Thursday, May 26, 2016

MARS PLANET - Space Weather Causing Martian Atmospherics

Space Weather Causing Martian Atmospherics:



Hubble Space Telescope view of a plume high in the martian atmosphere seen in May 1997. Credit: NASA/ESA


Strange plumes in Mars’ atmosphere first recorded by amateur astronomers four year ago have planetary scientists still scratching their heads. But new data from European Space Agency's orbiting Mars Express points to coronal mass ejections from the Sun as the culprit.







On two occasions in 2012 amateurs photographed cloud-like features rising to altitudes of over 155 miles (250 km) above the same region of Mars. By comparison, similar features seen in the past haven’t exceeded 62 miles (100 km). On March 20th of that year, the cloud developed in less than 10 hours, covered an area of up to 620 x 310 miles (1000 x 500 kilometers), and remained visible for around 10 days.



Back then astronomers hypothesized that ice crystals or even dust whirled high into the Martian atmosphere by seasonal winds might be the cause. However, the extreme altitude is far higher than where typical clouds of frozen carbon dioxide and water are thought to be able to form.



Indeed at those altitudes, we've entered Mars' ionosphere, a rarified region where what air there is has been ionized by solar radiation. At Earth, charged particles from the Sun follow the planet's global magnetic lines of force into the upper atmosphere to spark the aurora borealis. Might the strange features observed be Martian auroras linked to regions on the surface with stronger-than-usual magnetic fields?







Once upon a very long time ago, Mars may have had a global magnetic field generated by electrical currents in a liquid iron-nickel core much like the Earth’s does today. In the current era, the Red Planet has only residual fields centered over regions of magnetic rocks in its crust.







Instead of a single, planet-wide field that funnels particles from the Sun into the atmosphere to generate auroras, Mars is peppered with pockets of magnetism, each potentially capable of connecting with the wind of particles from the Sun to spark a modest display of the "northern lights." Auroras were first discovered on Mars in 2004 by the Mars Express orbiter, but they're faint compared to the plumes, which were too bright to be considered auroras.



Still, this was a step in the right direction. What was needed was some hard data of a possible Sun-Earth interaction which scientists ultimately found when they looked into plasma and solar wind measurements collected by Mars Express at the time. David Andrews of the Swedish Institute of Space Physics, lead author of a recent paper reporting the Mars Express results, found evidence for a large coronal mass ejection or CME from the Sun striking the martian atmosphere in the right place and at around the right time.







CMEs are enormous explosions of hot solar plasma — a soup of electrons and protons — entwined with magnetic fields that blast off the Sun and can touch off geomagnetic storms and auroras when they encounter the Earth and other planets.



"Our plasma observations tell us that there was a space weather event large enough to impact Mars and increase the escape of plasma from the planet’s atmosphere," said Andrews. Indeed, the plume was seen along the day–night boundary, over a region of known strong crustal magnetic fields.







But again, a Mars aurora wouldn't be expected to shine so brightly. That's why Andrews thinks that the CME prompted a disturbance in the ionosphere large enough to affect dust and ice grains below:



"One idea is that a fast-traveling CME causes a significant perturbation in the ionosphere resulting in dust and ice grains residing at high altitudes in the upper atmosphere being pushed around by the ionospheric plasma and magnetic fields, and then lofted to even higher altitudes by electrical charging," according to Andrews.







With enough dust and ice twinkling high above the planet's surface, it might be possible for observers on Earth to see the result as a wispy plume of light. Plumes appear to be rare on Mars as a search through the archives has revealed. The only other, seen by the Hubble Space Telescope in May 1997, occurred when a CME was hitting the Earth at the same time. Unfortunately, there's no information from Mars orbiters at the time about its effect on that planet.



Observers on Earth and orbiters zipping around the Red Planet continue to monitor Mars for recurrences. Scientists also plan to use the webcam on Mars Express for more frequent coverage. Like a dog with a bone, once scientists get a bite on a tasty mystery, they won't be letting go anytime soon.

The post Space Weather Causing Martian Atmospherics appeared first on Universe Today.

ALIENS - Finding Aliens May Be Even Easier Than Previously Thought

Finding Aliens May Be Even Easier Than Previously Thought:



Finding extra-terrestrial life may be easier, now that we know what to look for. Credit: NASA/Serge Brunier


Finding examples of intelligent life other than our own in the Universe is hard work. Between spending decades listening to space for signs of radio traffic - which is what the good people at the SETI Institute have been doing - and waiting for the day when it is possible to send spacecraft to neighboring star systems, there simply haven't been a lot of options for finding extra-terrestrials.



But in recent years, efforts have begun to simplify the search for intelligent life. Thanks to the efforts of groups like the Breakthrough Foundation, it may be possible in the coming years to send "nanoscraft" on interstellar voyages using laser-driven propulsion. But just as significant is the fact that developments like these may also make it easier for us to detect extra-terrestrials that are trying to find us.



Not long ago, Breakthrough Initiatives made headlines when they announced that luminaries like Stephen Hawking and Mark Zuckerberg were backing their plan to send a tiny spacecraft to Alpha Centauri. Known as Breakthrough Starshot, this plan involved a refrigerator-sized magnet being towed by a laser sail, which would be pushed by a ground-based laser array to speeds fast enough to reach Alpha Centauri in about 20 years.



https://youtu.be/_MCVaLMWQbA



In addition to offering a possible interstellar space mission that could reach another star in our lifetime, projects like this have the added benefit of letting us broadcast our presence to the rest of the Universe. Such is the argument put forward by Philip Lubin, a professor at the University of California, Santa Barbara, and the brains behind Starshot.



In a paper titled "The Search for Directed Intelligence" - which appeared recently in arXiv and will be published soon in REACH – Reviews in Human Space Exploration - Lubin explains how systems that are becoming technologically feasible on Earth could allow us to search for similar technology being used elsewhere. In this case, by alien civilizations. As Lubin shared with Universe Today via email:



"In our SETI paper we examine the implications of a civilization having directed energy systems like we are proposing for both our NASA and Starshot programs. In this sense the NASA (DE-STAR) and Starshot arrays represent what other civilizations may possess. In another way, the receive mode (Phased Array Telescope) may be useful to search and study nearby exoplanets."
DE-STAR, or the Directed Energy System for Targeting of Asteroids and exploRation, is another project being developed by scientists at UCSB. This proposed system will use lasers to target and deflect asteroids, comets, and other Near-Earth Objects (NEOs). Along with the Directed Energy Propulsion for Interstellar Exploration (DEEP-IN), a NASA-backed UCSB project that is based on Lubin's directed-energy concept, they represent some of the most ambitious directed-energy concepts currently being pursued.







