samedi 6 mars 2021

Searching for the unknown


CERN - European Organization for Nuclear Research logo.

March 6, 2021

In the final part of the LHC Physics at Ten series, we look at the searches that go beyond our current understanding of the universe

Image above: A CMS event display from 2016 containing 10 jets (orange cones) and a muon (red line), which is representative for the signatures that certain supersymmetry models would leave in the CMS detector. (Image: CMS/CERN).

Count all the known kinds of particles in the universe. Now double it. This is the promise of a family of theoretical models known as Supersymmetry, or SUSY for short.

The notion of theories predicting a doubling of observed particles may not be as bizarre as it seems. In fact, it has historical precedent with the story of antimatter.

“The first hints of antimatter came from Paul Dirac trying to solve problems in relativistic quantum mechanics,” says Laura Jeanty, who co-leads the Supersymmetry (SUSY) group on the ATLAS experiment at the Large Hadron Collider. “He came up with equations that essentially had four solutions instead of two, and the symmetries of the maths allow positive as well as negative values.” In 1928, Dirac concluded that if the negative values represented electrons, the positive values must represent an equivalent positively charged particle. The positron, or antielectron, was eventually discovered by Carl Anderson in 1932.

“At the time of Dirac’s theoretical work, however,” Jeanty adds, “it was a mathematical quirk that didn’t have any known physical reality.” Today, we have discovered antiparticles for all the charged particles in the “Standard Model” of particle physics – the best description we have of our universe at the quantum scale. The Standard Model, however, has important limitations, and SUSY provides a theoretical extension to it by introducing new mathematical symmetries.

Inexplicable hierarchies

As a scientific theory, the Standard Model is incredibly robust. Frustratingly so for physicists, because they are aware that this theory does not explain everything about the infinitesimal world of particles and quantum forces. Nevertheless, experimentalists have found no chinks in its armour, no deviations from its very accurate predictions, despite its limitations.

One such limitation is that the Standard Model accounts for only three of the known quantum forces in the universe: the strong, electromagnetic and weak forces; gravity is not in the mix. A symptom of this is known as the hierarchy problem, pertaining to the vast difference between the strengths of the strong, electromagnetic and weak forces on one hand and gravity on the other. Despite its name, the weak force is around 24 orders of magnitude (1024) stronger than gravity. But why does this matter?

“The hierarchy problem,” remarks Pieter Everaerts, Laura’s counterpart on the CMS experiment, “tells us that there have to be corrections to our current knowledge of physics.” The problem affects, for example, the mass of the Higgs boson that was discovered by ATLAS and CMS in 2012. According to quantum mechanics, the Higgs boson should have a mass several orders of magnitude higher than what was observed, because of its interactions with ephemeral virtual particles that pop in and out of existence.

SUSY provides an elegant theoretical solution to this problem. It does this by proposing the following: fermions – particles that make up matter – have force-carrying super-partners known as “sfermions”, while bosons – force-carriers in the Standard Model – are paired up with fermionic “bosinos”.

“With SUSY, the Higgs boson has twice as many particles to interact with,” adds Everaerts. Neatly, this allows the excess values of its expected mass coming from its interactions with ordinary particles to cancel out with the values of its interactions with supersymmetric particles. You are left with a predicted mass for the Higgs boson that is close to the observed mass of 125 GeV.

All that remains is the one small detail of finding at least one of the predicted SUSY particles.

Optimism at a new frontier

Before the LHC began colliding protons together, there was a buzz of expectation among experimental and theoretical particle physicists.

“It seems strange to say this now,” continues Everaerts, “but when the LHC began colliding protons in 2010, some were expecting us to discover six or seven SUSY particles immediately.”

There was even concern that too many SUSY particles (or “sparticles”) at a low enough mass would add to the “background”, or noise, and make it harder to study Standard Model processes at the LHC. This optimism had to quickly face reality when no sparticles manifested. Indeed, no deviations from the Standard Model have been observed in the nearly 15 million billion (15 000 000 000 000 000) proton–proton collisions that have taken place inside each of ATLAS and CMS.

Animation above: The density of allowed supersymmetric models before and after ATLAS had searched through Run-1 data (data gathered up to February 2013)(Image: ATLAS/CERN).

Over the years, data collected by ATLAS and CMS enabled the collaborations to discard several of the simpler SUSY models, ruling out sparticles with masses up to around a teraelectronvolt (or TeV). All this showed, though, was that the most rudimentary interpretations of the theories were inadequate. “When we rule things out to a certain energy, we are aware that these are not realistic models, they are benchmarks,” says Federico Meloni of ATLAS. “And when you look at the same data through a less simplified interpretation, what we call an analysis in multidimensional parameter space,” he continues, “a limit of 2 TeV can become 500 GeV [gigaelectronvolt] or maybe we don’t have a limit at all. When looking at the big picture, it is only after ten years of operations that we are starting to be able to make interesting statements about the key issues.”

For the moment, in the absence of a discovery, SUSY remains firmly in the realm of theory alone. “Supersymmetry in the way we were thinking has been ruled out and we have to now look for it in a different way,” says Gian Giudice, head of CERN’s Theoretical Physics department. “We continue to advance techniques to search for supersymmetric particles,” Jeanty adds. “More LHC data will help us to look further into the challenging corners of phase space, where new physics could still be lurking.”

The LHC however is after more than just SUSY. Indeed, extensions of the Standard Model come in many forms, and on ATLAS and CMS the several teams performing searches for physics beyond the Standard Model are grouped together under the name “Exotics”. (The name “Miscellaneous” is quite obviously less exciting.) Some of these searches seem to come right out of science fiction…

Extra dimensions and micro black holes

Elementary particle physics concerns itself with the very small: tiny particles interacting through quantum forces at an unimaginably minuscule scale. Gravity, on the other hand, applies to the very large – think planets, stars and galaxies – and has sat apart from the quantum domain in our understanding of the universe. A quantum theory of gravity has remained the holy grail of high-energy physics for decades.

“If there is a quantum description of gravity, is there a particle that is responsible for mediating gravity?” asks Carl Gwilliam, a former coordinator of ATLAS exotic physics.

Discovery of such a particle, known as a graviton, would help settle the debate on the many theoretical models that attempt to unify gravity with the other three forces.

ATLAS and CMS are searching for gravitons directly, as for any other new particle, by looking for a bump in a smoothly falling distribution in the data. But, because the theories that predict the existence of a graviton also predict the existence of more than four dimensions of spacetime, the physicists are also looking for particles that are produced in collisions before they disappear into the extra dimensions. You cannot detect these disappearing particles directly; indeed, you cannot even ask the detectors to take snapshots of such collision events because there is nothing to “trigger” the detectors. You can, however, infer their presence by detecting an accompanying jet of particles produced from the same collision and observing simultaneously a lot of missing energy from the interaction itself. Niki Saoulidou, who co-leads the CMS Exotics team, points out that before the LHC was switched on, it was thought that these kinds of mono-jet searches, which also look for dark matter or supersymmetric particles, were too challenging for hadron-collider environments. “But we have evolved our tools, our techniques, our detector and our physics understanding so much that we now consider these as standard searches,” she says.

