Posted on by Fraser Cain

Asteroid Threat Ruled Out

Over the past week, several independent efforts were made to search for pre-discovery observations of 2004 mn4. These efforts proved successful today when Jeff Larsen and Anne Descour of the Spacewatch Observatory near Tucson, Arizona, were able to detect and measure very faint images of asteroid 2004mn4 on archival images dating to 15 March 2004. These observations extended the observed time interval for this asteroid by three months allowing an improvement in its orbit so that an Earth impact on 13 April 2029 can now be ruled out.

As is often the case, the possibility of future Earth impacts for some near-Earth objects cannot be entirely ruled out until the uncertainties associated with their trajectories are reduced as a result of either future position observations, or in this case, heretofore unrecognized, pre-discovery observations. When these additional observations were used to update the orbit of 2004 MN4, the uncertainties associated with this object’s future positions in space were reduced to such an extent that none of the object’s possible trajectories can impact the Earth (or Moon) in 2029.

In the accompanying diagram, the most likely position of asteroid 2004 MN4 is shown at the end of the blue line near the Earth on 13 April 2029. However, since the asteroid’s position in space is not perfectly known at that time, the white dots at right angles to the blue line are possible alternate positions of the asteroid. Neither the nominal position of the asteroid, nor any of its possible alternative positions, touches the Earth, indicating that an Earth impact in 2029 is ruled out.

The passage of the asteroid by the Earth in 2029 alters its subsequent trajectory and expands the asteroid’s position uncertainty region (i.e., the line of white dots increases in extent) so the asteroid’s subsequent motion is less certain than it was prior to the 2029 close Earth approach. However, our current risk analysis for 2004 MN4 indicates that no subsequent Earth encounters in the 21st century are of any concern.

Original Source: NASA News Release

Posted on by Fraser Cain

Opportunity Finds its Heat Shield

After six fruitful months exploring the interior of “Endurance Crater,” the Opportunity rover has successfully climbed out of the crater onto the surrounding flatland of Meridiani Planum. Once out, the rover examined some of its own tracks that it had laid down prior to entering the crater. It compared them side-by-side with fresh tracks in order to observe any weathering effects in the intervening 200 sols. Opportunity is now making its way toward an engineering examination of its heat shield, which is located about 200 meters (220 yards) from the edge of Endurance. Now that the vehicle is on the relatively flat plain rather than tilted toward the Sun on the north-facing inner slope of the crater, electrical output from its solar array has declined by about 15 percent. Opportunity remains in excellent health as it begins a new phase of exploration.

Sol 312 and 313 were planned in a single planning cycle. Opportunity was still inside Endurance Crater. On sol 312 the plan began with backing up and using the panoramic camera and miniature thermal emission spectrometer to observe a rock target called “Wharenhui,” which had been treated with the rock abrasion tool on earlier sols. Subsequent commands were to turn cross-slope, drive 7 meters (23 feet), turn upslope, and drive an additional 6 meters (20 feet) uphill. Opportunity performed the drive perfectly, ending up approximately 5 meters (16.4 feet) from the rim of Endurance Crater. Opportunity’s tilt went from 25 degrees pre-drive to 19 degrees post-drive.

Sol 313 was a restricted sol because results from the sol 312 drive were not available for planning sol 313. That meant that no driving or robotic-arm activities were permitted. So Opportunity performed about two hours of observations using the panoramic camera and miniature thermal emission spectrometer and then went to sleep in the early afternoon. The rover woke up to support late-afternoon and early-morning communication relays by the orbiting Mars Odyssey.

Sols 314 through 316 were planned in another single planning cycle. The plan was to complete the egress from Endurance Crater on sol 315, so sol 314 was another remote sensing sol. This would be the last full sol inside Endurance. Opportunity spent about two and a half hours observing with the panoramic camera and miniature thermal emission spectrometer. It also performed a nighttime observation with the miniature thermal emission spectrometer just before midnight. To ensure that Opportunity had adequate power, the early-morning communication-relay session with Odyssey was canceled and Opportunity went into a modified deep sleep after completing the late-night observation.

Sol 315 was the big day for Opportunity. The rover was finally going to leave Endurance Crater after spending 181 sols there! Opportunity was instructed to drive 7 meters (23 feet) up and out of the crater. It was a textbook drive. Everything went as planned and Opportunity had finally, successfully completed a long and detailed series of observations inside Endurance. Opportunity ended up on the plains of Meridiani ready to begin the next chapter of its adventures.

