TL;DR
- Astronomers have discovered and studied in detail the most distant source of radio emission known to date. The source is a ‘radio-loud’ quasar — a bright object with powerful jets emitting at radio wavelengths — that is so far away its light has taken 13 billion years to reach us. The discovery could provide important clues to help astronomers understand the early Universe.
- Researchers are taking scientific inspiration from an unlikely source: the biblical tale of Noah’s Ark. Rather than two of every animal, however, his solar-powered ark on the moon would store cryogenically frozen seed, spore, sperm and egg samples from 6.7 million Earth species. The proposed structure would be built within the moon’s enormous, underground lava tubes, which have been untouched for billions of years.
- 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.
- Comet Catalina 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.
- In the new study, researchers analyzed the composition of solar energetic particles heading towards Earth, and found they had the same ‘fingerprint’ as plasma located low in the Sun’s corona, close to the middle region of the Sun’s atmosphere, the chromosphere.
- A newly discovered planet could be our best chance yet of studying rocky planet atmospheres outside the solar system, a new international study involving UNSW Sydney shows.
- Red supergiants are a class of stars that end their lives in supernova explosions. Their life cycles are not fully understood, partly due to difficulties in measuring their temperatures. For the first time, astronomers develop an accurate method to determine the surface temperatures of red supergiants.
- Researchers have introduced a new method for taking high-resolution images of fast-moving and rotating objects in space, such as satellites or debris in low Earth orbit. They created an imaging process that first utilizes a novel algorithm to estimate the speed and angle at which an object in space is rotating, then applies those estimates to develop a high-resolution picture of the target.
- Until now, researchers have found no evidence of global tectonic activity on planets outside our solar system. Scientists have now found that the material inside planet LHS 3844b flows from one hemisphere to the other and could be responsible for numerous volcanic eruptions on one side of the planet.
- NASA hikes prices for commercial ISS users.
- SpaceX launched a prototype of its Starship next-generation vehicle March 3, landing it safely only to have the vehicle explode minutes later.
- Deployment of 60 Starlink satellites confirmed.
- Space Force planning for a future of smaller, cheaper satellites.
- Upcoming industry events. And more!
Space industry in numbers
Last summer, the Space Foundation published the second-quarter findings of its 2019 issue of The Space Report, revealing that:
- The global space economy grew 8.1% in 2018 to USA 414.75 billion, exceeding USD 400 billion for the first time.
- Global launches in 2018 increased by 46% over the number of launches a decade ago.
- Global launches in 2018 exceeded 100 for the first time since 1990.
Analysts at Morgan Stanley and Goldman Sachs have predicted that economic activity in space will become a multi-trillion-dollar market in the coming decades. Morgan Stanley’s Space Team estimates that the roughly USD 350 billion global space industry could surge to over USD 1 trillion by 2040.
Source: Satellite Industry Association, Morgan Stanley Research, Thomson Reuters. *2040 estimates
Space industry news
Falcon 9 launches Starlink satellites, lands booster
SpaceX launches and lands Starship prototype, which later explodes
China, Russia enter MoU on international lunar research station
NASA confirms plan to fly astronaut on upcoming Soyuz mission
Blue Origin to simulate lunar gravity on suborbital flights for NASA
MEV-2 servicer closing in on Intelsat-10–02 docking attempt
Startup using Soviet-era technology to build satellite servicing vehicle
Space Force awards ULA, SpaceX contracts for four national security missions
RUAG International transforms into space-focused ‘beyond gravity’
Vega rocket passes readiness review for April return to flight
Japan budgets a record $4.14 billion for space activities
Momentus founders to divest shares after Defense Department concerns
China rolls out out new Long March 7A for second launch attempt
Georgia spaceport proponents upbeat despite latest delay
SpaceX takes aim at satellite mobility operators with Starlink expansion
Telespazio reshapes for emerging space integration opportunities
Space Force planning for a future of smaller, cheaper satellites
NSF report estimates Arecibo cleanup cost at up to $50 million
Lawmakers ask Biden administration to keep oversight committees in the loop on space activities
Linquest gets $500 million contract from U.S. Space Force for analysis support
Whitesides steps down from Virgin Galactic
Space Force sounding rocket launches experiment to study Earth’s ionosphere
NASA hikes prices for commercial ISS users
DoD space agency to award multiple contracts for up to 150 satellites
S. Korea’s Kencoa Aerospace expands space business in U.S. with new capital
Biden’s first strategic guidance sets broad national security priorities
Delayed Indonesian broadband satellite SATRIA fully funded
Foust Forward | Will Jeff Bezos kick-start Blue Origin? Does he need to?