Image above: A multi-jet event display observed by the CMS detector in 2015 in the search for microscopic black holes. (Image: CMS/CERN).

Another way of detecting extra dimensions made headlines before the LHC began operations: micro black holes. If produced in high-energy proton–proton collisions at the LHC, these tiny black holes would instantly evaporate, leaving behind multiple jets of particles. “The thing with black-hole searches is that they would be very spectacular!” remarks Gwilliam. “You would expect to see a black-hole event very early on in a new energy regime.” Since it began operations, the LHC has explored three new high-energy regimes: 7 TeV, 8 TeV and 13 TeV. ATLAS and CMS also searched at the lower energy of 900 GeV. “Unfortunately, these have not showed up in the data,” adds Gwilliam, “so we have set very strong limits on their existence.”

What does this mean for unifying gravity with the quantum forces? Saoulidou is philosophical: “It could be that we don’t have a quantum theory of gravity for a very good reason, which nature knows but we don’t.”

Nevertheless, those 15 million billion collisions that ATLAS and CMS have analysed make up only 5% of the total data volume the LHC will deliver over the course of its lifetime. The graviton could still be out there.

Mysterious missing pieces and uncanny coincidences

“Results from searches for exotic physics were at the forefront of work done at the start of the LHC era,” says Adish Vartak, former co-leader of the CMS Exotics team. There was a lot of potential for finding new physics, given that the LHC was operating at an energy of around four times higher than the previous highest-energy collider, the Tevatron at Fermilab.

“When the LHC started,” Vartak continues, “we wanted to see whether there was a new resonance – a new particle – at a few TeV or so, at energies that the Tevatron could not probe.”

It is not only the spectacular that particle physicists are after. Many of the searches conducted by the Exotics groups of ATLAS and CMS look for answers to particularly puzzling questions. For example, the data have so far shown that quarks are elementary particles; that is, they are themselves not made up of any particles. But we don’t know for sure if that is the case. Finding quarks in excited states at high energies would demonstrate that they have inner substructure. Another puzzle is that the two families of fermions – leptons and quarks – curiously come in three generations each. There is no particular reason for this, unless they are somehow related to one another. ATLAS and CMS are therefore looking for leptoquarks, particles predicted to be hybrids of both kinds of fermions.

Physicists are also looking for previously unobserved quantum forces, which would manifest in the form of heavier versions of the electroweak-force-carrying W and Z bosons, called W′ (“W-prime”) and Z′ (“Z-prime”). In the case of neutrinos, the reason for their extremely light but non-zero mass could be explained by discovering heavier exotic neutrinos, which balance the lighter regular neutrinos through a “see-saw” mechanism.

Other searches are for heavier Higgs bosons, charged Higgs bosons and even composite (non-elementary) Higgs bosons. Yet more focus on hypothesised magnetic monopoles (a single north or south pole) that, rather than bending in the high magnetic fields of ATLAS and CMS, would get accelerated through them.

Of course, experimentalists are also looking for any new particles and phenomena, even ones not explicitly predicted by theory. Giudice, a theorist, adds: “Experimentalists can make progress without a theorist telling them, ‘Oh, this comes from this model.’ Before the LHC, much of the analysis was done in terms of models. Now they try to present the data without relying on a specific model but rather on a broader language.”

The 750-GeV bump-that-was-not

This model-independent approach caused much excitement in 2015. Over the course of the first year of the LHC’s second run, both ATLAS and CMS began to notice something peculiar in their data. There appeared to be a slight excess of events in the two-photon channel at a mass of 750 GeV/c² in both their data sets. Initially the excess was of very low statistical significance, far from the 5-sigma threshold for claiming a discovery. Nevertheless it intrigued experimentalists and theorists alike. “As data began to be collected,” Vartak recounts, “there was a lot of hope that a new kind of physics – one that had evaded us previously – would show up.”

Image above: Graph showing the sharp rise in arXiv paper submissions after December 2015, as theorists attempted to explain the 750-GeV bump in the data (Image: André David).

In December, at the annual end-of-year seminar from the LHC experiments, excitement reached fever pitch. ATLAS and CMS presented data showing the significance of the excess was around 3 sigma. In the following three months, around 300 papers were submitted to arXiv by theorists seeking to explain the inexplicable. By the time all of the data from Run 2 (2015–2018) were studied, the excess had evaporated. There is a reason physicists wait until the 5-sigma threshold is breached: smaller excesses are not unusual and are usually statistical fluctuations and low-significance flukes.

For the Exotics teams, though, it was the closest they came to something from beyond the Standard Model.

Changes in strategy and the road ahead

The lessons learnt so far are helping shape the search strategies of the future. For one, the triggers that select the collision data worth storing for further analysis are being recalibrated to handle so-called “long-lived particles”, which might transform into lighter particles outside of the typical timeframe when the triggers take their snapshots of collisions. Efforts are also underway to reanalyse the data recorded so far using novel techniques.

The challenges provide more than adequate motivation and inspiration. “I’ve always had a lot of fun with my research,” Everaerts says with a smile. “Collaborating with people from different backgrounds to work on a common goal: I find that amazing!”

So what is the legacy of the LHC after its first decade of operation? Giudice is emphatic: “The LHC has changed radically the way we view the world of particle physics today.” It might not have shown what theorists hoped it would, but it has helped make important strides in both theory and experiment. “When I start with an idea and then it turns out to be wrong, it’s not a question of failure; it is the scientific method,” Giudice continues. “You make a hypothesis, you check it with experiment, if it is right you keep on going but if it is wrong, you explore a different hypothesis.”

“As experimentalists,” Meloni adds, “when we search beyond the Standard Model, our job is to look for everything. We know that we look for something, we look for it everywhere, and chances are it’s not going to be there. Still, our job is to understand our measurement, our search, and get to the result. And then the results are up for interpretation.”

After all, looking and not finding is not the same as not looking.


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 23 Member States.

Related links:

Large Hadron Collider (LHC):

ATLAS experiment:

CMS experiment:

Higgs boson:

For more information about European Organization for Nuclear Research (CERN), Visit:

Images (mentioned), Text, Credits: CERN/By: Achintya Rao.

Best regards,

59 new hadrons and counting


CERN - European Organization for Nuclear Research logo.

March 6, 2021

Over the past 10 years, the LHC has found more than 50 new particles called hadrons

Image above: Professor Murray Gell-Mann in the ATLAS cavern in 2012. Gell-Mann proposed the quark model and the name “quark” in 1964 and received the Nobel Prize in Physics in 1969. (Image: CERN).

How many new particles has the LHC discovered? The most widely known discovery is of course that of the Higgs boson. Less well known is the fact that, over the past 10 years, the LHC experiments have also found more than 50 new particles called hadrons. Coincidentally, the number 50 appears in the context of hadrons twice, as 2021 marks the 50th anniversary of hadron colliders: on 27 January 1971, two beams of protons collided for the first time in CERN’s Intersecting Storage Rings accelerator, making it the first accelerator in history to produce collisions between two counter-rotating beams of hadrons.

