Tag Archives: MSL

Space Sunday: mesas, dunes NEOs, comets and launches

A dramatic look back: in the foreground is the lower slope of one of the "Murray Buttes", in the far distance the tall peaks of Gale Crater's huge rim. One of the final images taken by Curiosity from within the region of the buttes on Thursday, September 8th, the rover's 1,454 sol on Mars. Credit: NASA/JPL / MSSS

A dramatic look back: in the foreground is the lower slope of one of the “Murray Buttes”, in the far distance the tall peaks of Gale Crater’s huge rim. One of a series of images taken by NASA’s Curiosity rover on Thursday, September 8th, the rover’s 1,454 sol on Mars. Credit: NASA/JPL / MSSS

NASA’s Mars Science Laboratory rover, Curiosity, has said “farewell” to “Murray Buttes” in a stunning series of images, as it continues its climb up the slopes of “Mount Sharp”, a massive mound of deposited material located at the central impact peak of Gale Crater.

The mesas of “Murray Buttes” mark the upper extend of the transitional “Murray Formation”, where the material deposited during the earliest centuries of “Mount Sharp’s” formation merge with the rock comprising the crater floor. Curiosity has been passing by the area of the buttes for a little over a month now, carrying out examinations of the rock surface and gathering samples of mudstone for analysis.

Murray Buttes with the faint outlines of Gale Crater beyond, as images on Thursday, September 8th 2016, by NASA's Curiosity rover during its 1m454 sol on Mars. Credit: NASA/JPL / MSSS

“Murray Buttes” with the faint outlines of Gale Crater beyond, as images on Thursday, September 8th 2016, by NASA’s Curiosity rover during its 1,454 sol on Mars. Credit: NASA/JPL / MSSS

Believed to be the eroded remnants of ancient sandstone that originated when winds deposited sand after lower “Mount Sharp” had formed, the buttes rival anything of a similar nature found on Earth in terms of dramatic looks and structure. So much so that while we’re hardly likely to see Clint Eastwood ride his horse around the base of one, they would nevertheless fit neatly into a Sergio Leone western.

Several of the pictures – mosaics of images captured by the rover which have been white-balanced to match typical Earth daylight lighting conditions and then stitched together to offer complete scenes – reveal the deeply layered nature of the sandstone, sandwiched in what is referred to as “cross-bedding”. This indicates that the formations are the result of both wind deposition of material and then wind erosion, further confirming the idea that “Mount Sharp” was initially formed as a formed as a result of Gale Crater once being home to a great lake, before the waters receded and wind action took over.

A closer view of the layered nature of the sandstone deposits forming "Murray Buttes", showing the "cross bedding" of the layers, indicative of the role that wind played in their deposition / formation. This picture comprises a mosaic of images captured by Curiosity rover on Thursday, September 8th, 2016 during its 1,454 sol on Mars. Credit: NASA/JPL / MSSS

A closer view of the layered nature of the sandstone deposits forming “Murray Buttes”, showing the “cross bedding” of the layers, indicative of the role that wind played in their deposition / formation. This picture comprises a mosaic of images captured by Curiosity rover on Thursday, September 8th, 2016 during its 1,454 sol on Mars. Credit: NASA/JPL / MSSS

The images were taken as Curiosity traversed the base of the final butte, where it gathered a final drilling sample on September 9th. On completion of the sample-gathering, the rover will continue farther south and higher up Mount Sharp, leaving these spectacular formations behind.

Curiosity's route up the slopes of "Mount Sharp". Credit: T.Reyes / NASA/JPL

Curiosity’s route up the slopes of “Mount Sharp” – click for full size. Credit: T.Reyes / NASA/JPL

The Sand Dunes of Shangri-La

On September 7th, NASA issued a video showing the latest radar images captured by the Cassini probe of the surface of Saturn’s largest moon, mighty Titan. The data was gathered as the probe swept by the huge moon – which is blanketed by a thick atmosphere and is known to have lakes and rivers of liquid hydrocarbons on its surface – at a distance of some 976 km (607 mi) on July 25th, 2016 – one of the closest passes over the moon the vehicle has ever made.