Using these as a teplate, Lubin believes that other species in the Universe could be using this same kind of directed energy systems for the same purposes - i.e. propulsion, planetary defense, scanning, power beaming, and communications. And by using a rather modest search strategy, he and colleagues propose observing nearby star and planetary systems to see if there are any signs of civilizations that possess this technology.



This could take the form of "spill-over", where surveys are able to detect errant flashes of energy. Or they could be from an actual beacon, assuming the extra-terrestrials us DE to communicate. As is stated in the paper authored by Lubin and his colleagues:



"There are a number of reasons a civilization would use directed energy systems of the type discussed here. If other civilizations have an environment like we do they might use DE system for applications such as propulsion, planetary defense against “debris” such as asteroids and comets, illumination or scanning systems to survey their local environment, power beaming across large distances among many others. Surveys that are sensitive to these “utilitarian” applications are a natural byproduct of the “spill over” of these uses, though a systematic beacon would be much easier to detect."
According to Lubin, this represents a major departure from what projects like SETI have been doing for the past few decades. These efforts, which can be classified as "passive" were understandable in the past, owing to our limited means and the challenges in sending out messages ourselves. For one, the distances involved in interstellar communication are incredibly vast.
Even using directed-energy, which moves at the speed of light, it would still take a message over 4 years to the nearest star, 1000 years to reach the Kepler planets, and 2 million years to the nearest galaxy (Andromeda). So aside from the nearest stars, these time scales are far beyond a human lifetime; and by the time the message arrived, far better means would have evolved to communicate.



Second,  there is also the issue of the targets being in motion over the vast timescales involved. All stars have a transverse velocity relative to our line of sight, which means that any star system or planet targeted with a burst of laser communication would have moved by the time the beam arrived. So by adopting a pro-active approach, which involves looking for specific kinds of behavior, we could bolster our efforts to find intelligent life on distant exoplanets.



But of course, there are still many challenges that need to be overcome, not the least of which are technical. But more than that, there is also the fact that what we are looking for may not exist. As Lubin and his colleagues state in one section of the paper: "What is an assumption, of course, is that electromagnetic communications has any relevance on times scales that are millions of years and in particular that electromagnetic communications (which includes beacons) should have anything to do with wavelengths near human vision."



In other words, assuming that aliens are using technology similar to our own is potentially anthropocentric. However, when it comes to space exploration and finding other intelligent species, we have to work with what we have, and with what we know. And as it stands, humanity is the only example of a space-faring civilization known to us. As such, we can hardly be faulted for projecting ourselves out there.



Here's hoping ET is out there, and relies on energy beaming to get things done. And, fingers crossed, here's hoping they aren't too shy about being noticed!



Further Reading: arXiv



The post Finding Aliens May Be Even Easier Than Previously Thought appeared first on Universe Today.

PLUTO PLANET - Take A Virtual Reality Tour Of Pluto

Take A Virtual Reality Tour Of Pluto:



With a new app provided by the NY Times, viewers can explore distant Pluto  using only a smartphone or a virtual reality viewer. Credit: New York Times


On July 14th, 2015, the New Horizons probe made history as it passed within 12,500 km (7,800 mi) of Pluto, thus making it the first spacecraft to explore the dwarf planet up close. And since this historic flyby, scientists and the astronomy enthusiasts here at Earth have been treated to an unending stream of breathtaking images and scientific discoveries about this distant world.



And thanks to the New York Times and the Universities Space Research Association's Lunar and Planetary Institute in Texas, it is now possible to take a virtual reality tour of Pluto. Using the data obtained by the New Horizon's instruments, users will be able to experience what it is like to explore the planet using their smartphone or computer, or in 3D using a VR headset.



The seven-minute film, titled "Seeking Pluto's Frigid Heart", which is narrated by science writer Dennis Overbye of the New York Times - shows viewers what it was like to approach the dwarf planet from the point of the view of the New Horizon's probe. Upon arrival, they are then able to explore Pluto's surface, taking in 360 degree views of its icy mountains, heart-shaped plains, and largest moon, Charon.



https://youtu.be/jIxQXGTl_mo



This represents the most detailed and clear look at Pluto to date. A few decades ago, the few maps of Pluto we had were the result of close observations that measured changes in the planet's total average brightness as it was eclipsed by its largest moon, Charon. Computer processing yielded brightness maps, which were very basic by modern standards.



In the early 2000s, images taken by the Hubble Space Telescope were processed in order to create a more comprehensive view. Though the images were rather undetailed, they offered a much higher resolution view than the previous maps, allowing certain features - like Pluto's large bright spots and the dwarf planet's polar regions - to be resolved for the first time.



However, with the arrival of the New Horizons mission, human beings have been finally treated to a close-up view of Pluto and its surface.  This included Pluto's now-famous heart-shaped plains, which were captured by the probe's Long Range Reconnaissance Imager (LORRI) while it was still several days away from making its closest approach.







This was then followed-up by very clear images of its surface features and atmosphere, which revealed floating ice hills, mountains and icy flow plains, and surface clouds composed of methane and tholins. From all of these images, we now know what the surface of this distant world looks like with precision. All of this has allowed scientists here at Earth to reconstruct, in stunning detail, what it would be like to travel to Pluto and stand on its surface.



Amazingly, only half of New Horizon's images and measurements have been processed so far. And with fresh data expected to arrive until this coming October, we can expect that scientists will be working hard for many years to analyze it all. One can only imagine what else they will learn about this mysterious world. And one can only hope that any news findings will be uploaded to the app (and those like it)!



The VR app can be downloaded at the New York Times VR website, and is available for both Android and Apple devices. It can also be viewed using headset's like Google Cardboard, a smartphone, and a modified version exists for computer browsers.
The post Take A Virtual Reality Tour Of Pluto appeared first on Universe Today.

SATURN PLANET - A Lord of Rings: Saturn at Opposition 2016

A Lord of Rings: Saturn at Opposition 2016:



Saturn 2016


They're back. After a wintertime largely devoid of evening worlds, the planets are once again in the evening sky. First Jupiter, then Mars have crossed opposition over the past few months, and now Saturn is set to take center stage later next week, reaching opposition at 7:00 Universal Time (UT) on the night of June 2/3rd. This places the ringed world in a position of favorable evening viewing, rising in the east as the Sun sets in the west, and riding highest near local midnight across the meridian.



