Tag: Mars

Space Sunday: a rover and some astronomy

Posted on by Inara Pey

After a treacherous journey, NASA’s Curiosity Mars rover has reached an area that is thought to have formed billions of years ago when the Red Planet’s water disappeared.

Lying part-way up the slopes of “Mount Sharp”, the mound of material deposited at the centre of Gale Crater (and formally called Aeolis Mons), is rich in salty minerals scientists think were left behind when the streams and ponds on the slopes of the mound finally dried up. As such, this region could hold tantalizing clues about how the Martian climate changed from being similar to Earth’s to the frozen, barren desert we know today.

These salty minerals were first spotted from orbit by NASA’s Mars Reconnaissance Orbiter before Curiosity arrived on Mars in 2012, and that discovery marked the deposits as a prime target for the rover to examine.  However, such is the rich diversity of rocks and minerals making up “Mount Sharp”, all of which have been subject to examination by the rover, it has taken the mission almost a decade to reach this “prime” target.

Even so, before Curiosity could obtain any samples from the site, the rover faced a couple of challenges.

The first lay in the fact that the rover’s position on “Mount Sharp” meant that the mission team had to drive and position the rover to ensure its antenna could remain aligned with the various orbiters it needs to use to communicate with Earth; this made navigating to the deposits a challenge, as has ensuring it can reach rocks that might yield interesting samples.

A view through “Paraitepuy Pass” captured by the MastCam on NASA’s Curiosity rover on August 14th, 2022, the 3,563rd Martian day, or sol, of the mission. Credits: NASA/JPL / MSSS

The second required further tests had to be carried out on the rover’s sample-gathering drill to ensure it would handle the stresses in cutting into the region’s rocks. As designed, the drill was intended to use a percussive action as it drilled into any target- but as I’ve reported in these pages, this hammering action started to affect the drilling mechanism as a whole, so a new algorithm was created and uploaded to the rover to minimise any use of the percussive action.

Because of this, the mission team now approach each sample gathering operation with an additional step: after scouring the surface of a sample rock to remove dust and debris, the team then position the drill bit against the rock and attempt to scratch the surface – any resultant marks would be a good indication the rock is soft enough to be drilled without the need for the hammer option.

In the case of this rock – nicknamed “Canaima” – no marks were left, indicating it might prove a difficult subject. However, a further test with the drill head turning revealed it could cut the rock without the use of the hammer action, so on October 3rd, 2022, Curiosity successfully obtained its 36th sample for on-board analysis.

A MastCam view of the 36th successful sample hole Curiosity has drilled, this one on the sulphate-rich rock dubbed “Canaima.” Inset: the hole as imaged by the Mars Hand Lens Imager (MAHlI) mounted on rover’s robot arm, along with the drill mechanism. These mages were taken on October 3rd, 2022, the mission’s 3,612th Martian day, or sol. Credits: NASA/JPL / MSSS

The route to this sulphate-rich area also required Curiosity pass through a narrow, sand-rich location dubbed “Paraitepuy Pass”, bordered on either side by slopes the rover could not drive over or along. Such is the nature of the sand the rover took over a month to traverse the pass, moving cautiously in order to avoid getting bogged-down. This meant that the rover celebrated its 10th anniversary crossing the pass.

The challenges also haven’t ended; the salty region comprises rocky terrain that is so uneven, it will be difficult for Curiosity to place all six wheels on stable ground. This isn’t a problem when on the move, but it could limit science operations in the area: if all of the rovers wheels are not in firm contact with the ground under them, operators won’t risk unfolding its instruments-loaded robot arm in case it clashes with jagged rocks.

Even so, the rover still has a lot of opportunities for science and discovery as it continues to climb “Mount Sharp”.

JWST Wows, HST, Chandra and IXPE Respond

It is now 100 days since the James Webb Space Telescope commenced operations, and in their most recent updates, NASA released a stunning image the observatory captured of the iconic Pillars of Creation.

The Pillars of Creation as imaged by the James Webb Space Telescope. Credit: NASA / ESA

Located in the Serpens constellation, roughly 6,500-7,000 light-years from Earth, the Pillars are gigantic “elephant trunks” of interstellar gas and dust, a birthplace of new stars,  constantly, if slowly being changed by the very stars born within them. They were imaged by the Hubble Space Telescope (HST) in 1995, the image becoming famous the world-over despite HST imaging them again it 2014. However, the image developed by JWST’s Near Infra-red Camera (NIRCam) eclipses the Hubble image, revealing the pillars and their surroundings in incredible detail.

Newly formed stars lie outside of the column. Seen merely as a few bright red orbs with strong diffraction spikes radiating from them, they are reveal by JWST as in their truer colours – blues, yellows, whites, indicative of their spectral classes, a veritable sea of stars, These are the stars that are causing the pillars to change and collapse as a mix of their gravities and radiative energy influence their form.

