Space Sunday: A year on Mars and the Polaris Programme

Mars 2020 rover Perseverance. Credit: NASA/JPL

On February 18th, 2021, NASA’s Mars 2020 mission arrived in Jezero Crater, Mars to commence operations.

In the year since then, the 1 tonne Perseverance rover and its tiny companion, the 1.8 Kg helicopter drone Ingenuity, have achieved a tremendous amount, with Ingenuity far exceeding expectations and the rover really still in the earliest phase of its mission (it’s “sister” rover, Curiosity has now been exploring Gale Crater on Mars for over nine years).

Currently, Perseverance is close to wrapping up its first science campaign, studying the basin of the 45 km wide Jezero Crater, a place believed to have once been the home of a lake billions of years ago, and which features some of the oldest rocks scientists have been able to study up close via a rover.

Nor is the rover studying those rocks purely in situ. As I’ve reported in these pages, the rover has been gathering samples in seal containers which – much later in the mission – be deposited in at least one cache on the surface of Mars to await collection by a hoped-for future sample return mission.

So far, six samples have been gathered, and while Martian pebbles got caught in a part of the sample transfer mechanism in January (see: Space Sunday: pebbles, ALH84001 and a supernova) suspending further coring operations, these were finally cleared at the end of the month, leaving the way clear for the rover to collect two more samples in the next couple of weeks.

A raw (unprocessed for Earth lighting conditions) image taken via the forward Hazard Avoidance Cameras (Hazcams) on NASA’s Mars 2020 rover Perseverance as it uses its robot arms to examine an area of exposed rock dubbed “Rimplas” during the rover’s return trip to its landing point. This image was captured on February 8th, 2022 (Sol 345 for the mission). Credit: NASA/JPL

These will come from a type of dark, rubbly rocks seen across much of the crater floor and which have been dubbed Ch’ał (the Navajo term for “frog”). It is hoped that if returned to Earth, samples of these rocks could provide an age range for Jezero’s formation and the lake that once resided there.

The samples Perseverance has been collecting will provide a key chronology for the formation of Jezero Crater. Each one is carefully considered for its scientific value.

– Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate

As well as gathering and assessing samples, Perseverance has used the MOXIE (Mars Oxygen In-Situ Resource Utilisation Experiment) to produce oxygen from the Martian atmosphere – such capabilities will be vital for future Mars missions, not only for producing oxygen, but also methane fuel.   

The rover also recently broke the record for the most distance driven by a Mars rover in a single day, travelling 320 metres on February 14th, 2022. This was achieved using the AutoNav software that allows Perseverance to find its own path around rocks and other obstacles.

Having spent the first year of operations studying the crater floor, Perseverance recently started heading towards one of the major features within the crater, a large river delta that once helped feed water into the crater.

On Earth, river deltas are great at preserving carbon-containing organic compounds – the building blocks of life as we know it. As such, much of the rover’s second year on Mars will be spent exploring and study the Jerero river delta.

We are incredibly excited to finally get to the delta [it is] the reason we chose the landing site, and we hope to get to it later this spring. Once we’re there, we’ll be able to look at the bottom of the ancient lake that once filled Jezero to search for signs of ancient microbial life, and we plan to spend the whole next year travelling through the ancient lake deposits and ancient river deposits that are within the delta.

– Briony Horgan, associate professor of planetary science at Purdue University

In order to reach the delta, Perseverance has been backtracking from a rugged part of the crater floor called “South Séítah”, which it has been exploring for the last several months, and will return to its landing site – now called Octavia E. Butler Landing – in the next two week or so. From there, it will drive west to reach the delta region.

While this might sound a long-winded way of doing things, the fact is that the route back from “South Séítah” is known and therefore “safe”, and the landing site provides direct access to the river delta. Whereas going “cross country” from “South Séítah” to the delta would take the rover across a dune field, with the risk of it becoming stuck.

Exactly where the rover will start its studies in the delta has still to be determined, as there are several points of interest that have already been spotted by the science team. One of these is a hilly feature dubbed “Kodiak Hill”, which the rover imaged from the landing point just after it arrived on Mars, and which could provide a good vantage point from which to properly survey the delta as a whole.

It’s likely a final determination of where to go to first with the delta  may be made with the assistance of Ingenuity.

Having completed its regime of five test flights early in the mission, during which Perseverance was relegated to the role of passive observer, the little drone has completed a total of 19 flights and doesn’t show any sign of stopping. While there had been some concern that a recent dust storm might impact its ability to obtain sufficient sunlight to keep its batteries charged, Ingenuity came through in good condition and, once its batteries had been fully charged, proved itself to be able to take to the air once more.

Ingenuity manages to catch Preservice in one of the images it captured which manoeuvring during a test flight in April 2021. Credit: NASA/JPL

For the majority of its flights, Ingenuity had acted as an aerial scout for Perseverance, imaging its surroundings in order to help mission planners determine potential route the rover could follow and / or identify potential points of interest the rover could be directed to study. As such, it has proven itself an invaluable part of the overall mission and more than proven the benefit of having UAVs operating in support of surface missions.

I’ll continue to report on the mission’s progress – and that of Curiosity, as and when NASA provides updates.

Isaacman’s Polaris Programme

Jared Isaacman, the billionaire who paid for and commanded the first non-professional astronaut flight into space, Inspiration4 in September 2021 aboard a SpaceX Crew Dragon vehicle (see: Space Sunday: Inspiration4 and Chinese Flights), is now planning a series of similar space flights  – potentially culminating in the first crewed flight of the Starship vehicle.

On February 14th, 2022 Isaacman announced the establishment of the Polaris Programme, which will run in cooperation with SpaceX.

Polaris is a series of pioneering Dragon space missions that will aim to rapidly advance capabilities for human exploration. This programme has been purposefully designed to advance long-duration human spaceflight capabilities and guiding us toward the ultimate goal of facilitating Mars exploration.