So what are these new hadrons, which number 59 in total? Let’s start at the beginning: hadrons are not elementary particles – physicists have known that since 1964, when Murray Gell-Mann and George Zweig independently proposed what is known today as the quark model. This model established hadrons as composite particles made out of new types of elementary particles named quarks. But, in the same way as researchers are still discovering new isotopes more than 150 years after Dmitri Mendeleev established the periodic table, studies of possible composite states formed by quarks are still an active field in particle physics.

Large Hadron Collider (LHC). Animation Credit: CERN

The reason for this lies with quantum chromodynamics, or QCD, the theory describing the strong interaction that holds quarks together inside hadrons. This interaction has several curious features, including the fact that the strength of the interaction does not diminish with distance, leading to a property called colour confinement, which forbids the existence of free quarks outside of hadrons. These features make this theory mathematically very challenging; in fact, colour confinement itself has not been proven analytically to this date. And we still have no way to predict exactly which combinations of quarks can form hadrons.

What do we know about hadrons then? Back in the 1960s, there were already more than 100 known varieties of hadrons, which were discovered in accelerator and cosmic-ray experiments. The quark model allowed physicists to describe the whole “zoo” as different composite states of just three different quarks: up, down and strange. All known hadrons could be described as either consisting of three quarks (forming baryons) or as quark–antiquark pairs (forming mesons). But the theory also predicted other possible quark arrangements. Already in Gell-Mann’s original 1964 paper on quarks, the notion of particles containing more than three quarks appeared as a possibility. Today we know that such particles do exist, but it took several decades to confirm in experiments the first four-quark and five-quark hadrons, or tetraquarks and pentaquarks.

A full list of the 59 new hadrons found at the LHC is shown in the image below. Of these particles, some are pentaquarks, some are tetraquarks and some are new higher-energy (excited) states of baryons and mesons. The discovery of these new particles, together with measurements of their properties, continues to provide important information for testing the limits of the quark model. This in turn enables researchers to further their understanding of the strong interaction, to verify theoretical predictions and to tune models. This is especially important for the research done at the Large Hadron Collider, since the strong interaction is responsible for the vast majority of what happens when hadrons collide. The better we can understand the strong interaction, the more precisely we can model these collisions and the better are our chances of seeing small deviations from expectations that could hint at possible new physics phenomena.

Image above: The full list of new hadrons found at the LHC, organised by year of discovery (horizontal axis) and particle mass (vertical axis). The colours and shapes denote the quark content of these states. (Image: LHCb/CERN).

The hadron discoveries from the LHC experiments keep coming, mainly from LHCb, which is particularly suited to studying particles containing heavy quarks. The first hadron discovered at the LHC, χb(3P), was discovered by ATLAS, and the most recent ones include a new excited beauty strange baryon observed by CMS and four tetraquarks detected by LHCb.

Read also this article in the CERN Courier:


CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 23 Member States.

Related links:

Discovered by ATLAS:

Observed by CMS:

Detected by LHCb:

CERN’s Intersecting Storage Rings:

Higgs boson:

For more information about European Organization for Nuclear Research (CERN), Visit:

Images (mentioned), Animation (mentioned), Text, Credits: CERN/By Piotr Traczyk.


NASA’s Perseverance Drives on Mars’ Terrain for First Time


NASA - Mars 2020 Perseverance Rover logo.

March 06, 2021

NASA’s Mars 2020 Perseverance rover performed its first drive on Mars March 4, covering 21.3 feet (6.5 meters) across the Martian landscape. The drive served as a mobility test that marks just one of many milestones as team members check out and calibrate every system, subsystem, and instrument on Perseverance. Once the rover begins pursuing its science goals, regular commutes extending 656 feet (200 meters) or more are expected.

Image above: This image was captured while NASA’s Perseverance rover drove on Mars for the first time on March 4, 2021. One of Perseverance’s Hazard Avoidance Cameras (Hazcams) captured this image as the rover completed a short traverse and turn from its landing site in Jezero Crater. Image Credits: NASA/JPL-Caltech.

“When it comes to wheeled vehicles on other planets, there are few first-time events that measure up in significance to that of the first drive,” said Anais Zarifian, Mars 2020 Perseverance rover mobility test bed engineer at NASA’s Jet Propulsion Laboratory in Southern California. “This was our first chance to ‘kick the tires’ and take Perseverance out for a spin. The rover’s six-wheel drive responded superbly. We are now confident our drive system is good to go, capable of taking us wherever the science leads us over the next two years.”

Image above: NASA's Mars Perseverance rover acquired this image using its onboard Left Navigation Camera (Navcam). The camera is located high on the rover's mast and aids in driving. This image was acquired on Mar. 6, 2021 (Sol 15) at the local mean solar time of 16:49:29. Image Credits: NASA/JPL-Caltech.

The drive, which lasted about 33 minutes, propelled the rover forward 13 feet (4 meters), where it then turned in place 150 degrees to the left and backed up 8 feet (2.5 meters) into its new temporary parking space. To help better understand the dynamics of a retrorocket landing on the Red Planet, engineers used Perseverance’s Navigation and Hazard Avoidance Cameras to image the spot where Perseverance touched down, dispersing Martian dust with plumes from its engines.

More Than Roving

The rover’s mobility system is not only thing getting a test drive during this period of initial checkouts. On Feb. 26 – Perseverance’s eighth Martian day, or sol, since landing – mission controllers completed a software update, replacing the computer program that helped land Perseverance with one they will rely on to investigate the planet.

More recently, the controllers checked out Perseverance’s Radar Imager for Mars’ Subsurface Experiment (RIMFAX) and Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE) instruments, and deployed the Mars Environmental Dynamics Analyzer (MEDA) instrument’s two wind sensors, which extend out from the rover’s mast. Another significant milestone occurred on March 2, or sol 12, when engineers unstowed the rover’s 7-foot-long (2-meter-long) robotic arm for the first time, flexing each of its five joints over the course of two hours.

Animation above: NASA's Mars Perseverance rover acquired this images using its onboard Left Navigation Camera (Navcam). The camera is located high on the rover's mast and aids in driving. This images was acquired on Mar. 5, 2021 (Sol 14) at the local mean solar time of 14:49:44. Animation Credits: NASA/JPL-Caltech/ Aerospace/Roland Berga.

“Tuesday’s first test of the robotic arm was a big moment for us,” said Robert Hogg, Mars 2020 Perseverance rover deputy mission manager. “That’s the main tool the science team will use to do close-up examination of the geologic features of Jezero Crater, and then we’ll drill and sample the ones they find the most interesting. When we got confirmation of the robotic arm flexing its muscles, including images of it working beautifully after its long trip to Mars – well, it made my day.”

Upcoming events and evaluations include more detailed testing and calibration of science instruments, sending the rover on longer drives, and jettisoning covers that shield both the adaptive caching assembly (part of the rover’s Sample Caching System) and the Ingenuity Mars Helicopter during landing. The experimental flight test program for the Ingenuity Mars Helicopter will also take place during the rover’s commissioning.