The Pillars of Creation as images by the Hubble Space Telescope in visible light (1995 – left) and by the James Webb Space Telescope in the near infra-red (right – 2022). Credit: NASA / ESA

Also visible along the edge of the pillars are wavy forms, the ejections of gas and dust from stars that are still forming. The crimson glow seen within some of these wave-like forms is the result of energetic hydrogen molecules interacting with the supersonic outbursts of the still-forming stars. Within the cloudy forms of the pillar are red points of light – newly-formed stars that are just a few hundred thousand years old, the light just stars to break through the surrounding clouds of dust and material.

Around all of this is a translucent blue glow, a mix of dust and gas known as the interstellar medium, found in the densest part of our galaxy’s disk. It serves to block the view of the deeper universe, bringing the Pillars of Creation to the fore.

This new view of the Pillars will help researchers revamp their models of star formation by identifying far more precise counts of newly formed stars, along with the quantities of gas and dust in the region. Over time, they will begin to build a clearer understanding of how stars form and burst out of these dusty clouds over millions of years.

Continue reading “Space Sunday: a rover and some astronomy” →

Space Sunday: minerals on Mars, space politics and more Dream Chaser

Posted on by Inara Pey

As I looked at the Mars 2020 mission in my previous Space Sunday piece (see: Space Sunday: A year on Mars and the Polaris Programme), I thought it time to catch up on some of the most recent news about NASA’s other “big rover” working on Mars, Perseverance’s “older sister”, Curiosity, the rover of the Mars Science Laboratory (MSL) mission, which will mark its tenth anniversary on Mars later in 2022.

Curiosity’s mission to Gale Crater, almost half a world away from Perseverance continued onwards despite the dearth of regular updates posted to the official blog (but them, updates on Perseverance have been far less voluminous than see during the first year of MSL operations on Mars, largely thanks to NASA opting to make greater use of social media tools like Twitter to hand out bite-size nibbles of updates.

However, one recent discovery that got some hearts all a-flutter recently was that of a curious formation Curiosity imaged on flank of “Mount Sharp”, the huge mound rising from the middle of the crater – and officially called Aeolis Mons. At first glance, it appears to show a petrified flower sprouting from the surface of the planet – and while it is most certainly not any such thing or even the first of these formation Curiosity had encountered – the raw images captured by Curiosity were released sans any indication of scale, getting some website and individuals a little over-excited.

The “raw” image of the “flower-like” object captured by the Curiosity rover on February 25th, 2022 (mission Sol 3397 by the Mars Hand Lens Imager (MAHLI) instrument mounted on the rover’s robot arm. Credit: NASA/JPL

The object is in fact a mineral structure called a diagenetic crystal cluster. Essentially they are a collection of crystals formed by mineral precipitating from water, undergoing diagenetic recombination in the process, creating this beautiful, but tiny three-dimensional structures.

In fact, the rover first encountered structures like this since around Sol 870 of the mission, as it explored the Pahrump Hills at the base of “Mount Sharp”. However, this particular structure is somewhat different, as the structures found at Pahrump were formed by sulphate (salt) crystals, leached out of receding waters as the lakes that once repeatedly filled Gale Crater finally vanished. This structure formed from salts and other minerals, and most likely formed inside a small rock over which water coming off the slopes of “Mount Sharp” once flowed, before it was left to the mercy of the Martian wind, which slowly eroded it over the aeons until only this delicate-looking but tough structure remained.

The same image of the structure, this to overlaid with a to-scale US Lincoln penny (one of which also adorns Curiosity’s bodywork), provided by mission scientist Abigail Fraeman to give an impression of the object’s actual size. Credit: NASA/JPL / A. Faeman

The other interesting point with the image is the manner in which it was created. For most its mission, Curiosity has captured images of objects and structures, stored them, and then transmitted them to Earth for post-processing. Here, however, MAHLI took around eight images of the object all from very slightly different angles. The images were then processed by the rover itself, using a software package referred to as the onboard focusing process, which allowed them to be combined and adjusted to produce a single frame of great depth and detail that could then be transmitted to Earth.

In fact, so detailed is the  structure – dubbed Blackthorn Salt – in the image, and such is the depth afforded by the picture Simeon Schmauss was able to produce a 3D model of it using Sketchfab, allowing us to see it really up close and from almost any angle – click the image below and see for yourself. However, when doing so, please note that the blurred and “draped” grey elements seen “hanging” from the structure’s arm / branches when looking at it from the side are not a part of the structure, but are artefacts of the Sketchfab rendering process, as the image from MAHLI doesn’t show what is directly below the arms / branches.

Curiosity itself continues to explore and climb “Mount Sharp”, attempting to make its way to higher slopes. Most recently, it has been making its way along a shallow and short “valley” that will hopefully provide access to the “Greenheugh Pediment” – a comparatively gentle slope, formed by water erosion and lying at the base of the mound’s steeper slopes. It is hoped that by crossing the Pediment will lead to a long valley (Gediz Vallis), which is hoped will provide a route further up “Mount Sharp”.

Since arriving on Mars in august 2012, the rover has travelled 27.3 kilometres and has gathered and analysed 34 rock samples and six soil samples, all of which indicate Gale Crater was once a warm, wet environment that may well once have harboured all the fundamentals for life to form.