Raymond: Space Force ‘not a political issue’
Space exploration
The Discovery of a Highly Accreting, Radio-loud Quasar at z = 6.82
by Eduardo Bañados, Chiara Mazzucchelli, Emmanuel Momjian, Anna-Christina Eilers, Feige Wang, Jan-Torge Schindler, Thomas Connor, Irham Taufik Andika, Aaron J. Barth, Chris Carilli, Frederick B. Davies, Roberto Decarli, Xiaohui Fan, Emanuele Paolo Farina, Joseph F. Hennawi, Antonio Pensabene, Daniel Stern, Bram P. Venemans, Lukas Wenzl, Jinyi Yang in The Astrophysical Journal
With the help of the European Southern Observatory’s Very Large Telescope (ESO’s VLT), astronomers have discovered and studied in detail the most distant source of radio emission known to date. The source is a “radio-loud” quasar — a bright object with powerful jets emitting at radio wavelengths — that is so far away its light has taken 13 billion years to reach us. The discovery could provide important clues to help astronomers understand the early Universe.
Quasars are very bright objects that lie at the centre of some galaxies and are powered by supermassive black holes. As the black hole consumes the surrounding gas, energy is released, allowing astronomers to spot them even when they are very far away.
The newly discovered quasar, nicknamed P172+18, is so distant that light from it has travelled for about 13 billion years to reach us: we see it as it was when the Universe was just around 780 million years old. While more distant quasars have been discovered, this is the first time astronomers have been able to identify the telltale signatures of radio jets in a quasar this early on in the history of the Universe. Only about 10% of quasars — which astronomers classify as “radio-loud” — have jets, which shine brightly at radio frequencies.
P172+18 is powered by a black hole about 300 million times more massive than our Sun that is consuming gas at a stunning rate. “The black hole is eating up matter very rapidly, growing in mass at one of the highest rates ever observed,” explains astronomer Chiara Mazzucchelli, Fellow at ESO in Chile, who led the discovery together with Eduardo Bañados of the Max Planck Institute for Astronomy in Germany.
The astronomers think that there’s a link between the rapid growth of supermassive black holes and the powerful radio jets spotted in quasars like P172+18. The jets are thought to be capable of disturbing the gas around the black hole, increasing the rate at which gas falls in. Therefore, studying radio-loud quasars can provide important insights into how black holes in the early Universe grew to their supermassive sizes so quickly after the Big Bang.
“I find it very exciting to discover ‘new’ black holes for the first time, and to provide one more building block to understand the primordial Universe, where we come from, and ultimately ourselves,” says Mazzucchelli.
P172+18 was first recognised as a far-away quasar, after having been previously identified as a radio source, at the Magellan Telescope at Las Campanas Observatory in Chile by Bañados and Mazzucchelli. “As soon as we got the data, we inspected it by eye, and we knew immediately that we had discovered the most distant radio-loud quasar known so far,” says Bañados.
However, owing to a short observation time, the team did not have enough data to study the object in detail. A flurry of observations with other telescopes followed, including with the X-shooter instrument on ESO’s VLT, which allowed them to dig deeper into the characteristics of this quasar, including determining key properties such as the mass of the black hole and how fast it’s eating up matter from its surroundings. Other telescopes that contributed to the study include the National Radio Astronomy Observatory’s Very Large Array and the Keck Telescope in the US.