Through it all, the rover is sending down images from the most advanced suite of cameras ever to travel to Mars. The mission’s cameras have already sent about 7,000 images. On Earth, Perseverance’s imagery flows through the powerful Deep Space Network (DSN), managed by NASA’s Space Communications and Navigation (SCaN) program. In space, several Mars orbiters play an equally important role.

“Orbiter support for downlink of data has been a real gamechanger,” said Justin Maki, chief engineer for imaging and the imaging scientist for the Mars 2020 Perseverance rover mission at JPL. “When you see a beautiful image from Jezero, consider that it took a whole team of Martians to get it to you. Every picture from Perseverance is relayed by either the European Space Agency’s Trace Gas Orbiter, or NASA’s MAVEN, Mars Odyssey, or Mars Reconnaissance Orbiter. They are important partners in our explorations and our discoveries.”

The sheer volume of imagery and data already coming down on this mission has been a welcome bounty for Matt Wallace, who recalls waiting anxiously for the first images to trickle in during NASA’s first Mars rover mission, Sojourner, which explored Mars in 1997. On March 3, Wallace became the mission’s new project manager. He replaced John McNamee, who is stepping down as he intended, after helming the project for nearly a decade.

“John has provided unwavering support to me and every member of the project for over a decade,” said Wallace. “He has left his mark on this mission and team, and it has been my privilege to not only call him boss but also my friend.”

Touchdown Site Named

With Perseverance departing from its touchdown site, mission team scientists have memorialized the spot, informally naming it for the late science fiction author Octavia E. Butler. The groundbreaking author and Pasadena, California, native was the first African American woman to win both the Hugo Award and Nebula Award, and she was the first science fiction writer honored with a MacArthur Fellowship. The location where Perseverance began its mission on Mars now bears the name “Octavia E. Butler Landing."

Official scientific names for places and objects throughout the solar system – including asteroids, comets, and locations on planets – are designated by the International Astronomical Union. Scientists working with NASA’s Mars rovers have traditionally given unofficial nicknames to various geological features, which they can use as references in scientific papers.

“Butler’s protagonists embody determination and inventiveness, making her a perfect fit for the Perseverance rover mission and its theme of overcoming challenges,” said Kathryn Stack Morgan, deputy project scientist for Perseverance. “Butler inspired and influenced the planetary science community and many beyond, including those typically under-represented in STEM fields.”

Image above: NASA has named the landing site of the agency’s Perseverance rover “Octavia E. Butler Landing,” after the science fiction author Octavia E. Butler. The landing location is marked with a star in this image from the High Resolution Imaging Experiment (HiRISE) camera aboard NASA’s Mars Reconnaissance Orbiter (MRO). Image Credits: NASA/JPL-Caltech/University of Arizona.

“I can think of no better person to mark this historic landing site than Octavia E. Butler, who not only grew up next door to JPL in Pasadena, but she also inspired millions with her visions of a science-based future,” said Thomas Zurbuchen, NASA associate administrator for science. “Her guiding principle, ‘When using science, do so accurately,’ is what the science team at NASA is all about. Her work continues to inspire today’s scientists and engineers across the globe – all in the name of a bolder, more equitable future for all.”

Butler, who died in 2006, authored such notable works as “Kindred,” “Bloodchild,” “Speech Sounds,” “Parable of the Sower,” “Parable of the Talents,” and the “Patternist” series. Her writing explores themes of race, gender, equality, and humanity, and her works are as relevant today as they were when originally written and published.

More About the Mission

A key objective of Perseverance’s mission on Mars is astrobiology, including the search for signs of ancient microbial life. The rover will characterize the planet’s geology and past climate, pave the way for human exploration of the Red Planet, and be the first mission to collect and cache Martian rock and regolith.

Subsequent NASA missions, in cooperation with ESA (European Space Agency), would send spacecraft to Mars to collect these sealed samples from the surface and return them to Earth for in-depth analysis.

The Mars 2020 Perseverance mission is part of NASA’s Moon to Mars exploration approach, which includes Artemis missions to the Moon that will help prepare for human exploration of the Red Planet.

JPL, which is managed for NASA by Caltech in Pasadena, built and manages operations of the Perseverance rover.

Related links:

Radar Imager for Mars’ Subsurface Experiment (RIMFAX):

Mars Oxygen In-Situ Resource Utilization Experiment (MOXIE):

Mars Environmental Dynamics Analyzer (MEDA):

Sample Caching System:

Mars Reconnaissance Orbiter (MRO):

For more about Perseverance: and

For more information about NASA’s Mars missions, go to:

Images (mentioned), Animation (mentioned), Text, Credits: NASA/Alana Johnson/Grey Hautaluoma/JPL/DC Agle.

Best regards,

vendredi 5 mars 2021

Asteroid Apophis Pays Earth a Visit This Weekend


Asteroid Watch logo.

March 5, 2021

When a potentially hazardous asteroid glides safely past Earth on March 6th, astronomers will conduct a dress rehearsal for a dramatic close-miss pass in 2029.

Astronomers have been playing cat-and-mouse with the asteroid 99942 Apophis for nearly two decades.

Six months after its discovery in June 2004, dynamicists calculated that it had a scary 1-in-20 chance of striking Earth in 2029. Then, thanks to more observations, they realized it would sail by safely on that pass but threaten our planet in 2036 instead. Now there’s no danger of a collision in 2036 — radar range measurements ruled that out several years ago — but an ever-so-slight chance of impact remains possible in 2068.

(Perhaps fittingly, Apophis is the Greek name for the Egyptian deity Apep, the god of chaos.)

Image above: On April 13, 2029, a ¼-mile-wide asteroid named Apophis will pass close enough to Earth (within 20,000 miles) to briefly appear as a 3rd-magnitude star in the night sky. Image Credits: Dan Durda/

All this number-crunching is of much more than academic interest. With a diameter of roughly 350 meters (not quite ¼ mile), Apophis would cause devastating destruction to whatever region on Earth it might hit. So it is in our planet’s best interest to know exactly where this big, dangerous rock will be for the foreseeable future.

That’s why so many astronomers are turning their attention and instrumentation to Apophis this week. It is passing by at the very safe distance of about 16.9 million km (10.5 million miles) on March 6th at 1:15 Universal Time. And although it’ll be closest during evening hours for eastern North America, Apophis will be only 16th magnitude at best and thus a challenging telescopic target.

Still, the ongoing flyby is the final “dress rehearsal” before this potentially hazardous asteroid skims some 31,500 km (19,500 miles) from Earth’s surface on April 13, 2029. So observers are looking to firm up what’s known about Apophis before the “big show” 8 years from now.

What is Apophis Really Like?

For example, radar maps obtained during a somewhat-closer visit in late 2012 reveal that Apophis has an irregular, somewhat elongated shape — with hints that it might have two connected lobes. Meanwhile, telescopic measurements of its light curve showed that the asteroid is probably tumbling slowly, rotating every 263 ± 6 hours but precessing around its spin axis every 30.6 hours.

