Posted on by Nancy Atkinson

Opportunity Rover Glimpses Conditions Suitable for Life

Whitewater Lake is the large flat rock in the top half of the image. From left to right it is about 30 inches (0.8 meter) across. The dark blue nubby rock to the lower left is “Kirkwood,” which bears non-hematite spherules. Credit: NASA/JPL-Caltech/ Cornell Univ./Arizona State Univ.

Steve Squyres, Principal Investigator for the Mars Explorations Rovers, cracked open the equivalent of the Opportunity rover’s field geologist’s notebook to describe what he called “a delightful geological puzzle.”

“This is a work in progress,” Squyres said at the American Geophsical Union conference today, “But this is our first glimpse ever at conditions on ancient Mars that clearly show us a chemistry that would have been suitable for life.”

While both the MER rovers have found evidence of past water on Mars, all indications are that it would have been very acidic, with “battery-acid kind of numbers making it very challenging for life,” Squyres said.

Newly found clays that are sprinkled with two different kinds of previously unseen features point to a different type of water “that you could drink,” Sqyures added.

Orbital data from the Mars Reconnaissance Orbiter’s CRISM (Compact Reconnaissance Imaging Spectrometer for Mars) instrument originally led the MER team to Endeavour Crater, the huge crater where Opportunity is now traversing around the rim.

“It was discovered from CRISM that there were clay minerals there,” Squyres said, “and clays form in a watery environment, and only form under a neutral pH, water that is not acidic.”

The rover has found a region filled with light-toned rocks, such as the Whitewater Lake rock, above, around a small hill named “Matijevic Hill” in the “Cape York” segment of the rim of Endeavour Crater. Squyres described it as the “sweet spot” where clays are known to be present.

This map shows the route driven by NASA’s Mars Exploration Rover Opportunity during a reconnaissance circuit around an area of interest called “Matijevic Hill” on the rim of a large crater. Image credit: NASA/JPL-Caltech/University of Arizona

They have since driven the rover around Matijevic Hill to survey the clays, “which is what you would do if you were a geologist at a site, you’d walk the outcrop,” Squyres said. “We’ve got a good map of where the good, interesting stuff is at Matijevic Hill.”

Interspersed on the light-toned rocks are fine veins of even lighter material, which has never been seen before. Additionally, there are “fins” of darker rock sticking up in the region, and within the fins are dense concentrations of spherical little features, about 3 mm in size that are very similar to the hematite Martian “blueberries” that Opportunity has seen before. But when they looked at the chemical composition of these spheres, the science team found they weren’t blueberries, because they contained no iron, which is what hematite is made from.

“It’s something totally different, and I’ve started calling them ‘newberries’,” said Squyres.

Small spherical objects fill the field in this mosaic combining four images from the Microscopic Imager on NASA’s Mars Exploration Rover Opportunity. Image credit: NASA/JPL-Caltech/Cornell Univ./ USGS/Modesto Junior College

It is difficult for the rover to determine the chemical make-up of the newberries and the light-colored veins because they are such small features, the rover can’t focus merely on those features. But Squyres and team have come up with a to-do list to try and figure out the mystery of the clays and newberries:

Task one is to understand the Whitewater Lake rock better and look at the rock’s sediments, to understand the layers in the rock: were the layers laid down by water, impact or another process?

The second task is to figure out what the newberries made of. They will have to observe regions that have different concentrations of the spherules to eke out what minerals are and aren’t part of the newberries.

Task three is to find a “contact place” where the light-toned clay rocks like Whitewater are touching the breccias – the broken and fused rock born of the impact that created the crater – that is present all around the rim of Endeavour. They haven’t yet found a place where the two are together.

Task four is to figure out what the fine veins are in the clay rocks.

The tasks are intertwined, Squyres said. “Figuring out the newberries will be important for figuring out the how these clays were laid down. So the stories aren’t independent, they are woven together and we still have homework to do,” he said.

But the team will have to work fast.

Opportunity image of light, flat rocks containing clay and mysterious darker rocks jutting through them. NASA/JPL-Caltech/ Cornell Univ./Arizona State Univ

They have about 6 months before winter sets in again in Meridiani Planum on Mars.

“We’ll soon start doing some serious winter planning,” said Diana Blaney, Deputy Project Scientist. When asked about the potential for Oppy to make it through another winter, Blaney said it all depends on the amount of dust build-up on the solar panels and how much power can be generated. “We don’t have any reason not to expect to survive, but it is a dynamic situation, and are looking ahead to find potential wintering sites,” that have beneficial tilt for the rover to absorb as much sunlight as possible.

The last winter the Opportunity rover endured was the first time the rover had to remain stationary due to power concerns because of dust accumulation on the solar arrays.

“We’re nine years into a 90 day mission,” Squyres said, “and every day is a gift at this point and we’re just going to keep pushing ourselves and the rover.”

A 3-D mosaic of the Cape York region where Opportunity is now working. Credit: NASA/JPL-Caltech/ Cornell Univ./Arizona State Univ

For additional information, see this NASA press release.

Posted on by Jason Major

NASA Reveals Plans for New Mars Rover

Sequels are all the rage these days… even for NASA, apparently.

At the American Geophysical Union 2012 convention in San Francisco today, NASA’s associate administrator for science John Grunsfeld revealed the agency’s plans for another Mars mission. Slated to land in 2020, it will be a rover based on the same design as Mars Science Laboratory. Estimated cost of the mission was announced to be $1.5 billion.

