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.

Posted on by Carnival of Space

Carnival of Space #278

This week’s Carnival of Space is hosted by Amy Shira Teitel at her awesome Vintage Space website.

Click here to read Carnival of Space #278

And if you’re interested in looking back, here’s an archive to all the past Carnivals of Space. If you’ve got a space-related blog, you should really join the carnival. Just email an entry to [email protected], and the next host will link to it. It will help get awareness out there about your writing, help you meet others in the space community – and community is what blogging is all about. And if you really want to help out, sign up to be a host. Send an email to the above address.

Posted on by Jason Major

Titan Shines in Latest Cassini Shots

Color-composite raw image of Titan’s southern hemisphere. Note the growing south polar vortex. (NASA/JPL/SSI/Jason Major)

Last Thursday, November 29, Cassini sailed past Titan for yet another close encounter, coming within 1,014 kilometers (603 miles) of the cloud-covered moon in order to investigate its thick, complex atmosphere. Cassini’s Visible and Infrared Mapping Spectrometer (VIMS), Composite Infrared Spectrometer (CIRS) and Imaging Science Subsystems (ISS) instruments were all busy acquiring data on Titan’s atmosphere and surface… here are a couple of color-composites made from raw images captured in visible light channels as well as some of the more interesting monochrome raw images. Enjoy!

The structure of Titan’s upper-level hazes, which extend ten times the height of Earth’s atmosphere. (NASA/JPL/SSI)

Cassini captured this view of Titan’s crescent during its approach, from a distance of 193,460 kilometers (NASA/JPL/SSI/Jason Major)

Cassini’s continuum filter (CB3) allows it to image Titan’s surface. The dark areas are vast fields of hydrocarbon sand dunes (NASA/JPL/SSI)

These images have not been validated or calibrated by NASA or the mission team.

Read more about the T-88 flyby here.

Posted on by Ken Kremer

Vote ‘Curiosity’ as TIME Person of the Year

I Need You ! Vote for ‘Curiosity’ as TIME magazine Person Of The Year. NASA’s new Curiosity Mars rover snapped this Head and Shoulders Self-Portrait on Sol 85 (Nov. 1 , 2012) as Humanity’s emissary to the Red Planet in Search of Signs of Life. Mosaic Credit: NASA/JPL-Caltech/MSSS/Ken Kremer/Marco Di Lorenzo

Caption – I Need You ! Vote for ‘Curiosity’ as TIME magazine Person Of The Year.
NASA’s new Curiosity Mars rover snapped this Self-Portrait on Sol 85 (Nov. 1 , 2012) as Humanity’s emissary to the Red Planet in Search of Signs of Life. Mosaic Credit: NASA/JPL-Caltech/MSSS/Ken Kremer/Marco Di Lorenzo

You can make it happen. Vote Now ! Vote Curiosity !

Vote for ‘Curiosity’ as the Time magazine Person of the Year

Make your voice heard – Help send a message to the Feds to “Save Our Science” as the Fiscal Cliff nears and threatens our Science.

Perhaps you are a doubter. Well think again. Because at this moment NASA’s Curiosity Mars rover has thrust forward into 5th Place, inching ahead of – comedian Stephen Colbert, according to the running tally at TIME’s Person of the Year website.

NASA’s SUV-sized Curiosity Mars rover is the most powerful science robot ever dispatched as Humanity’s emissary to the surface of the Red Planet. She is searching for Signs of Life and may shed light on the ultimate questions – “Are We Alone?” – “Where do We fit In?

Curiosity is NASA’s first Astrobiology mission to Mars since the twin Viking landers of the 1970’s.

TIME’s editors are soliciting your input on worthy candidates for Person of the Year, although they will choose the ultimate winner.