Image above: In early 2013, NASA's 70-m-wide Goldstone radio dish recorded delay-Doppler "images," at right, that crudely resolved asteroid Apophis. In these views and in the smoothed images in the middle, the radar illumination is from the top. In the resulting shape models at left, the pink arrow represents the spin axis; red, green, and blue shafts mark the three axes of the shape model's ellipsoid. Image Credits: Marina Brozović & others/Icarus.

Observers hope to improve their knowledge of the body’s spin state in the coming days, but the loss of Arecibo Observatory and its unmatched radar capability will hamper that effort. According to a team of radar specialists led by Marina Brozović (Jet Propulsion Laboratory), Arecibo’s radar maps would likely have resolved surface details on Apophis as small 15 m (50 feet).

Instead, radar studies will now rely on NASA’s big 70-m (230-foot) Goldstone dish in California in combination with the 100-m Green Bank Telescope in West Virginia. The hope, notes Lance Benner (JPL), is to refine the asteroid’s orbit and maybe to obtain coarse images to improve knowledge of the spin state and shape.

It would be a big plus to nail down the asteroid’s size and shape, which in turn would improve estimates of its mass. NASA’s NEOWISE spacecraft will sweep over Apophis and measure its brightness at the infrared wavelength of 4.6 microns and perhaps 3.4 microns. Those measurements, combined with visible-light photometry from ground-based telescopes, should lead to a more accurate diameter.

Even better, notes deputy principal investigator Joe Masiero (Caltech), NEOWISE might yield a measurement of the asteroid’s thermal inertia, key to understanding the nature of its surface. Right now, observers only know Apophis to be a uniform gray overall. But is it rocky or deeply dusty? Do lighter and darker patches cover its surface?

Getting a better baseline of these characteristics now will be crucial to observations planned for 2029. During that super-close pass, dynamicists expect that the gravitational pull of Earth will do more than bend Apophis’s trajectory by 28° and yank it onto a new orbit. There’s also a good chance that terrestrial tides will alter the asteroid’s spin significantly and maybe causes some shifting of its surface material — important clues to the state of its interior.

Tracking the Yarkovsky Effect

Dynamicists now realize that the orbits of small rocky bodies can be slowly change just by the power of sunlight. When sunlight is absorbed by a rotating object and then reradiated as heat in some other direction, the result is a gentle but persistent nudging (generally called the Yarkovsky effect) that over many years can alter the object’s orbit appreciably. Predictions of its location in the distant future — especially if it has some chance of striking Earth — can be thrown off by this dynamical wild card.

Image above: A spinning body radiates the most heat from its afternoon side, creating a slight thermal imbalance called the Yarkovsky effect. Over time an asteroid rotating in the same sense as its motion around the Sun is gradually accelerated and pushed into a wider orbit. Conversely, a retrograde spinner is doomed to spiral inward toward the Sun. Image Credit: Sky & Telescope.

In principle, a tumbling Apophis should be good news, because the Yarkovsky effect would become randomized and ultimately alter the orbit very little. But extremely precise positional measurements observations made a year ago by David Tholen (University of Hawai’i) and others with the Subaru Telescope show that Apophis is in fact drifting away from a purely gravitational orbit by about 170 meters (560 feet) per year — which, Tholen points out, is “enough to keep the 2068 impact scenario in play.”

So it’s no surprise that Tholen and many other astronomers worldwide held a dedicated 3-day Apophis workshop in December and have mounted an extensive campaign to observe Apophis by any means possible during this month’s fleeting flyby. Even dedicated amateurs are involved, as they try to record the asteroid’s split-second passage in front an 8th-magnitude star in Hydra on the night of March 6–7.

Image above: Gianluca Masi photographed 99942 Apophis on February 15, 2021. He invites you to see the asteroid live on his Virtual Telescope website starting at 0 UT on March 6th (7 p.m. Eastern, March 5th) during its current close passage of Earth. Image Credit: Gianluca Masi.

And even if you’re not equipped to track down Apophis as it slips by Earth, you can join the hunt vicariously thanks to Gianluca Masi’s Virtual Telescope, which will track the asteroid in real time beginning at 0:00 UT on March 6th (Friday, March 5th, at 7:00 p.m. EST, 4:00 p.m. PST).

Editor's Note:

This article is the 10,000th edited and written on this blog by Aerospace / Roland Berga.

Related articles:

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Herschel Intercepts Asteroid Apophis

NASA Rules Out Earth Impact in 2036 for Asteroid Apophis

NASA Releases Workshop Data and Findings on Asteroid 2011 AG5

Asteroids - The trajectory of the disaster

Related links:

Virtual Telescope website:

For more information about asteroids and near-Earth objects, visit: Updates about near-Earth objects are also available by following AsteroidWatch on Twitter at

Images (mentioned), Text, Credits: Sky & Telescope/By: Kelly Beatty.


U.S., Japanese Astronauts Conclude Solar Array Mods Spacewalk


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March 5, 2021

NASA astronaut Kate Rubins and Japan Aerospace Exploration Agency (JAXA) astronaut Soichi Noguchi concluded their spacewalk at 1:33 p.m. EST, after 6 hours and 56 minutes. In the fourth spacewalk of the year outside the International Space Station, the two astronauts successfully completed the installation of modification kits required for upcoming solar array upgrades.

The duo worked near the farthest set of existing solar arrays on the station’s left (port) side, known as P6, to install a modification kit on solar array 4B and reconfigure the modification kit on 2B, completing tasks that were started during the Feb. 28 spacewalk.

Image above: (From left) Astronauts Soichi Noguchi and Kate Rubins work to install a solar array modification kit during the fourth spacewalk of 2021. Image Credit: NASA TV.

Due to time constraints, the secondary tasks of troubleshooting the Columbus Parking Position (PAPOS) Interface and removing and replacing a Wireless Video System External Transceivers Assembly (WETA) were deferred to a later spacewalk. The astronauts did, however, complete an additional task of relocating an Articulating Portable Foot Restraint (APFR).

NASA is augmenting six of the eight existing power channels of the space station with new solar arrays, which will be delivered on SpaceX’s 22nd commercial resupply services mission. The new solar arrays, a larger version of the Roll-Out Solar Array (ROSA) technology, will be positioned in front of six of the current arrays, ultimately increasing the station’s total available power from 160 kilowatts to up to 215 kilowatts and ensuring sufficient power supply for NASA’s exploration technology demonstrations for Artemis and beyond. The current solar arrays are functioning well but have begun to show signs of degradation, as expected, as they were designed for a 15-year service life.

Spacewalk at the International Space Station

This was the fourth career spacewalk for both Rubins and Noguchi. Rubins has now spent a total of 26 hours and 46 minutes spacewalking. Noguchi now has spent a total of 27 hours and 1 minute spacewalking.

Space station crew members have conducted 236 spacewalks in support of assembly and maintenance of the orbiting laboratory. Spacewalkers have now spent a total of 61 days, 21 hours and 7 minutes working outside the station.