This news brought mixed reactions from many of those in attendance as well as followers online, as while more exploration of the Red Planet is certainly an exciting concept, we have all heard — and seen — countless tales of budget cuts and funding problems throughout NASA over recent years, and many proposed missions and collaborations have had to be shelved or cut short due to lack of funds (remember ExoMars?) Even though the budget for this mission is supposedly “not being taken from other areas,” it’s clearly not going to them either. It will be interesting to see how this plays out across the agency.

The full press release from NASA can be seen below:

(Via NASA)

Building on the success of Curiosity’s Red Planet landing, NASA has announced plans for a robust multi-year Mars program, including a new robotic science rover set to launch in 2020. This announcement affirms the agency’s commitment to a bold exploration program that meets our nation’s scientific and human exploration objectives.

“The Obama administration is committed to a robust Mars exploration program,” NASA Administrator Charles Bolden said. “With this next mission, we’re ensuring America remains the world leader in the exploration of the Red Planet, while taking another significant step toward sending humans there in the 2030s.”

The planned portfolio includes the Curiosity and Opportunity rovers; two NASA spacecraft and contributions to one European spacecraft currently orbiting Mars; the 2013 launch of the Mars Atmosphere and Volatile EvolutioN (MAVEN) orbiter to study the Martian upper atmosphere; the Interior Exploration using Seismic Investigations, Geodesy and Heat Transport (InSight) mission, which will take the first look into the deep interior of Mars; and participation in ESA’s 2016 and 2018 ExoMars missions, including providing “Electra” telecommunication radios to ESA’s 2016 mission and a critical element of the premier astrobiology instrument on the 2018 ExoMars rover.

The plan to design and build a new Mars robotic science rover with a launch in 2020 comes only months after the agency announced InSight, which will launch in 2016, bringing a total of seven NASA missions operating or being planned to study and explore our Earth-like neighbor.

The 2020 mission will constitute another step toward being responsive to high-priority science goals and the president’s challenge of sending humans to Mars orbit in the 2030s.

The future rover development and design will be based on the Mars Science Laboratory (MSL) architecture that successfully carried the Curiosity rover to the Martian surface this summer. This will ensure mission costs and risks are as low as possible, while still delivering a highly capable rover with a proven landing system. The mission will constitute a vital component of a broad portfolio of Mars exploration missions in development for the coming decade.

The mission will advance the science priorities of the National Research Council’s 2011 Planetary Science Decadal Survey and responds to the findings of the Mars Program Planning Group established earlier this year to assist NASA in restructuring its Mars Exploration Program.

“The challenge to restructure the Mars Exploration Program has turned from the seven minutes of terror for the Curiosity landing to the start of seven years of innovation,” Grunsfeld said. “This mission concept fits within current and projected Mars exploration budget, builds on the exciting discoveries of Curiosity, and takes advantage of a favorable launch opportunity.”

The specific payload and science instruments for the 2020 mission will be openly competed, following the Science Mission Directorate’s established processes for instrument selection. This process will begin with the establishment of a science definition team that will be tasked to outline the scientific objectives for the mission.

This mission fits within the five-year budget plan in the president’s Fiscal Year 2013 budget request, and is contingent on future appropriations.

Plans also will include opportunities for infusing new capabilities developed through investments by NASA’s Space Technology Program, Human Exploration and Operations Mission Directorate, and contributions from international partners.

________________________

NASA and John Grunsfeld will be hosting a follow-up press conference later today at AGU, which will be streamed live online at 7 p.m. EST/4 p.m. PST. Stay tuned for more information.

 

Posted on by Jason Major

The Brightest Galaxies in the Universe Were Invisible… Until Now

Hubble images of six of the starburst galaxies first found by ESA’s Herschel Space Observatory (Keck data shown below each in blue)

Many of the brightest, most actively star-forming galaxies in the Universe were actually undetectable by Earth-based observatories, hidden from view by thick clouds of opaque dust and gas. Thanks to ESA’s Herschel space observatory, which views the Universe in infrared, an enormous amount of these “starburst” galaxies have recently been uncovered, allowing astronomers to measure their distances with the twin telescopes of Hawaii’s W.M. Keck Observatory. What they found is quite surprising: at least 767 previously unknown galaxies, many of them generating new stars at incredible rates.

Although nearly invisible at optical wavelengths these newly-found galaxies shine brightly in far-infrared, making them visible to Herschel, which can peer through even the densest dust clouds. Once astronomers knew where the galaxies are located, they were able to target them with Hubble and, most importantly, the two 10-meter Keck telescopes — the two largest optical telescopes in the world.

By gathering literally hundreds of hours of spectral data on the galaxies with the Keck telescopes, estimates of their distances could be determined as well as their temperatures and how often new stars are born within them.

“While some of the galaxies are nearby, most are very distant; we even found galaxies that are so far that their light has taken 12 billion years to travel here, so we are seeing them when the Universe was only a ninth of its current age,” said Dr. Caitlin Casey, Hubble fellow at the UH Manoa Institute for Astronomy and lead scientist on the survey. “Now that we have a pretty good idea of how important this type of galaxy is in forming huge numbers of stars in the Universe, the next step is to figure out why and how they formed.”

A representation of the distribution of nearly 300 starbursts in one 1.4 x 1.4 degree field of view.

The galaxies, many of them observed as they were during the early stages of their formation, are producing new stars at a rate of 100 to 500 a year — with a mass equivalent of several thousand Suns — hence the moniker “starburst” galaxy. By comparison the Milky Way galaxy only births one or two Sun-mass stars per year.

The reason behind this explosion of star formation in these galaxies is unknown, but it’s thought that collisions between young galaxies may be the cause.

Another possibility is that galaxies had much more gas and dust during the early Universe, allowing for much higher star formation rates than what’s seen today.