You have until 11:59 p.m. on Dec. 12 to cast your vote. The winner of the people’s choice will be announced on Dec. 14. The magazine itself with the ultimate winner appears on newsstands on Dec. 21

Image caption: Curiosity trundling across Mars surface inside Gale Crater on Sol 24 (Aug. 30, 2012). Colorized mosaic stitched together from Navcam images. This panorama is featured on PBS NOVA ‘Ultimate Mars Challenge’ documentary which premiered on PBS TV on Nov. 14. Credit: NASA / JPL-Caltech / Ken Kremer / Marco Di Lorenzo

Read TIME’s statement about voting for Curiosity:

You may own a cool car — you may even own a truly great car — but it’s a cinch that no matter how fantastic it is, it can never be anything more than the second best car in the solar system. The greatest of all is the Mars Curiosity rover, one ton of SUV-size machine now 160 million miles from Earth and trundling across the Martian surface. It was the rover’s landing on Mars last August that first caught people’s eyes: an improbable operation that required a hovering mother ship to lower the rover to the surface on cables like a $2.5 billion marionette. But it’s the two years of exploration Curiosity has ahead of it — with a suite of instruments 10 times as large as any ever carried to Mars before — that will make real news. NASA built the country one sweet ride, and yes, alas, it’s sweeter than yours.

Cast your vote for Curiosity now, and avoid the long lines – before it’s too late

Ken Kremer

…..

Learn more about Curiosity’s groundbreaking discoveries and NASA missions at my upcoming pair of free presentations for the general public at two colleges in New Jersey:

Dec 6: Free Public lecture titled “Atlantis, The Premature End of America’s Shuttle Program and What’s Beyond for NASA” including Curiosity, Orion, SpaceX and more by Ken Kremer at Brookdale Community College/Monmouth Museum and STAR Astronomy club in Lincroft, NJ at 8 PM

Dec 11: Free Public lecture titled “Curiosity and the Search for Life on Mars (in 3 D)” and more by Ken Kremer at Princeton University and the Amateur Astronomers Association of Princeton (AAAP) in Princeton, NJ at 8 PM – Princeton U Campus at Peyton Hall, Astrophysics Dept.

Posted on by Jason Major

In an Isolated, Ice-Covered Antarctic Lake Far Below Freezing, Life is Found

Lake Vida lies within one of Antarctica’s cold, arid McMurdo Dry Valleys (Photo: Desert Research Institute)

Even inside an almost completely frozen lake within Antarctica’s inland dry valleys, in dark, salt-laden and sub-freezing water full of nitrous oxide, life thrives… offering a clue at what might one day be found in similar environments elsewhere in the Solar System.


Researchers from NASA, the Desert Research Institute in Nevada, the University of Illinois at Chicago and nine other institutions have discovered colonies of bacteria living in one of the most isolated places on Earth: Antarctica’s Lake Vida, located in Victoria Valley — one of the southern continent’s incredibly arid McMurdo Dry Valleys.

These organisms seem to be thriving despite the harsh conditions. Covered by 20 meters (65 feet) of ice, the water in  Lake Vida is six times saltier than seawater and contains the highest levels of nitrous oxide ever found in a natural body of water. Sunlight doesn’t penetrate very far below the frozen surface, and due to the hypersaline conditions and pressure of the ice water temperatures can plunge to a frigid -13.5 ºC (8 ºF).

Yet even within such a seemingly inhospitable environment Lake Vida is host to a “surprisingly diverse and abundant assemblage of bacteria” existing within water channels branching through the ice, separated from the sun’s energy and isolated from exterior influences for an estimated 3,000 years.

Originally thought to be frozen solid, ground penetrating radar surveys in 1995 revealed a very salty liquid layer (a brine) underlying the lake’s year-round 20-meter-thick ice cover.

“This study provides a window into one of the most unique ecosystems on Earth,” said Dr. Alison Murray, one of the lead authors of the team’s paper, a molecular microbial ecologist and polar researcher and a member of 14 expeditions to the Southern Ocean and Antarctic continent. “Our knowledge of geochemical and microbial processes in lightless icy environments, especially at subzero temperatures, has been mostly unknown up until now. This work expands our understanding of the types of life that can survive in these isolated, cryoecosystems and how different strategies may be used to exist in such challenging environments.”