While the team are excited about their discovery, to appear in The Astrophysical Journal, they believe this radio-loud quasar could be the first of many to be found, perhaps at even larger cosmological distances. “This discovery makes me optimistic and I believe — and hope — that the distance record will be broken soon,” says Bañados.
Observations with facilities such as ALMA, in which ESO is a partner, and with ESO’s upcoming Extremely Large Telescope (ELT) could help uncover and study more of these early-Universe objects in detail.
More information here:
Engineers propose solar-powered lunar ark as ‘modern global insurance policy’
by University of Arizona College of Engineering
University of Arizona researcher Jekan Thanga is taking scientific inspiration from an unlikely source: the biblical tale of Noah’s Ark. Rather than two of every animal, however, his solar-powered ark on the moon would store cryogenically frozen seed, spore, sperm and egg samples from 6.7 million Earth species.
Thanga and a group of his undergraduate and graduate students outline the lunar ark concept, which they call a “modern global insurance policy,” in a paper presented over the weekend during the IEEE Aerospace Conference.
“Earth is naturally a volatile environment,” said Thanga, a professor of aerospace and mechanical engineering in the UArizona College of Engineering. “As humans, we had a close call about 75,000 years ago with the Toba supervolcanic eruption, which caused a 1,000-year cooling period and, according to some, aligns with an estimated drop in human diversity. Because human civilization has such a large footprint, if it were to collapse, that could have a negative cascading effect on the rest of the planet.”
Climate change, he added, is another concern: If sea levels continue to rise, many dry places will go underwater — including the Svalbard Seedbank, a structure in Norway that holds hundreds of thousands of seed samples to protect against accidental loss of biodiversity. Thanga’s team believes storing samples on another celestial body reduces the risk of biodiversity being lost if one event were to cause total annihilation of Earth.
Totally Tubular
Scientists discovered a network of about 200 lava tubes just beneath the moon’s surface in 2013. These structures formed billions of years ago, when streams of lava melted their way through soft rock underground, forming underground caverns. On Earth, lava tubes are often similar in size to subway tunnels, and can be eroded by earthquakes, plate tectonics and other natural processes. This network of lunar lava tubes are about 100 meters in diameter. Untouched for an estimated 3 billion to 4 billion years, they could provide shelter from solar radiation, micrometeorites and surface temperature changes.
The idea of developing a lunar base, or human settlement on the moon, has been around for hundreds of years, and the lava tube discovery renewed the space community’s enthusiasm for the concept. But the moon isn’t exactly a hospitable environment where humans can spend extended periods. There isn’t water or breathable air, and it’s about minus 25 degrees Celsius, or minus 15 degrees Fahrenheit. It’s also not a very eventful place.
On the other hand, those same features make it a great place to store samples that need to stay very cold and undisturbed for hundreds of years at a time.
Building a lunar ark is no small undertaking, but, based on some “quick, back-of-the-envelope calculations,” Thanga said it’s not as overwhelming as it may sound. Transporting about 50 samples from each of 6.7 million species would require about 250 rocket launches. It took 40 rocket launches to build the International Space Station.
“It’s not crazy big,” Thanga said. “We were a little bit surprised about that.”
Cryogenics and Quantum Levitation
The mission concept builds on another project Thanga and his group previously proposed, in which miniature flying and hopping robots called SphereX enter a lava tube in teams. There, they would collect samples of regolith, or dust and loose rock, and gather information about the layout, temperature and makeup of the lava tubes. This information could inform the construction of the lunar base.
The team’s model for the underground ark includes a set of solar panels on the moon’s surface that would provide electricity. Two or more elevator shafts would lead down into the facility, where petri dishes would be housed in a series of cryogenic preservation modules. An additional goods elevator shaft would be used to transport construction material so that the base can be expanded inside the lava-tubes.