“It’s a hotly debated topic that requires details on the shape and rotation of the galaxies before it can be resolved,” said Dr. Casey.

Still, the discovery of these “hidden” galaxies is a major step forward in understanding the evolution of star formation in the Universe.

“Our study confirms the importance of starburst galaxies in the cosmic history of star formation. Models that try to reproduce the formation and evolution of galaxies will have to take these results into account.”

– Dr. Caitlin Casey, Hubble fellow at the UH Manoa Institute for Astronomy

“For the first time, we have been able to measure distances, star formation rates, and temperatures for a brand new set of 767 previously unidentified galaxies,” said Dr. Scott Chapman, a co-author on the studies. “The previous similar survey of distant infrared starbursts only covered 73 galaxies. This is a huge improvement.”

The papers detailing the results were published today online in the Astrophysical Journal.

Sources: W.M. Keck Observatory article and ESA’s news release.

Image credits: ESA–C. Carreau/C. Casey (University of Hawai’i); COSMOS field: ESA/Herschel/SPIRE/HerMES Key Programme; Hubble images: NASA, ESA. Inset image courtesy W. M. Keck Observatory.

Posted on by Nancy Atkinson

Astrophoto: Jet Black Moon

Jet crossing the Moon on December 2, 2012. Credit: Sculptor Lil on Flickr

A little play on words for the headline, but we just had to share this great shot by astrophotographer Sculptor Lil from London, England!

Want to get your astrophoto featured on Universe Today? Join our Flickr group or send us your images by email (this means you’re giving us permission to post them). Please explain what’s in the picture, when you took it, the equipment you used, etc.

Posted on by Jason Major

Black Hole Jets Might Be Molded by Magnetism

Visible-light Hubble image of the jet emitted by the 3-billion-solar-mass black hole at the heart of galaxy M87 (Feb. 1998) Credit: NASA/ESA and John Biretta (STScI/JHU)

Even though black holes — by their definition and very nature — are the ultimate hoarders of the Universe, gathering and gobbling up matter and energy to the extent that not even light can escape their gravitational grip, they also often exhibit the odd behavior of flinging vast amounts of material away from them as well, in the form of jets that erupt hundreds of thousands — if not millions — of light-years out into space. These jets contain superheated plasma that didn’t make it past the black hole’s event horizon, but rather got “spun up” by its powerful gravity and intense rotation and ended up getting shot outwards as if from an enormous cosmic cannon.

The exact mechanisms of how this all works aren’t precisely known as black holes are notoriously tricky to observe, and one of the more perplexing aspects of the jetting behavior is why they always seem to be aligned with the rotational axis of the actively feeding black hole, as well as perpendicular to the accompanying accretion disk. Now, new research using advanced 3D computer models is supporting the idea that it’s the black holes’ ramped-up rotation rate combined with plasma’s magnetism that’s responsible for shaping the jets.

In a recent paper published in the journal Science, assistant professor at the University of Maryland Jonathan McKinney, Kavli Institute director Roger Blandford and Princeton University’s Alexander Tchekhovskoy report their findings made using computer simulations of the complex physics found in the vicinity of a feeding supermassive black hole. These GRMHD — which stands for General Relativistic Magnetohydrodynamic — computer sims follow the interactions of literally millions of particles under the influence of general relativity and the physics of relativistic magnetized plasmas… basically, the really super-hot stuff that’s found within a black hole’s accretion disk.

Read more: First Look at a Black Hole’s Feast

What McKinney et al. found in their simulations was that no matter how they initially oriented the black hole’s jets, they always eventually ended up aligned with the rotational axis of the black hole itself — exactly what’s been found in real-world observations. The team found that this is caused by the magnetic field lines generated by the plasma getting twisted by the intense rotation of the black hole, thus gathering the plasma into narrow, focused jets aiming away from its spin axes — often at both poles.

At farther distances the influence of the black hole’s spin weakens and thus the jets may then begin to break apart or deviate from their initial paths — again, what has been seen in many observations.

This “magneto-spin alignment” mechanism, as the team calls it, appears to be most prevalent with active supermassive black holes whose accretion disk is more thick than thin — the result of having either a very high or very low rate of in-falling matter. This is the case with the giant elliptical galaxy M87, seen above, which exhibits a brilliant jet created by a 3-billion-solar-mass black hole at its center, as well as the much less massive 4-million-solar-mass SMBH at the center of our own galaxy, Sgr A*.

Read more: Milky Way’s Black Hole Shoots Out Brightest Flare Ever

Using these findings, future predictions can be better made concerning the behavior of accelerated matter falling into the heart of our galaxy.

Read more on the Kavli Institute’s news release here.

Inset image: Snapshot of a simulated black hole system. (McKinney et al.) Source: The Kavli Institute for Particle Astrophysics and Cosmology (KIPAC)

Posted on by Nancy Atkinson

Voyager 1 Riding on a Magnetic Highway Out of the Solar System

Artist concept of NASA’s Voyager 1 spacecraft exploring a new region in our solar system called the “magnetic highway.” Credit: NASA/JPL-Caltech

The Voyager 1 spacecraft has not left the solar system, as was speculated earlier this year, but has now entered a new region at the edge of the solar system that scientists didn’t even know was there. It appears to be a “highway” of magnetic particles, shepherding Voyager 1 out into interstellar space.

“When you’ve gone where nothing has gone before, you expect to make new discoveries,” said Arik Posner, Voyager Program Scientist at a press briefing today.

“This is really another exciting step in the Voyager journey of exploration,” said Project Scientist Ed Stone. “Voyager’s discovered a new region of the heliosphere that we had not realized was there. It’s a magnetic highway where the magnetic field of the Sun is connected to the outside. So it’s like a highway, letting particles in and out.”

