bizarre, fantasy-like structures.
These one-light-year-tall pillars of cold hydrogen and dust, imaged by the Hubble Space Telescope, are located in the Carina Nebula. Violent stellar winds and powerful radiation from massive stars are sculpting the surrounding nebula. Inside the dense structures, new stars may be born.
This image of dust pillars in the Carina Nebula is a composite of 2005 observations taken of the region in hydrogen light (light emitted by hydrogen atoms) along with 2010 observations taken in oxygen light (light emitted by oxygen atoms), both times with Hubble's Advanced Camera for Surveys. The immense Carina Nebula is an estimated 7,500 light-years away in the southern constellation Carina.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C.
Americas From the Moon
As LRO orbits the Moon every two hours sending down a stream of science data, it is easy to forget how close the Moon is to the Earth. The average distance between the two heavenly bodies is just 384,399 km (238,854 miles). Check your airline frequent flyer totals, perhaps you have already flown the distance to the Moon and back on a single airline! Contrast the current image with the NAC view taken last June, which revealed much of central Asia.
The Moon is a spectacular sight in the nighttime sky. Now imagine the Earth from the Moon, four times larger, a delicate blue, and it does not rise nor set. To astronauts, the Earth is a constant companion, at least on the nearside. Of course, on the farside you can never see the Earth.
Chandra Finds Evidence for Stellar Cannibalism
Evidence that a star has recently engulfed a companion star or a giant planet has been found using NASA's Chandra X-ray Observatory. The likely existence of such a "cannibal" star provides new insight into how stars and the planets around them may interact as they age.
The star in question, known as BP Piscium (BP Psc), appears to be a more evolved version of our Sun, but with a dusty and gaseous disk surrounding it. A pair of jets several light years long blasting out of the system in opposite directions has also been seen in optical data. While the disk and jets are characteristics of a very young star, several clues including the new results from Chandra suggest that BP Psc is not what it originally appeared to be.
Instead, astronomers have suggested that BP Psc is an old star in its so-called red giant phase. And, rather than being hallmarks of its youth, the disk and jets are, in fact, remnants of a recent and catastrophic interaction whereby a nearby star or giant planet was consumed by BP Psc.
When stars like the Sun begin to run of nuclear fuel, they expand and shed their outer layers. Our Sun, for example, is expected to swell so that it nearly reaches or possibly engulfs Earth, as it becomes a red giant star.
"It appears that BP Psc represents a star-eat-star Universe, or maybe a star-eat-planet one," said Joel Kastner of the Rochester Institute of Technology, who led the Chandra study. "Either way, it just shows it's not always friendly out there."
Several pieces of information have led astronomers to rethink how old BP Psc might be. First, BP Psc is not located near any star-forming cloud, and there are no other known young stars in its immediate vicinity. Secondly, in common with most elderly stars, its atmosphere contains only a small amount of lithium. Thirdly, its surface gravity appears to be too weak for a young star and instead matches up with one of an old red giant.
Chandra adds to this story. Young, low-mass stars are brighter than most other stars in X-rays, and so X-ray observations can be used as a sign of how old a star may be. Chandra does detect X-rays from BP Psc, but at a rate that is too low to be from a young star. Instead, the X-ray emission rate measured for BP Psc is consistent with that of rapidly rotating giant stars.
The spectrum of the X-ray emission that is how the amount of X-rays changes with wavelength -- is consistent with flares occurring on the surface of the star, or with interactions between the star and the disk surrounding it. The magnetic activity of the star itself might be generated by a dynamo caused by its rapid rotation. This rapid rotation can be caused by the engulfment process.
"It seems that BP Psc has been energized by its meal," said co-author Rodolfo (Rudy) Montez Jr., also from the Rochester Institute of Technology.
The star's surface is obscured throughout the visible and near-infrared bands, so the Chandra observation represents the first detection at any wavelength of BP Psc itself.
"BP Psc shows us that stars like our Sun may live quietly for billions of years," said co-author David Rodriguez from UCLA, "but when they go, they just might take a star or planet or two with them."
Although any close-in planets were presumably devastated when BP Psc turned into a giant star, a second round of planet formation might be occurring in the surrounding disk, hundreds of millions of years after the first round. A new paper using observations with the Spitzer Space Telescope has reported possible evidence for a giant planet in the disk surrounding BP Psc. This might be a newly formed planet or one that was part of the original planetary system.
"Exactly how stars might engulf other stars or planets is a hot topic in astrophysics today," said Kastner. "We have many important details that we still need to work out, so objects like BP Psc are really exciting to find."
These results appeared in The Astrophysical Journal Letters. Other co-authors on the study were Nicolas Grosso of the University of Strasbourg, Ben Zuckerman from UCLA, Marshall Perrin from the Space Telescope Science Institute, Thierry Forveille of the Grenoble Astrophysics Laboratory in France and James Graham from University of California, Berkeley.
NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.
NASA's Magnetospheric Mission Passes Major Milestone
The universe is still an arcane place that scientists know very little about, but a new NASA Solar Terrestrial Probe mission is going to shed light on one especially mysterious event called magnetic reconnection. It occurs when magnetic lines of force cross, cancel, and reconnect releasing magnetic energy in the form of heat and charged-particle kinetic energy.
On the sun, magnetic reconnection causes solar flares more powerful than several atomic bombs combined. In Earth's atmosphere, magnetic reconnection dispenses magnetic storms and auroras, and in laboratories on Earth it can cause big problems in fusion reactors.
Although the study of magnetic reconnection dates back to the 1950s and despite numerous scientific papers addressing this perplexing issue, scientists still cannot agree on one accepted model.
In 2014, NASA is scheduled to launch a satellite that will greatly increase our understanding of this phenomenon when it launches the Magnetospheric Multiscale (MMS) mission, a suite of four identical spacecraft that will study magnetic reconnection in the best possible laboratory – the Earth’s magnetosphere. The spacecraft will obtain measurements necessary to test prevailing theories as to how reconnection is enabled and how it progresses.
Recently, NASA and members of an independent review board painstakingly reviewed every aspect of the MMS mission, and successfully completed the mission’s critical design review. This technical review is held to ensure that a mission can proceed into fabrication, demonstration and test and can meet stated performance requirements, including cost, schedule, risk and other system constraints.
According to MMS deputy project scientist Mark Adrian of NASA’s Goddard Space Flight Center in Greenbelt, Md., “This is the last hurdle before the spacecraft and instrument teams begin to build actual flight hardware.”
MMS was approved for implementation in June 2009 following a successful Preliminary Design Review in May 2009.
Dr. James L. Burch of the Southwest Research Institute in San Antonio, Texas, will lead the MMS science team. According to Burch, “Magnetic reconnection is a fundamental physical process that occurs throughout the universe,” says Burch. “MMS will enable us to study this dynamic process in the near-Earth space environment, where it transfers energy from the solar wind to the magnetosphere and drives disturbances known as space weather.”
Goddard is the lead Center for the mission. Engineers there will perform the required environmental testing, build the spacecraft and integrate all four sets of instruments into the MMS satellites, support launch vehicle integration and operations, and develop the Mission Operations Center which to monitor and control the spacecraft.
MMS will carry identical suites of plasma analyzers, energetic particle detectors, magnetometers, and electric field instruments as well as a device to prevent spacecraft charging from interfering with the highly sensitive measurements required in and around the diffusion regions.
Scientists and engineers at Goddard have designed and will build one of the instruments – the Fast Plasma Instrument, which will measure the ion and electron distributions and the electric and magnetic fields with unprecedentedly high millisecond time resolution and accuracy.
Currently, MMS is scheduled to launch in August 2014 from Cape Canaveral Air Force Station, FL aboard an Atlas V rocket.
NASA and ATK Successfully Test Five-Segment Solid Rocket Motor
With a loud roar and mighty column of flame, NASA and ATK Aerospace Systems successfully completed a two-minute, full-scale test of the largest and most powerful solid rocket motor designed for flight. The motor is potentially transferable to future heavy-lift launch vehicle designs.
The stationary firing of the first-stage development solid rocket motor, dubbed DM-2, was conducted by ATK, a division of Alliant Techsystems of Brigham City, Utah. DM-2 is the most heavily instrumented solid rocket motor in NASA history, with a total of 53 test objectives measured through more than 760 instruments.
Prior to the static test, the solid rocket motor was cooled to 40 degrees Fahrenheit to verify the performance of new materials and assess motor performance at low temperatures during the full-duration test. Initial test data showed the motor performance met all expectations.
"For every few degrees the temperature rises, solid propellant burns slightly faster and only through robust ground testing can we understand how material and motor performance is impacted by different operating conditions," said Alex Priskos, first stage manager for Ares Projects at NASA's Marshall Space Flight Center in Huntsville, Ala. "Ground-testing at temperature extremes pushes this system to its limits, which advances our understanding of five-segment solid rocket motor performance."
The first-stage solid rocket motor is designed to generate up to 3.6-million pounds of thrust at launch. Information collected from this test, together with data from the first development motor test last year, will be evaluated to better understand the performance and reliability of the design.
Although similar to the solid rocket boosters that help power the space shuttle to orbit, the five-segment development motor includes several upgrades and technology improvements implemented by NASA and ATK engineers. Motor upgrades from a shuttle booster include the addition of a fifth segment, a larger nozzle throat, and upgraded insulation and liner. The motor cases are flight-proven hardware used on shuttle launches for more than three decades. The cases used in this ground test have collectively launched 59 previous missions.