Related articles:

Spacewalkers Conclude Today’s Spacewalk

Astronauts Rubins and Glover Begin Spacewalk

Spacewalkers Wrap Up Battery Work and Camera Installations

New Solar Arrays to Power NASA’s International Space Station Research

Related links:

Roll-Out Solar Array (ROSA):

International Space Station (ISS):

Image (mentioned), Video, Text, Credits: NASA/Mark Garcia/NASA TV.

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Observations Around Solar System With Parker Solar Probe’s 7th Solar Encounter


NASA - Parker Solar Probe patch.

Mar 5, 2021

During Parker Solar Probe’s seventh swing by the Sun, culminating in its closest solar approach, or perihelion, on Jan. 17, 2021, celestial geometry posed a special opportunity. The configuration of this particular orbit placed Parker Solar Probe on the same side of the Sun as Earth — meaning that Earth-bound observatories could observe the Sun and its outpouring of solar wind from the same perspective as Parker’s. This comes on the heels of a similar observation campaign in the winter of 2020.

Parker Solar Probe. Animation Credit: NASA

“Along with the global science community, the Parker Solar Probe team can’t wait to see this new data,” said Nour Raouafi, the Parker Solar Probe project scientist from the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland. “Combining it with contributions from observatories around the globe will help us to put Parker observations in a broader context and build a complete picture of the phenomena observed in the solar atmosphere.”

Read on for snapshots from a few missions that observed the Sun and the solar system during Parker Solar Probe’s seventh solar encounter.


JAXA/NASA Hinode Observes the Sun on Jan. 17, 2021

These images were captured by the X-ray Telescope, or XRT, aboard the Japan Aerospace Exploration Agency’s and NASA’s Hinode spacecraft. XRT watches the Sun in X-rays, a high-energy type of light that reveals the extremely hot material in the Sun’s atmosphere, the corona. These images from XRT were captured on Jan. 17, when Parker Solar Probe was closest to the Sun. Scientists can use XRT’s images with Parker Solar Probe’s direct measurements of the environment around the Sun to better understand how the Sun’s corona could drive changes in the space environment farther away from the Sun. Video Credits: JAXA/NASA/Hinode.

Solar Dynamics Observatory (SDO)

The Sun Seen by NASA’s Solar Dynamics Observatory Jan. 12-23, 2021

NASA’s Solar Dynamics Observatory, or SDO, keeps a constant eye on the Sun from its vantage point in orbit around Earth. SDO captures images of the Sun in extreme ultraviolet light — a type of light that is invisible to our eyes — and visible light, as well as magnetic maps of the Sun. SDO’s data can help scientists understand the connection between conditions on the Sun and what is measured in the solar wind by spacecraft like Parker Solar Probe.

These images were captured in 211 angstroms, a wavelength of extreme ultraviolet light emitted by material at around 3 million degrees Fahrenheit. This wavelength highlights both active regions — seen as bright spots in the image — and coronal holes, areas of open magnetic field on the Sun from which high-seed solar wind can rush out into space. Coronal holes appear as dark areas in this wavelength of light. Video Credits: NASA/SDO.


NASA’s Interface Region Imaging Spectrograph Sees the Sun on Jan. 17, 2021

NASA’s Interface Region Imaging Spectrograph, or IRIS, captures images of the lower regions of the Sun’s atmosphere in ultraviolet light, along with spectra that break down how much light is visible across different wavelengths. These images, captured on Jan. 17, show an active region on the Sun, an area of intense and complex magnetic fields that is prone to explosions of light and solar material. This particular active region was targeted for IRIS observations based on model predictions that suggested that magnetic field lines from this region could be ones Parker Solar Probe would cross and measure during its solar encounter.

The images cycle through different wavelengths of light — corresponding to views of different heights above the solar surface — to reveal features in various regions of the Sun’s structure. This imagery shows features from the solar surface to a few thousand miles above at the top of the chromosphere, a region of the Sun’s atmosphere that interfaces with the extended solar atmosphere beyond. Video Credits: NASA/IRIS.


Animation Credits: Global Oscillation Network Group/National Solar Observatory/AURA/NSF.

The National Science Foundation’s Global Oscillation Network Group, or GONG, is a network of solar imagers distributed around the globe. They make use of the Zeeman effect — how light splits into multiple wavelengths under the influence of a magnetic field — to create magnetic maps of the solar surface. This video shows GONG’s magnetic maps, updated hourly, from Jan. 12-23, 2021. The black areas represent areas where the magnetic field is pointing in towards the Sun’s surface, and white areas are where the magnetic field is pointing out into space.

As the solar wind streams out from the Sun, it carries the solar magnetic field with it. But identifying precisely which regions on the Sun are the source for solar wind measured by spacecraft like Parker Solar Probe is a challenging task for several reasons: The Sun rotates, solar wind leaves the Sun at varying speeds, and strong magnetic fields near the Sun can change the solar wind’s path as it flows out.

The Parker Solar Probe team uses GONG’s magnetic maps, along with data from NASA’s Solar Dynamics Observatory, to make predictions of which regions on the Sun are sending out material and magnetic field lines toward the spacecraft. Drawing these connections between the Sun itself and the solar wind that Parker Solar Probe is measuring directly can help scientists trace how conditions on the Sun propagate out into space.


A trio of NASA’s THEMIS spacecraft — short for Time History of Events and Macroscale Interactions during Substorms — orbit Earth to measure particles and electric and magnetic fields in near-Earth space. THEMIS’ data helps researchers untangle the complicated factors that govern the response of near-Earth space to dynamics in Earth’s magnetic field, changes in the Sun’s constantly outflowing solar wind, and activity on the Sun.

These measurements were taken by THEMIS-E, one of the spacecraft in orbit around Earth, on Jan. 20. It takes about two to three days for solar wind to cross the tens of millions of miles from the Sun to Earth, so the solar wind conditions observed by Parker Solar Probe during its close solar approach on Jan. 17 did not begin to influence near-Earth space until about Jan. 19-20.

Image Credits: NASA/THEMIS.

THEMIS-E began the day traveling through the Van Allen radiation belts — concentric bands of charged particles nested in Earth’s magnetic field — as it approached Earth. THEMIS-E then traveled back outward through the radiation belts. Both transits through the radiation belts are reflected in the areas of intense coloring in the lower left part of the plot at the beginning of the day.

Mid-morning, THEMIS-E left Earth’s magnetic field and entered the magnetosheath — the region just outside the outermost Sun-facing boundary of Earth’s magnetic field where solar wind piles up as it collides with Earth’s magnetic field. Throughout the day, gusts in the solar wind temporarily pushed the boundaries of the magnetosphere Earthward, meaning that THEMIS-E repeatedly left and re-entered the magnetosheath. For about 15 hours — until its orbit carried it back into the magnetosphere late in the day — THEMIS-E alternately observed the unperturbed solar wind outside the magnetosheath and piled-up solar wind in the magnetosheath. The undisturbed solar wind observed by THEMIS-E was a bit slower than usual, but also about twice as dense as typical solar wind — observations also confirmed by NASA’s Advanced Composition Explorer and Wind spacecraft, which orbit further upstream between the Sun and Earth.