Opposition 2016 sees the planet Saturn looping through the southern realm of the constellation Ophiuchus, making a retrograde run this summer at the Scorpius border before looping back and resuming eastward motion. That's right: Saturn currently occupies the dreaded '13th house,' of Ophiuchus, for all you Snake-Bearers out there. Saturn is currently at bright as it can be, at magnitude +0.04.







Saturn reaches opposition once every 378 days, as it orbits the Sun at a leisurely pace every 29.5 years. 2016 and the next few oppositions sees Saturn 'bottoming out,' sitting around -20 degrees south. Saturn won't peek northward across the celestial equator again until March 2026. This places the 2016 appearance of Saturn high in the sky south of the equator, transiting about 30 degrees above the southern horizon around midnight for folks observing around 40 degrees north latitude. Saturn also begins looping towards the star-rich region of the galactic equator for a crossing it late next year in December 2017. Saturn sits 9 Astronomical Units (AU) or 1.4 billion kilometers distant on June 3rd, a slightly larger distance than usual, owing to the fact that the planet is headed towards aphelion on April 17th, 2018.



The waxing gibbous Moon passes 3.2 degrees north from Saturn on Sunday, June 19th, just a day before reaching Full.







Watch for a sudden brightening of the planet in early June, known as an 'opposition surge' due to what is known as the Seeliger effect. This is a coherent back-scattering of light, focusing it similar to highway retro-reflectors shining your headlights back at you at night. In this case, the Sun is the 'headlight,' and the millions of snowball moonlets hiding their shadows from view reaching 100% illumination are the highway retro-reflectors. The effect is subtle, to be sure, but serves to raise the brightness of the planet by about half a magnitude. This should be apparent in an animation sequence shot before, during and after over the span of a about a week. Any takers?







And speaking of the rings, here's another reason to check out Saturn this opposition 2016 season. The tilt of rings is about 26 degrees wide as seen from our Earthly perspective... about as wide as they can be. Saturn's rings were last edge on in 2009, and reach a maximum width of 27 degrees on October 16th, 2017 before slowly heading towards edge on again in 2025.







At the eyepiece, Saturn shows a yellowish disk 18” extended to 43” across if you count the rings. Crank up the magnification to over 100x under good seeing, and the black thread of the Cassini division jumps into view. Saturn has 62 moons in all, with +9th magnitude Titan being the brightest. You're looking at the most distant surface outpost of humanity, the site of the 2005 landing of the European Space Agency's Huygens lander. Six moons are readily visible in a small telescope, while the fainter moons Hyperion and Phoebe present a challenge to owners of extreme light buckets. Also, as Saturn heads past opposition and towards eastern quadrature 90 degrees from the Sun on September 2nd, 2016, watch for the shadow of the bulk of the planet, cast back across the rings.







We never miss a chance to observe Saturn if it's above the horizon. Saturn is a sure-fire crowd-pleaser for any sidewalk astronomy session, and no one forgets their first glimpse of the glorious ringed world. You can just imagine how much consternation this bizarre-looking planet must have caused Galileo. You can tell just how primitive his first telescope was, as his sketches show off Saturn as more of a two-handled 'coffee cup' in appearance. Christaan Huygens first deduced something of the true nature of Saturn's rings in 1655, correctly claiming that they are physically separated from the disk.



Don't miss Saturn at opposition next week!

The post A Lord of Rings: Saturn at Opposition 2016 appeared first on Universe Today.

THE UNIVERSE - Milky Way Over the Spanish Peaks

Milky Way Over the Spanish Peaks:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2016 May 24


See Explanation. Moving the cursor over the image will bring up an annotated version. Clicking on the image will bring up the highest resolution version available.


Milky Way Over the Spanish Peaks

Image Credit & Copyright: Martin Pugh; Rollover Annotation: Judy Schmidt


Explanation: That's not lightning, and it did not strike between those mountains. The diagonal band is actually the central band of our Milky Way Galaxy, while the twin peaks are actually called the Spanish Peaks -- but located in Colorado, USA. Although each Spanish peak is composed of a slightly different type of rock, both are approximately 25 million years old. This serene yet spirited image composite was meticulously created by merging a series of images all taken from the same location on one night and early last month. In the first series of exposures, the background sky was built up, with great detail being revealed in the Milky Way dust lanes as well as the large colorful region surrounding the star Rho Ophiuchus just right of center. One sky image, though, was taken using a fogging filter so that brighter stars would appear more spread out and so more prominent. As a bonus, the planets Mars and Saturn are placed right above peaks and make an orange triangle with the bright star Antares. Later that night, after the moonrise, the Moon itself naturally illuminated the snow covered mountain tops.

Tomorrow's picture: NGC 5078 and Friends



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STARRY NIGHT - NGC 5078 and Friends

NGC 5078 and Friends:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2016 May 25



See Explanation. Clicking on the picture will download the highest resolution version available.
Explanation: This sharp telescopic field of view holds two bright galaxies. Barred spiral NGC 5101 (top right) and nearly edge-on system NGC 5078 are separated on the sky by about 0.5 degrees or about the apparent width of a full moon. Found within the boundaries of the serpentine constellation Hydra, both are estimated to be around 90 million light-years away and similar in size to our own large Milky Way galaxy. In fact, if they both lie at the same distance their projected separation would be only 800,000 light-years or so. That's easily less than half the distance between the Milky Way and the Andromeda Galaxy. NGC 5078 is interacting with a smaller companion galaxy, cataloged as IC 879, seen just left of the larger galaxy's bright core. Even more distant background galaxies are scattered around the colorful field. Some are even visible right through the face-on disk of NGC 5101. But the prominent spiky stars are in the foreground, well within our own Milky Way.

Monday, May 23, 2016

THE FIRST DWARF PLANET DISCOVERED - DAWN

THE FIRST DWARF PLANET DISCOVERED - DAWN



An intrepid interplanetary explorer is now powering its way down through the gravity field of a distant alien world. Soaring on a blue-green beam of high-velocity xenon ions, Dawn is making excellent progress as it spirals closer and closer to Ceres, the first dwarf planet discovered. Meanwhile, scientists are progressing in analyzing the tremendous volume of pictures and other data the probe has already sent to Earth.