Because of the moon’s thick atmosphere, conventional camera systems cannot be used to probe Titan’s mysteries, so Cassini uses a radar system to “map” surface features in black-and-white. Of particular interest to mission scientists during the July 25th flyby was a dark patch along Titan’s equator, previously images by the radar system at much greater distances and dubbed “Shangri-La”. And area which revealed itself to be – in part – a region of linear dunes, mostly likely comprised of grains derived from hydrocarbons that have settled out of Titan’s atmosphere, and which have been sculpted by Titan’s surface winds. Scientists can use the dunes to learn about winds, the sands they’re composed of, and highs and lows in the landscape.

Also captured by the radar is an arena dubbed “Xanadu annex”, believed to be an out-thrust of chaotic terrain from a region dubbed “Xanadu” just to the north of “Shangri-La”. First imaged by the Hubble Space Telescope in 1994, just before the Cassini / Huygens mission was launched, “Xanadu” and its annex are thought to be remnants of the moon’s icy crust before it was covered by organic sediments from the atmosphere.

OSIRIS-REx Lifts-off as an Asteroid Sweep By Earth

On Thursday, September 8th, NASA successfully launched OSIRIS-REx on a 7-year trek to reach asteroid Bennu, where it will gather surface samples and return them to Earth for analysis. The mission, which I previewed in my last Space Sunday report, lifted-off flawlessly from Space Launch Complex 41 at Cape Canaveral Air Force Station at 19:05 EDT, atop its Atlas V booster at the start of a journey which will carry it a total of 7.2 billion kilometres (4.5 billion miles).

The Atlas V booster carrying OSIRIS-REx shortly after lift-off on Thursday, September 8th. Credit: Ken Kremer

The Atlas V booster carrying OSIRIS-REx shortly after lift-off on Thursday, September 8th. Credit: Ken Kremer

Witnessing the launch was principal investigator Dante Lauretta, from the University of Arizona. “I can’t tell you how thrilled I was this evening, thinking of the people who played a part in this,” he said following the launch.

“This represents the hopes and dreams and blood, sweat and tears of thousands of people who have been working on this for years.”

The mission will gather samples from the surface of the asteroid – a remnant from the formation of the solar system – and will also map Bennu’s orbit around the Sun and the influences affecting it.

This is because the asteroid is a near-Earth object (NEO): an asteroid which periodically passes across Earth’s orbit around the Sun, and can come very close to our planet whilst doing so. So close, in fact, that some estimates of Bennu’s future orbit suggest it will collide with Earth towards the end of the next century.

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Space Sunday: exoplanets, dark matter, rovers and recoveries

An artist's impression of Proxima b with Proxima Centauri low on the horizon. The double star above and to the right of it is Alpha Centauri A and B. Credit: ESO

An artist’s impression of Proxima b with Proxima Centauri low on the horizon. The double star above and to the right of it is Alpha Centauri A and B. Credit: ESO

On August 15th, I wrote about rumours that an “Earth-like” planet has been found orbiting our nearest stellar neighbour, Proxima Centauri, 4.25 light years away from our own Sun. The news was first leaked by the German weekly magazine, Der Spiegel, which indicated the discovery had been made by a team at the European Southern Observatory’s (ESO)  La Silla facility – although ESO refused to comment at the time.

However, during a press conference held on August 24th, ESO did confirm the detection of a rocky planet orbiting Proxima Centauri. Dubbed Proxima b, the planet lies within the so-called “Goldilocks” habitable zone around its parent star – the orbit in which conditions are “just right” for the planet to harbour liquid water and offer the kind of conditions in which life might arise.

Comparing Proxima b with Earth. Credit: Space.com

Comparing Proxima b with Earth. Credit: Space.com

The ESO data reveals that Proxima b is orbits its parent star at a distance of roughly 7.5 billion km (4.7 billion miles), at the edge of the habitable zone, and does so every 11.2 terrestrial days and is about 1.3 times as massive as the Earth. The discovery came about by comparing multiple observations of the star over extended periods using two instruments at La Silla to look for signs of the star “wobbling” in its own spin as a result of planetary gravitational influences. Once identified, ESO called on other observatories around the world to carry out similar observations / comparisons to confirm their findings.