Related links:

Hinode (Solar B):

IRIS (Interface Region Imaging Spectrograph):

SDO (Solar Dynamics Observatory):

THEMIS (Time History of Events and Macroscale Interactions During Substorms):

Parker Solar Probe:

Image (mentioned), Animations (mentioned), Videos (mentioned), Text, Credits: NASA/GSFC/By Sarah Frazier.


Comet Catalina Suggests Comets Delivered Carbon to Rocky Planets


NASA & DLR - SOFIA Mission patch.

Mar 5, 2021

In early 2016, an icy visitor from the edge of our solar system hurtled past Earth. It briefly became visible to stargazers as Comet Catalina before it slingshot past the Sun to disappear forevermore out of the solar system.

Among the many observatories that captured a view of this comet, which appeared near the Big Dipper, was the Stratospheric Observatory for Infrared Astronomy, NASA’s telescope on an airplane. Using one of its unique infrared instruments, SOFIA was able to pick out a familiar fingerprint within the dusty glow of the comet’s tail – carbon.

Now this one-time visitor to our inner solar system is helping explain more about our own origins as it becomes apparent that comets like Catalina could have been an essential source of carbon on planets like Earth and Mars during the early formation of the solar system. New results from SOFIA, a joint project of NASA and the German Aerospace Center, were published recently in the Planetary Science Journal:

Image above: Illustration of a comet from the Oort Cloud as it passes through the inner solar system with dust and gas evaporating into its tail. SOFIA’s observations of Comet Catalina reveal that it’s carbon-rich, suggesting that comets delivered carbon to the terrestrial planets like Earth and Mars as they formed in the early solar system. Image Credits: NASA/SOFIA/Lynette Cook.

“Carbon is key to learning about the origins of life,” said the paper’s lead author, Charles “Chick” Woodward, an astrophysicist and professor at the University of Minnesota’s Minnesota Institute of Astrophysics, in Minneapolis. “We’re still not sure if Earth could have trapped enough carbon on its own during its formation, so carbon-rich comets could have been an important source delivering this essential element that led to life as we know it.”

Frozen in Time

Originating from the Oort Cloud at the farthest reaches of our solar system, Comet Catalina and others of its type have such long orbits that they arrive on our celestial doorstep relatively unaltered. This makes them effectively frozen in time, offering researchers rare opportunities to learn about the early solar system from which they come.

SOFIA’s infrared observations were able to capture the composition of the dust and gas as it evaporated off the comet, forming its tail. The observations showed that Comet Catalina is carbon-rich, suggesting that it formed in the outer regions of the primordial solar system, which held a reservoir of carbon that could have been important for seeding life.

While carbon is a key ingredient of life, early Earth and other terrestrial planets of the inner solar system were so hot during their formation that elements like carbon were lost or depleted. While the cooler gas giants like Jupiter and Neptune could support carbon in the outer solar system, Jupiter’s jumbo size may have gravitationally blocked carbon from mixing back into the inner solar system. So how did the inner rocky planets evolve into the carbon-rich worlds that they are today?

Primordial Mixing

Researchers think that a slight change in Jupiter’s orbit allowed small, early precursors of comets to mix carbon from the outer regions into the inner regions, where it was incorporated into planets like Earth and Mars. Comet Catalina’s carbon-rich composition helps explain how planets that formed in the hot, carbon-poor regions of the early solar system evolved into planets with the life-supporting element.

“All terrestrial worlds are subject to impacts by comets and other small bodies, which carry carbon and other elements,” said Woodward. “We are getting closer to understanding exactly how these impacts on early planets may have catalyzed life.”

Observations of additional new comets are needed to learn if there are many other carbon-rich comets in the Oort Cloud, which would further support that comets delivered carbon and other life-supporting elements to the terrestrial planets.

Boeing 747P bay door telescope opening. Animation Credit: NASA

SOFIA is a joint project of NASA and the German Aerospace Center. NASA’s Ames Research Center in California’s Silicon Valley manages the SOFIA program, science, and mission operations in cooperation with the Universities Space Research Association, headquartered in Columbia, Maryland, and the German SOFIA Institute at the University of Stuttgart. The aircraft is maintained and operated by NASA’s Armstrong Flight Research Center Building 703, in Palmdale, California.

Related links:



Image (mentioned), Animation (mentioned), Text, Credits: NASA/Kassandra Bell/Elizabeth Landau/Ames Research Center/Alison Hawkes.

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Space Station Science Highlights: Week of March 1, 2021


ISS - Expedition 64 Mission patch.

Mar 5, 2021

The week of March 1, crew members aboard the International Space Station conducted a number of scientific experiments, including a demonstration of water recovery technology, analyzing how gravity affects cell gene expression, and testing new cooling technology for spacesuits.

International Space Station (ISS). Animation Credit: ESA

The seven crew members currently inhabiting the station include four from NASA’s Commercial Crew Program, providing increased crew time for science activities on the orbiting lab. The space station has been continuously inhabited by humans for 20 years and has supported many scientific breakthroughs during that time. The station provides a platform for long-duration research in microgravity and for learning to live and work in space, experience that supports Artemis, NASA’s program to go forward to the Moon and on to Mars.

Here are details on some of the microgravity investigations currently taking place:

Improving water recovery

Image above: The Brine Processor Assembly (BPA), which uses a dual-membrane bladder to recover additional available water from urine. Image Credits: NASA/Robert Markowitz.

The space station’s Environmental Control and Life Support System (ECLSS) includes a Water Recovery System that provides clean water for astronaut use by recycling urine; condensate from crew sweat, respiration, and hygiene; and water recovered from the Air Revitalization System. Part of this system, the Urine Processor Assembly, recovers 87% of water from urine. The Brine Processor System (BPS) demonstrates technology to purify and recover a higher percentage of available water from urine, which will be necessary on long-duration exploration missions. This technology ultimately could help scientists build better systems for future Moon and Mars missions and habitats. During the week, crew members worked on installing the BPS.

Examining gravity’s effect on gene translation changes

The crew conducted operations during the week in support of the Ribosome Profiling experiment from the Japan Aerospace Exploration Agency (JAXA). In 4 billion years or so of life on Earth, living things have evolved to function in Earth’s gravity. However, scientists are not sure how cells use gravity in gene expression. This investigation uses a technique called ribosome profiling to evaluate genome-wide changes in gene translation in cell cultures in microgravity. Results could provide insight into how gravity affects gene expression.

Designing a cooler space suit

Image above: Set up on the space station for the SERFE investigation, which demonstrates a technology using evaporation of water to remove heat from spacesuits. Image Credit: NASA.

SERFE demonstrates a technology using evaporation of water to remove heat from spacesuits and maintain appropriate temperatures for crew members and equipment during space walks. The investigation determines whether microgravity affects performance of the technology and evaluates its effect on contamination and corrosion of spacesuit material. During the week, crew members visually checked a SERFE water sample after approximately 48 hours of incubation and reported observations to the ground.