Sol 316 was the third sol of a three-sol plan, and because Opportunity had driven on sol 315, sol 316 was restricted to remote-sensing observations. The rover performed about two hours of remote sensing and went to sleep. Out on the plains, Opportunity went from a northerly tilt that is very good for solar exposure, to a southerly tilt that is not so good for solar exposure. The tilt was expected to be as high as 10 degrees, but Opportunity’s actual tilt was about 5 degrees. Daily output from the solar panels went from 840 watt-hours in the crater, to 730 watt-hours on the plains.

Since the team continues to be operating in restricted sol mode, sols 317 and 318 were planned together as a two-sol plan. For sol 317, the science team elected to drive toward wheel tracks that Opportunity had made before entering Endurance Crater. The rover backed up about 5 meters (16.4 feet), performed some mid-drive imaging, and then continued another 10 meters (33 feet) to put the old rover tracks into the work volume of the robotic arm. Sol 318 was another remote-sensing sol, during which Opportunity imaged its still-distant heat shield and conducted a miniature thermal emission spectrometer observation of the tracks.

After the drive, both old and new tracks were directly in front of the rover. On sol 319 Opportunity captured microscopic imager mosaics of both types of tracks, then drove about 40 meters (131 feet) closer to the heat shield, which will be examined carefully in future sols. Sol 319 ended on Dec. 17.

Original Source: NASA News Release

Posted on by Fraser Cain

Huygens is On Its Way

The European Space Agency?s Huygens probe was successfully released by NASA?s Cassini orbiter early this morning and is now on a controlled collision course toward Saturn?s largest and most mysterious moon, Titan, where on 14 January it will make a descent through one of the most intriguing atmospheres in the solar system to an unknown surface.

The separation occurred at 02:00 UTC (03:00 CET): A few minutes after separation, Cassini turned back to Earth and relayed back information about the separation. This signal then took 1 hour and 8 minutes to cross the 1.2 billion kilometres separating the Cassini spacecraft and Earth.

?Today?s release is another successful milestone in the Cassini/Huygens odyssey?, said Dr David Southwood, ESA?s Director of Science Programmes. ?This was an amicable separation after seven years of living together. Our thanks to our partners at NASA for the lift. Each spacecraft will now continue on its own but we expect they?ll keep in touch to complete this amazing mission. Now all our hopes and expectations are focused on getting the first in-situ data from a new world we?ve been dreaming of exploring for decades?.

Final stage of a seven-year odyssey
The Cassini/Huygens mission, jointly developed by NASA, ESA and the Italian space agency (ASI), began on 15 October 1997, when the composite spacecraft were launched from Cape Canaveral, Florida, atop a Titan 4B/Centaur vehicle. Together, the two probes weighed 5548 kg at launch and became the largest space mission ever sent to the outer planets. To gain sufficient velocity to reach Saturn, they had to conduct four gravity-assist manoeuvres by flying twice by Venus, once by the Earth and once by Jupiter. On 1 July Cassini/Huygens eventually became the first spacecraft to enter an orbit around Saturn.

On 17 December, while on its third orbit around the ringed planet, the Cassini orbiter performed a manoeuvre to enter a controlled collision trajectory towards Titan. As planned, a fine tuning of the trajectory took place on 22 December to place Huygens on its nominal entry trajectrory. While Huygens will remain on this trajectory till it plunges into Titan?s atmosphere on 14 January, the orbiter will perform a deflection manoeuvre on 28 December to avoid crashing onto the moon. Today?s separation was achieved by the firing of pyrotechnic devices. Under the action of push-off springs, ramps and rollers, the probe was released at a relative velocity of about 0.3 m/s with a spin rate of 7 rpm. Telemetry data confirming the separation were collected by NASA?s Deep Space Network stations in Madrid, Spain and Goldstone, California, when the telemetry playback signal from Cassini eventually reached the Earth.

The Huygens probe is now dormant and will remain so for its 20-day coast phase to Titan. Four days before its release, a triply-redundant timer was programmed in order to wake-up the probe?s systems shortly before arrival on Titan.