4th Mapping Orbit (LAMO)


Dawn’s spiral descent from its third mapping orbit (HAMO), at 915 miles (1,470 kilometers), to its fourth (LAMO), at 240 miles (385 kilometers). The two mapping orbits are shown in green. The color of Dawn’s trajectory progresses through the spectrum from blue, when it began ion-thrusting in HAMO, to red, when it arrives in LAMO. The red dashed sections show where Dawn is coasting for telecommunications. It requires 118 spiral revolutions around Ceres to reach the low altitude (and additional revolutions to prepare for and conduct the trajectory correction maneuver described below). Compare this to the previous spiral. (Readers with total recall will note that this is fewer loops than illustrated last year. The flight team has made several improvements in the complex design since then, shortening the time required and thus allowing more time for observing Ceres.) Image credit: NASA/JPL-Caltech
Dawn is flying down to an average altitude of about 240 miles (385 kilometers), where it will conduct wide-ranging investigations with its suite of scientific instruments. The spacecraft will be even closer to the rocky, icy ground than the International Space Station is to Earth’s surface. The pictures will be four times sharper than the best it has yet taken. The view is going to be fabulous!

Dawn will be so near the dwarf planet that its sensors will detect only a small fraction of the vast territory at a time. Mission planners have designed the complex itinerary so that every three weeks, Dawn will fly over most of the terrain while on the sunlit side. (The neutron spectrometer, gamma ray spectrometer and gravity measurements do not depend on illumination from the sun, but the camera, infrared mapping spectrometer and visible mapping spectrometer do.)

Obtaining the planned coverage of the exotic landscapes requires a delicate synchrony between Ceres’ and Dawn’s movements. Ceres rotates on its axis every nine hours and four minutes (one Cerean day). Dawn will revolve around it in a little less than five and a half hours, traveling from the north pole to the south pole over the hemisphere facing the sun and sailing northward over the hemisphere hidden in the darkness of night. Orbital velocity at this altitude is around 610 mph (980 kilometers per hour).

Last year we had a preview of the plans for this fourth and final mapping orbit (sometimes also known as the low altitude mapping orbit, or LAMO), and we will present an updated summary next month.

The planned altitude differs from the earlier, tentative value of 230 miles (375 kilometers) for several reasons. One is that the previous notion for the altitude was based on theoretical models of Ceres’ gravity field. Navigators measured the field quite accurately in the previous mapping orbit (using the method outlined here), and that has allowed them to refine the orbital parameters to choreograph Dawn’s celestial pas de deux with Ceres. In addition, prior to Dawn’s investigations, Ceres’ topography was a complete mystery. Hubble Space Telescope had shown the overall shape well enough to allow scientists to determine that Ceres qualifies as a dwarf planet, but the landforms were indiscernible and the range of relative elevations was simply unknown. Now that Dawn has mapped the topography, we can specify the spacecraft’s average height above the ground as it orbits. With continuing analyses of the thousands of stereo pictures taken in August – October and more measurements of the gravity field in the final orbit, we will further refine the average altitude. Finally, we round the altitude numbers to the nearest multiple of five (both for miles and kilometers), because, as we will discuss in a subsequent Dawn Journal, the actual orbit will vary in altitude by much more than that. (We described some of the the ups and dawns of the corresponding orbit at Vesta here. The variations at Ceres will not be as large, but the principles are the same.)



Dawn HAMO Image 50


Dawn had this view of Urvara crater in mapping cycle #4 from an altitude of 915 miles (1,470 kilometers) during the third mapping orbit. (Urvara is a Vedic goddess associated with fertile lands and plants.) The crater is 101 miles (163 kilometers) in diameter. It displays a variety of features, including a particularly bright region on the peak at the center, ridges nearby, a network of fissures, some smooth regions and much rougher terrain. You can locate all the areas shown in this month’s photos on the Ceres map presented last month. Full image and caption. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
To attain its new orbit, Dawn relies on its trusty and uniquely efficient ion engine, which has already allowed the spacecraft to accomplish what no other has even attempted in the 58-year history of space exploration. This is the only mission ever to orbit two extraterrestrial destinations. The spaceship orbited the protoplanet Vesta for 14 months in 2011-2012, revealing myriad fascinating details of the second most massive object in the main asteroid belt between Mars and Jupiter, before its March 2015 arrival in orbit around the most massive. Ion propulsion enables Dawn to undertake a mission that would be impossible without it.

While the ion engine provides 10 times the efficiency of conventional spacecraft propulsion, the engine expends the merest whisper of xenon propellant, delivering a remarkably gentle thrust. As a result, Dawn achieves acceleration with patience, and that patience is rewarded with the capability to explore two of the last uncharted worlds in the inner solar system. This raises an obvious question: How cool is that? Fortunately, the answer is equally obvious: Incredibly cool!

The efficiency of the ion engine enables Dawn not only to orbit two destinations but also to maneuver extensively around each one, optimizing its orbits to reap the richest possible scientific return at Vesta and Ceres. The gentleness of the ion engine makes the maneuvers gradual and graceful. The spiral descents are an excellent illustration of that.

Dawn began its elegant downward coils on Oct. 23 upon concluding more than two months of intensive observations of Ceres from an altitude of 915 miles (1,470 kilometers). At that height, Ceres’ gravitational hold was not as firm as it will be in Dawn’s lower orbit, so orbital velocity was slower. Circling at 400 mph (645 kilometers per hour), it took 19 hours to complete one revolution around Ceres. It will take Dawn more than six weeks to travel from that orbit to its new one. (You can track its progress and continue to follow its activities once it reaches its final orbit with the frequent mission status updates.)



PIA19993: Dawn HAMO Image 51


Dawn took this picture of Dantu crater from an altitude of 915 miles (1,470 kilometers) during the third mapping orbit, in mapping cycle #4. (Dantu is a timekeeper god who initiates the cycle of planting rites among the Ga people of the Accra Plains of southeastern Ghana. You can find Dantu, but not Ghana, on this map.) The crater is about 77 miles (125 kilometers) across. Note the isolated bright regions, the long fissures, and the zigzag structure at the center. Scientists are working to understand what these indicate about the geological processes on Ceres. Full image and caption. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
On Nov. 16, at an altitude of about 450 miles (720 kilometers), Dawn circled at the same rate that Ceres turned. Now the spacecraft is looping around its home even faster than the world beneath it turns.

When ion-thrusting ends on Dec. 7, navigators will measure and analyze the orbital parameters to establish how close they are to the targeted values and whether a final adjustment is needed to fit with the intricate observing strategy. Several phenomena contribute to small differences between the planned orbit and the actual orbit. (See here and here for two of our attempts to elucidate this topic.) Engineers have already thoroughly assessed the full range of credible possibilities using sophisticated mathematical methods. This is a complex and challenging process, but the experienced team is well prepared. In case Dawn needs to execute an additional maneuver to bring its orbital motion into closer alignment with the plan, the schedule includes a window for more ion-thrusting on Dec. 12-14 (concluding on Dawn’s 3000th day in space). In the parlance of spaceflight, this maneuver to adjust the orbit is a trajectory correction maneuver (TCM), and Dawn has experience with them.