Sterile environments had to be set up within tents on Lake Vida’s surface so the researchers could be sure that the core samples they were drilling were pristine, and weren’t being contaminated with any introduced organisms.

According to a NASA press release, “geochemical analyses suggest chemical reactions between the brine and the underlying iron-rich sediments generate nitrous oxide and molecular hydrogen. The latter, in part, may provide the energy needed to support the brine’s diverse microbial life.”

“This system is probably the best analog we have for possible ecosystems in the subsurface waters of Saturn’s moon Enceladus and Jupiter’s moon Europa.”

– Chris McKay, co-author, NASA’s Ames Research Center

What’s particularly exciting is the similarity between conditions found in ice-covered Antarctic lakes and those that could be found on other worlds in our Solar System. If life could survive in Lake Vida, as harsh and isolated as it is, could it also be found beneath the icy surface of Europa, or within the (hypothesized) subsurface oceans of Enceladus? And what about the ice caps of Mars? Might there be similar channels of super-salty liquid water running through Mars’ ice, with microbes eking out an existence on iron sediments?

“It’s plausible that a life-supporting energy source exists solely from the chemical reaction between anoxic salt water and the rock,” explained Dr. Christian Fritsen, a systems microbial ecologist and Research Professor in DRI’s Division of Earth and Ecosystem Sciences and co-author of the study.

“If that’s the case,” Murray added, “this gives us an entirely new framework for thinking of how life can be supported in cryoecosystems on earth and in other icy worlds of the universe.”

Read more: Europa’s Hidden Great Lakes May Harbor Life

More research is planned to study the chemical interactions between the sediment and the brine as well as the genetic makeup of the microbial communities themselves.

The research was published this week in the Proceedings of the National Academy of Science (PNAS). Read more on the DRI press release here, and watch a video below showing highlights from the field research.

Funding for the research was supported jointly by NSF and NASA. Images courtesy the Desert Research Institute. Dry valley image credit: NASA/Landsat. Europa image: NASA/Ted Stryk.)

Posted on by Nancy Atkinson

Vision of the Future? SLS Model “Flies” in Wind Tunnel Test

NASA’s Space Launch System buffet model in NASA’s Langley Researcher Center’s Transonic Dynamics Tunnel. Image credit: NASA/LaRC

This week, researchers tested a ten-foot-long model of the new Space Launch System, NASA’s next big thing for launching humans beyond Earth orbit. The test was conducted at the Langley Research Center’s Transonic Dynamics Tunnel (TDT).

“This is a critical milestone for the design of the vehicle,” said Langley research engineer, Dave Piatak.

Data retrieved will help prepare SLS for its first mission in 2017, Exploration Mission-1 (EM-1), which will deliver an uncrewed Orion spacecraft to lunar orbit to check out the vehicle’s systems. But before SLS’s first flight, the safety vehicle must be demonstrated through analysis and testing. An important step in ensuring a safe flight to orbit is buffet wind-tunnel testing to help determine launch vehicle structural margins.

To do this, a wind-tunnel model is put through its paces at transonic and low supersonic speeds reaching up to Mach 1.2. Testing aerodynamics at these speeds is essential to understanding the structural interaction to the flow field around the vehicle and determining loads on the flight vehicle.

360 miniature sensors on the model’s surface are scanned by a data acquisition system scanning at thirteen thousand scans-per-second. Unlike the rigid SLS buffet wind-tunnel model, the real launch vehicle is quite flexible. The rocket will bend and shake in response to forces during flight, and engineers use tests like this to determine that the resulting bending loads and vibrations are within the launch vehicle’s safe limits.

NASA engineers are now analyzing the data, and will be used to help refine the design of the SLS vehicle before the full-size rocket is built for flight tests. After completing EM-1, SLS will perform its second mission in 2021, Exploration Mission-2, launching Orion with its first crew of astronauts to demonstrate orbit around the Moon.

Source: PhysOrg