Space Sunday: Mars rovers, molecules & 1.8 billion pixels

NASA’s Mars 2020 rover. Credit: NASA/JPL

It might look like the Mars Science Laboratory (MSL) rover Curiosity, but the vehicle seen above (in an artist’s impression) is in fact the Mars 2020 rover that is due to be launched on its way to the red planet in July of this year to arrive in early 2021.

Based on the chassis, body and power plant used by Curiosity, the 2020 rover is a very different vehicle that is tasked with very different roles. And now the 2020 rover has a name as well: Perseverance.

The name was selected following a US national competition in which K-12 students (kindergarten through to 17-19 years of age) were invited to suggest a name for the rover in essay form ( a practice NASA has taken with a number of missions to Mars, including the MER rovers Spirit and Opportunity and with Curiosity). From the initial entries received, NASA narrowed the choice down to nine possible names, with the public asked to cast their vote for their favourite – although the final decision on any name remained with NASA management. Those nine names were: Clarity, Courage, Endurance, Fortitude, Ingenuity, Perseverance, Promise, Tenacity and Vision, with each name identified by a single essay selected by NASA as best representing the goals of the pace agency.

The final choice of name, based on a combination of votes for the nine and an internal decision at NASA, was made by the agency’s associate administrator for science missions, Thomas Zurbuchen, who selected the name Perseverance based on an essay by 13-year-old Alexander Mather of Virginia. The formal announcement of the name was made by Zurbuchen at a special event at Alexander’s school on Friday, March 5th.

In making the announcement, Zurbuchen made note of the fact that Curiosity actually started its journey to Mars when Alexander and many of the other competition entrants were babies – or had yet to be born – citing their involvement in the competition as an example of the innate curiosity that draws us to want to explore the planets and stars around us. He also noted why he felt Perseverance was a particularly apt name for the new rover.

Yes, it’s curiosity that pulls us out there, but it’s perseverance that does not let us give up. There’s no exploration without perseverance.

Alex’s entry captured the spirit of exploration. Like every exploration mission before, our rover is going to face challenges, and it’s going to make amazing discoveries. It’s already surmounted many obstacles to get us to the point where we are today – processing for launch. Alex and his classmates are the Artemis generation, and they’re going to be taking the next steps into space that lead to Mars. That inspiring work will always require perseverance. We can’t wait to see that nameplate on Mars.

– Thomas Zurbuchen, NASA’s associate administrator for science missions

As noted above, Perseverance may look like Curiosity, but it is a very different vehicle in terms of mission and capabilities.

An artist’s illustration of the Mars 2020 rover Perseverance, showing the “turret” of science instruments at the end of the rover’s robot arm. Credit: NASA/JPL

In terms of overall science mission, Curiosity was tasked with identifying conditions and finding evidence that show that Mars may have once been capable of supporting life on its surface – a primary mission it actually achieved within three months of arriving on Mars. However, it was not actually capable of identifying whether any of that life – and we’re talking microbial life here – may still be present, or of what it might have been. Perseverance will take the next logical step in the process:  it will look for actual signs of past life, or biosignatures, capturing samples of rocks and soil that could be retrieved by future missions and returned to Earth for in-depth study.

To achieve this, Perseverance will carry a host of new science instruments and more advanced versions of some of the systems found on Curiosity, together with additional enhancements born of lessons learned in operating the MSL rover on Mars for the past 8 years.

This means that the rover is slightly larger than Curiosity somewhat heavier, massing just over a metric tonne compared to Curiosity’s 899 kg. Part of this extra weight is accounted for by the systems that allow it to obtain samples of sub-surface material and seal them in containers for possible later retrieval by sample return missions. These include a larger, more robust drilling system mounted on the “turret” at the end of the rover’s robot arm, which also in part accounts for the increase in weight of that unit from 30 kg to 45 kg.

Perseverance rover: instruments and systems

Also, while Curiosity is equipped with 17 camera systems, with only four of them colour imagers. Perseverance has 23 cameras, the majority of which are colour imaging systems. These include a suite of 7 cameras that will provide unique views of the rover’s descent and landing, including views of the parachute deployment and views of it being winched to the ground by its hovering “skyhook” platform It also has a pair of “ears” – microphones that, if they work (NASA’s past attempts to operate microphones on Mars haven’t been successful), will allow us to hear the Red Planet for the first time.

Two further key differences between the two rovers are that Perseverance has a different set of wheels that are larger and designed to better handle Martian terrain, which has taken its toll on Curiosity’s six wheels. Perseverance’s steering  has been updated to give it better manoeuvring capabilities, while the second major difference is that Perseverance has a massively updated self-driving capability. These updates mean that Perseverance will be able to map its route far better than Curiosity, calculating route options five times faster than the older rover. This will eventually seen the time required to map and plan each stage in the rover’s drive route reduced from around a day to about 5 hours. In turn, this means that while Perseverance will travel at the same speed as Curiosity, it will be able to cover more ground in the same time periods, and gather more samples over the course of its prime mission.

Perseverance rover: the camera systems

Perseverance is due to be launched on July 17th, 2020, and touchdown in Jezero Crater on Mars on February 18th 2021, some 6,050 km from Curiosity. Like Gale Crater, Curiosity’s “home”, Jezero Crater was once home to a lake up to 250m in depth (3.9 to 3.5 billion years ago), and it features a prominent river delta where water flowing through it deposited masses of sediment over the eons, which is “extremely good at preserving biosignatures”. I plan to cover both the launch and arrival of the mission in these pages.