To be cryopreserved, the seeds must be cooled to minus 180 C (minus 292 F) and the stem cells kept at minus 196 C (minus 320 F). As a reference for just how cold this is, the Pfizer COVID-19 vaccine must be stored at minus 70 C, or minus 94 F. The fact that the lava tubes are so cold, and the samples must be even colder, means there’s a risk the metal parts of the base could freeze, jam or even cold-weld together. On Earth, commercial airlines stop working when ground temperatures reach minus 45 to minus 50 C (minus 49 to minus 58 F).
However, there’s a way to take advantage of the extreme temperatures by using an otherworldly phenomenon called quantum levitation. In this process, a cryo-cooled superconductor material — or a material that transfers energy without losing any heat, like a traditional cable does — floats above a powerful magnet. The two pieces are locked together at a fixed distance, so wherever the magnet goes, the superconductor follows.
“It’s like they’re locked in place by strings, but invisible strings,” Thanga said. “When you get to cryogenic temperatures, strange things happen. Some of it just looks like magic but is based on tried and laboratory-tested physics principles at the edge of our understanding.”
The team’s ark design uses this phenomenon to make the shelves of samples float above metal surfaces and have robots navigate through the facility above magnetic tracks.
There is much more research to be done on how to build and operate the ark, from investigating how the preserved seeds might be affected by a lack of gravity to fleshing out a plan for base communications with Earth.
“What amazes me about projects like this is that they make me feel like we are getting closer to becoming a space civilization, and to a not-very-distant future where humankind will have bases on the moon and Mars,” said Álvaro Díaz-Flores Caminero, a UArizona doctoral student leading the thermal analysis for the project. “Multidisciplinary projects are hard due to their complexity, but I think the same complexity is what makes them beautiful.”
NASA’s Perseverance Drives on Mars’ Terrain for First Time
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.
“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.”
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.
“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.”
“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.
The Coma Dust of Comet C/2013 US10 (Catalina): A Window into Carbon in the Solar System
by Charles E. Woodward, Diane H. Wooden, David E. Harker, Michael S. P. Kelley, Ray W. Russell, Daryl L. Kim in The Planetary Science Journal
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 slingshotted 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 (SOFIA), 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.
“Carbon is key to learning about the origins of life,” said the paper’s lead author, Charles “Chick” Woodward, an astrophysicist and professor in the University of Minnesota Twin Cities Minnesota Institute of Astrophysics. “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.
Primordial Mixing
So how did the inner rocky planets evolve into the carbon-rich worlds that they are today?
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,” Woodward said. “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. As the world’s largest airborne observatory, SOFIA’s mobility allows it to quickly observe newly discovered comets as they make a pass through the solar system.
The source of the major solar energetic particle events from super active region 11944
by David H. Brooks, Stephanie L. Yardley in Science Advances
The source of potentially hazardous solar particles, released from the Sun at high speed during storms in its outer atmosphere, has been located for the first time by researchers at UCL and George Mason University, Virginia, USA.
These particles are highly charged and, if they reach Earth’s atmosphere, can potentially disrupt satellites and electronic infrastructure, as well as pose a radiation risk to astronauts and people in airplanes. In 1859, during what’s known as the Carrington Event, a large solar storm caused telegraphic systems across Europe and America to fail. With the modern world so reliant on electronic infrastructure, the potential for harm is much greater.
To minimise the danger, scientists are seeking to understand how these streams of particles are produced so they can better predict when they might affect Earth.
In the new study, researchers analysed the composition of solar energetic particles heading towards Earth, and found they had the same “fingerprint” as plasma located low in the Sun’s corona, close to the middle region of the Sun’s atmosphere, the chromosphere.
Co-author Dr Stephanie Yardley (UCL Mullard Space Science Laboratory, MSSL) said: “In our study we have observed for the first time exactly where solar energetic particles come from on the Sun. Our evidence supports theories that these highly charged particles originate from plasma that has been held down low in the Sun’s atmosphere by strong magnetic fields. These energetic particles, once released, are then accelerated by eruptions that travel at a speed of a few thousand kilometres a second.
