Posted on by Nancy Atkinson

SDO Seeing ‘Butterfly Effect’ on the Sun

A new view of the sun from the Solar Dynamics Observatory. Credit: NASA

[/caption]
Already, the Solar Dynamics Observatory, or SDO, has taken over 5 million images, and the firehose of data and spectacular images is allowing solar scientists to begin understanding the dynamic nature of solar storms. With SDO, scientists are seeing that even minor solar events can have large effects across the Sun. “In essence, we are watching the butterfly effect in action on the Sun,” said Dean Pesnell, SDO project scientist.

The Atmospheric Imaging Assembly (AIA), one of three instruments aboard SDO, records high-resolution full-disk images of the Sun’s corona and chromosphere in more channels and at a higher rate than ever before. “This will allow us to zoom in on small regions and see far more detail in time and space, and zoom in on any part we want,” said Pesnell. “By looking at entire Sun we can see how one part of the Sun affects another. You can then zoom in to measure the changes in great detail.”

Large eruptive prominence on the sun's edge, as seen by SDO. Credit: NASA

Shortly after AIA opened its doors on March 30, scientists observed a large eruptive prominence on the sun’s edge, followed by a filament eruption a third of the way across the star’s disk from the eruption.

“Even small events restructure large regions of the solar surface,” said Alan Title, AIA principal investigator at Lockheed Martin Advanced Technology Center. “It’s been possible to recognize the size of these regions because of the combination of spatial, temporal and area coverage provided by AIA.”

At the 216th American Astronomical Society meeting this week, Title said that some of the initial data from SDO is providing maps of magnetic fields and movies that are giving scientists some confidence in trying to decipher the cause and effect of solar storms

AIA observed a number of very small flares that have generated magnetic instabilities and waves with clearly-observed effects over a substantial fraction of the solar surface. The instrument is capturing full-disk images in eight different temperature bands that span 10,000 to 36-million degrees Fahrenheit. This allows scientists to observe entire events that are very difficult to discern by looking in a single temperature band, at a slower rate, or over a more limited field of view.

Solar storms produce disturbances in electromagnetic fields that can induce large currents in wires, disrupting power lines and causing widespread blackouts here on Earth. The storms can interfere with global positioning systems, cable television, and communications between ground controllers and satellites and airplane pilots flying near Earth’s poles. Radio noise from solar storms also can disrupt cell phone service.

To help scientists and the public to understand and have access to the large amount of data being returned by SDO, the science team has built some tools to help communicate the data.

New websites will help researchers find data sets relative to their topics of interest and provide an overview to the casual observer.

“SDO generates as much data in a single day as the TRACE mission produced in five years,” said Neal Hurlburt from SDO mission, from Lockheed Martin. “We want to share it with the public, but we want to do it in an effective way, so we developed the Heliophysics Events Knowledgebase (HEK) and the Sun Today Website.”

The Sun Today website displays the current state of events on the sun. These can guide researchers and others to more detailed descriptions and access to associated SDO data.

HEK includes the Event and Coverage Registries (HER, HCR), Inspection & Analysis Tools, Event Identification System and Movie Processing. Event services enable web clients to interact with the HEK.

There is also a tutorial on how to work with the data, and extract images and movies from the SDO data.

More info: SDO website.

Posted on by Nancy Atkinson

New Image Shows Phoenix Lander’s Solar Panel is Missing

wo images of the Phoenix Mars lander taken from Martian orbit in 2008 and 2010. The 2008 lander image shows two relatively blue spots on either side corresponding to the spacecraft's clean circular solar panels. In the 2010 image scientists see a dark shadow that could be the lander body and eastern solar panel, but no shadow from the western solar panel. Image credit: NASA/JPL-Caltech/University of Arizona

[/caption]

The Phoenix lander will not be phoning home. A new image of Phoenix taken this month by the HiRISE camera (High Resolution Imaging Science Experiment) on board the Mars Reconnaissance Orbiter shows signs of severe ice damage to the lander’s solar panels, with one panel appearing to be completely gone. The Phoenix team says this is consistent with predictions of how Phoenix could be damaged by harsh winter conditions. It was anticipated that the weight of a carbon-dioxide ice buildup could bend or break the solar panels.

“Before and after images are dramatically different,” said Michael Mellon of the University of Colorado in Boulder, a science team member for both Phoenix and HiRISE. “The lander looks smaller, and only a portion of the difference can be explained by accumulation of dust on the lander, which makes its surfaces less distinguishable from surrounding ground.”