Curiosity’s Thiophenes: Best Evidence for Early Life on Mars?

As mentioned above, Curiosity isn’t equipped to directly find evidence of current or past life on Mars – but it is fully capable of finding evidence that Mars may once have had conditions conducive to the evolution of basic life, and a new study coming via the Washington State university suggests the rover may have already have found its best evidence for past life on the planet.

Thiophenes are organic compounds found in a range of materials on Earth including coal, crude oil and white truffles. They comprise four carbon atoms and a sulphur atom arranged in a ring, linked to hydrogen atoms, and are most commonly the result of organic interactions, although they can be produced abiotic processes, such as when sedimentary material is compressed into sedimentary rock.

Thiophene structure. Credit: Jynto

Thiophenes have also been discovered by Curiosity on Mars. However, as the rover has tended to encounter evidence for them when sampling sedimentary rock, the assumption has been that they are the result of abiotic processes similar to those at work on Earth in similar conditions. However, the Washington State university study, carried out in association with the Technische Universität in Berlin, suggests the Martian thiophenes may actually be the result of a biological process.

The study notes that – again in general terms – the abiotic formation of thiophenes requires a process called thermochemical sulphate reduction, in which compounds are heated above 120º C (248º F) – which for Mars is an extreme of surface, or near-surface temperature. But if other evidence pointing to the possible existence of bacteria on the surface of Mars as revealed by Curiosity are taken at face value, then the formation of Martian thiophenes could have been the result of an entirely natural, biological sulphate reduction process that avoids the extremes of heating otherwise required. Further, a biological process would in turn allow for bacteria to also break down the thiophenes themselves, making them the rare occurrence Curiosity has found them to be.

The study’s authors are the first to note that their case is not 100% indicative of a biological process being responsible for the presence of Martian thiophenes but it is perhaps the simplest, leading to a possible Occam’s Razor situation. However, they also note that more in situ research – such as by Europe’s upcoming Mars rover, the Rosalind Franklin, due to arrive on Mars in March 2021 – is required before any definitive conclusions might be drawn.

We identified several biological pathways for thiophenes that seem more likely than chemical ones, but we still need proof. If you find thiophenes on Earth, then you would think they are biological, but on Mars, of course, the bar to prove that has to be quite a bit higher. As Carl Sagan said ‘extraordinary claims require extraordinary evidence.’

– Dirk Schulze-Makuch, study co-author

Even so, the argument for an organic origin for the Martian Thiophenes is an intriguing one.

1.8 Billion Pixels: Curiosity’s Mars Panorama

On March 4th, NASA’s Jet Propulsion Laboratory released a video showing the highest resolution panorama of Mars thus far produced.

The video shows 360º view around the rover revealing the “Glen Torridon” region of “Mount Sharp” (formally Aeolis Mons), the mound in the middle of Gale Crater. It comprises more than 1,200 images captured between November 24th 2019 and December 1st, during NASA’s Thanksgiving holiday break.

Rather than have the rover sitting largely idle during the break, the mission team instructed it to perform several complete imaging sweeps around itself to fully capture its surroundings. Once received back on Earth, the images were processed and carefully stitched together over a 3-month period to produce an image, containing almost 1.8 billion pixels!

With the majority of the images taken in high definition, what is remarkable about this video is the depth of detail it offers, particularly when zooming in on distant elements, such as the rim of the crater – so sit back and enjoy the view!

In Brief

Voyager 2 Faces a Lonely 11 Months

Voyager 2, which recently suffered and recovered from a glitch that forced it into a “safe” operational mode now faces a lonely 11 months as it continues its journey into interstellar space. This is because the one communications dish within NASA’s Deep Space Network (DSN) that can be used to contact the distant probe, now over 18 billion km from Earth, is being taken off-line for a major refurbishment.

The massive 70m radio dish and its systems, located 40 km south-west of Canberra, Australia’s capital, has been operation for almost 50 years, and while it has received upgrades to its systems in that time, it is overdue for a complete overhaul.

The 70m DSS43 radio communications dish at NASA’s Deep Space Network facility near Canberra, Australia. The only means of communicating with Voyager 2, it is due to go off-line for 11 months

Ironically, it was the fact that Voyager 2 itself  stopped transmitting data to the dish that convinced NASA to start the upgrade now: when the problem occurred, it initially wasn’t clear if Voyager 2 was at fault or the dish itself. While the work is in progress, Voyager 2 will be watched over by its fault protection system.

WFIRST Passes Milestone, Trump Administration Still Wants it Cancelled

NASA’s Wide Field Infrared Survey Telescope (WFIRST) has passed a critical milestone review, allowing hardware development and testing to go ahead.

Intended to be launched and commence operations in the mid-2020s, the project has been a repeated target for cancellation by the Trump Administration, which originally wanted the project cancelled on the grounds that “other means” (such as the Hubble Space Telescope – HST – and the upcoming James Webb Space Telescope – JWST) make W-FIRST’s mission redundant, and more recently that the cost savings presented by WFIRST’s cancellation would ease the budget overruns being experienced by JWST.

However, WFIRST’s mission – which encompasses both visible light and infra-red studies – is vastly different to either HST or JWST (although arguably it is well placed to take over from HST, which has been in operation for 30 years come this April). It is also a remarkably cost-effective undertaking, with a $3.9 billion price tag spend over 10-12 years, and which includes contingency overruns and the first 5 years of on-orbit operations costs. As such it represents remarkable value for money and could deliver stunning science, as the video below explains.