Exploring Titan?s atmosphere
Huygens is scheduled to enter Titan?s atmosphere at about 09:06 UTC (10:06 CET) on 14 January, entering at a relatively steep angle of 65? and a velocity of about 6 km/s. The target is over the southern hemisphere, on the day side. Protected by an ablative thermal shield, the probe will decelerate to 400 m/s within 3 minutes before it deploys a 2.6 m pilot chute at about 160 km. After 2.5 seconds this chute will pull away the probe?s aft cover and the main parachute, 8.3 m in diameter, will deploy to stabilise the probe. The front shield will then be released and the probe, whose main objective is to study Titan?s atmosphere, will open inlet ports and deploy booms to collect the scientific data. All instruments will have direct access to the atmosphere to conduct detailed in-situ measurements of its structure, dynamics and chemistry. Imagery of the surface along the track will also be acquired. These data will be transmitted directly to the Cassini orbiter, which, at the same time, will be flying over Titan at 60 000 km at closest approach. Earth-based radiotelescopes will also try to detect the signal?s tone directly.

Huygens changing its parachutes
After 15 minutes, at about 120 km, Huygens will release its main parachute and a smaller 3 m drogue chute will take over to allow a deeper plunge through the atmosphere within the lifetime of the probe?s batteries.

The descent will last about 140 minutes before Huygens impacts the surface at about 6 m/s. If the probe survives all this, its extended mission will start, consisting in direct characterisation of Titan?s surface for as long as the batteries can power the instruments and the Cassini orbiter is visible over the horizon at the landing site, i.e. not more than 130 minutes.

At that time, the Cassini orbiter will reorient its main antenna dish toward Earth in order to play back the data collected by Huygens, which will be received by NASA?s 70-m diameter antenna in Canberra, Australia, 67 minutes later. Three playbacks are planned, to ensure that all recorded data are safely transmitted to Earth. Then Cassini will continue its mission exploring Saturn and its moons, which includes multiple additional flybys of Titan in the coming months and years.

A probe deep into space and time
Bigger than Mercury and slightly smaller than Mars, Titan is unique in having a thick hazy nitrogen-rich atmosphere containing carbon-based compounds that could yield important clues about how Earth came to be habitable. The chemical makeup of the atmosphere is thought to be very similar to Earth?s before life began, although colder (-180?C) and so lacking liquid water. The in-situ results from Huygens, combined with global observations from repeated flybys of Titan by the Cassini orbiter, are thus expected to help us understand not only one of the most exotic members of our Solar System but also the evolution of the early Earth’s atmosphere and the mechanisms that led to the dawn of life on our planet.

Europe?s main contribution to the Cassini mission, the Huygens probe, was built for ESA by an industrial team led by Alcatel Space. This 320 kg spacecraft is carrying six science instruments to study the atmosphere during its descent. Laboratories and research centres from all ESA member countries, the United States, Poland and Israel have been involved in developing this science payload. The Huygens atmospheric structure instrument package (HASI) will measure temperature and pressure profiles, and characterise winds and turbulences. It will also be able to detect lightning and even to measure the conductivity and permittivity of the surface if the probe survives the impact. The gas chromatograph mass spectrometer (GCMS) will provide fine chemical analysis of the atmosphere and the aerosols collected by the aerosol collector and pyrolyser (ACP). The descent imager/spectral radiometer (DISR) will collect images, spectra and other data on the atmosphere, the radiation budget, cloud structures, aerosols and the surface. The doppler wind experiment (DWE) will provide a zonal wind profile while the surface science package (SSP) will characterise the landing site if Huygens survives the impact.

The Cassini-Huygens mission is a cooperation between NASA, the European Space Agency and ASI, the Italian space agency. The Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, is managing the mission for NASA?s Office of Space Science, Washington. JPL designed, developed and assembled the Cassini orbiter.

Original Source: ESA News Release

Posted on by Fraser Cain

Asteroid Threat Upgraded to 1 in 45

The probability that Asteroid 2004 MN4 will strike the Earth on April 13, 2029 has actually been upgraded to a 1-in-43 chance now that more observations have been made. The asteroid has reached an uprecedented 4 on the Torino scale. Of course, this still means that there’s a 98% chance that it’ll completely miss the Earth. The space rock is 400 metres (1,300 feet) across, so a direct impact with our planet would cause a significant amount of damage on a regional level. Update: as of Dec. 28th, the probability has been significantly downgraded thanks to further observations. It’ll definitely miss.

Posted on by Fraser Cain

Jovian Moon Was Probably Captured

The first ground based infrared spectrum of Jupiter’s moon Amalthea reveals that it must have formed far from its current location. This new result, based on observations with the Subaru telescope and the NASA Infrared Telescope Facility by a team of researchers from the National Astronomical Observatory of Japan, the University of Hawaii, and the University of Tokyo, sheds new light on our Solar System’s turbulent past.