This artist’s concept shows plasma flows around NASA’s Voyager 1 spacecraft as it approaches interstellar space. Image credit: NASA/JPL-Caltech/JHUAPL

The heliosphere is a huge bubble of charged particles, and previously the Sun’s lower-energy charged particles have dominated. Now, Voyager 1 is in a region where it is surrounded almost entirely from cosmic rays from outside our solar system,as the lower-energy particles appear to be zooming out and higher-energy particles from outside are streaming in.

The first indication that something new was happening was on July 28 of this year when the level of lower-energy particles originating from inside our Solar System dropped by half. However, in three days, the levels had recovered to near their previous levels. But then the bottom dropped out at the end of August.

The two Voyager spacecraft have been heading outward since their launches 16 days apart in 1977. Voyager 1 is now near the edge of the solar system, and Voyager 2 is not far behind. Scientists feel this new region at the far reaches of our solar system is the final area the spacecraft has to cross before reaching interstellar space.

The Voyager team infers this region is still inside our solar bubble because the direction of the magnetic field lines has not changed. The direction of these magnetic field lines is predicted to change when Voyager breaks through to interstellar space.

“We believe this is the last leg of our journey to interstellar space,” Stone said. “Our best guess is it’s likely just a few months to a couple years away. The new region isn’t what we expected, but we’ve come to expect the unexpected from Voyager.”

Since December 2004, when Voyager 1 crossed a point in space called the termination shock, the spacecraft has been exploring the heliosphere’s outer layer, called the heliosheath. In this region, the stream of charged particles from the Sun, known as the solar wind, abruptly slowed down from supersonic speeds and became turbulent. Voyager 1’s environment was consistent for about five and a half years. The spacecraft then detected that the outward speed of the solar wind slowed to zero.

The intensity of the magnetic field also began to increase at that time.

“If we had only looked at the particle data alone, we would have said well, we’re out, goodbye solar system,” said Stamatios Krimigis, principal investigator for Voyager’s low-energy charged particle instrument. “We need to look at what all the instruments are telling us, because nature is very imaginative, and Lucy pulled out the football again.”

That’s because the magnetic field direction has not yet changed to the expected north-south orientation of interstellar space.

“We’re quite confident that there’s really no reason to believe we’re outside the heliosphere,” said Leonard Burlaga, with the Voyager magnetometer team. “There’s no evidence that we have entered the interstellar magnetic field. We are in a magnetic region unlike any we’ve been in before — about 10 times more intense than before the termination shock. The magnetic field data turned out to be the key to pinpointing when we crossed the termination shock. And we expect these data will tell us when we first reach interstellar space.”

As for the future of the spacecraft, which are powered by plutonium 238, they each lose about 4 watts of power a year and by 2020, the science team will have to start turning off instruments in order to conserve power. By 2025, there will probably not be enough power for any of the instruments to run, but there will be enough power to “ping” the spacecraft and have it answer. But by that time, they should be well out of the solar system. However, the spacecraft likely won’t encounter much, as it would take about 40,000 years for one of the Voyagers to reach another star system.

Voyager 1 is the most distant human-made object, about 18 billion kilometers (11 billion miles) away from the Sun. The signal from Voyager 1 takes approximately 17 hours to travel to Earth. Voyager 2, the longest continuously operated spacecraft, is about 15 billion kilometers (9 billion miles) away from our Sun. While Voyager 2 has seen changes similar to those seen by Voyager 1, the changes are much more gradual. Scientists do not think Voyager 2 has reached the magnetic highway.

Sources: Press briefing, JPL

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: December 3-9, 2012



NGC 457 Courtesy of Ken and Emilie Siarkiewicz/Adam Block/NOAO/AURA/NSF

Greetings, fellow SkyWatchers! With a whole lot less Moon present in the early evenings, it’s time to do some very different studies – from North to South! We’ll be having a look at planetary nebulae, globular clusters, galactic star clusters and some great galaxies, too! Need more? Then SH viewers can kick back and relax to a meteor shower, too! Whenever you’re ready, just meet me in the back yard…

Monday, December 3 – Today in 1971, the Soviet Mars 3 became the first spacecraft to make a soft landing on the red planet, and two years later on this same date the Pioneer 10 mission became the first spacecraft to fly by Jupiter. One year later on this same date? Pioneer 11 did the same thing!

Tonight let’s familiarize ourselves with the vague constellation of Fornax. Its three brightest stars form a shallow V just south of the Cetus/Eridanus border and span less than a handwidth of sky. Although it’s on the low side for northern observers, there is a wealth of sky objects in this area.

Try having a look at the easternmost star – 40-light-year distant Alpha. At magnitude 4, it is not easy, but what you’ll find there is quite beautiful. For binoculars, you’ll see a delightful cluster of stars around this long-term binary – but telescopes will enjoy it as a great golden double star! First measured by John Herschel in 1835, the distance between the pair has narrowed and widened over the last 172 years and it is suspected its orbital period may be 314 years. While the 7th magnitude secondary can be spotted with a small scope – watch out – because it may also be a variable which drops by as much as a full magnitude!

Tuesday, December 4 – Today in 1978, the Pioneer/Venus Orbiter became the first spacecraft to orbit Venus. And in 1996, the Mars Pathfinder mission was launched!

For larger telescopes, set sail for Beta Fornacis tonight and head 3 degrees southwest (RA 02 39 42.5 Dec -34 16 08.0) for a real curiosity – NGC 1049.