The operations team takes advantage of every precious moment at Ceres they can, so while they are determining whether to perform the TCM and then developing the final flight plan to implement it, they will ensure the spacecraft continues to work productively. Dawn carries two identical cameras, a primary and a backup. Engineers occasionally operate the backup camera to verify that it remains healthy and ready to be put into service should the primary camera falter. On Dec. 10, the backup will execute a set of tests, and Dawn will transmit the results to Earth on Dec. 11. By then, the work on the TCM will be complete.

Although it is likely a TCM will be needed, if it turns out to be unnecessary, mission control has other plans for the spacecraft. In this final orbit, Dawn will resume using its reaction wheels to control its orientation. By electrically changing the speed at which these gyroscope-like devices rotate, the probe can control its orientation, stabilizing itself or turning. We have discussed their lamentable history on Dawn extensively, with two of the four having failed. Although such losses could have been ruinous, the flight team formulated and implemented very clever strategies to complete the mission without the wheels. Exceeding their own expectations in such a serious situation, Dawn is accomplishing even more observations at Ceres than had been planned when it was being built or when it embarked on its ambitious interplanetary journey in 2007.



PIA20000: Dawn HAMO Image 57


Dawn took this picture in its third mapping orbit at an altitude of 915 miles (1,470 kilometers) in mapping cycle #5 of its third mapping orbit. The prominent triplet of overlapping craters nicely displays relative ages, which are apparent by which ones affect others and hence which ones formed later. The largest crater, Geshtin, is 48 miles (77 kilometers) across and is the oldest. (Geshtin is a Sumerian and Assyro-Babylonian goddess of the vine.) A subsequent impact that excavated Datan crater, which is 37 miles (60 kilometers) in diameter, obliterated a large section of Geshtin’s rim and made its own crater wall in Geshtin’s interior. (Datan is one of the Polish gods who protect the fields but apparently not this crater.) Still later, Datan itself was the victim of a sizable impact on its rim (although not large enough to have merited an approved name this early in the geological studies of Ceres). Full image and caption. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Now the mission lifetime is limited by the small supply of conventional rocket propellant, expelled from reaction control system thrusters strategically located around the spacecraft. When that precious hydrazine is exhausted, the robot will no longer be able to point its solar arrays at the sun, its antenna at Earth, its sensors at Ceres or its ion engines in the direction needed to travel elsewhere, so the mission will conclude. The lower Dawn’s orbital altitude, the faster it uses hydrazine, because it must rotate more quickly to keep its sensors pointed at the ground. In addition, it has to fight harder to resist Ceres’ relentless gravitational tug on the very large solar arrays, creating an unwanted torque on the ship.

Among the innovative solutions to the reaction wheel problems was the development of a new method of orienting the spacecraft with a combination of only two wheels plus hydrazine. In the final orbit, this “hybrid control” will use hydrazine at only half the rate that would be needed without the wheels. Therefore, mission controllers have been preserving the units for this final phase of the expedition, devoting the limited remaining usable life to the time that they can provide the greatest benefit in saving hydrazine. (The accuracy with which Dawn can aim its sensors is essentially unaffected by which control mode is used, so hydrazine conservation is the dominant consideration in when to use the wheels.) Apart from a successful test of hybrid control two years ago and three subsequent periods of a few hours each for biannual operation to redistribute internal lubricants, the two operable wheels have been off since August 2012, when Dawn was climbing away from Vesta on its way out of orbit.

Controllers plan to reactivate the wheels on Dec. 15. However, in the unlikely case that the TCM is deemed unnecessary, they will power the wheels on on Dec. 11. The reaction wheels will remain in use for as long as both function correctly. If either one fails, which could happen immediately or might not happen before the hydrazine is depleted next year, it and the other will be powered off, and the mission will continue, relying exclusively on hydrazine control.



PIA20124: Dawn HAMO Image 62


Dawn recorded this view in its third mapping orbit at an altitude of 915 miles (1,470 kilometers) in mapping cycle #5. The region shown is located between Fluusa and Toharu craters. The largest crater here is 16 miles (26 kilometers) across. The well defined features indicate the crater is relatively young, so subsequent small impacts have not degraded it significantly. As elsewhere on Ceres, some strikingly bright material is evident, particularly in the walls. Full image and caption. Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA
Dawn will measure the energies and numbers of neutrons and gamma rays emanating from Ceres as soon as it arrives in its new orbit. With a month or so of these measurements, scientists will be able to determine the abundances of some of the elements that compose the material near the surface. Engineers and scientists also will collect new data on the gravity field at this low altitude right away, so they eventually can build up a profile of the dwarf planet’s interior structure. The other instruments (including the camera) have narrower fields of view and are more sensitive to small discrepancies in where they are aimed. It will take a few more days to incorporate the actual measured orbital parameters into the corresponding plans that controllers will radio to the spacecraft. Those observations are scheduled to begin on Dec. 18. But always squeezing as much as possible out of the mission, the flight team might actually begin some photography and infrared spectroscopy as early as Dec. 16.

Now closing in on its final orbit, the veteran space traveler soon will commence the last phase of its long and fruitful adventure, when it will provide the best views yet of Ceres. Known for more than two centuries as little more than a speck of light in the vast and beautiful expanse of the stars, the spacecraft has already transformed it into a richly detailed and fascinating world. Now Dawn is on the verge of revealing even more of Ceres’ secrets, answering more questions and, as is the marvelous nature of science and exploration, raising new ones.

Dawn is 295 miles (470 kilometers) from Ceres. It is also 3.33 AU (309 million miles, or 498 million kilometers) from Earth, or 1,270 times as far as the moon and 3.37 times as far as the sun today. Radio signals, traveling at the universal limit of the speed of light, take 55 minutes to make the round trip.

Dr. Marc D. Rayman

5:00 p.m. PST November 30, 2015
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STELLAR EXPLOSION - Chandra Movie Captures Expanding Debris From a Stellar Explosion

Chandra Movie Captures Expanding Debris From a Stellar Explosion:



Tycho's Supernova Remnant


When the star that created this supernova remnant exploded in 1572, it was so bright that it was visible during the day. And though he wasn't the first or only person to observe this stellar spectacle, the Danish astronomer Tycho Brahe wrote a book about his extensive observations of the event, gaining the honor of it being named after him.

In modern times, astronomers have observed the debris field from this explosion - what is now known as Tycho's supernova remnant - using data from NASA's Chandra X-ray Observatory, the NSF's Karl G. Jansky Very Large Array (VLA) and many other telescopes. Today, they know that the Tycho remnant was created by the explosion of a white dwarf star, making it part of the so-called Type Ia class of supernovas used to track the expansion of the Universe.