– Jared Isaacman, February 14th

Thus far, only the first mission in the programme has any specifics associated with it – and these are sketchy in places, at least for the moment. Called Polaris Dawn, it appears to be jointly funded by Isaacman and SpaceX. It will take place no sooner than the last quarter of 2022 and will comprise Isaacman as commander, Scott “Kidd” Poteet, a retired Air Force pilot who was one of the ground directors for the Inspiration Inspiration4, as pilot and mission specialists Sarah Gillis and Anna Menon, both SpaceX employees – Menon is married to Anil Menon, a former SpaceX flight surgeon who left the company to join NASA at the end of 2021 as part of its latest astronaut intake.

The other details revealed for the mission are:

  • It will aim to break the record for the highest Earth-orbiting crewed space flight That record was set in 1966, when Charles “Pete” Conrad Jr and Richard F. Gordon Jr piloted Gemini 11, the ninth crewed flight of that series in an extended elliptical orbit with a perigee of just 268 km and an apogee of 1,368 km.
  • This high altitude will allow the crew to study the radiation environment at the edge of interplanetary space – which is vastly different to that experienced by the majority of people who have flown into space – human missions rarely exceed 450 km above the Earth.


The Polaris Dawn crew (from L to R): Anna Menon, Scott Poteet, Jared Isaacman, and Sarah Gillis. Credit: Polaris Programme/John Kraus
  • The programme will aim to “raise funds and awareness” for St. Jude Children’s Research Hospital (the Inspiration4 mission raised a total of US $240 million for the hospital) as a part of “a global health initiative” that will involve SpaceX, their Starlink satellite broadband network. But again, precise details as to what this will mean / entail were no elaborated.
  • The flight will include the first EVA (extravehicular activity) spacewalk by a commercial crewed mission.

This last aspect has drawn the most attention, as it will entail the entire crew utilising a modified version of the suits currently worn by crews using Dragon to fly to / from the International Space Station. It will also be a further hark-back to the Gemini (and Apollo) missions. Like the vehicles used in those programmes, Crew Dragon does not carry an airlock, so the entire vehicle will have to be depressurised the the EVA – something that shouldn’t be a problem, as the vehicle has from the start been designed to be able to vent down to vacuum. However, the exact purpose of the EVA – together with the overall science objectives for the mission – has yet to be detailed.

How many Polaris missions will take place after Dawn is unclear; in terms of Crew Dragon, Isaacman appears to suggest the number of missions will be dependent on how quickly Starship moves from development through operational status as a cargo vehicle to being capable for flying with crews.

This is not something that we can expect in the next few years; SpaceX have a lot to do just to prove Starship and Super Heavy form a viable cargo launch vehicle, after which the vehicle will have to go through an assessment and rating to clear it for flying crews and passengers. This is itself not a simple process – for example, it is expected that crewed launch vehicle have so form of abort / escape system, something  Elon Musk has thus far only “supposed” this could be possible for Starship.

However, for all the gaps in what has thus far been presented, the Polaris Project would appear to be an interesting new venture – one the goals that again reach beyond mere space tourism.

Space Sunday: pebbles, ALH84001 and a supernova

Mars 2020 rover Perseverance. Credit: NASA/JPL

NASA’s Mars 2020 rover Perseverance rover is suffering what might considered a case of kidney stones that’s proving hard to clear up.

On December 29th, 2021, the rover drilled into a rock the mission team had dubbed “Issole”, coring the material out using the percussive drill at the end of its 2.1 m robotic arm. The coring went smoothly enough, the sample being cached inside one of the titanium tubes used for obtaining sample that are to be geocached on Mars for future collection by a joint NASA-ESA sample-return mission, however, it was then that a problem occurred.

The rover’s sample-gathering system is actually extremely complex, comprising three separate robotic systems. The first is the robot arm itself, which houses the drill mechanism and bit.

Mars 2020 SHArm robotic arm: hidden underneath the rover, SHArm is responsible for handling sample tubes (highlighted in yellow) before / after they have been used to gather core samples gathered by the rover’s drill. Credit: NASA/JPL

The second is another robot arm called SHArm – the Sample Handling Arm -, tucked into the underside of the rover. Its function is to select unused sample tubes from the storage cache at the back of the rover, and pass them forward so that they can be made available to the robot arm and the drill for sample gathering. This also takes tubes containing samples and delivers them to a number of sub-systems before sealing them and stowing them back into the cache area.

Between these two, and acting as a go-between, is the “bit carousel”. This is a wheel-like robot at the front of the rover. This is a go-between for both the main robot arm and SHArm, allowing empty tubes to be delivered to a position where they can be transferred to the robot arm / drill mechanism, and full tubes to be rotated down to where SHArm can collect them. In all the carousel has capacity for up to 10 full / empty sample tubes as they are moved between the robot arm and SHArm.

The “bit carousel” (highlighted in grey) with the robot arm and the drill head it carries (the large object on the left) transferring a sample core tube (yellow) to one of its transfer recesses. Credit: NASA/JPL

It was when attempting to transfer the tube with the latest sample to the carousel that the problem occurred, prompting the mission team to order Perseverance to return the tube to the drill mechanism and then rotate the robot’s hand to allow the WATSON image to photograph the carousel – revealing small pebbles of rock were caught in the mechanism.

While the carousel is designed to operate with a degree of dirt and debris in its mechanism, the decision was taken to attempt a debris removal operation and essentially “reset” the sample gathering mechanisms. This has also proven to be a complicated operation. Firstly, the carousel had to be carefully images to understand the full extent of the debris distribution. Then the ground beneath the rover needed to be imaged for an initial set of “before” photos.

A WATSON close-up of one of the sample tube recesses in the “bit carousel”, showing some of the pebble-like debris caught in the mechanism. Credit: NASA/JPL

After this, the main robot arm was order to rotate to a position where the current sample tube could be emptied, allowing it to be re-used in a future coring of “Issole”. Then, over the course of the weekend, the entire “bit carousel” was due to be put through two rotation operations designed to help shift some of the debris. Once completed, WATSON will again be used to image the mechanism – and the ground under the rover – to ascertain the status of the debris and what further actions need to be taken to clear the remaining debris.

In all, mission engineers believe it could be the end of the week before the sample system is ready to resume operations, at which point a decision will be taken on whether or not to gather a further sample from “Issole”.

 The Riddle of ALH84001 Finally Resolved?

In 1996 a fragment of a Martian meteorite that was found in the Allan Hills, Antarctica and designated ALH84001 (marking it as the first Martian meteorite found in the area 12 years earlier, in 1984), caused a storm of controversy- which appears to now being laid to rest.