At magnitude 13, this globular cluster is a challenge for even large scopes – and with good reason. It isn’t in our galaxy. This globular cluster is a member of the Fornax Dwarf Galaxy – a one degree span that’s so large it was difficult to recognize as extra-galactic – or at least it was until the great Harlow Shapely figured it out! NGC 1049 was first discovered and cataloged by John Herschel in 1847, only to be reclassified as “Hodge 3″ in a 1961 study of the system’s five globular clusters by Paul Hodge. Since that time, yet another globular has been discovered! Good luck…

Wednesday, December 5 – How about something a little more suited to the mid-sized scope tonight? Set your sights on Alpha Fornacis and let’s head about 3 fingerwidths northeast (RA 03 33 14.65 Dec -25 52 18.0) for NGC 1360.

In a 6? telescope, you’ll find the 11th magnitude central spectroscopic double star of this planetary nebula to be very easy – but be sure to avert because the nebula itself is very elongated. Like most of my favorite things, this planetary is a rule-breaker since it doesn’t have an obvious shell structure. But why? Rather than believe it is not a true planetary by nature, studies have shown that it could quite possibly be a very highly evolved one – an evolution which has allowed its gases to begin to mix with the interstellar medium. Although faint and diffuse for northern observers, those in the south will recognize this as Bennett 15!

Tonight let’s take advantage of early dark and venture further into Cassiopeia. Returning to Gamma, we will move towards the southeast and identify Delta. Also known as Ruchbah, this long-term and very slight variable star is about 45 light-years away, but we are going to use it as our marker as we head just one degree northeast and discover M103. As the last object in the original Messier catalog, M103 (NGC 581) was actually credited to Mechain in 1781. Easily spotted in binoculars and small scopes, this rich open cluster is around magnitude 7, making it a prime study object. At about 8000 light-years away and spanning approximately 15 light-years, M103 offers up superb views in a variety of magnitudes and colors, with a notable red in the south and a pleasing yellow and blue double to the northwest.

Viewers with telescopes and larger binoculars are encouraged to move about a degree and half east of M103 to view a small and challenging chain of open clusters, NGCs 654 (Right Ascension: 1 : 44.1 – Declination: +61 : 53), 663 and 659! Surprisingly larger than M103, NGC 663 (Right Ascension: 1:46.0 – Declination: +61:15) is a lovely fan-shaped concentration of stars with about 15 or so members that resolve easily to smaller aperture. For the telescope, head north for NGC 654, (difficult, but not impossible to even a 114mm scope) which has a bright star on its southern border. South of NGC 663 is NGC 659 (Right Ascension: 1 : 44.2 – Declination: +60 : 42) which is definitely a challenge for small scopes, but its presence will be revealed just northeast of two conspicuous stars in the field of view.

Thursday, December 6 – For northern observers clamoring for brighter stellar action, look no further tonight than the incredible “Double Cluster” about four fingerwidths southeast of Delta Cassiopeiae (Right Ascension: 2 : 22.4 – Declination: +57 : 07). At a dark sky site, this incredible pair is easily located visually and stunning in any size binoculars and telescopes. As part of the constellation of Perseus, this double delight is around 7000 light-years away and less than 100 light-years separates the pair. While open clusters in this area are not really a rarity, what makes the “Double Cluster” so inviting is the large amount of bright stars within each of them. Well known since the very beginnings of astronomy, take the time to have a close look at both Chi (NGC 884) and H Persei very carefully. Note how many colorful stars you see, and the vast array of double, multiple and variable systems!

Now, let’s return again to Cassiopeia and start at the central-most bright star, Gamma. Four degrees southeast is our marker for this starhop, Phi Cassiopeiae. By aiming binoculars or telescopes at this star, it is very easy to locate an interesting open cluster, NGC 457 (Right Ascension: 1 : 19.1 – Declination: +58:20), because they will be in the same field of view.

This bright and splendid galactic cluster has received a variety of names over the years because of its uncanny resemblance to a figure. Some call it an “Angel,” others see it as the “Zuni Thunderbird;” I’ve heard it called the “Owl” and the “Dragonfly,” but perhaps my favorite is the “E.T. Cluster,” As you view it, you can see why! Bright Phi and HD 7902 appear like “eyes” in the dark and the dozens of stars that make up the “body” appear like outstretched “arms” or “wings.” (For E.T. fans? Check out the red “heart” in the center.)

All this is very fanciful, but what is NGC 457, really? Both Phi and HD 7902 may not be true members of the cluster. If 5th magnitude Phi were actually part of this grouping, it would have to have a distance of approximately 9300 light-years, making it the most luminous star in the sky, far outshining even Rigel! To get a rough idea of what that means, if we were to view our own Sun from this far away, it would be no more than magnitude 17.5. The fainter members of NGC 457 comprise a relatively young star cluster that spans about 30 light-years. Most of the stars are only about 10 million years old, yet there is an 8.6 magnitude red supergiant in the center. No matter what you call it, NGC 457 is an entertaining and bright cluster that you will find yourself returning to again and again. Enjoy!

Friday, December 7 – Today is the birthday of Gerard Kuiper. Born 1905, Kuiper was a Dutch-born American planetary scientist who discovered moons of both Uranus and Neptune. He was the first to know that Titan had an atmosphere, and he studied the origins of comets and the solar system.

Tonight let’s honor his achievements as we have a look at another bright open cluster known by many names: Herschel VII.32, Melotte 12, Collinder 23, and NGC 752. You’ll find it three fingerwidths south (RA 01 57.8 Dec +37 41) of Gamma Andromedae…

Under dark skies, this 5.7 magnitude cluster can just be spotted with the unaided eye, is revealed in the smallest of binoculars, and can be completely resolved with a telescope. Chances are it was first discovered by Hodierna over 350 years ago, but it was not cataloged until Sir William gave it a designation in 1786. But give credit where credit is due… For it was Caroline Herschel who observed it on September 28, 1783! Containing literally scores of stars, galactic cluster NGC 752 could be well over a billion years old, strung out in chains and knots in an X pattern of a rich field. Take a close look at the southern edge for orange star 56: while it is a true binary star, the companion you see is merely optical. Enjoy this unsung symphony of stars tonight!