Mellon calculated hundreds of pounds of ice probably coated the lander in mid-winter. Several attempts to contact Phoenix during the past few months came up empty.

Phoenix parachute and backshell from 2008 (left) and 2010. Credit: NASA/JPL/U of Arizona

“We can see that the lander, heat shield, and backshell-plus-parachute are now covered by dust,” said Mellon and Alfred McEwen on the HiRISE website, “so they lack the distinctive colors of the hardware or the surfaces where the pre-landing dust was disturbed. But if the lander is structurally intact, it should cast the same shadows. While that is indeed the case for the shadow cast by the backshell (which came to rest on its side), that does not appear to be the case for the lander.”

See the larger image of all the various pieces of Phoenix on the HiRISE website.

So now, the Phoenix mission is officially over.

But during its mission on Mars, Phoenix confirmed and examined patches of the widespread deposits of underground water ice detected by Odyssey and identified a mineral called calcium carbonate that suggested occasional presence of thawed water. The lander also found soil chemistry with significant implications for life and observed falling snow. The mission’s biggest surprise was the discovery of perchlorate, an oxidizing chemical on Earth that is food for some microbes and potentially toxic for others.

“We found that the soil above the ice can act like a sponge, with perchlorate scavenging water from the atmosphere and holding on to it,” said Peter Smith, Phoenix principal investigator at the University of Arizona in Tucson. “You can have a thin film layer of water capable of being a habitable environment. A micro-world at the scale of grains of soil — that’s where the action is.”

The perchlorate results are shaping subsequent astrobiology research, as scientists investigate the implications of its antifreeze properties and potential use as an energy source by microbes. Discovery of the ice in the uppermost soil by Odyssey pointed the way for Phoenix. More recently, the Mars Reconnaissance Orbiter detected numerous ice deposits in middle latitudes at greater depth using radar and exposed on the surface by fresh impact craters.

“Ice-rich environments are an even bigger part of the planet than we thought,” Smith said. “Somewhere in that vast region there are going to be places that are more habitable than others.”

For more info and a look back at Phoenix, check out the Phoenix mission website.

Source: NASA

Posted on by Nancy Atkinson

New Weekly Sun Fix: SDO’s Pick of the Week

View of action on the Sun during this past week. Credit: NASA/SDO team

[/caption]

Images and data are starting to roll in from the Solar Dynamics Observatory, and the images are nothing short of stunning. So, the SDO website has started a couple of new image gallery features, which will provide a “best of” weekly fix without overloading your Sun senses (and no sunscreen needed!) The first one is Pick of the Week. The image above is the first “pick” and what a pick it is! This SDO close-up shows a filament and active region on the Sun, taken in extreme UV light on May 18, 2010. It shows a dark and elongated filament hovering above the Sun’s surface, with bright regions beneath it. The filaments are cooler clouds of gas that are suspended by tenuous magnetic fields that are often unstable and commonly erupt. This one is estimated to be at least 60 Earth diameters long (about 805,000 km, or 500,000 miles). Wowza!

Click here to see a super-huge full disk image.

See below for another new SDO feature, Hot Shots.

Solar flare on May 17, 2010, as seen by the AIA instrument on SDO. Credit: NASA

Hot Shots will feature some great looking flares. This image from the Atmospheric Imaging Assembly (AIA) instrument shows a solar eruption and a flare. The dark regions show the site of evacuated material from the eruption, and the large magnetic loops were formed during the flare. AIA takes images of the solar atmosphere in multiple wavelengths to study link changes in the surface and how they related to interior changes in the Sun. AIA takes images of the Sun in 10 wavelengths every 10 seconds.

For more see the SDO website.

Posted on by Nancy Atkinson

Launch Dates Narrowed for Mars Science Lab

This artist's concept from an animation depicts Curiosity, the rover to be launched in 2011 by NASA's Mars Science Laboratory, as it is being lowered by the mission's rocket-powered descent stage during a critical moment of the "sky crane" landing in 2012. Image Credit: NASA/JPL-Caltech

[/caption]

Mission planners have narrowed the field for possible launch dates for NASA’s next generation rover to Mars, the Mars Science Laboratory, nicknamed Curiosity. Taking into account orbital mechanics, planetary alignment, and communications issues, MSL’s launch will occur between Nov. 25 and Dec. 18, 2011, with landing will taking place between Aug. 6 and Aug. 20, 2012. The actual landing site is still being decided, between four different locations on Mars (read about the four sites here.)