Although the planet lies within the “Goldilocks zone”, just how habitable is it likely to be is still open to question. Stars like Proxima Centauri, which is roughly one-seventh the diameter of our Sun, or just 1.5 times bigger than Jupiter, are volatile in nature, all activity within them entirely convective in nature, giving rise to massive stellar flares. As Proxima-B orbits so close to the star, it is entirely possible that over the aeons, such violent outbursts from Proxima Centauri have stripped away the planet’s atmosphere.

Proxima Cantauri compared with other stellar bodies - and Jupiter (Credit: Space.com)

Proxima Cantauri compared with other stellar bodies – and Jupiter. Credit: Space.com

In addition, the preliminary data from ESO suggests the planet is either tidally locked to Proxima Centauri, or may have a 3:2 orbital resonance (i.e. three rotations for every two orbits) – either of which could make it an inhospitable place for life to gain a toe-hold. The first would leave one side in perpetual daylight and the other in perpetual night, while the second would limit any liquid water on the surface to the tropical zones.

Nevertheless, the discovery of another world in one part of our stellar backyard does raise the question of what NASA’s upcoming TESS mission might find when it starts searching the hundreds of nearby stars for evidence of exoplanets in 2018.

Juno’s Second Pass Over Jupiter

NASA’s Juno space craft made a second successful close sweep over the cloud-tops of Jupiter on Saturday, August 27th to complete its first full orbit around the planet. Speeding over the planet at a velocity of 208,000 km/h (130,000 mph) relative to Jupiter, Juno passed just 2,400 km (2,600 miles) above the cloud tops before heading back out into space, where it will again slowly decelerate under the influence of Jupiter’s immense gravity over the next 27 days, before it once again swing back towards the gas giant.

“Early post-flyby telemetry indicates that everything worked as planned and Juno is firing on all cylinders,” said Rick Nybakken, Juno project manager at NASA’s Jet Propulsion Laboratory, as telemetry on the flyby started being received on Earth some 48 mins after the flyby, which occurred at 13:44 UTC.

A twin view of Jupiter captured by Juno on August 23rd, when the spacecraft was some 4.4 million km (2.8 million miles) from the gas giant and approaching Jupiter to complete its first full orbit. On the left is a colour image from JunoCam, on the right an infra-red image Credit: NASA/JPL-Caltech/SwRI/MSSS

A twin view of Jupiter captured by Juno on August 23rd, when the spacecraft was some 4.4 million km (2.8 million miles) from the gas giant and approaching Jupiter to complete its first full orbit. On the left is a colour image from JunoCam, on the right an infra-red image. Credit: NASA/JPL / SwRI / MSSS

All of Juno’s science suite was in operation during the passage over Jupiter’s clouds. However, due to speed at which the gathered data can be returned to Earth, and given it cannot all be relayed in one go or necessarily continuously, it will be a week or more before everything has been transmitted back to Earth. Nevertheless the science team are already excited by the flyby.

“We are getting some intriguing early data returns as we speak,” Scott Bolton, principal investigator of Juno from the Southwest Research Institute, stated. Some of that data included initial images of Jupiter captured as Juno swept towards the planet during the run-up to periapsis. “We are in an orbit nobody has ever been in before, and these images give us a whole new perspective on this gas-giant world,” Bolton added.

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Space Sunday: of Martian and lunar robots, distant worlds and ET

CuriosityAugust 2016 sees NASA’s Mars Science Laboratory rover Curiosity rack up four (terrestrial) years of operations on the surface of Mars.

The rover marked this anniversary rather quietly, by preparing to take further rock samples, this time from a target dubbed “Marimba”. Once gathered, the samples will be subjected to on-board analysis by Curiosity using the compact laboratory systems contained the rover’s body.

The sampling take place as the rover is engaged in a multi-month ascent of a mudstone geological unit as it continues its climb towards higher and progressively younger geological areas on “Mount Sharp” (more correctly, Aeolis Mons), which will include some rock types not yet explored.