Now, let’s go back to Cassiopeia. Remembering Alpha’s position as the westernmost star, go there with your finderscope or binoculars and locate bright Sigma and Rho (each has a dimmer companion). They will appear to the southwest of Alpha. It is between these two stars that you will find NGC 7789 (RA 23 57 24.00 Dec +56 42 30.0).

Absolutely one of the finest of rich galactic opens bordering on a loose globular, NGC 7789 has a population of about 1000 stars and spans a mind-boggling 40 light-years. At well over a billion years old, the stars in this 5000 light-year distant galactic cluster have already evolved into red-giants or super-giants. Discovered by Caroline Herschel in the 18th century, this huge cloud of stars has an average magnitude of 10, making it a great large binocular object, a superb small telescope target, and a total fantasy of resolution for larger instruments.

Saturday, December 8 – Today in history (1908) marks “first light” for the 60? Hale Telescope at Mt. Wilson Observatory. Not only was it the largest telescope of the time, but it ended up being one of the most productive of all. Almost 100 years later, the 60? Hale is still in service as a public outreach instrument. If we could use the 60? tonight to study, where would we go? My choice would be the Fornax Galaxy Cluster!

Containing around 20 galaxies brighter than 13th magnitude in a one degree field, here is where a galaxy hunter’s paradise begins! About a degree and a half north of Tau Fornacis is the large, bright and round spiral NGC 1398 (Right Ascension: 3 : 38.9 – Declination: -26 : 20). A little more than a degree west-northwest is the easy ring of the planetary nebula NGC 1360. Look for the concentrated core and dark dustlane of NGC 1371 a degree north-northeast – or the round NGC 1385 which accompanies it. Why not visit Bennett 10 or Caldwell 67 as we take a look at NGC 1097 (Right Ascension: 2:46.3 – Declination: -30:17) about 6 degrees west-southwest of Alpha? This one is bright enough to be caught with binoculars!

Telescopes will love NGC 1365 (Right Ascension: 3:33.6 – Declination: -36:08) at the heart of the cluster proper. This great barred spiral gives an awesome view in even the smallest of scopes. As you slide north, you will encounter a host of galaxies, NGCs 1386, 1389, 1404, 1387, 1399, 1379, 1374, 1381 and 1380. There are galaxies everywhere! But, if you lose track? Remember the brightest of these are two ellipticals – 1399 and 1404. Have fun!

Now, let’s haunt Cassiopeia one last time – with studies for the seasoned observer. Our first challenge of the evening will be to return to Gamma where we will locate two patches of nebulosity in the same field of view. IC 59 and IC 63 are challenging because of the bright influence of the star, but by moving the star to the edge of the field of view you may be able to locate these two splendid small nebulae. If you do not have success with this pair, why not move on to Alpha? About one and a half degrees due east, you will find a small collection of finderscope stars that mark the area of NGC 281 (RA 00 52 25.10 Dec +56 33 54.0). This distinctive cloud of stars and ghostly nebulae make this NGC object a fine challenge!

The last things we will study are two small elliptical galaxies that are achievable in mid-sized scopes. Locate Omicron Cassiopeiae about 7 degrees north of M31 and relocate our earlier study, a galactic pair that is associated with the Andromeda group – NGC 185 (RA 00 38 57.40 Dec +48 20 14.4) and NGC 147 (RA 00 33 11.79 Dec +48 30 24.8). The constellation of Cassiopeia contains many, many more fine star clusters, and nebulae – and even more galaxies. For the casual observer, simply tracing over the rich star fields with binoculars is a true pleasure, for there are many bright asterisms best enjoyed at low power. Scopists will return to “rock with the Queen” year after year for its many challenging treasures. Enjoy it tonight!

Sunday, December 9 – Southern Hemisphere viewers, you’re in luck! This is the maximum of the Puppid-Velid meteor shower. With an average fall rate of about 10 per hour, this particular meteor shower could also be visible to those far enough south to see the constellation of Puppis. Very little is known about this shower except that the streams and radiants are very tightly bound together. Since studies of the Puppid-Velids are just beginning, why not take the opportunity to watch? Viewing will be possible all night long and although most of the meteors are faint, this one is known to produce an occasional fireball.

Since we’re favoring the south tonight, let’s set northern observers toward a galaxy cluster – Abell 347 – located almost directly between Gamma Andromedae and M34. Here you will find a grouping of at least a dozen galaxies that can be fitted into a wide field view. Let’s tour a few…

The brightest and largest is NGC 910 (Right Ascension: 2 : 25.4 – Declination: +41:50), a round elliptical with a concentrated nucleus. To the northwest you can catch faint, edge-on NGC 898. NGC 912 is northeast of NGC 910, and you’ll find it quite faint and very small. NGC 911 to the north is slightly brighter, rounder, and has a substantial core region. NGC 909 further north is fainter, yet similar in appearance. Fainter yet is more northern NGC 906, which shows as nothing more than a round contrast change. Northeast is NGC 914, which appears almost as a stellar point with a very small haze around it. To the southeast is NGC 923 which is just barely visible with wide aversion as a round contrast change. Enjoy this Abell quest!

And the countdown is on… Enjoy these last few weeks of the SkyWatcher, cuz’ the old woman is going to retire at the end of this year! Until then? Clear skies!