“The key factor was a choice between different strategies for sending communications during the critical moments before and during touchdown,” said Michael Watkins, mission manager at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “The shorter trajectory is optimal for keeping both orbiters in view of Curiosity all the way to touchdown on the surface of Mars. The longer trajectory allows direct communication to Earth all the way to touchdown.”

Landing on Mars is always very difficult, and NASA has put a high priority on communication during Mars landings, especially after a landing failure in 1999. Therefore, the flight schedule allows for favorable positions for the Mars Odyssey and the Mars Reconnaissance Orbiter, currently orbiting Mars, which can both obtain information during descent and landing of MSL.

The simplicity of direct-to-Earth communication from Curiosity during landing has appeal to mission planners, but the direct-to-Earth option allows a communication rate equivalent to only about 1 bit per second, while the relay option allows about 8,000 bits or more per second.

“It is important to capture high-quality telemetry to allow us to learn what happens during the entry, descent and landing, which is arguably the most challenging part of the mission,” said Fuk Li, manager of NASA’s Mars Exploration Program at JPL. “The trajectory we have selected maximizes the amount of information we will learn to mitigate any problems.”

Curiosity will use several innovations during entry, descent and landing in order to hit a relatively small target area on the surface and set down a rover too heavy for the cushioning air bags used in earlier Mars rover landings. MSL will use employ of the largest parachutes ever used in a space mission to land a car-sized rover on the Red Planet. Most interesting is the final phase of landing, where a “sky-crane,” a rocket-powered descent stage will lower Curiosity on a tether for a wheels-down landing directly onto the surface.

Even though Curiosity won’t be communicating directly with Earth at touchdown, data about the landing will reach Earth promptly. Odyssey will be in view of both Earth and Curiosity, in position to immediately forward to Earth the data stream it is receiving during the touchdown. Odyssey performed this type of “bent-pipe” relay during the May 25, 2008, arrival of NASA’s Phoenix Mars Lander.

Curiosity will rove extensively on Mars, carrying an analytical laboratory and other instruments to examine a carefully selected landing area. It will investigate whether conditions there have favored development of microbial life and its preservation in the rock record. Plans call for the mission to operate on Mars for a full Martian year, which is equivalent to two Earth years.

More information about NASA’s Mars Science Laboratory.

Source: JPL

Posted on by Nancy Atkinson

Last Chance for Phoenix to Call Home Starts Today

Artists rendition of Phoenix on Mars. Credit: NASA/JPL

[/caption]

Starting today, the Mars Odyssey orbiter will be listening once again for the Phoenix Mars Lander, lending an ear to hear if Phoenix has come back to life. Until May 21,Odyssey will listen for a signal from Phoenix during 61 flights over the lander’s site on Mars’ northern arctic region. Earlier attempts to detect a transmission from the lander — totaling 150 overflights in January, February and April – were not successful.

NASA decided to add another round of listening sessions that weren’t originally scheduled.


“To be thorough, we decided to conduct this final session around the time of the summer solstice, during the best thermal and power conditions for Phoenix,” said Chad Edwards, chief telecommunications engineer for the Mars Exploration Program at NASA’s Jet Propulsion Laboratory.

Phoenix quit communicating with Earth in November, 2008, and since that time endured a long and fierce Mars winter, where it was likely encased in CO2 ice in temperatures under -150 C. The solar arrays may have cracked and fallen off the vehicle, and the electronics probably became brittle and broke in the severe cold, so the wiring boards probably are nonfunctional.

Phoenix worked superbly for five months before reduced sunlight caused energy to become insufficient to keep the lander functioning. The solar-powered robot was not designed to survive through the dark and cold conditions of a Martian arctic winter.

Northern Mars experienced its maximum-sunshine day, the summer solstice, on May 12 (Eastern Time; May 13, Universal Time), so the sun will be higher in the sky above Phoenix during the fourth listening campaign than during any of the prior ones. Still, expectations of hearing from the lander remain low.
But nobody is ready to give up just yet.

We’ll let you know if Phoenix phones home.