August 2nd, 2016 (Sol 1,418)T: the Navigation Camera (Navcam) on Curiosity's mast images the rover's extended robot arm over a section of the "Marimba" target rock, ready to use the wire brush mounted on the "hand" at the end of the arm in order to scour surface material which otherwise might contaminate and samples gathered from the rock, prior to the rover taking a drilling sample. Credit: NASA/JPL / MSSS

August 2nd, 2016 (Sol 1,418)T: the Navigation Camera (Navcam) on Curiosity’s mast images the rover’s extended robot arm over a section of the “Marimba” target rock, ready to use the wire brush mounted on the “hand” at the end of the arm in order to scour surface material which otherwise might contaminate and samples gathered from the rock, prior to the rover taking a drilling sample. Credit: NASA/JPL / MSSS

In the meantime, examining the samples gathered from “Marimba” will allow a direct comparison with mudstone samples gathered further down the slopes of “Mount Sharp” and from the flatlands of Gale Crater. This will enable scientists to  build a more complete picture of the mineral and chemical  environment the rover is travelling through, and so further understand the general conditions which may have once have existed within the crater.

Goodnight from a Lunar Jade Rabbit

China has finally bid farewell to Yutu (“Jade Rabbit”, named for the companion to the Moon goddess Chang’e), its first lunar robotic explorer, after 31 months of surface operations.

The little solar-powered rover arrived on the lunar surface as part of Chain’s Chang’e 3 lander / rover mission on December 13, 2013, and was deployed from the lander some  7.5 hours after touch-down.

Yutu as imaged from the Chang'e 3 lander (part of the solar pnael from which can be seen in the lower right corner). Credit: National Astronomical Observatories of China

Yutu as imaged from the Chang’e 3 lander (part of the solar panel from which can be seen in the lower right corner). Credit: National Astronomical Observatories of China

However, due to the vast temperature differential experienced between the sunlit and shadowed parts of the rover at the time of the landing, operations didn’t commence until December 21st, when the rover was uniformly lit by the Sun. It’s first activity was to drive part-way around its parent lander and photograph it. After this, the rover travelled some 40 metres (130 ft) from the lander to commence independent science operations studying the lunar surface.

Yutu was designed to operate for just three months and travel up to 10 km (6.2 mi) within an area of 3 square kilometres (1.2 sq mi). Following its expose to the first 14-day long lunar “night”, the rover resumed operations in January 2014. However, as the second lunar night period approached (lasting 14 terrestrial days), the rover suffered a glitch in its drive mechanisms, leaving it susceptible to the harsh cold of the night-time, and on February 12th, following its second Lunar night, the rover was declared lost … only to resume communications with Earth within 24 hours.

Since that time, although immobilised, the little rover has maintained almost regular contact with Earth, but with each night period taking an increasing tolls on its systems. Even so, its continued survival gained it a huge and loyal following on the Chinese micro-blogging site, Weibo, where in a leaf firmly pulled from NASA’s book of social media engagement, Yutu had a first-person account.

It was via that social media account that Yutu’s final demise was announced, as if from the rover itself, on August 2nd 2016:

This time it really is goodnight. There are still many questions I would like answers to, but I’m the rabbit that has seen the most stars. The Moon has prepared a long dream for me, I don’t know what it will be like – will I be a Mars explorer, or be sent back to Earth?

The message gained a huge response from the rover’s 600,000 followers, and the Chinese space agency officially confirmed the rover had “died”, on Wednesday, August 3rd.

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Space Sunday: celestial harmonics, breathing air and singing for Pluto

July 14th: Jupiter with Io, Europa and Ganymede as seen by Juno after the craft had finished its critical orbital burn to slip into a 53.5 day orbit around the giant planet

July 10th: Jupiter with Io, Europa and Ganymede as seen by Juno after the craft had finished its critical orbital burn to slip into a 53.5 day orbit around the giant planet on July 4th. Credit: NASA/JPL / SwRI / MSSS (click and image for full size)

The banner image, captured by NASA’s Juno spacecraft, might look like the one I used in my last Space Sunday update, but there is one important difference. The images used last time around had been captured by Juno on June as it approached the Jovian system on June 29th, five days before the craft had to complete a critical engine burn whilst almost scraping the planet’s cloud tops, to place itself in an extended orbit around Jupiter. The image above was captured on July 10th, as Juno headed away from Jupiter, having successfully completed the manoeuvre.