Planets like Earth and Jupiter formed from the disk of gas and dust swirling around the Sun at the time of its birth. Rocky planets like Earth formed in the high temperature environment close to the Sun, while large gaseous planets like Jupiter formed in the cooler regions farther away. Similarly, Jupiter, the largest planet in the solar system, probably had its own disk of gas and dust. The four moons of Jupiter discovered by Galileo (Io, Europa, Ganymede, and Callisto) are likely to have been born from this disk.

In addition to the Galilean moons, Jupiter has two other types of satellites: four small inner moons orbiting Jupiter within the orbit of Io, the inner most Galilean satellite, and at least fifty five small outer moons outside the orbit of Callisto, the outer most Galilean satellite. All the outer satellites have tell-tale orbits that reveal that they must have been captured by Jupiter during or after the formation of the planet and its larger moons.

The origin of the four small inner moons remain a mystery, however. They have orbits compatible with the hypothesis that they formed in orbit around Jupiter like the Galilean moons. On the other hand, their small irregular shapes and their comparatively low reflectivity and low densities resemble asteroids and suggest that they were captured by Jupiter’s gravitational pull just like the outer moons.

The mystery persists because of the challenge inherent in observing Jupiter’s small inner moons from Earth. The moons are small and therefore faint, and they are obscured by the bright glare from Jupiter. Although NASA’s space probes Voyager and Galileo have captured detailed images of Jupiter’s small inner moons, these data have been insufficient for resolving the question of their origin.

Naruhisa Takato from the National Astronomical Observatory of Japan and his collaborators have now had success in obtaining the first infrared spectrum of two of Jupiter’s small inner moons, Amalthea and Thebe. To obtain a spectrum over a wide range of infrared wavelengths, the group combined the strengths of two instruments on two telescopes on the summit of Mauna Kea, Hawaii. For high resolution spectroscopy at wavelengths longer than 3 ?m ,the group used the Infrared Camera and Spectrograph on the Subaru telescope. For shorter wavelengths, the group used SpeX on the NASA IRTF, which has broad wavelength coverage.

The new spectrum of Amalthea shows the characteristic signatures of water. The most likely location of this water is within water containing hydrous minerals. Such minerals typically form in low temperature environments, ruling out the possibility that Amalthea could have formed in the high temperature environment of Jupiter’s immediate neighborhood while the planet was forming and where Amalthea
now is.

If Amalthea did not form near its present location, where did it come from? The surface of Amalthea resembles regions of Callisto that are not covered by ice. This suggests that Amalthea may have been one of the many small “micro-satellites” orbiting Jupiter that was sucked into an inner orbit when the Galilean moons formed. However, the spectrum of Amalthea has similarities with asteroids orbiting the Sun, suggesting that is was a “micro-planet” that was pulled into Jupiter’s orbit when Jupiter itself was forming.

Takato says “although we think Jupiter’s moons formed as an assembly of many smaller bodies, the same way we think planets formed from ‘planetesimals’, until now we have not found any example of the original building blocks of a planet’s moon. However, our results strengthen the argument that Amalthea is one of the few remaining pieces of the material that formed the Galilean moons. Amalthea may have ended up in orbit close to Jupiter rather than get incorporated into a larger moon or Jupiter itself. If this is the case, Amalthea would be the first known example of a ‘satellitesimal.'”

Original Source: Subaru News Release

Posted on by Fraser Cain

Cargo Ship Launches with Supplies for the Station

A Russian cargo spacecraft is on its way to the International Space Station. The Progress resupply ship launched at 4:19:31 p.m. CST from the Baikonur Cosmodrome, Kazakhstan, and less than 10 minutes later settled into orbit. Moments after that, automatic commands deployed its solar arrays and navigational antennas.

As the Progress launched, Expedition 10 Commander and NASA Station Science Officer Leroy Chiao and Flight Engineer Salizhan Sharipov were a few minutes from the start of their sleep period. The Station was flying over western Chile at an altitude of 225 statute miles at the time of lift off.

Engine firings are scheduled overnight to raise and refine the Progress’ orbit and its path to the Station for an automated docking at 5:31 p.m. CST Dec. 25. It will dock to the aft port of the Station’s Zvezda living quarters module. This will be the 16th Progress spacecraft to dock with the Station. The Christmas Day docking will be broadcast live on NASA Television beginning at 4:30 p.m. CST. The Johnson Space Center newsroom will be open concurrent with the NASA TV coverage of docking.