Other investigations on which the crew performed work:

Image above: NASA astronaut Shannon Walker sets up hardware for the PBRE investigation, which explores how liquids and gases behave together in microgravity. Results may enable design of more energy efficient and lightweight thermal management and life support systems for future space exploration missions. Image Credit: NASA.

- The Packed Bed Reactor Experiment-Water Recovery (PBRE-WR) investigation examines flow rates of gas and liquid through filters in the space station water processor.

- A-HoSS demonstrates software to modify the Hybrid Electronic Radiation Assessor (HERA), the primary radiation detection system for Orion and certified for flight on Artemis 2, to operate on the space station. The investigation provides an opportunity to evaluate this hardware in the space radiation environment prior to the Artemis 2 flight.

- RTPCG-2 demonstrates new methods for producing high-quality crystals for up to eight proteins for detailed analysis on Earth. Previous work has shown that microgravity produces high-quality protein crystals that can be analyzed to identify possible targets for drugs to treat disease.

- Mochii is a miniature scanning electron microscope with spectroscopy capabilities that can conduct real-time, on-site imaging of particles on the space station and measure their composition. Small and microscopic particles can cause vehicle and equipment malfunctions and threaten crew health.

- Antimicrobial Coatings tests a coating to control microbial growth on several different materials that represent high-touch surfaces. Some microbes change characteristics in microgravity, potentially creating new risks to crew health and spacecraft.

- Food Acceptability looks at how the appeal of food changes during long-duration missions. Whether crew members like and actually eat foods directly affects caloric intake and associated nutritional benefits.

- ISS Ham Radio gives students in schools, camps, museums and planetariums around the world the opportunity to converse with astronauts on the space station. To date, more than 1,300 organizations from 63 countries have contacted the space station using ham radio.

Image above: The city lights of Montreal as seen from the International Space Station as it orbits 262 miles above Quebec, Canada. Image Credit: NASA.

- Sally Ride EarthKAM allows students to remotely control a digital camera on the space station to take photographs of features and phenomena on Earth. The EarthKAM team posts the students’ images online for the public and participating classrooms to view.

Related links:

Expedition 64:

Brine Processor System (BPS):

Ribosome Profiling:


ISS National Lab:

Spot the Station:

Space Station Research and Technology:

International Space Station (ISS):

Images (mentioned), Animation (mentioned), Text, Credits: NASA/Michael Johnson/John Love, ISS Research Planning Integration Scientist Expedition 64.

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Hubble Beholds a Big, Beautiful Blue Galaxy


NASA - Hubble Space Telescope patch.

Mar 5, 2021

NGC 2336 is the quintessential galaxy — big, beautiful, and blue — and it is captured here by the NASA/ESA Hubble Space Telescope. The barred spiral galaxy stretches an immense 200,000 light-years across and is located approximately 100 million light-years away in the northern constellation of Camelopardalis (the Giraffe).

Its spiral arms glitter with young stars, visible in their bright blue light. In contrast, the redder central part of the galaxy is dominated by older stars.

NGC 2336 was discovered in 1876 by German astronomer Wilhelm Tempel, using a 0.28 meter (11 inch) telescope. This Hubble image is so much better than the view Tempel would have had — Hubble’s main mirror is 2.4 meters (7.9 feet) across, nearly 10 times the size of the telescope Tempel used. In 1987, NGC 2336 experienced a Type-Ia supernova, the only observed supernova in the galaxy since its discovery 111 years earlier.

Hubble Space Telescope (HST)

For more information about Hubble, visit:

Text Credits: European Space Agency (ESA)/NASA/Lynn Jenner/GSFC/Claire Andreoli/Image, Animation Credits: ESA/Hubble & NASA, V. Antoniou; Acknowledgment: Judy Schmidt.


Key tests for the Russian-European project ExoMars-2022


ESA & ROSCOSMOS - ExoMars Mission patch.

Mar. 5, 2021

Currently, as part of the continuation of work on the Russian-European project ExoMars-2022, a number of key tests are being carried out to confirm the operability of the main elements of the mission. The ExoMars-2022 spacecraft in its entirety: the flight module, the landing module, the Kazachok landing platform and the Rosalind Franklin rover have successfully passed dynamic balancing tests.

Two types of tests were carried out: for a composite vehicle in its entirety and for a landing module with an adapter. Flight prototypes were used in all tests carried out in the finishing chamber at Thales Alenia Space (Cannes, France). During the tests, the composite vehicle and the landing module were rotated at a speed of up to 30 rpm, which corresponds to a centrifugal acceleration of 2g at the outer edge of the airfoil shield of the landing module.

During the flight to Mars, the spacecraft will rotate at a speed of approximately 2.75 rpm to stabilize it on the flight path. Dynamic balancing tests are needed to check that there is no imbalance that can lead to unstable motion of the vehicle in space, which entails too much fuel consumption to compensate for the imbalance. In addition, balance is important to maintain the antenna pointing to the ground and to be able to provide robust radio communications. After the drop of the landing module, approximately 30 minutes before entering the atmosphere of Mars, the initial rotation speed will be maintained until atmospheric effects take effect and the first parachute is deployed. A complete stop of rotation will occur at the moment of turning on the propulsion system of the landing platform near the surface of Mars.

In mid-March 2021, after the completion of field tests, ExoMars-2022 will return to the Thales Alenia Space campaign (Turin, Italy) for further functional tests. Also in preparation for the trip to Mars, the Rosalind Franklin test model in the finishing chamber (Rover Control Center in Turin) for the first time performed test work from the scientific program, including work with soil samples and close-up photography. Using a test model, the rover operators simulate the Rosalind Franklin rover's complex of actions during an interplanetary flight, landing on Mars, and also during the first days after landing.

Soon, the test mock will move to a site in the Mars Rover Control Center, simulating the terrain of Mars, for training motion commands and other functional tests. The Rosalind Franklin rover is installed on the Kazachok landing platform. NPO Lavochkina (part of the Roscosmos State Corporation) is the developer and manufacturer of the landing platform and the landing module for the ExoMars-2022 mission. The landing module provides a soft landing on the surface of Mars.

A new parachute system test strategy has been developed to ensure a launch into the launch window in 2022. It involves the manufacture of new parachutes by Airborne Systems, which helped NASA to carefully deliver the Perseverance rover to the surface of Mars in February 2021. Tests are scheduled for May-June 2021 in Sweden and February-March 2022 in the United States.

ExoMars spacecraft composite in dynamic balancing test

The ExoMars-2022 mission is the second stage of the largest joint project of the Roscosmos State Corporation and the European Space Agency (ESA) for the exploration of the surface and subsurface layer of Mars in the immediate vicinity of the landing site, conducting geological research and searching for traces of the possible existence of life on the planet. The launch of the mission is scheduled within the "astronomical window" in September-October 2022.

ROSCOSMOS Press Release:


Images, Text, Credits: ROSCOSMOS/ESA/Thales-Alenia/ Aerospace/Roland Berga.

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