Since much of the material being flung out from the shattered star has been heated by shock waves - similar to sonic booms from supersonic planes - passing through it, the remnant glows strongly in X-ray light. Astronomers have now used Chandra observations from 2000 through 2015 to create the longest movie of the Tycho remnant's X-ray evolution over time, using five different images. This shows the expansion from the explosion is still continuing about 450 years later, as seen from Earth's vantage point roughly 10,000 light years away.

By combining the X-ray data with some 30 years of observations in radio waves with the VLA, astronomers have also produced a movie, using three different images. Astronomers have used these X-ray and radio data to learn new things about this supernova and its remnant.

The researchers measured the speed of the blast wave at many different locations around the remnant. The large size of the remnant enables this motion to be measured with relatively high precision. Although the remnant is approximately circular, there are clear differences in the speed of the blast wave in different regions. The speed in the right and lower right directions is about twice as large as that in the left and the upper left directions. This difference was also seen in earlier observations.

This range in speed of the blast wave's outward motion is caused by differences in the density of gas surrounding the supernova remnant. This causes an offset in position of the explosion site from the geometric center, determined by locating the center of the circular remnant. The astronomers found that the size of the offset is about 10% of the remnant's current radius, towards the upper left of the geometric center. The team also found that the maximum speed of the blast wave is about 12 million miles per hour.

More information at http://chandra.si.edu/photo/2016/tycho/index.html

-Megan Watzke, CXC

EARTH PLANET - What is the Highest Place on Earth?

What is the Highest Place on Earth?:



Mount Chimborazo


Whenever the question is asked, what is the highest point on planet Earth?, people naturally assume that the answer is Mt. Everest. In fact, so embedded is the notion that Mt. Everest is the highest point on the world that most people wouldn't even think twice before answering. And even when we talk of other huge mountains in the Solar System (like Mars' Olympus Mons), we invariably compare them to Mt. Everest.







But in truth, Everest does not hold the record for being the highest point on Earth. Due to the nature of our planet - which is not shaped like a perfect sphere but an oblate spheroid (i.e. a sphere that bulges at the center) - points that are located along the equator are farther away than those located at the poles. When you factor this in, Everest and the Himalayas find themselves falling a bit short!



Earth as a Sphere:

The understanding that Earth is spherical is believed to have emerged during the 6th century BCE in ancient Greece. While Pythagoras is generally credited with this theory, it is equally likely that it emerged on its own as a result of travel between Greek settlements – where sailors noticed changes in what stars were visible at night based on differences in latitudes.







By the 3rd century BCE, the idea of a spherical Earth began to become articulated as a scientific matter. By measuring the angle cast by shadows in different geographical locations, Eratosthenes – a Greek astronomer from Hellenistic Libya (276–194 BCE) – was able to estimate Earth’s circumference within a 5% – 15% margin of error. With the rise of the Roman Empire and their adoption of Hellenistic astronomy, the view of a spherical Earth became widespread throughout the Mediterranean and Europe.



This knowledge was preserved thanks to the monastic tradition and Scholasticism during the Middle Ages. By the Renaissance and the Scientific Revolution (mid 16th - late 18th centuries), the geological and heliocentric views of Earth became accepted as well. With the advent of modern astronomy, precise methods of measurement, and the ability to view Earth from space, our models of its true shape and dimensions have come to be refined considerably.



Modern Models of the Earth:

To clarify matters a little, the Earth is neither a perfect sphere, nor is it flat. Sorry Galileo, and sorry Flat-Earthers (not sorry!), but it's true. As already noted, it is an oblate spheroid, which is a result of the rotation of the Earth. Basically, its spin results in a flattening at the poles and a bulging at its equatorial. This is true for many bodies in the Solar System (such as Jupiter and Saturn) and even rapidly-spinning stars like Altair.







Based on some of the latest measurements, it is estimated that Earth has a polar radius (i.e. from the middle of Earth to the poles) of 6,356.8 km, whereas its equatorial radius (from the center to the equator) is 6,378.1 km. In short, objects located along the equator are 22 km further away from the center of the Earth (geocenter) than objects located at the poles.



Naturally, there are some deviations in the local topography where objects located away from the equator are closer or father away from the center of the Earth than others in the same region. The most notable exceptions are the Mariana Trench - the deepest place on Earth, at 10,911 m (35,797 ft) below local sea level - and Mt. Everest, which is 8,848 meters (29,029 ft) above local sea level. However, these two geological features represent a very minor variation when compared to Earth's overall shape - 0.17% and 0.14% respectively.



Highest Point on Earth:

To be fair, Mt. Everest is one of the highest points on Earth, with its peak ascending to an altitude of 8,848 meters (29,029 ft) above sea level. However, due to its location within the Himalayan Mountain Chain in Nepal, some 27° and 59 minutes north of the equator, it is actually lower than mountains located in Ecuador.



It is here, where the land is dominated by the Andes mountain chain, that the highest point on planet Earth is located. Known as Mt. Chiborazo, the peak of this mountain reaches an attitude of 6,263.47 meters (20,549.54 ft) above sea level. But because it is located just 1° and 28 minutes south of the equator (at the highest point of the planet's bulge), it receives a natural boost of about 21 km.







In terms of how far they are from the geocenter, Everest lies at a distance of 6,382 kilometers (3,965 miles) from the center of the Earth while Chimborazo reaches to a distance of 6,384 kilometers (3,967 miles). That's a difference of about 3.2 km (2 miles), which may not seem like much. But if we're talking about rankings and titles, it pays to be specific!



Naturally, there are those who would stress that Mt. Everest is still the tallest mountain, measured from base to peak. Unfortunately, here too, they would be incorrect. That prize goes to Mauna Kea, a dormant volcano located on the island of Hawaii. Measuring 10,206 meters (33,484 ft) from base to summit, it is the highest mountain in the world. However, since its base is several thousand meters below seat level, we only see the top 4,207 m (13,802 ft) of it.



But if one were to say that Everest was tallest mountain based on its altitude, they would be correct. In terms of its summit's elevation above sea level, Everest is ranked as being as the tallest mountain in the world. And when it comes to the sheer difficulty of ascending it, Everest will always be ranked no. 1, both in the records books and in the hearts of climbers everywhere!



We have written many interesting articles about the Earth and mountains here at Universe Today. Here's Planet Earth, What is the Earth's Diameter?, The Rotation of the Earth, and Mountains: How Are They Formed?



For more information, be sure to check out NASA’s Visible Earth, and "Highest Mountain in the World" at Geology.com.