The Progress is carrying 5,000 pounds of food, fuel, oxygen, water, spare parts and holiday presents to the crew. It’s loaded with 1,234 pounds of propellant, 110 pounds of oxygen and air, 926 pounds of water, and more than 2,700 pounds of spare parts, life support system components and experiment hardware. The manifest also includes about a 112-day supply of food in 69 containers to replenish the Station pantry. Other items on the Progress include new laptop computers, replacement parts for the U.S. spacesuits and additional components for the arrival next year of the European Automated Transfer Vehicle, another type of automated cargo craft.

Chiao and Sharipov are scheduled to open the hatch to the Progress shortly after 12 p.m. CST Sunday to begin unloading the cargo.

The Progress spacecraft that had been at the Station since August was undocked yesterday by Russian flight controllers at 1:37 p.m. CST. Filled with discarded items, it was commanded to deorbit about four hours later and burned up in the Earth’s atmosphere.

The crew also continued their science research this week. Chiao and Sharipov conducted another in a series of tests of the Advanced Diagnostic Ultrasound in Micro-G experiment.

On the first day, they took turns performing bone and dental scans on each other. One day later, after six hours of fasting, Sharipov was the subject for abdominal scans. Chiao also performed an abdominal scan on Sharipov to recover from a previous session during which data was lost.

They also used the Crew Medical Restraint System for positioning the subject and electrodes for electrocardiogram recording. The scanning and post-scan activities were videotaped and photographed for downlinking to the ground for interpretation. The experiment tests the diagnostic capability of ultrasound for medical contingencies that could occur in a space environment

Later in the week, Chaio and the ground team conducted their post-session analysis to discuss the successful ultrasound scans and in particular the abdominal scan conducted on Salizhan. Conducting the scans repeatedly increases the proficiency of crewmembers.

The experiment has already demonstrated the capability of non-medical personnel to downlink diagnostic information for evaluation by medical specialists on the ground. This “telemedicine” technique has application to emergency medical care in remote areas of the earth, as well as for astronaut crews traveling beyond low earth orbit.

Information about crew activities on the Space Station, future launch dates and Station sighting opportunities from Earth, is available on the Internet at:

http://spaceflight.nasa.gov/

For information about NASA and other agency missions, visit:

http://www.nasa.gov

Original Source: NASA News Release

Posted on by Fraser Cain

Huygens Set to Detach Today

Image credit: ESA
After a seven-year and 3.2 billion km journey from Earth to Saturn, ESA?s Huygens probe, travelling on board NASA?s Cassini mother craft and powered through an umbilical cable, is now ready to separate and continue its journey alone toward Titan, Saturn?s largest moon.

On Christmas night (25 December at 03:00 CET- orbiter time/04:08 CET on the ground) Huygens will be cut loose from Cassini and will coast toward Titan for 20 days, to arrive at its destination on 14 January.

?We have the green light for separation. The joint ESA/NASA team has done all that had to be done to be ready for release. We are looking forward to receiving data on 14 January at ESA?s Spacecraft Operations Centre in Darmstadt, Germany.?, said Claudio Sollazzo, ESA?s Head of Huygens Spacecraft Operations Unit at NASA/JPL in Pasadena, California.

At separation, tension-loaded springs will gently push Huygens away from Cassini onto a ballistic 4-million kilometre path to Titan. The Huygens probe will remain dormant until the on-board timer, which has been loaded on 21 December, wakes it up shortly before it reaches Titan’s upper atmosphere on 14 January.

?We will then have to wait patiently for the most exciting phase of our mission, when Cassini will send back to Earth the Huygens data. The Huygens descent will be accomplished in less then two and half hours and, if the probe survives the impact with the surface, we could expect up to two extra hours of science results before the onboard batteries die out? said Jean-Pierre Lebreton, ESA?s Huygens Mission Manager and Project Scientist, preparing to follow the separation from NASA/JPL in Pasadena.

At about 1200 km above the surface of Titan, the Huygens probe will begin a dramatic plunge through Titan?s thick haze, with the task to analyze the chemical makeup and composition of the moon?s atmosphere as it descends to touchdown on its surface. With Cassini listening to the probe for 4.5 hours, the data gathered during the descent and on the surface will be transmitted continuously by the probe and recorded onboard the Cassini orbiter.

Cassini will then turn away from Titan and point its antenna to Earth and relay the data through NASA’s Deep Space Network to JPL and on to ESA’s Space Operations Centre ESOC in Darmstadt, Germany where the Huygens probe data will be analysed by scientists.

After a successful probe release, on 28 December, the Cassini orbiter will perform a deflection manoeuvre to keep it from following Huygens into Titan’s atmosphere and to establish the required geometry between the probe and the orbiter for radio communications during the probe?s descent. The Cassini-Huygens mission is a cooperation between NASA, the European Space Agency and ASI, the Italian Space Agency. The Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, is managing the mission for NASA?s Office of Space Science, Washington.