Posted on by Nancy Atkinson

Curiosity Update: No Definitive Discovery of Organics…Yet

NASA’s Curiosity Mars rover documented itself in the context of its work site, an area called “Rocknest Wind Drift,” on the 84th Martian day, or sol, of its mission (Oct. 31, 2012). The rover worked at this location from Sol 56 (Oct. 2, 2012) to Sol 100 (Nov. 16, 2012). Image credit: NASA/JPL-Caltech/MSSS

The scientists from the Mars Science Laboratory mission had some good news and bad news at the much-anticipated briefing from the American Geophysical Union conference today. The good news is that all instruments are working well on the Curiosity rover, and they have found some potentially interesting compounds … organic compounds. The bad news is they are not sure if the organics are from Mars or not.

“SAM has no definitive detection to report of organic compounds,” said Paul Mahaffy, principal investigator for the Sample Analysis at Mars (SAM) instrument on the Curiosity rover.

This graph compares the elemental composition of typical soils at three landing regions on Mars: Gusev Crater, where NASA’s Mars Exploration Rover Spirit traveled; Meridiani Planum, where Mars Exploration Rover Opportunity still roams, and now Gale Crater, where the Curiosity rover is currently investigating. Credit: NASA/JPL-Caltech/University of Guelph

Interestingly – but not surprisingly – much of the data from the Curiosity rover is similar to previous Mars landers/rovers, such as Viking, the MER rovers and Phoenix. Curiosity’s instruments found chlorine, sulfur and water in Mars soil. Plus, remember the perchlorates that the Phoenix lander found on Mars four years ago? The Sample Analysis at Mars (SAM) instrument on Curiosity has “tentatively” identified perchlorate, which is an oxygen and chlorine compound, which is highly reactive. Reactions with other chemicals heated in SAM formed chlorinated methane compounds, which are one-carbon organics. The MSL scientists said that the chlorine is of Martian origin, but it is possible the carbon may be of Earth origin, carried along from Earth by Curiosity.

Something like this happened previously, where a detection of methane by the SAM suite of instruments turned out to be air that was brought along from Florida, as air leaked into the Tunable Laser Spectrometer (TLS) while the spacecraft was awaiting launch. The initial readings from the TLS, full of methane, were very exciting to the Curiosity scientists until they realized it was from Earth.

And so, with these latest data, the science team wants to make sure these organic compounds truly come from Mars, or if it is from contamination brought along to Mars onboard Curiosity. And one other fly in the ointment is that the organics could also be primordial material from the cosmos delivered to Mars from meteorites, and not be of Martian origin.

But the good news here is that MSL’s suite of instruments should be able to determine the origin of the organics, no matter when they come from.

“This is the first fully integrated measurement on the mission in which every instrument participated in analysis,” said Curiosity Project Scientist John Grotzinger. “And all the instruments working together can tell us if it isn’t originally from Mars… but there’s a complicated decision pathway, and we have to explore each one systematically.”

Grotzinger said they would have to decide whether or not those formation pathways are abiotic or biologic. But that will take a while, as this missions is “moving at the speed of science.”

“This mission is about integrated science,” he said. “No single measurement will produce a hallelujah moment… We are going to pull it all together and take our time and after that if we’ve found something significant we’ll be happy to report that.”

Grotzinger was asked about how his comments a few weeks ago to an NPR reporter were construed as suggesting that an “earth-shaking” discovery had been made by the team, setting off wild speculation of what the rover found.

“What I’ve learned from this is that you have to be careful about what you say,” he said during the briefing, “and even more careful about how you say it. We’re doing science at the speed of science. But we live in a world that’s sort of at the pace of Instagrams. The enthusiasm that we had, that I had, that our whole team has about what’s going on here, I think it was just misunderstood.”
“The great thing about this was, as the days went by, I thought it was terrific this mission has such wide appeal and public interest,” Grotzinger said.

The exciting part, Grotzinger said, is when you have multiple measurements by the instruments that provide similar results. “When we saw SAM replicating results, we knew team would have stuff to chew on for years to come. That’s why we were excited,” he said.

Mahaffy said before the mission, they knew terrestrial contamination could be an issue.

“We’ve gone to great care to address potential confusion that could be caused by terrestrial contamination,” he said. “We have an organic check material along, a silica glass. In the end, we will drill into organic check material that we brought along. If we see same stuff, then it may be terrestrial.”

The Mars Hand Lens Imager (MAHLI) on NASA’s Mars rover Curiosity acquired close-up views of sands in the “Rocknest” wind drift. Credit: NASA/JPL/MSSS

The Curiosity team purposely looked for an area to study that they thought would be rather benign. Curiosity took five scoops of soil from the Rock Nest site, basically a small sand dune. They found sand grains of various sizes, which Ken Edgett from the Hand Lens Imager team described as thick grains “like the salt grains on those big hot pretzels you can get” to much finer material with “grain sizes kind of like artificial sweeteners.”

This plot of data from NASA’s Mars rover Curiosity shows the variety of gases that were released from sand grains upon heating in the Sample Analysis at Mars instrument, or SAM. The gases detected were released from fine-grain material, and include water vapor, carbon dioxide, oxygen and sulfur dioxide. Credit: NASA/JPL-Caltech/GSFC

As we reported earlier, the first scoops were used to clean out the chemistry system. The real analysis of a sample came when it was heated to about 500°C and the gases that were released were studied. The most abundant gas was water from water, but the amount of water wouldn’t be enough to support any sort of life, the team said, even though it was higher than expected. And interestingly, the deuterium to hydrogen ratio on the surface of Mars is five times heavier than that in Earth’s oceans.