Curiosity’s route up “Mount Sharp” from Pahrump Hills to its currently location, where it is making its way towards “Greenheugh Pediment”, which offers a way to Gediz Vallis (below the bottom edge of this image), a route upwards to the upper reaches of the mound, and which appears to be a confluence of numerous channels, possibly formed by water, running downslope from the high ground. Credit: NASA/JPL

Russia Stops Soyuz Launches out of Europe’s Spaceport, French Guiana

Following the sanctions imposed on Russia due to the invasion of Ukraine, Roscosmos has announced it is halting all cooperation with Europe with regards to Soyuz launches out of Europe’s Spaceport, French Guiana and withdrawing its 87 support personnel from the launch site.

The announcement will immediately impact the launch of two Galileo navigation satellites that had been scheduled for April aboard Soyuz, and potentially a follow-up launch of another pair of Galileo satellites due later in the year.

Also potentially impacted are Two ESA missions: the EarthCARE Earth science mission (developed in partnership with JAXA (Japanese space agency) and scheduled for February 2023, and the Euclid infrared space telescope (March 2023), together with the French government’s military CSO-3 reconnaissance satellite.

The Soyuz launch platform at Europe’s Spaceport, Kourou,

Soyuz is offered as a launch vehicle through French launch service provider Arianespace alongside of Ariane and Vega launch vehicles, with Arianespace, through its shareholding in Starsem, can also broker payload launches on Soyuz out of the Baikonaur spaceport, Kazakhstan. However, the future of Soyuz launches out of French Guiana has been the subject to debate for some time, given that Arainespace has been keen to move customers to their new Ariane 6 and Vega-C launchers, both of which are set to enter service from 2022.

No comment has been made by either the European Space Agency or Arianespace on the matter – but both are due to meet to discuss matters on Monday, February 28th. In terms of space cooperation, suspending Soyuz launches out of French Guiana is pretty much the only lever on space matters Russia can pull without adversely impacting their own operations; something that is in stark contrast to 2014, when Russia annexed Crimea.

At that time, the United States was reliant on Russia for both crewed launches to the ISS, and the supply of RD-180 motors used by the Atlas 5 vehicle. However, the US now has the SpaceX Crew Dragon vehicle for ISS missions, which should, in 2023, be joined by Boeing’s Starliner, while United Launch Alliance will be retiring the Atlas 5 (there are only 25 more launches on the books, and has sufficient RD-180 motors for many of those flights).

Dmitry Rogozin, the head of Roscosmos also suggested that sanctions could impact Russian co-operation with the ISS, warning that without Russian support, the space station could fall into “uncontrolled descent from orbit and then falling onto the territory of the United States or Europe”.

Progress resupply craft (green, in the background of this image) have generally used to periodically boost the altitude of the ISS – a job previously performed by the US space shuttle. However, there is no reason why the Orbital Science’s Cygnus resupply vehicle could not perform the same role. Credit: NASA

The threat is based on the fact that Russian Progress resupply vehicles are periodically used to raise the space station’s orbit as drag with the tenuous atmosphere causes it to lower. However, the US and Japan both have the potential means to boost the orbit, whilst away from Rogozin’s tweets, NASA and Roscosmos alike have stated ISS operations continue to pretty much be “business as usual”.

Notably excluded from any threats – for the time being – is the European ExoMars mission, due to see the Rosalind Franklin rover and a Roscosmos-made lander launched to Mars from Baikonur in September atop a Proton-M rocket. This is a particularly critical launch, as the available window only lasts 12 days and if missed will mean another 26-month delay to the mission, which had initially been set to launch 2020.

Space Image of the Week¹

I am virtually sure it’s the most detailed ISS lunar transit to date 😊
I had to ride 250 km from home and find a remote place in the countryside between the blankets of fog, for this 1/2 second transit at 27000 km/h.

– Thierry Legault

The above comments refer to the image below, showing the International Space Station crossing between Earth and the Moon, captured by French amateur astronomer and astro-photographer Thierry Lagault, who travelled from Paris to Bourges in January 2022 in the hope that the winter weather would allow him to capture the space’s passage across the full Moon.

ISS lunar transit by Thierry Legault, Note the image is oriented so south is at the top of the image. The bright crater above and to the right of the ISS in Tycho. Credit: Thierry Legault.
The image is being credited at one of the most detailed pictures of a ISS lunar transit every captured. It is so detailed, is it possible to see details of the primary solar arrays at either end of the station’s main truss structure, as can the structure of the station’s pressurised modules.

An enlarged version of the image, rotated through 90º so that south is to the right, reveals even more detail – the Russian modules of the ISS pointing towards the top of the image, and the US / international modules pointing down.

ISS lunar transit by Thierry Legault (enlarged and rotated). Credit: Thierry Legault.

Continue reading “Space Sunday: minerals on Mars, space politics and more Dream Chaser” →

Space Sunday: A year on Mars and the Polaris Programme

Posted on by Inara Pey
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: touching the Sun and Martian organics

Posted on by Inara Pey
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

Posted on by Inara Pey
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 / NASASpaceflight.com

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: Mars, Starship and a meteor that flattened a city

Posted on by Inara Pey
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” →