Original Source: ESA News Release

Posted on by Fraser Cain

Asteroid 2004 MN4 Gets the Highest Score on the Torino Scale

A recently rediscovered 400-meter Near-Earth Asteroid (NEA) is predicted to pass near the Earth on 13 April 2029. The flyby distance is uncertain and an Earth impact cannot yet be ruled out. The odds of impact, presently around 1 in 300, are unusual enough to merit special monitoring by astronomers, but should not be of public concern. These odds are likely to change on a day-to-day basis as new data are received. In all likelihood, the possibility of impact will eventually be eliminated as the asteroid continues to be tracked by astronomers around the world.

This object, 2004 mn4, is the first to reach a level 2 (out of 10) on the Torino Scale. According to the Torino Scale, a rating of 2 indicates “a discovery, which may become routine with expanded searches, of an object making a somewhat close but not highly unusual pass near the Earth. While meriting attention by astronomers, there is no cause for public attention or public concern as an actual collision is very unlikely. New telescopic observations very likely will lead to re-assignment to Level 0 [no hazard].” This asteroid should be easily observable throughout the coming months.

The brightness of 2003 qq47 suggests that its diameter is roughly 400 meters (1300 feet) and our current, but very uncertain, best estimate of the flyby distance in 2029 is about twice the distance of the moon, or about 780,000 km (480,000 miles). On average, an asteroid of this size would be expected to pass within 2 lunar distances of Earth every 5 years or so.

Most of this object’s orbit lies within the Earth’s orbit, and it approaches the sun almost as close as the orbit of Venus. 2004mn4’s orbital period about the sun is 323 days, placing it within the Aten class of NEAs, which have an orbital period less than one year. It has a low inclination with respect to the Earth’s orbit and the asteroid crosses near the Earth’s orbit twice on each of its passages about the sun.

2004 MN4 was discovered on 19 June 2004 by Roy Tucker, David Tholen and Fabrizio Bernardi of the NASA-funded University of Hawaii Asteroid Survey (UHAS), from Kitt Peak, Arizona, and observed over two nights. On 18 December, the object was rediscovered from Australia by Gordon Garradd of the Siding Spring Survey, another NASA-funded NEA survey. Further observations from around the globe over the next several days allowed the Minor Planet Center to confirm the connection to the June discovery, at which point the possibility of impact in 2029 was realized by the automatic SENTRY system of NASA’s Near-Earth Object Program Office. NEODyS, a similar automatic system at the University of Pisa and the University of Valladolid, Spain also detected the impact possibility and provided similar predictions.

Original Source: NASA News Release

Posted on by Fraser Cain

Mars Volcanoes Were Active Recently

Image credit: ESA
This perspective view, taken by the High Resolution Stereo Camera (HRSC) on board ESA’s Mars Express spacecraft, shows the complex caldera of Olympus Mons on Mars, the highest volcano in our Solar System. It may also offer the best chance to find more geologically recent volcanic activity on Mars.

“We would be very lucky to see [an eruption], but it would be a massive event,” said Gerhard Neukum in USA Today. Neukum is a professor at Berlin’s Free University and lead author of a study in Nature magazine suggesting a revised timeline for lava on Mars.

While Mars is littered with collapsed volcano remnants, none have been observed as active right now. The new images indicate some of these volcanoes are merely dormant, not dead. The timeline proposed from studying the complex Olympus Mons caldera suggests there have been lava flows from intense volcanic activity within the past 2 million years.

To geologists, two million years is regarded as recent since it corresponds to the last one percent of the planet’s history.

For instance, the curved striations on the left and foreground, in the southern part of the caldera, are tectonic faults. After lava production has ceased the caldera collapsed over the emptied magma chamber. Through the collapse the surface suffers from extension and so extensional fractures are formed.

“I suspect that as we get more spacecraft in orbit that it will increase the chances of seeing some kind of active eruption,” said Dr. James W. Head III, a professor of geological sciences at Brown. As quoted in Associated Press commentary, Dr. Head is one of more than 40 scientists who contributed to analysis of the images.

The level plain inside the crater on which these fractures can be observed represents the oldest caldera collapse. Later lava production caused new caldera collapses at different locations (the other circular depressions). They have partly destroyed the circular fracture pattern of the oldest one.

This perspective view of the caldera was calculated from the digital elevation model derived from the stereo channels and combined with the nadir and color channels of the HRSC.