A cartoon by Kevin Kallaugher that appeared in the Baltimore Sun on August 8th, 1996 highlighting the media’s response to the ALH84001 announcement by David McKay and his team

To summarise: when parts of the meteorite were examined by a group of scientists (it is not uncommon for multiple years to pass between meteorites being found , catalogued and stored and actually being examined) announcing they may have found trace evidence of past microscopic life from Mars. Unfortunately, the press responded in a manner typified by a cartoon from the time.

The pronouncement, over-amplified by the press, garnered immediate push-back by others in the scientific community which in turn resulted in the science team – which included David S. McKay, Chief Scientist for astrobiology at the Johnson Space Centre, Texas, during the Apollo programme to double down on their claims they have discovered fossilised Martian bacteria.

Since then, the debate concerning how the objects –  chain structures nanometres in length resembling living organisms – and whether or not they might be organic in origin has raged back and forth – although it did diminish somewhat following McKay passing away in 2013. Not another team of scientists believe they have definitive proof that whilst the structures were organic in nature, they are not signs of life having once been active on Mars.

Instead, the new study – the result of an extensive study of ALH84001 samples and all that has been learned about it in the intervening 25 years – points to the organic structures being the result of abiotic organic chemistry – that is, they formed as a result of chemical reactions between water and rock that did not involve any genuine organic processes.

The chemical interactions likely took place around 4 billion years ago – at a time when Mars was believed to be much warmer and wetter than it is now, and a time when life might have originated on the planet. However, in the case of ALH84001, the team carrying out this study found that the organic compounds in the meteorite are closely associated with serpentine-like minerals. Serpentine is a dark green mineral, sometimes mottled or spotted like a snake’s skin, that is associated with once-wet environments.

On Earth, this kind of association between organics and serpentine is often associated with water percolating / circulating through magnesium-rich volcanic rocks change their mineral nature, producing hydrogen. If the water is slightly acidic and contains dissolved carbon dioxide, it can additionally result in carbonate minerals also being deposited…When taken together, these two processes – referred to as serpentinization in the case of the first and carbonation in the second – can result in deposits that appear to be of an entirely organic origination.

An electron microscopy image showing chain structures resembling living organisms fossilised in meteorite fragment ALH84001. Credit: NASA

Given the rocks in which ALH84001 were formed 4 billion years ago and were exposed to a long period of repeated water interaction, and the similarity they share with similar abiotic mineral deposits found on Earth, the team believes they are more than likely of a similar, non-organic origin.

However, the study doesn’t discount the potential for life to ever have arisen on Mars – it may actually strengthen it. This is because while these abiotic processes are not the result of organic processes, they do leave deposits of chemicals and minerals that can go on to help kick-start microbial life. What’s more, the sheer age of the ALH84001 marks it as the first Martian rock fragment that is old enough to provide evidence that abiotic processes were at work at a time when Mars was warm and wet – and when other processes may have been at work that might have utilised the deposited compounds to get basic life started. And if the rocks in which ALH84001 formed – there may be other similar ancient deposits on the planet that microbial life may have been leveraged.

Astronomers Witness a Star’s Death and a Supernova’s Birth in Real-Time

For the first time, a team of astronomers have imaged in real-time as a red super giant star reached the end of its life, watching as it convulsed in its death throes before finally exploding as a supernova.

The star was about 10 times more massive than the Sun and lay within the NGC 5731 galaxy about 120 million light-years away – meaning what astronomers saw actually occurred 120 million years ago.

In the summer of 2020, astronomers using the Pan-STARRS observatory on Haleakala, Maui noticed the progenitor tar suddenly go through a dramatic rise in luminosity. This warned them something massive was about to happen, focusing attention at Pan-STARRS on the star, and also brought in the W. M. Keck Observatory on Mauna kea, Hawaii Island in to observe the star as it collapsed over 130 days, before it gave a bright flash prior to its final exceptionally violent detonation into supernova SN 2020tlf..

The data from the observations is relatively boring – the star was far, far, far too far away to be actually images by either observatory, so it amounts to lines and dots on a chart. However, it has allows the event to be computer modelled. More particularly, the event has given astronomers first-hand insight into a supernova event involving a red super giant, and raised some puzzling questions.

For a red super giant to go supernova is not uncommon. Normally, however, there is a period of shrinkage and material ejection, referred to as circumstellar material (CSM) prior to core collapse. But that process generally takes place on a much longer timescales than the 130 days experienced by SN 2020tlf, suggesting something unusual or unexpected was taking place within the star.

In addition, the mysterious bright flash prior to the final detonation was unexpected and – thus far – unexplained, although it is thought it be somehow related to the ejected CSM – although astronomers are currently at a loss to explain what this might be. The flash appears to also be liked to a mammoth ejection of gas from the star, another aspect that doesn’t fit with established understanding of red super giant supernovae.

All of this adds up to the end of the star and the birth of SN 2020tlf being far more violent that has been the accepted case for red super giants. The question now is: was this event out of the ordinary for such stars, or does it reflect a more expected behaviour for them. However, given the sudden rise in luminosity witnessed ahead of the event, astronomers involved in projects such as the Young Supernova Experiment now have a clue to what to look for when seeking future potential red super giant supernovae.

Space Sunday: touching the Sun and Martian organics

Parker Solar Probe. Credit NASA

The Parker Solar Probe has finally reached the atmosphere of the Sun.

The NASA spacecraft has spent more than three years winding its way by planets and creeping gradually closer to our star to learn more about the origin of the solar wind, which pushes charged particles across the solar system.

Since solar activity has a large effect on living on Earth, from generating auroras to threatening infrastructure like satellites, scientists want to know more about how the Sun operates to better make predictions about space weather, and gain a better understanding of the mechanisms at work in and around our star. Over the years, we’ve done this with a number of missions – but the most fascinating of all to date is the Parker Solar Probe, a NASA mission that has literally touched the face of the Sun.