Source: JPL

Posted on by Nancy Atkinson

New Views of Meridiani Planum Show Deposits of Volcanic Ash

Mars Express' view of Meridiani Planum. Credits: ESA/DLR/FU Berlin (G. Neukum)

[/caption]

Earth isn’t the only place we’re seeing volcanic ash these days. New high resolution color images from ESA’s Mars Express of Meridiani Planum on Mars – the Opportunity rover’s neighborhood — shows evidence of volcanic ash in a small impact crater that is about 50 km wide. The wind-blown dark material also provides clues to the prevailing wind direction in this region of Mars. These images are stunning, especially in the large hi-resolution versions, so click on each image to see Mars up close and personal.

Perspective view of Meridiani Planum. Credits: ESA/DLR/FU Berlin (G. Neukum)

Mars is only about one-half the size of Earth, but yet has several volcanoes larger than anything we have on our home planet. The most massive volcanoes are located on huge uplifts or domes in the Tharsis and Elysium regions of Mars. Meridiani Planum lies close to Tharsis, and is a large plain at the northern edge of the southern highlands of Mars.

Poking through the dark covering are small mounds, probably made of harder, more resistant material. The softer material around them has been eroded and blown out of the crater by north-easterly winds and now lies outside the crater, forming dark streaks at the bottom left of the image.

This dark crater is close to Mars’ equator, and early on this area was chosen as a central reference point for Mars’ geographical coordinate system, so the martian prime meridian runs right through here. Hence the name “Meridiani.”

Meridiani Planum extends 127 km by 63 km and covers an area of roughly 8000 sq km

Three craters stretch across Meridiani Planum. Credits: ESA/DLR/FU Berlin (G. Neukum)

Three craters stretch across Meridiani Planum, as seen in this image. The nearest is an old crater, almost worn away. It is 34 km across. The second is covered in dark material, most likely a substance resembling volcanic ash. It is 50 km wide. The third crater, more distant, is smaller at 15 km wide. Again it possesses a dark floor, perhaps because material from the largest crater has been blown out by the wind and has settled in the smallest one.

The image below gives a broader perspective of the area. The color images were actually taken in 2005 and were just recently released by ESA.

Meridiani Planum at the northern edge of the southern highlands of Mars. The region lies at about 2°N/352°E . Credits: ESA/DLR/FU Berlin (G. Neukum)/MOLA
Posted on by Nancy Atkinson

WISE Pictures the Tadpole Nebula with a String of Pearls

This image from WISE shows the Tadpole nebula. Image credit: NASA/JPL-Caltech/UCLA

[/caption]

The Tadpole nebula is looking very stylish in this new infrared image from the WISE spacecraft, NASA’s Wide-field Infrared Survey Explorer. An asteroid appears like a string of pearls — seen as a line of yellow-green dots in the boxes near center — in this stitched together mosaic. The Tadpole is a star-forming region in the Auriga constellation about 12,000 light-years from Earth. As WISE scanned the sky, it happened to catch asteroid 1719 Jens in action, moving across WISE’s field of view. A second asteroid was also observed cruising by, as highlighted in the boxes near the upper left (the larger boxes are blown-up versions of the smaller ones).

More on this image below, but the WISE team received a bit of bad news this week.

WISE principal investigator Ned Wright and his team had proposed a three-month “warm” extension of the mission after the supply of hydrogen that cools the telescope and detectors on board runs out. However, according to an article in Space News, NASA’s 2010 Astrophysics Senior Review Committee recommended that the mission not be extended, and end as originally planned in October of this year.

While WISE is expected to produce significant results, the committee said there was not adequate scientific justification to continue the mission.

The proposed additional three months, known as Warm WISE – where the spacecraft would observe in two of the four infrared wavelengths it has available when WISE is cooled –would have added $6.5 million to the program’s $320 million price tag.

Currently, WISE produces approximately 7,500 images a day.

And this latest image is a “gem.”

It consists of twenty-five frames, taken at all four of the wavelengths and were combined into one image: infrared light of 3.4 microns is color-coded blue: 4.6-micron light is cyan; 12-micron-light is green; and 22-micron light is red.

But wait, there’s more! Also visible in the image are two satellites orbiting above WISE (highlighted in the ovals). They streak through the image, appearing as faint green trails. The apparent motion of asteroids is slower than satellites because asteroids are much more distant, and thus appear as dots that move from one WISE frame to the next, rather than streaks in a single frame.