University of Buffalo volcanologist, Dr. Tracy Gregg, discussed the scientific appeal of studying Martian volcanoes in detail. “If both of these [Opportunity and Spirit] landers survive with airbag technology, then it blows the doors wide open for future Mars landing sites with far more interesting terrain. A landing site near a volcano might be possible, now that the airbag technology has worked so wonderfully.”

The current generation of Mars missions has adopted the theme, “Follow the Water”, as a quest to understand the complex geological history of a planet that may have had significant reserves once. For that much warmer and wetter Mars, this motto also requires other ingredients for microbial life, including primordial “fire” in the form of biological temperature ranges and potentially geothermal heat.

“I’d like to see us land ON a volcano,” said Gregg. “Right on the flanks. Often the best place to look for evidence of life on any planet is near volcanoes.”

“That may sound counterintuitive, but think about Yellowstone National Park , which really is nothing but a huge volcano,” said Gregg. “Even when the weather in Wyoming is 20 below zero, all the geysers, which are fed by volcanic heat, are swarming with bacteria and all kinds of happy little things cruising around in the water. So, since we think that the necessary ingredients for life on earth were water and heat, we are looking for the same things on Mars, and while we definitely have evidence of water there, we still are looking for a source of heat.”

While Olympus Mons is dormant today, volcanologists are not entirely convinced more isn’t going on geothermally on Mars. “If you’d asked me [if there were not active surface volcanoes] 10 years ago–or even 5–I might’ve said yes,” said Gregg. “Now I’m not so sure.”

On Mars, “where would I look for recent volcanic activity? Depends on how you want to define it on Mars,” said Gregg. “I strongly suspect there are still molten (or at least mushy) magma bodies beneath the huge Tharsis volcanoes , and beneath Elysium Mons .”

“But the youngest surficial activity discovered to date (and it’s probably 1 million years old, which would be considered quite young, and possibly ‘active’ on Mars) is in a region that contains no large volcanic structures of any kind,” said Gregg. “Instead, there are cracks in the ground, and a few low-lying volcanoes that can’t even be seen except in the high-resolution topography (they are too subtle for imagery to reveal). This area is called Cerberus Fossae .”

Seeing important events surrounding Olympus Mons is not entirely just about geology, as the famed science fiction writer, Sir Arthur C. Clarke, indicated this was the site for his own version of desktop terraforming. “Soon after maps of the real Mars became available, I received a generous gift from computer genius John Hinkley–his Vistapro image-processing system. This prompted me to do some desktop terraforming (a word, incidently, invented by science fictions’ Grandest of Grand Masters, Jack Williamson). I must confess that in ‘The Snows of Olympus: A Garden on Mars’ (1995) I frequently allowed artistic considerations to override scientific ones. Thus I couldn’t resist putting a lake in the caldera of Mount Olympus, unlikely though it is that the strenuous efforts of future colonists will produce an atmosphere dense enough to permit liquid water at such an altitude.”

Original Source: NASA Astrobiology Magazine

Posted on by Fraser Cain

Radio Telescopes Will Contribute to Huygens’ Mission

When the European Space Agency’s Huygens spacecraft makes its plunge into the atmosphere of Saturn’s moon Titan on January 14, radio telescopes of the National Science Foundation’s National Radio Astronomy Observatory (NRAO) will help international teams of scientists extract the maximum possible amount of irreplaceable information from an experiment unique in human history. Huygens is the 700-pound probe that has accompanied the larger Cassini spacecraft on a mission to thoroughly explore Saturn, its rings and its numerous moons.

The Robert C. Byrd Green Bank Telescope (GBT) in West Virginia and eight of the ten telescopes of the continent-wide Very Long Baseline Array (VLBA), located at Pie Town and Los Alamos, NM, Fort Davis, TX, North Liberty, IA, Kitt Peak, AZ, Brewster, WA, Owens Valley, CA, and Mauna Kea, HI, will directly receive the faint signal from Huygens during its descent.

Along with other radio telescopes in Australia, Japan, and China, the NRAO facilities will add significantly to the information about Titan and its atmosphere that will be gained from the Huygens mission. A European-led team will use the radio telescopes to make extremely precise measurements of the probe’s position during its descent, while a U.S.-led team will concentrate on gathering measurements of the probe’s descent speed and the direction of its motion. The radio-telescope measurements will provide data vital to gaining a full understanding of the winds that Huygens encounters in Titan’s atmosphere.