The spacecraft – launched in 2018 – is in a complex dance around the Sun that involves skimming closer and closer to our life-giving star, and they sweeping away again, far enough to cross back over the orbit of Venus – indeed, to use Venus as a means to keep itself looping around the Sun in orbits that allow it to gradually get closer and closer, with the aim of actually diving into and out of the Sun’s corona, what we might regard as the Sun’s seething, broiling atmosphere.

In fact, the probe actually first flew through the corona in April 2021; however, it was a few months before the data to confirm this could be returned to Earth, and a few more months to verify it; hence why the news has only just broken about the probe’s success. One of the aims of pushing the probe into the Sun’s corona was to try to locate the a boundary called the Alfvén critical surface. This is the boundary where the solar atmosphere  – held in check by the Sun’s gravity – end, and the solar wind – energetic particles streaming outwards from the Sun with sufficient velocity to break free of that gravity – begins, creating the outwards flow of radiation from our star.

Up until Parker’s April 2021 passage into the corona, scientists has only been able to estimate where Alfvén critical surface lay, putting it at somewhere between 6.9 million and 13.8 million km from the gaseous surface of the Sun. As it passed through the corona, Parker found these estimates to be fairly accurate: the data it returned to Earth put the outer “peaks” of the boundary at 13 million km above the Sun’s surface – or photosphere; the data also revealed the boundary is not uniform; there are “spikes and valleys” (as NASA termed them) where the boundary stretches away from the photosphere at some points, and collapses down much close to it in others. While it has yet to be confirmed, it is theorised this unevenness is the result of the Sun’s 11-year active cycle and various interactions of the atmosphere and solar wind.

The Parker Solae Probe. Credit: NASA / I. Pey

The April “dip” into the corona lasted for five hours – as the mission goes on, future “dips” will be for longer periods). But give the spacecraft is travelling at 100 kilometres per second, it was able to gather a lot of data as it zipped around the Sun – and even sample the particles within the corona. The probe’s passage revealed that the corona is dustier than expected, the cause of which has yet to be properly determined, as well as revealing more about the magnetic fields within the corona and how they drive the Sun’s “weather”, generating outbursts like solar flares and coronal mass ejections (CREs), both of which can have considerable impact on life here on Earth.

To survive the ordeal of passing through the corona, where temperatures soar to millions of degrees centigrade, far hotter than those found at the Sun’s photosphere.  – Parker relied on its solar shadow-shield: a hexagonal unit 2.3 m across made of reinforced carbon–carbon composite 11.4 cm thick with an outer face is covered in a white reflective alumina surface layer. This shield is so efficient in absorbing / reflecting heat, whilst passing through the corona the sunward face is heated to around 1,370ºC, but the vehicle, sitting inside the shadow cast by the shield never experiences temperatures higher than 30ºC.

In addition to mapping the Alfvén critical surface, Parker’s April 2021 trip into the Sun’s corona, the probe also passed through a “pseudostreamer,” one of the huge, bright structures that rise above the Sun’s surface and are visible from Earth during solar eclipses. This was compared to flying into the eye of a storm the probe recorder calmer, quieter conditions within the streamer, with few energetic particles within it. Exactly what this means is again unclear at this time, but it does point to further incredibly complex actions and interactions occurring with the Sun.

Since April, Parker has dipped back into the corona twice more, with the November 2021 passage bringing it to around 9.5 million km of the Sun’s photosphere – although again, the data from that pass has yet to be received and analysed. The next passage in February 2022 will again be at roughly the same distance from the photosphere, with a further five passes to follow at the same distance in 2022/23, before a flyby of Venus allows Parker to fly even deeper in to corona. By December 2025, and the mission’s final orbits, it will be descending through the corona to just 6.9 million km from the photosphere.

An artist’s depiction of magnetic switchbacks in the solar wind. Credit: NASA Goddard/CIL/Adriana Manrique Gutierrez

But that’s not all. Because Parker is in an elliptical around the Sun, it spends a part of its time much further away. This both allows the craft to dissipate absorbed heat from its shield, and for it to observe the Sun from a distance, giving scientists much broader opportunities to study the Sun, such as allowing them to study the physics of “switchbacks”. These are zig-zag-shaped structures in the solar wind, first witness by the joint ESA-NASA Ulysses mission that occupied a polar orbit around the Sun in the 1990s.

In particular, Parker’s observations suggest that rather then being discrete events, switchbacks occur in patches, and that these “patches” of switchbacks are aligned with magnetic funnels coming from the photosphere called called supergranules. These tunnels are thought to be where fast particles of the solar wind originate; so switchbacks may have something of a role to play in the generation of the solar wind or they may be a by-product of its generation or, given they seem to have a higher percentage of helium than other aspects of the solar wind, may serve a highly specialised role as a part of the solar wind.

Right now, scientists are unclear on what might be the case, or what actually generates switchbacks; but gaining clearer insight into their creation, composition and interaction with other particles in the solar wind, and with the Sun’s magnetic field might provide explanations for a number of solar mechanisms, including just why the corona is so much hotter than the photosphere.

Mars 2020 Mission Update

Scientists with NASA’s Mars 2020 Perseverance rover mission have discovered that the bedrock their six-wheeled explorer has been driving on since landing in February likely formed from red-hot magma. It’s a discovery with implications for our understanding and accurately dating critical events in the history of Jezero Crater – as well as the rest of the planet.

Even before the Mars 2020 mission arrived on Mars, there have been much debate about the formation of the rocks in the crater: whether they might be sedimentary in origin, the result compressed accumulation of mineral particles possibly carried to the location by an ancient river system, or whether they might be they igneous, possibly born in lava flows rising to the surface from a now long-extinct Martian volcano. However, whilst studying exposed bedrock at location dubbed “South Séítah” within Jezero, the science team noted a peculiar rock they dubbed “Brac”, selecting it as a location from which to collect further samples of Martian bedrock using the rover’s drill.

When taking samples of this kind, booth Perseverance and her elder sister, Curiosity, operating in Gale Crater half a world away, are both instructed to scour target rocks clean of surface dust and dirt that otherwise might contaminate samples. This is done by using an abrasion tool (think wire brush) mounted alongside the drilling mechanism. However, in checking the work on “Brac”, the mission team realised the abrasion process had revealed the rock was rich in crystalline formations.