The scientists said this could be a result of Mars’ gradual loss of atmospheric material, in which lighter isotopes were preferentially lost.

The CheMin instrument found the Rock Nest samples were about half and half common volcanic minerals and non-crystalline minerals such as glass.

This map shows where the Curiosity has driven since landing at a site subsequently named “Bradbury Landing,” and traveling to an overlook position near beside “Point Lake,” in drives totaling 1,703 feet (519 meters). Credit: NASA/JPL-Caltech/Univ. of Arizona

Beyond that, the team focused on saying this is just the beginning of the mission with lots of time and potential science ahead.

“We’re working on a mission where it’s always going to be difficult to describe in a general way what we’re discovering,” said Grotzinger. “We do want to be very careful about each step along the way. MSL is a mission that is looking for habitable environments. And for that, we would need a source of water, a source of energy and a source of carbon, an essential building block for biological structures.”

Grotzinger said that what tends to happen is that a lot of attention is paid to the third component, and added that the news last week that organics were found on Mercury shows that organics are common in the solar system. And even though the Curiosity rover has already found a water source – the streambed in Gale Crater, along with the water in the soil — the issue is the relative non-abundance of the organics on Mars, so far.

“If we would have found something that was so abundant, that would have been a surprise for us,” he said.

See the JPL press release.

Posted on by Nancy Atkinson

Stunning Star Trails Mania

You like star trails? We’ve got star trails! One of our favorite timelapse gurus, Gavin Heffernan from Sunchaser Pictures shot this stunning footage, and as he says, no special effects of any kind are needed to create star trails: just leave your shutter open and the natural rotation of Earth takes care of the rest!

But wait… there’s more!

Have you ever compared how different star trails look in the northern hemisphere compared to the southern hemisphere?

César Cantú has:

From the northern hemisphere, stars appear to move counterclockwise around the north pole of the sky; but if you stand at any point in the earth’s southern hemisphere, the stars appear to move clockwise around the south pole of the sky. César, who mans the Chilidog Observtory, took star trail footage from Mexico and Africa and combined the two to create an incredible “Hemispheric Countersense” video. See more about it here.

Combining star trails from Mexico and Africa. Credit: César Cantú

Scene from Sunchaser Star Trails. Credit: Gavin Heffernan. Footage shot in Big Bear Lake, Joshua Tree, and also Canada. Used Canon 5D & 7D, with a 24mm/1.4 lens and a 28mm/1.8.

SUNCHASER STAR TRAILS from Sunchaser Pictures on Vimeo.

Posted on by Jason Major

Are Venus’ Volcanoes Still Active?

Artist’s impression of an active volcano on Venus (ESA/AOES)

Incredibly dense, visually opaque and loaded with caustic sulfuric acid, Venus’ atmosphere oppresses a scorched, rocky surface baking in planet-wide 425 ºC (800 ºF) temperatures. Although volcanoes have been mapped on our neighboring planet’s surface, some scientists believe the majority of them have remained inactive — at least since the last few hundreds of thousands of years. Now, thanks to NASA’s Pioneer Venus and ESA’s Venus Express orbiters, scientists have nearly 40 years of data on Venus’ atmosphere — and therein lies evidence of much more recent large-scale volcanic activity.

The last six years of observations by Venus Express have shown a marked rise and fall of the levels of sulfur dioxide (SO2) in Venus’ atmosphere, similar to what was seen by NASA’s Pioneer Venus mission from 1978 to 1992.

These spikes in SO2 concentrations could be the result of volcanoes on the planet’s surface, proving that the planet is indeed volcanically active — but then again, they could also be due to variations in Venus’ complex circulation patterns which are governed by its rapid “super-rotating” atmosphere.

“If you see a sulphur dioxide increase in the upper atmosphere, you know that something has brought it up recently, because individual molecules are destroyed there by sunlight after just a couple of days,” said Dr. Emmanuel Marcq of Laboratoire Atmosphères in France, lead author of the paper, “Evidence for Secular Variations of SO2 above Venus’ Clouds Top,” published in the Dec. 2 edition of Nature Geoscience.

“A volcanic eruption could act like a piston to blast sulphur dioxide up to these levels, but peculiarities in the circulation of the planet that we don’t yet fully understand could also mix the gas to reproduce the same result,” added co-author Dr Jean-Loup Bertaux, Principal Investigator for the instrument on Venus Express.

The rise and fall of sulphur dioxide in the upper atmosphere of Venus over the last 40 years, expressed in units of parts per billion by volume. Credits: Data: E. Marcq et al. (Venus Express); L. Esposito et al. (earlier data); background image: ESA/AOES

Because Venus’ dense atmosphere whips around the planet at speeds of 355 km/hour (220 mph), pinpointing an exact source for the SO2 emissions is extremely difficult. Volcanoes could be the culprit, but the SO2 could also be getting churned up from lower layers by variations in long-term circulation patterns.

Read: Venus Has a Surprisingly Chilly Layer

Venus has over a million times the concentration of sulfur dioxide than Earth, where nearly all SO2 is the result of volcanic activity. But on Venus it’s been able to build up, kept stable at lower altitudes where it’s well shielded from solar radiation.

Regardless of its source any SO2 detected in Venus’ upper atmosphere must be freshly delivered, as sunlight quickly breaks it apart. The puzzle now is to discover if it’s coming from currently-active volcanoes… or something else entirely.

“By following clues left by trace gases in the atmosphere, we are uncovering the way Venus works, which could point us to the smoking gun of active volcanism,” said Håkan Svedhem, ESA’s Project Scientist for Venus Express.

Read more on the ESA release here.