Currently, scientists know little about Titan’s winds. Data from the Voyager I spacecraft’s 1980 flyby indicated that east-west winds may reach 225 mph or more. North-south winds and possible vertical winds, while probably much weaker, may still be significant. There are competing theoretical models of Titan’s winds, and the overall picture is best summarized as poorly understood. Predictions of where the Huygens probe will land range from nearly 250 miles east to nearly 125 miles west of the point where its parachute first deploys, depending on which wind model is used. What actually happens to the probe as it makes its parachute descent through Titan’s atmosphere will give scientists their best-ever opportunity to learn about Titan’s winds.

During its descent, Huygens will transmit data from its onboard sensors to Cassini, the “mother ship” that brought it to Titan. Cassini will then relay the data back to Earth. However, the large radio telescopes will be able to receive the faint (10-watt) signal from Huygens directly, even at a distance of nearly 750 million miles. This will not be done to duplicate the data collection, but to generate new data about Huygens’ position and motions through direct measurement.

Measurements of the Doppler shift in the frequency of Huygens’ radio signal made from the Cassini spacecraft, in an experiment led by Mike Bird of the University of Bonn, will largely give information about the speed of Titan’s east-west winds. A team led by scientists at NASA’s Jet Propulsion Laboratory in Pasadena, CA, will measure the Doppler shift in the probe’s signal relative to Earth. These additional Doppler measurements from the Earth-based radio telescopes will provide important data needed to learn about the north-south winds.

“Adding the ground-based telescopes to the experiment will not only help confirm the data we get from the Cassini orbiter but also will allow us to get a much more complete picture of the winds on Titan,” said William Folkner, a JPL scientist.

Another team, led by scientists from the Joint Institute for Very Long Baseline Interferometry in Europe (JIVE), in Dwingeloo, The Netherlands, will use a world-wide network of radio telescopes, including the NRAO telescopes, to track the probe’s trajectory with unprecedented accuracy. They expect to measure the probe’s position within two-thirds of a mile (1 kilometer) at a distance of nearly 750 million miles.

“That’s like being able to sit in your back yard and watch the ball in a ping-pong game being played on the Moon,” said Leonid Gurvits of JIVE.

Both the JPL and JIVE teams will record the data collected by the radio telescopes and process it later. In the case of the Doppler measurements, some real-time information may be available, depending on the strength of the signal, but the scientists on this team also plan to do their detailed analysis on recorded data.

The JPL team is utilizing special instrumentation from the Deep Space Network called Radio Science Receivers. One will be loaned to the GBT and another to the Parkes radio observatory. “This is the same instrument that allowed us to support the challenging communications during the landing of the Spirit and Opportunity Mars rovers as well as the Cassini Saturn Orbit Insertion when the received radio signal was very weak,” said Sami Asmar, the JPL scientist responsible for the data recording.

When the Galileo spacecraft’s probe entered Jupiter’s atmosphere in 1995, a JPL team used the NSF’s Very Large Array (VLA) radio telescope in New Mexico to directly track the probe’s signal. Adding the data from the VLA to that experiment dramatically improved the accuracy of the wind-speed measurements.

“The Galileo probe gave us a surprise. Contrary to some predictions, we learned that Jupiter’s winds got stronger as we went deeper into its atmosphere. That tells us that those deeper winds are not driven entirely by sunlight, but also by heat coming up from the planet’s core. If we get lucky at Titan, we’ll get surprises there, too,” said Robert Preston, another JPL scientist.

The Huygens probe is a spacecraft built by the European Space Agency (ESA). In addition to the NRAO telescopes, the JPL Doppler Wind Experiment will use the Australia Telescope National Facility and other radio telescopes in Parkes, Mopra, and Ceduna, Australia; Hobart, Tasmania; Urumqi and Shanghai, China; and Kashima, Japan. The positional measurements are a project led by JIVE and involving ESA, the Netherlands Foundation for Research in Astronomy, the University of Bonn, Helsinki University of Technology, JPL, the Australia Telescope National Facility, the National Astronomical Observatories of China, the Shanghai Astronomical Observatory, and the National Institute for Communication Technologies in Kashima, Japan.

The Joint Institute for VLBI in Europe is funded by the national research councils, national facilities and institutes of The Netherlands (NWO and ASTRON), the United Kingdom (PPARC), Italy (CNR), Sweden (Onsala Space Observatory, National Facility), Spain (IGN) and Germany (MPIfR). The European VLBI Network is a joint facility of European, Chinese, South African and other radio astronomy institutes funded by their national research councils. The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Original Source: NRAO News Release