Rather than going ahead and drilling the rock for a sample, scientists ordered the rover to study the formations using the Planetary Instrument for X-Ray Lithochemistry (PIXL) instrument  – which is designed to map the elemental composition of rocks. PIXL revealed the formations to be composed of an unusual abundance of large olivine crystals engulfed in pyroxene crystal, indicating the formations grew in slowly cooling magma, offering some confirmation that volcanism has at least be partially involved in Jezero Crater’s history. However, PIXL’s data also suggested the rock, once hardened, has subsequently altered as a result of water action – confirming free-flowing water also had a role to play in the crater’s past..

The crystals within the rock provided the smoking gun … a treasure trove that will allow future scientists to date events in Jezero, better understand the period in which water was more common on its surface, and reveal the early history of the planet. Mars Sample Return is going to have great stuff to choose from.

– Ken Farley, Perseverance Project Scientist

The Sample Return mission has yet to be fully defined, let alone funded, but is being looked at as a mission for the early 2030s, quite possibly with European Space Agency involvement. In the meantime, a question Farley and his colleagues would love to answer is whether the olivine-rich rock formed in a thick lava lake cooling on the surface of Mars, or originated in a subterranean chamber that was later exposed by erosion; knowing the answer to this could determine the early history of Jezero Crater and its surroundings.

This 60-second video pans across an enhanced-color composite image, or mosaic, of the delta at Jezero Crater on Mars. The delta formed billions of years ago from sediment that an ancient river carried to the mouth of the lake that once existed in the crater. Taken by the Mastcam-Z instrument aboard NASA’s Perseverance rover, the video begins looking almost due west of the rover, and sweeps to the right until it faces almost due north.

Also within the latest updates from the Mars 2020 team is the news that Perseverance has found organic compounds within the rocks of Jezero Crater and in the dust that covers them. This discovery was made as a result of a review of findings from the SHERLOC (Scanning Habitable Environments with Raman & Luminescence for Organics & Chemicals) instrument.

This does not mean that the rover has discovered evidence of past microbial life on Mars; these carbon compounds can be created by both organic and inorganic processes. However, the fact that they have been found at a number of locations explored by the rover means that the science team can map their spatial distribution, relate them to minerals found in their locations, and thus both further determine their organic / inorganic origins and trace the distribution of minerals, etc., within the crater.

Further, the fact that compounds like these have been identified by both the Curiosity and Perseverance rovers means that potential biosignatures (signs of life, whether past or present) could be preserved, too. IF so, then assuming they exist, there may come a time when one our other rover might happen upon them.

Continue reading “Space Sunday: touching the Sun and Martian organics”

Space Sunday: Mars wake-ups, SpaceX and NASA updates

Looking over Utopia Planitia – a panoramic image captured by the mastcams on China’s Zhurong rover ahead of its period of “hibernation” during the October 2021 conjunction. Credit: CNSA/PEC

The 2021 Earth-Sun-Mars conjunction that saw Earth and Mars on opposite sides of the Sun, interrupting all communications between the two, is now over. This means that the multi- national missions on and around the red planet (America, Europe, the UAE, and China) are switching back from automated activities to more regular operations.

China’s Tiawen 1 orbiter and their solar-powered rover surprised mission controllers by calling home earlier than had been anticipated, to report that they are resuming science operations after their enforced semi-hibernation. The wake-ups come in advance of a change in both missions that will be taking place in early November.

At that time, the Tianwen 1 will switch to a new mission phase, a global mapping and analysis of the Martian surface and subsurface with its suite of seven science instruments. This will reduce the opportunities the orbiter has to act as a communications relay for the rover from once a day to once every few days. To help fills the “gaps” when Tianwen 1 is unable to act as a relay, Europe’s long-running Mars Express orbiter is going to attempt to step up to the plate and relay communications between the rover and Earth – pending the outcome of several communications tests to take place at the start of November.

Another view across Utopia Planitia returned by Zhurong. Credit: CNSA/PEC

Down on Mars, the Zhurong rover had covered 1,182 metres from its landing platform before going into stand-by mode for the solar conjunction. Since waking up, it has resumed its trip south in Utopia Planitia, and is approaching the end of its second 90-sol period of operations, opening the door for a re-assessment of its science targets. Of particular interest to Chinese scientist are a series of “mud volcanoes” and features that may have been formed by movements of subsurface water and ice, where Zhurong’s ground-penetrating radar is expected to provide “fundamentally new perspectives” on potential subsurface Martian water ice, that might be applied to any development of past life on Mars and on the use of sub-surface water by future crewed missions.

For NASA’s Ingenuity helicopter, the end of the conjunction means a resumption of flight operations following tests to run its contra-rotating propellers at high-than-usual RPM to counter the thinning density of the atmosphere in Jezero crater as winter approaches.  This flight was initially scheduled for as early as Saturday, October 23rd, but at the time of writing had yet to be confirmed as having taken place.

Meanwhile, NASA has released a new video showcasing many of the sounds of Mars that have thus far been recorded by Ingenuity’s companion on Mars, the Perseverance rover.

“Percy” carries two off-the-shelf microphones, one mounted on it hull, the other on cover on the camera mounting frame located at the top of its instrument mast. Since the rover’s arrival on Mars, both microphones have been used to record a range of sounds both of Mars and of the rover and Ingenuity operating on the planet.

One of the two microphones mounted on the Mars 2020 Perseverance rover. Located on the moveable camera / imager housing at the top of the rover’s mast, this microphone is somewhat directional in nature. Credit: NASA/JPL

The Mars 2020 mission is the first to Mars to carry microphones that allow us to listen to the planet – but their inclusion is not merely due to idle curiosity. Listening to the sounds of the planet and the rover can reveal a lot, as mission scientist Nina Lanza, one of those behind the microphone project, explains:

First, we can learn about the atmosphere by understanding how sound propagates through it. We can also listen to the sounds of rover analyses on rocks and learn about rock material properties from that. And finally, we can also listen to the sounds the rover makes to help better understand the state of our instruments.

– Nina Lanza, Los Alamos National Laboratory

Analysis of the sound picked-up from Ingenuity’s rotors, for example, has revealed that sound propagates through the Martian atmosphere a lot different to how it had been believed. Changes in the sound the rover makes during driving and other operations could also help give an early indication of possible problems / mechanical issues, making the microphones invaluable.