After more testing, the first-stage solid rocket motor will be certified to fly at temperature ranges between 40-90 degrees Fahrenheit. The solid rocket motor was built as an element of NASA's Constellation Program and is managed by the Ares Projects Office at Marshall. ATK Aerospace Systems is the prime contractor.
Medicare Officially Safer After Health Reform
The President discusses a new Medicare Trustees report showing Medicare to be on much stronger footing as a result of the reforms in the Affordable Care Act. In addition, seniors are also already getting help with prescription drug costs when they fall into the infamous "donut hole."
Agatha leaves 82 dead in Guatemala, El Salvador
The remnants of Tropical Storm Agatha were headed into the Caribbean Sea late Sunday after leaving behind more than 80 dead in Guatemala and El Salvador, authorities in those countries reported.
Most of the dead were in Guatemala, where heavy rains triggered mudslides that collapsed homes and forced thousands to evacuate. The country's preliminary death toll was 73 on Sunday, with 49 of those reported in the province of Chimaltenango, said David de Leon, Spokesperson for the National Commission for the Reduction of National Disasters. That toll was expected to rise, he said.
And El Salvador reported nine deaths from the storm. The government issued a red alert, the highest warning level, which shut down schools and opened up shelters for families in the affected areas, President Mauricio Funes said.
Agatha, an Eastern Pacific storm, struck land Saturday and was downgraded from a tropical depression to a remnant storm on Sunday. It was last reported moving toward the western Caribbean on Sunday afternoon, but was expected to keep producing heavy rains through Monday, according to the U.S. National Hurricane Center.
In Guatemala, the storm damaged more than 3,500 homes and forced the evacuation of more than 61,000 people, the nation's emergency office said Sunday. And in Mexico, the government's National Meteorological Service predicted torrential rain for Chiapas state, intense downpours in Tabasco and strong showers in Quintana Roo.
Four other Mexican states were predicted to receive moderate rain. Strong winds also were forecast.
Swollen rivers and mudslides were a concern. In Guatemala, four children were buried in a landslide outside Guatemala City, the nation's capital. Four adults were killed in the capital, disaster officials said. Another two children and two adults were killed when a boulder, dislodged by heavy rains, crushed a house in the department of Quetzaltenango, 125 miles (200 km) west of Guatemala City, officials said.
Guatemala is already under a 15-day state of calamity because of Thursday's eruption of the Pacaya volcano, which killed at least three people. At least 1,800 people had already been evacuated to shelters. The volcano also shut down the capital's international airport.
Ash from the volcano that covered city streets and other areas mixed with the heavy rain, forming a goo that caused many drainage systems to clog.
Guatemalan President Alvaro Colom said damage from Agatha was probably worse than the destruction caused by Hurricanes Mitch in 1998 and Stan in 2005, both of which devastated the Central American country.
"The country is suffering a great tragedy, this attack by nature," Colom said from the Guatemalan emergency agency center.
Emergencies were reported in all of Guatemala's 22 states, called departments. The worst, Colom said, was the Pacific Ocean port of Champerico, which is isolated.
"We have no way of getting there to help the public, which is in danger because of flooding," Colom said.
The president said he has asked the international community for help.
Agatha is the first named storm of the Pacific hurricane season. The Atlantic hurricane season starts June 1.
CNN's Esprit Smith and journalist Merlin Rodriguez contributed to this report.
51 Miss US Pageant hopeful welcome at Planet Hollywood
Reigning Miss US Kristen Dalton welcome the 51 contestant of the 2010 Miss US Pageant this day to Planet Hollywood, and fans can meet all of them this afternoon external the hotel on the Strip for the official 5 p.m. Las Vegas welcome.
On hand will be Paula Shugart, Miss Universe president; Terry Jicinsky, Senior VP of Promotion for the Las Vegas gathering and Visitors Authority; and Marilyn Winn, president of Bally’s, Paris and Planet Hollywood. It’s the third successive year that Donald Trump’s pageant has been held at Planet Hollywood. The pageant airs live on NBC on May 16.
Sassy Joan Rivers and daughter Melissa Rivers will provide unexpected drama with their offstage zingers, with entertainment by Trace Adkins, Boys like Girls and co-hosts Natalie Morales and Australian cooking hunk Curtis Stone.
For the next 2 weeks, the 51 contestants, As well as Miss Nevada USA Julianna Erdesz, face a grueling schedule of events, dinners, photo shoots and then rehearsals -- all leading up to the big day. We posted yesterday in Strip Scribbles a fast rundown of their schedule.
Our contributing photographers will be on duty this afternoon with me, and we'll post their photographs as soon as likely following the official welcome.
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