Astronomy Cast also has a great episode on the subject – Episode 51: Earth.

The post What is the Highest Place on Earth? appeared first on Universe Today.

SPEED OF LIGHT - How Far Can You Travel?

How Far Can You Travel?:

In a previous article, I talked about how you can generate artificial gravity by accelerating at 9.8 meters per second squared. Do that and you pretty much hit the speed of light, then you decelerate at 1G and you’ve completed an epic journey while enjoying comfortable gravity on board at the same time. It’s a total win win.

What I didn’t mention how this acceleration messes up time for you and people who aren’t traveling with you. Here’s the good news. If you accelerate at that pace for years, you can travel across billions of light years within a human lifetime.

Here’s the bad news, while you might experience a few decades of travel, the rest of the Universe will experience billions of years. The Sun you left will have died out billions of years ago when you arrive at your destination.

Welcome to the mind bending implications of constantly accelerating relativistic spaceflight.

With many things in physics, we owe our understanding of relativistic travel to Einstein. Say it with me, “thanks Einstein.”

The effect of time dilation is negligible for common speeds, such as that of a car or even a jet plane, but it increases dramatically when one gets close to the speed of light.
The effect of time dilation is negligible for common speeds, such as that of a car or even a jet plane, but it increases dramatically when one gets close to the speed of light.
It works like this. The speed of light is always constant, no matter how fast you’re going. If I’m standing still and shine a flashlight, I see light speed away from me at 300,000 km/s. And if you’re traveling at 99% the speed of light and shine a flashlight, you’ll see light moving away at 300,000 km/s.

But from my perspective, standing still, you look as if you’re moving incredibly slowly. And from your nearly light-speed perspective, I also appear to be moving incredibly slowly – it’s all relative. Whatever it takes to make sure that light is always moving at, well, the speed of light.

This is time dilation, and you’re actually experiencing it all the time, when you drive in cars or fly in an airplane. The amount of time that elapses for you is different for other people depending on your velocity. That amount is so minute that you’ll never notice it, but if you’re traveling at close to the speed of light, the differences add up pretty quickly.

But it gets even more interesting than this. If you could somehow build a rocket capable of accelerating at 9.8 meters/second squared, and just went faster and faster, you’d hit the speed of light in about a year or so, but from your perspective, you could just keep on accelerating. And the longer you accelerate, the further you get, and the more time that the rest of the Universe experiences.

The really strange consequence, though, is that from your perspective, thanks to relativity, flight times are compressed.

I’m using the relativistic star ship calculator at convertalot.com. You should give it a try too.

Proxima Centauri. Credit: ESA/Hubble & NASA
Proxima Centauri. Credit: ESA/Hubble & NASA
For starters, let’s fly to the nearest star, 4.3 light-years away. I accelerate halfway at a nice comfortable 1G, then turn around and decelerate at 1G. It only felt like 3.5 years for me, but back on Earth, everyone experienced almost 6 years. At the fastest point, I was going about 95% the speed of light.

Let’s scale this up and travel to the center of the Milky Way, located about 28,000 light-years away. From my perspective, only 20 years have passed by. But back on Earth, 28,000 years have gone by. At the fastest point, I was going 99.9999998 the speed of light.

Let’s go further, how about to the Andromeda Galaxy, located 2.5 million light-years away. The trip only takes me 33 years to accelerate and decelerate, while Earth experienced 2.5 million years. See how this works?

The Andromeda Galaxy. Credit: NASA/JPL-Caltech/WISE Team
The Andromeda Galaxy. Credit: NASA/JPL-Caltech/WISE Team
I promised I’d blow your mind, and here it is. If you wanted to travel at a constant 1G acceleration and then deceleration to the very edge of the observable Universe. That’s a distance of 13.8 billion light-years away; you would only experience a total of 45 years. Of course, once you got there, you’d have a very different observable Universe, and billions of years of expansion and dark energy would have pushed the galaxies much further away from you.

Some galaxies will have fallen over the cosmic horizon, where no amount of time would ever let you reach them.

If you wanted to travel 100 trillion light years away, you could make the journey in 62 years. By the time you arrived, the Universe would be vastly different. Most of the stars would have died a long time ago, the Universe would be out of usable hydrogen. You would have have left a living thriving Universe trillions of years in the past. And you could never get back.

Our good friends over at Kurzgesagt  covered a very similar topic, discussing the limits of humanity’s exploration of the Universe. It’s wonderful and you should watch it right now.

Of course, creating a spacecraft capable of constant 1G acceleration requires energies we can’t even imagine, and will probably never acquire. And even if you did it, the Universe you enjoy would be a distant memory. So don’t get too excited about fast forwarding yourself trillions of years into the future.

The post How Far Can You Travel? appeared first on Universe Today.

DISCOVER THE COSMOS - When Cosmic Winds Collide

LL Orionis: When Cosmic Winds Collide:

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.

2016 May 22



See Explanation. Clicking on the picture will download the highest resolution version available.


LL Orionis: When Cosmic Winds Collide

Image Credit: Hubble Heritage Team (AURA / STScI), C. R. O'Dell(Vanderbilt U.), NASA


Explanation: What created this great arc in space? This arcing, graceful structure is actually a bow shock about half a light-year across, created as the wind from young star LL Orionis collides with the Orion Nebula flow. Adrift in Orion's stellar nursery and still in its formative years, variable star LL Orionis produces a wind more energetic than the wind from our own middle-aged sun. As the fast stellar wind runs into slow moving gas a shock front is formed, analogous to the bow wave of a boat moving through water or a plane traveling at supersonic speed. The slower gas is flowing away from the Orion Nebula's hot central star cluster, the Trapezium, located off the lower right hand edge of the picture. In three dimensions, LL Ori's wrap-around shock front is shaped like a bowl that appears brightest when viewed along the "bottom" edge. The complex stellar nursery in Orion shows a myriad of similar fluid shapes associated with star formation, including the bow shock surrounding a faint star at the upper right. Part of a mosaic covering the Great Nebula in Orion, this composite color image was recorded in 1995 by the Hubble Space Telescope.

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Sunday, May 22, 2016

HUMANS ON MARS - Scouting Needed for Red Planet Resources

Humans on Mars: Scouting Needed for Red Planet Resources: Leonard-David.jpg?1310481441

Humans on Mars: Scouting Needed for Red Planet Resources
Setting foot on Mars is one thing, but extended astronaut stays on the Red Planet will require tapping the planet's resources, experts say.

Credit: NASA/Paul Hudson


NASA's quest to put boots on Mars in the 2030s is advancing, bolstered by new studies about a multifunction, next-generation Mars orbiter and the best ways to use Red Planet resources to sustain astronaut pioneers.