SpaceX Update

With the public hearings into the Federal Aviation Authority’s draft Programmatic Environmental Assessment (PEA) report on the SpaceX “Starbase” production, test and launch facilities in Boca Chica, Texas, now completed, SpaceX continues to push ahead with preparations for its first Starship  / Super Heavy test flight and other work critical to that, and future Starship / Super Heavy launches.

The tank farm that will store and deliver propellants and other consumables to the launch facilities has seen the last of its vertical tanks and their concrete sheathing installed. At the same time as this work was progress, a set of horizontal tanks, thought to be intermediary tanks that may be used to hold propellants, etc., when detanking boosters between things like static firs tests, arrived for installation at the farm.

The Starbase tank farm showing the new horizontal tanks being installed, with the final sleeve for one of the upright tanks waiting to be lifted into position. Credit: RGV Aerial Photography

The launch facility itself has most recently seen the assembly and installation of the gigantic “Mechazilla”, the extraordinary mechanism that will both lift Super Heavy boosters onto the launch table and stack Starships on top of them (as well as being able to remove both from the launch facilities) and  – eventually – actually “catch” returning boosters and Starships, allowing (in theory) both to be rapidly turned around and re-used whilst eliminating the need for either to have complicated and heavy landing leg systems.

“Mechazilla” will achieve this by travelling up and down the launch support tower on three rails whilst having a “head” that can rotate around three side of the tower, and two huge “chopstick” arms than can open and close around a Super Heavy or Starship vehicle, allowing it to raise or lower them – and eventually catch them as they make a (hopefully) precision return to Earth that brings them down alongside the launch support tower.

The massive system will not be used for the first orbital flight attempt with Booster 4 (currently on the launch table) and Starship 20, but may be used in an attempt to catch Booster 5 (currently under construction as the “next generation” of Super Heavy vehicles)  when that launches in 2022. However, captures of Starship vehicles will not be seen for some time.

A rendering of “Mechazilla” and the QD arm mounted on the Super Heavy / Starship launch support tower at Boca Chica. Credit: Owe BL, with additional annotations

Also during the past week, Starship 20 has completed a series of static fire tests of its Raptor engines – including the first firing of a Raptor vacuum engine integrated into a Starship vehicle, and the first joint firing of a vacuum engine and a sea-level motor. Some of the vehicle’s heat shield titles were blown off during the tests, but otherwise the firings were viewed as successful.

Such is the progress at Boca Chica that Elon Musk has indicated the company will be ready to make that first orbital flight in November, pending regulatory approval. However, it would seem unlikely this would be granted in time for a November launch. The review period for the PEA doesn’t close until November 1st, and the public hearings mentioned above drew strong feedback both in support of, and against SpaceX’s expansion of the Boca Chica facilities, with the latter focused on already noticeable environmental issues.

The static fire test of a Raptor single vacuum engine and a single Raptor sea-level motor, marking the first time the both types of motor, integrated into a Starship, have been test fired. Credit: BocaChicaGal /

After November 1st, the FAA will require time to complete its report, incorporating all of this feedback and a separate report from the U.S. Fish and Wildlife Service. Even if the report is positive, it still has to be reviewed and digested by the arm of the FAA responsible for granting launch licences. Given that November is something of a “short” month in the US due to the Thanksgiving holiday, it seems doubtful the FAA would complete all this work and grant a licence to SpaceX for Super Heavy / Starship flights by the end of the month.

Continue reading “Space Sunday: Mars wake-ups, SpaceX and NASA updates”

Space Sunday: strange worlds, telescopes and rockets

An image of GW Orionis, a triple star system with a mysterious gap in its surrounding dust rings. UNLV astronomers hypothesize the presence of a massive planet in the gap, which would be the first planet ever discovered to orbit three stars. The left image, provided by the Atacama Large Millimetre/sub-millimetre Array (ALMA) telescope, shows the disc’s ringed structure, with the innermost ring separated from the rest of the disc. The observations in the right image show the shadow of the innermost ring on the rest of the disc. UNLV astronomers used observations from ALMA to construct a comprehensive model of the star system. Credit: ALMA (ESO/NAOJ/NRAO), ESO/Exeter/Kraus et al.

GW Orionis is a triple star system roughly 1,300 light years from Earth sitting within an extended protoplanetary disc that surrounds all three. This disc has been intriguing astronomers for the last decade, and now a team believe they have evident that the disc is home to at least one planet.

Systems of multiple stars bound by gravity are believed to be at least as common within our galaxy as single-star systems (like the Sun), and as such have oft been depicted as the home of worlds with exotic skies (think Star Wars and Tatooine’s iconic binary sunsets). But if correct, this will be the first time we have discovered a planet occupying a circumtriple orbit.

Using observations from the powerful Atacama Large Millimetre/sub-millimetre Array (ALMA) telescope in Chile, a team of astronomers set out to analyse the extended dust ring surrounding the three stars and they orbit their common centre, only to discover that rather than being fairly uniform, the dust ring has a substantial and persistent gap within it.

After running through a wide range of simulations to explain the gap, including trying to find some bizarre form of “gravitational torque” imposed on the disc by the three stars, the team resorted to Occam’s Razor: the simplest explanation is likely the most correct. In this case, and as several of their models demonstrated, the most consistent means to create such a gap in the disc is to plonk at least one large planet, around the size of Jupiter, into it.

It’s really exciting because it makes the theory of planet formation really robust. It could mean that planet formation is much more active than we thought which is pretty cool.

– Jeremy Smallwood, study lead author

In fact, such is the size of the gap, it is conceivable that it might be home to several planets – all of which are far too faint and too distant to be directly observed, but some of which might be Earth-sized solid bodies. This doesn’t mean they might harbour life, but they would make for a fascinating study.

Further work is to be conducted in an attempt to confirm the team’s findings and possibly refine their model of this complex system.

NASA Round-Up

SLS Launch “Likely” to Slip to 2022

As I’ve noted in a number of Space Sunday updates recently, the first flight of NASA’s Space Launch System (SLS) rocket has increasingly looked like it will slip back into 2022, the result of a number of programmatic slippages that, together with restricted working practices introduced by NASA during a good part of 2020 to deal with the SARS-CoV-2 situation, have resulted in most / all of the “spare” time built into the programme to handle unanticipated delays being been eaten up.