At the time the picture was captured, 17:30 UTC on July 10th, 2016, Juno was already  4.3 million kilometres (2.7 million miles) distant from the planet, and heading away from it at a relative velocity of 18,420 km / hour (11,446 mph) and decelerating under the influence of the Jupiter’s gravity.

Juno's flight around the poles of Jupiter and it's position on July 10th, as seen by the NASA Eyes application

Juno’s flight around the poles of Jupiter and it’s position on July 10th, as seen using the NASA Eyes simulator (click for full size)

Juno’s imaging system – JunoCam – had, along with other major systems aboard the craft, been shut down prior to the July 4th engine burn, both to conserve power – Juno had to turn its solar panels away from the Sun during the burn manoeuvre, limiting the available electrical power – and to protect them through the initial passage through Jupiter’s tremendous radiation fields. It wasn’t until July 6th that the instruments were all powered back up, and after testing them, the July 10th exercise was the first opportunity to have a look back at the Jovian system.

Juno will keep travelling outwards from Jupiter until the end of July, slowing to a relative velocity of just 1,939 km/h (1212 mph), before it starts to “fall” back towards the planet, making a second close flyby on August 27th. At this time, the craft will pass just 4,142 km (2,575 mi) above the Jovian cloud tops at a speed of 208,11 km/h (129,315 mph). More importantly, all of vehicle’s science instruments will remain powered-up, and JunoCam in particular should gain some stunning images of Jupiter during this second close pass.

To celebrate Juno’s arrival around Jupiter, NASA released a time-lapse video of the Jovian system as seen by the approaching spacecraft. It begins on June 12th with Juno 16 million km (10 million mi), and ends on June 29th, when JunoCam was shut down and Juno was 4.8 million km (3 million mi) distant.

Made possible by Juno’s high angle of approach into the Jovian system, it is the first close-up view of celestial harmonic motion we’ve ever had. Also, the 17-day duration of the movie means we see Callisto (flickering very faintly) make a full orbit around Jupiter, and get to see Ganymede, Europa and Io (counting inwards towards the planet) each experience eclipse as they pass through Jupiter’s shadow. Note that the flickering exhibited by the moons is an artefact of JunoCam, which is optimised to image bright features on Jupiter, rather than capturing the (relatively) dim pinpoints of the distant moons as they circle the planet.

Curiosity Resumes Operations as 2020 “Sister” Takes Shape

In my last update I reported that NASA Mars Science Laboratory, Curiosity, had entered a “safe” mode on July 2nd.  On July 9th, the mission team successfully recovered the rover from this safe mode – a precautionary state the rover will set for itself should it detected an event which could damage its on-board systems – and then subsequently returned Curiosity to a fully operational status on July 11th.

The cause of the problem lay in  a glitch in one of the modes by which images are transferred from the memory in some of the rover’s camera systems to its main computers. This generated a data mismatch warning, prompting the rover to active its “safe” mode and call Earth for assistance. Use of this particular data transfer mode between the identified camera systems and the computers is now being avoided in order to prevent a repeat of the problem.

Meanwhile, NASA’s next rover mission – designated Mars 2020 at present, as it will launch in the summer of that year to arrive on Mars in February 2021 – is taking shape. The basic vehicle will be based on the Curiosity class of rover, but will carry a different science suite and have somewhat different capabilities.

A CAD image of the Mars 2020 rover: visibly similar to MSL's Curiosity rover. Credit: NASA

A CAD image of the Mars 2020 rover: visibly similar to MSL’s Curiosity rover. Credit: NASA

In particular, the new rover will carry an entirely new subsystem to collect and prepare Martian rocks and soil samples which can be stored in sample tubes. About 30 of these sample tubes will be deposited at select locations, so that they might be collected by a possible future automated mission and returned to Earth for direct analysis for evidence of past life on Mars and possible health hazards for future human missions.

Two science instruments mounted on the rover’s robotic arm will be used to search for signs of past life and determine where to collect samples by analysing the chemical, mineral, physical and organic characteristics of Martian rocks, while a suite of advanced camera systems will be housed on the vehicle’s mast. As with Curiosity, Mars 2020 will carry a comprehensive meteorological suite for monitoring the Martian environment and weather, together with a ground penetrating radar system for determining what is going on under the rover’s wheels.

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