This Tadpole region is chock full of stars as young as only a million years old — infants in stellar terms — and masses over 10 times that of our sun. It is called the Tadpole nebula because the masses of hot, young stars are blasting out ultraviolet radiation that has etched the gas into two tadpole-shaped pillars, called Sim 129 and Sim 130. These “tadpoles” appear as the yellow squiggles near the center of the frame. The knotted regions at their heads are likely to contain new young stars. WISE’s infrared vision is helping to ferret out hidden stars such as these.

WISE is an all-sky survey, snapping pictures of the whole sky, including everything from asteroids to stars to powerful, distant galaxies.

Sources: JPL, Space News

Posted on by Nancy Atkinson

Young Stars Blast a Hole in Space

The black spot in the green-tinged cloud near the top of the image is a hole blown through NGC 1999 by the jets and winds of gas from the young stellar objects in this region of space. Credits: ESA/HOPS Consortium

[/caption]

There is a black patch of space in NGC 1999, and for years astronomers have thought it was just a dense cloud of gas and dust, blocking light from passing through. But the Herschel infrared space telescope – which has the ability to peer into these dense clouds — has made an unexpected discovery. This black patch is actually a hole that has been blown in the side of the nebula by the jets and winds of gas from the young stellar objects in this region of space. “No-one has ever seen a hole like this,” said Tom Megeath, of the University of Toledo in the USA. “It’s as surprising as knowing you have worms tunneling under your lawn, but finding one morning that they have created a huge, yawning pit.”

Any previous descriptions of NCG 1999 said that the ominous dark cloud in the center was actually a condensation of cold molecular gas and dust so thick and dense that it blocks light. And astronomers had no reason to believe otherwise, until Herschel’s powerful infrared eyes took a look from space.

A Hubble image of NCG 1999 showing the dark patch. Credit: Hubble Heritage Team (STScI) and NASA

When Herschel looked in the direction of this nebula to study nearby young stars, the cloud continued to look black. But, that should not be the case. Herschel’s infrared eyes are designed to see into such clouds. Either the cloud was immensely dense or something was wrong.

Investigating further using ground-based telescopes, astronomers found the same story however they looked: this patch looks black not because it is a dense pocket of gas but because it is truly empty. Something has blown a hole right through the cloud.

Stars are born in dense clouds of dust and gas. Although jets and winds of gas have been seen coming from young stars in the past, it has always been a mystery exactly how a star uses these to blow away its surroundings and emerge from its birth cloud. With Herschel, this may be the first time we can see this process.

The astronomers think that the hole must have been opened when the narrow jets of gas from some of the young stars in the region punctured the sheet of dust and gas that forms NGC 1999. The powerful radiation from a nearby mature star may also have helped to clear the hole. Whatever the precise chain of events, it could be an important glimpse into the way newborn stars disperse their birth clouds.

Source: ESA

Posted on by Nancy Atkinson

NASA Diagnoses Problem With Voyager 2

This artist's rendering depicts NASAs Voyager 2 spacecraft as it studies the outer limits of the heliosphere - a magnetic 'bubble' around the solar system that is created by the solar wind. Image credit: NASA/JPL-Caltech

[/caption]

What could be happening out near the edge of the solar system? The 33-year-old Voyager 2 spacecraft has experienced an anomaly where the data it sends back is unreadable. To try and understand the problem, engineers at JPL have shifted the spacecraft into a mode where it transmits only spacecraft health and status data. Preliminary engineering data received on May 1 show the spacecraft is basically healthy, and that the source of the issue is the flight data system, which is responsible for formatting the data to send back to Earth.

Voyager team members first noticed changes in the return of data packets from Voyager 2 on April 22, and have been working since then to troubleshoot the problem and resume the regular flow of science data. Because of a planned roll maneuver and moratorium on sending commands, engineers got their first chance to send commands to the spacecraft on April 30. It takes nearly 13 hours for signals to reach the spacecraft and nearly 13 hours for signals to come down to NASA’s Deep Space Network on Earth.

Voyager 2 is about 13.8 billion kilometers, or 8.6 billion miles, from Earth, and launched on August 20, 1977. Its twin, Voyager 1 is about 16.9 billion kilometers (10.5 billion miles) away from Earth, and launched almost two weeks after Voyager 2.

The original mission was a four-year journey to Saturn, and later the flybys of Uranus and Neptune were added to give us a “Grand Tour” of the outer solar system. If all goes well, Voyager 2 should leave the solar system and enter interstellar space in about five years.

Source: JPL