Last year, scientists proposed nearly 50 locations on Mars as possible places for future human landings. Those landing-zone sites contain "regions of interest" that can be reached from primary touchdown spots.

Good touchdown sites will allow crews to land safely and carry out operations; offer a wealth of interesting science activities; and provide resources that the astronauts could use. For example, any favored exploration zone should allow expeditionary crews to tap into at least 100 metric tons (110 U.S. tons) of water, NASA officials have said. [Watch: How Mars Landing Sites Will Evolve for Astronauts

Landing-site wish list

With its suite of instruments and cameras — particularly the sharp-shooting High Resolution Imaging Science Experiment (HiRISE) — NASA's Mars Reconnaissance Orbiter (MRO) is being put through a request process called "HiWish" to snag new images of landing-zone candidates."NASA's Human Exploration and Operations Directorate has begun to think about where human explorers should go on Mars, and what conditions and resources, as well as what science targets, may be present," said HiRISE principal investigator Alfred McEwen, director of the Planetary Image Research Lab at the University of Arizona in Tucson. "This is a sign that they are actually thinking about sending people to Mars." "Hopefully, this new interest in Mars will include support for future robotic missions needed to answer key questions," McEwen told Space.com.

Last year, scientists identified nearly 50 prospective human landing zones on Mars — locations that are safe, scientifically promising and resource-rich.
Last year, scientists identified nearly 50 prospective human landing zones on Mars — locations that are safe, scientifically promising and resource-rich.

Credit: NASA


New Mars orbiter

Indeed, many experts within and outside NASA would like the agency to launch a multifunctional, next-generation Mars orbiter, the potential benefits of which were laid out in a report published in December by the Science Analysis Group of the Mars Exploration Program Analysis Group.

NASA is considering launching a multifunctional, next-generation Mars orbiter sometime in the 2020s. Among other tasks, this spacecraft would scout out resources to help sustain human expeditionary crews.
NASA is considering launching a multifunctional, next-generation Mars orbiter sometime in the 2020s. Among other tasks, this spacecraft would scout out resources to help sustain human expeditionary crews.

Credit: NEX-SAG


This Mars orbiter could employ solar electric propulsion, carry advanced telecommunications gear and make use of powerful radar to scout out and better classify Martian resources for human landing parties. If approved, the spacecraft may be headed for Mars as early as 2022, NASA officials have said.

NASA has allocated funds to take some "very early preformulation" looks at a new Mars orbiter, said Steve Jurczyk, associate administrator of the Space Technology Mission Directorate at NASA headquarters in Washington, D.C. No mission is yet planned for 2022, he said, but a Mars telecommunications orbiter is under consideration, given the advanced age of some of NASA's current orbiters. (Mars Odyssey launched in 2001, for example, and MRO lifted off in 2005.)

"We use orbital assets at Mars for telecommunications relay from the surface … and they are getting a little long in the tooth," Jurczyk told Space.com.

Mission planners are thinking about adding a couple of technologies to a prospective Mars orbiter, Jurczyk said — perhaps high-power electric propulsion. Deep-space laser communications technology, which could boost bandwidth capabilities by a factor of 10 compared to standard radio-frequency hardware, might be on board as well, he added.

Pay dirt

Last month, NASA released the Mars Water In-Situ Resource Utilization (ISRU) Planning Study, which looked into how astronauts could tap into Red Planet water.

"There's an intuitive gut-level view," said Richard Davis, assistant director for science and exploration in the Science Mission Directorate at NASA headquarters. "Human beings in general don't go where there isn't water. That intuition is actually on the mark for Mars."

One small step — with big expectations to eventually homestead the Red Planet.
One small step — with big expectations to eventually homestead the Red Planet.

Credit: Bob Sauls/XP4D/M. Wade Holler, Digital Content and Media Strategy Explore Mars Inc. Used with permission.


Water on Mars is transformative, and not just for drinking and growing crops, many experts believe. Processing the stuff can generate breathable oxygen and propellant for Mars ascent vehicles, among other things that could aid extended human stays on the Red Planet.

"We're starting to converge on an attack plan that starts with reconnaissance," Davis told Space.com. The pay dirt on Mars is water, he added. [Human Mars Exploration: How Landing Sites Could Evolve (Video)]

Davis, who worked on the ISRU report, said new data from orbit are needed to identify Martian resources that expeditionary crews could use. But orbital information by itself is probably not enough, he added.

"In the end, you need ground-truthing by sending a lander to what you think is the human landing site to validate [resource availability]," Davis said.

Water extraction

One resource option the report ruled out is the extraction of water from the thin Martian atmosphere.

Setting up a semi-permanent Mars base will require crop growth on the planet to sustain explorers far from Earth, experts say.
Setting up a semi-permanent Mars base will require crop growth on the planet to sustain explorers far from Earth, experts say.

Credit: NASA


The mass, power, volume and mechanical complexity of the system needed for this approach are far beyond what is practical for deployment on the Red Planet, Davis said.

"The density of the water in the Martian atmosphere is so low, it would take a massive processing system," he said. "There's no way we can get there."

Water-rich minerals on Mars look far more promising, Davis said. "They require so much less power to actually free up the water molecules," he noted.

The idea of strip-mining Mars for subsurface ice deposits was reviewed in the study but got a thumbs-down, Davis said. A better approach, including to the report's authors, involves boring a hole down through the Martian dirt, vaporizing subsurface ice, bringing it up topside as a gas and then condensing that gas into liquid.

"You make the Martian environment work for us instead of against us," Davis said. "It looks very promising."

Resource feedstock

The new study is far from the last word on finding and using indigenous Martian resources, Davis said.

"For each resource feedstock on Mars that's validated, we need to understand the technology needed, the mass of the equipment required and the power it will take," he said.

Once a semi-permanent base on Mars is established, crews would set up ISRU equipment, make sure all the kinks in the gear are smoothed out and then start harvesting resources. ISRU hardware would also operate in autonomous mode when there were no humans at the base, Davis said.

"You don't achieve sustainability on Mars overnight. You grow to it," Davis said. "This is not a technical problem. Yes, there are technical issues. But it is a belief problem. If people believe it's achievable, then it will be achievable."

Leonard David is author of "Mars: Our Future on the Red Planet," to be published by National Geographic this October. The book is a companion to the National Geographic Channel six-part series coming in November. A longtime writer for Space.com, David has been reporting on the space industry for more than five decades. Follow us @Spacedotcom, Facebook or Google+. Originally published on Space.com.