Speaking on September 30th, 2021, NASA Associate Administrator Bob Cabana noted that while the agency was not committed to a specific launch date other than “late 2021” for the mission – called “Artemis 1” and intended to fly an uncrewed Orion capsule around the Moon and back in an extended flight – it will now “more than likely” see it slip into early 2022.

An unusual view of the first SLS stack inside NASA’s Vehicle Assembly Building at Kennedy Space Centre. A mass simulator on top of the rocket will soon be replaced by the Orion spacecraft. Credit: NASA/Frank Michaux

The vehicle stack of core stage, upper stage and solid rocket boosters have just completed a series of “modal tests” within the Vehicle Assembly Building (VAB) at the Kennedy Space Centre, Florida. These involved subjecting the stack to a range of vibrations and shaking it to determine the full range of frequencies and vibrations it will experience during launch and ascent in order to programme the flight software and navigation systems so they can be correctly responded to, and an deviance from the “norms” identified and dealt with.

These tests should have been completed in August 2021, paving the way for the Orion capsule and its service module to be mated with, and integrated into, the rocket. This work is now scheduled to commence on October 13th. After that, the entire stack will be rolled out to Launch Complex 39B for a wet dress rehearsal in which the core stage is loaded with propellants in a practice countdown that stops just before ignition of the four main RS-25 engines. Following the test, the rocket will roll back to the VAB for final reviews and pre-launch preparations, before taking a final ride to the pad ready for launch.

Space Telescopes Update

NASA’s James Webb Space Telescope (JWST), the next great space-based telescope, remains on course for a December 18th, 2021 launch. However, the observatory continues to be a source of controversy.

JWST is named for James E. Webb, the second NASA Administrator to be appointed, and the man who saw the agency through the Mercury and Gemini programmes – the latter critical to the Apollo lunar landings – between 1961 and 1968. However, prior to that, he served as Undersecretary of State from 1949–1952, a period which saw the “Lavender Scare”, when many LGBTQ people were driven from roles in government service – a fact that recently (and somewhat belatedly, given the life-time of the programme) has given rise to calls for the telescope to be re-named.

JWST with its primary mirror folded, undergoes a final testing in deploying its boat-like Sun shield earlier in 2021. Nasa has quietly stated that despite objections, the telescope will not be re-named. Credit: NASA

NASA had said it would look into the matter, but this week – without formal announcement or indication of precisely how it did so – leaked word via National Public Radio in the United States that it has conducted “an investigation” and found “no cause” for the telescope to be renamed. The decision and the manner in which NASA has handled it have heaped scorn upon the agency by those who launched the campaign and who signed a petition on the matter forwarded to NASA – many of whom are from the science and astronomy communities.

Elsewhere, the next space-based telescope NASA will launch after JWST – the Nancy Grace Roman Space Telescope (formerly WFIRST) – has received both good and bad news.

The good news is, the telescope successfully passed its critical design review, signalling that all developmental engineering work is now complete, and it can move on to the assembly and testing of the telescope itself.

A next-generation observatory, the NGRST will peer across vast stretches of space and time to survey the infrared universe. Thanks to the mission’s enormous field of view and fast survey speeds, astronomers will be able to observe planets by the thousands, galaxies by the millions, and stars by the billions. As such, it is very much an heir to the Hubble Space Telescope (HST) on which parts of it are based, and entirely complimentary to the work of JWST.

An artist’s rendering of the Nancy Grace Roman Space Telescope in space. Credit: NASA

The bad news is that the telescope – which the Trump Administration repeatedly tried to cancel despite its real-time low cost thanks to its use of “spare” HST elements – has now genuinely started to incur cost overruns. These are the direct result of the SARS-CoV-2 pandemic in 2020 as a result of the restrictive working practices NASA had to implement to protect their employees, together with disruption of critical supply chains also as a result of the pandemic. These have already caused a US $400 million increase in the telescope’s estimate US $3.9 billion cost, and further increases are now expected – although there is sufficient leeway in the NASA 2021-2022 budget to meet the added costs and the estimated 7-month delay so far incurred in the telescope’s development.

Continue reading “Space Sunday: strange worlds, telescopes and rockets”

Space Sunday: Mars, Starship and a meteor that flattened a city

September 10th, 2021: after successfully gather two samples from the rock dubbed “Rochette” (seen in the foreground, the bore holes clearly visible), the Mars 2020 rover Perseverance paused for a “selfie” using the WATSON imager mounted on the robot arm turret. Credit: NASA/JPL

It’s getting interesting on Mars. Jezero Crater, the home of the Mars 2020 mission is going through a change in seasons, bringing with it a drop in atmospheric density that is proving challenging for the Ingenuity helicopter, which recently completed its 13th flight.

The little drone was designed to fly in an atmosphere density around 1.2-1.5% that of Earth, but with the seasonal change, the average afternoon atmospheric density within the crater – the afternoon being the most stable period of the day for Ingenuity to take flight – has now dropped to around 1% that of Earth. This potentially leaves the helicopter unable to generate enough lift through its rotors to remain airborne.

The solution for this is to increase the rate of spin within rotors to something in excess of their nominal speed of around 2,500-2,550 rpm. However, this is not without risk: higher rpm runs the risk of a significant increase in vibrations through the helicopter that could adversely affect its science and flight systems. Also, depending on the wind, it could result in the propeller blades exceeding 80% of the Martian speed of sound. Sound this happen, the rotor would pick up enough drag to counter their ability to generate lift, leading to a mid-flight stall and crash.

To better evaluate handling and flight characteristics, therefore, the flight team are going back to basics an re-treading the steps taken to prepare Ingenuity for flight. This will see the propellers spun to 2,800 rpm with the helicopter remaining on the ground. Data gathered from this test will be used to make an initial assessment of blade speed required to get Ingenuity off the ground – believed to be somewhere between 2,700 and 2,800 rpm, and make an initial assessment of vibration passing through the helicopter’s frame. After this, it is planned to carry out a very simple flight: rise to no more than 5 metres, translate to horizontal flight for no more that a few metres, then land. Data from this flight – if successful – will then be used in an attempt to determine the best operating parameters for Ingenuity going forward.

The power of Perseverance’s camera: The lower image shows a true colour view of a feature dubbed “Delta Scarp”, captured by the rover’s MastCam Z system from a distance of 2.25 km. The upper picture shows details of the feature, as captured from the same distance, using the rover’s SuperCam instrument.. Credit: NASA/JPL

In the meantime, the Perseverance rover is continuing its work. Following the successful gathering of its first ample, the rover has been further revealing the power of its imaging systems, Mastcam Z and SuperCam, the two camera system mounted on its main mast.

Designed for different tasks, the two systems nevertheless work well together to provide contextual and up-close images of features the rover spies from distances in excess of 2 km away, allowing science teams to carry out detailed assessments before sending the rover to take a closer look. Also, in the wake of the sample gather exercise at the rock dubbed “Rochette”, NASA have provided a general introduction to two more of the rover’s instruments, which are mounted on the turret at the end of the rover’s robot arm. Catch the video below for more.

At the same time, and half a world away, the InSight mission Lander, despite suffering a severe degrading of its power capabilities as dust continues to accumulate on its circular solar arrays, has detected a  powerful Marsquake less than a month after detecting two equally powerful quakes originating at two different point under the planet’s surface.

All three were the latest in a long like of Marsquakes – also called “tumblors” – that have revealed much about the planet’s interior in the almost three years since InSight placed its seismometer on the planet’s surface, including the fact its core is larger than had been believed. The vast majority of the tumblors thus far detected have originated in the  Cerberus Fossae region of Mars, some 1,600 km from the lander. However, on August 25th, a quake measuring 4.1 magnitude was recorded with an epicentre just 925 km from the lander whilst marking it as the most powerful tremblor Insight had recorded (the previous record holder measure 3.7 – five times less powerful).

Captured in July 2021, this image shows InSight’s Seismic Experiment for Interior Structure (SEIS) instrument dome on the surface of Mars. This is the instrument that has been recording tremblors on Mars. Credit: NASA/JPL

But then on the same day, a second quake was detected, hitting 4.2 magnitude, marking it particularly powerful, given its epicentre was calculated to be 8,600 km from the lander, and possibly focused within Vallis Marineris, the “Grand Canyon of Mars. This was matched on September 18th by a further 4.2 magnitude quake – epicentre currently unknown. But what made this tremblor remarkable was its duration – almost 90 minutes! (By comparison, the longest recorded duration of an quake on Earth is under 5 minutes.) Exactly why and how such an event should or could last so long is unknown, and has the InSight science teams scratching their heads.

Did a Cosmic Event Give Rise to the Biblical Legend of Sodom and Gomorrah?

Tall el-Hammam was – up until 3,600 years ago – a thriving centre of life and commerce for an estimated 8,000 people. Located close to the Dead Sea in what is now modern day Jordan, the valley it occupied lay some  22 km west of the city of Jericho and was one of the most productive agricultural lands in the region before being practically deserted for some 500-700 years, the soil inundated with salts to the extent nothing would grow.

The location of the city has been subject to archaeological study since 2005, and researchers there have been struck by the curious nature of what little remains of the city: foundations with melted mud brick fragments, melted pottery, ash, charcoal, charred seeds, and burned textiles, all intermixed with pulverised mud brick and minerals that can only be produced under extremes of temperature and / or pressure. The more the city’s ruins were uncovered, the more the evidence pointed to some terrible calamity having befallen Tall el-Hammam and its surroundings, prompting the archaeologists to call in experts from the field of astronomy, geology, and physics. Their research has lead to the conclusion that the city was practically at the epicentre of a “cosmic airburst”.

Moment of detonation: an artist’s (rather mild) interpretation of the moment a 50m diameter chunk of rock travelling at 61,000 km/h detonated in the skies above Tall el-Hammam, Jordan, 3,600 years ago in a 15 megaton blast that obliterated the city in seconds. Credit: Allen West and Jennifer Rice, CC BY-ND

In short, 3,600 years ago, a piece of rock probably 50 metres across slammed into the atmosphere at 61,000 km/h. It survived the initial entry and fell to an altitude of approximately 4km above Tall el-Hammam before air resistance finally overcame its integrity. The result was a  15 megaton explosion that instant drove air temperatures to around 2,000ºC, enough to instantly flash-burn textiles, wood and flesh, and melt everything from swords and bronze tools to pottery and mud brick.

Seconds later, the shockwave from the explosion struck the city. Travelling at 1,200 km/h, it utterly pulverised what was not already aflame. Roughly a minute after the explosion, that same shockwave rolled over the city of Jericho, probably demolishing a good portion of its defensive wall and the buildings within it. That same shockwave also impacted the Dead Sea, potentially lifting vast amounts of salt water into the air, which rained back down over the valley, rendering it infertile for the next few hundred years, until rainfall could wash the salts out of the top soils.

The evidence for the cataclysm comes in multiple forms, from the melted pottery and mud brick through the clear evidence the city was pulverised in a manner that left a clearly defined “destruction layer” within the ruins, to the fact that within those ruins are deposits of shocked quartz, which are only formed when grains of sand are compressed with of force of 725,000 psi, and microscopic diamondoids, produced when carbon materials (e.g. plants, wood, etc.), are simultaneously exposed to massive extremes of temperature and pressure, and are a hallmark of ancient impact sites around the world.

A satellite image of the Middle East, showing the location of Tall el-Hammam on the northern coastal area of the Dead Sea. Satellite image via NASA

The ruins bring home the very real risk posed by near-Earth objects as they zap around the Sun, crossing and re-crossing Earth’s orbit. That a cosmic object also brought about the destruction of a small city and its 8,00 inhabitants raises the question of whether someone witnessed the event (obviously from many kilometres away) or its aftermath, and the telling and re-telling of the tale of destruction eventually morphed into the Biblical tale Sodom and Gomorrah, the two “cities of the plains” of the Dead Sea (and therefore potentially close to the site of Tall el-Hammam), supposedly destroyed by God in a rain of fire and rock falling from the sky.

Continue reading “Space Sunday: Mars, Starship and a meteor that flattened a city”