“Energetic particles can arrive at Earth very quickly, within several minutes to a few hours, with these events lasting for days. Currently, we can only provide forecasts of these events as they are taking place, as it is highly challenging to predict these events before they occur. By understanding the Sun’s processes better we can improve forecasts so that, when a major solar storm hits, we have time to act to reduce risks.”
Lead author Dr David Brooks (George Mason University and Honorary Associate Professor at UCL MSSL) said:
“Our observations provide a tantalising glimpse into where the material that produces solar energetic particles comes from in a few events from the last solar cycle. We are now starting a new solar cycle, and once it gets going we will use the same techniques to see if our results are generally true, or if these events are somehow unusual.
“We are lucky in that our understanding of the mechanisms behind solar storms and solar energetic particles is likely to advance quickly over coming years thanks to data that will be gained from two spacecraft — ESA’s Solar Orbiter and the NASA Parker Solar Probe — that are heading closer to the Sun than any spacecraft has been before.”
In the study, researchers used measurements from NASA’s Wind satellite, located between the Sun and Earth, to analyse a series of solar energetic particle streams, each lasting at least a day, in January 2014. They compared this to spectroscopy data from the JAXA-led Hinode spacecraft. (The EUV Imaging Spectrometer onboard the spacecraft was built by UCL MSSL and Dr Brooks is a member of the mission’s Operations Team in Japan.)
They found that the solar energetic particles measured by the Wind satellite had the same chemical signature — an abundance of silicon compared to sulphur — as plasma confined close to the top of the Sun’s chromosphere. These locations were at the “footpoints” of hot coronal loops — that is, at the bottom of loops of magnetic field and plasma extending out into the Sun’s outer atmosphere and back again.
Using a new technique, the team measured the coronal magnetic field strength at these footpoints, and found it was very high, in the region of 245 to 550 Gauss, confirming the theory that the plasma is held down in the Sun’s atmosphere by strong magnetic fields ahead of its release into space.
Solar energetic particles are released from the Sun and are accelerated by solar flares (large explosions) or coronal mass ejections — ejections of huge clouds of plasma and magnetic field. About 100 solar energetic particle events occur every 11-year solar cycle, although this number varies from cycle to cycle.
The latest findings support the idea that some solar energetic particles originate from a different source than the slow solar wind (the origin of which is still debated), as they are confined in specific conditions in hot coronal loops at the core of the source region. A faster solar wind is emitted continuously by the Sun; its encounter with the Earth’s atmosphere can generate the Northern Lights.
The high-energy particles released in January 2014 came from a volatile region of the Sun which had frequent solar flares and CMEs, and an extremely strong magnetic field. The region, known as 11944, was one of the largest active regions on the Sun at the time and was visible to observers on Earth as a sunspot — a dark spot on the surface of the sun.
A strong radiation storm alert was issued at the time by the NOAA / NWS Space Weather Prediction Center but the solar energetic particle event is not known to have caused any disruption within the Earth’s atmosphere, although computer systems on the Hinode spacecraft itself recorded several particle hits.
A measurement was taken of the magnetic field strength within the region 11944 in a separate study shortly after this time-period, and was one of the highest ever recorded in the Sun — 8.2kG.
A nearby transiting rocky exoplanet that is suitable for atmospheric investigation
by T. Trifonov, J. A. Caballero, J. C. Morales, A. Seifahrt, I. Ribas, A. Reiners, J. L. Bean, R. Luque, H. Parviainen, E. Pallé, S. Stock, M. Zechmeister, P. J. Amado, G. Anglada-Escudé, M. Azzaro, T. Barclay, V. J. S. Béjar, P. Bluhm, N. Casasayas-Barris, C. Cifuentes, et al. in Science
A newly discovered planet could be our best chance yet of studying rocky planet atmospheres outside the solar system, a new international study involving UNSW Sydney shows.
The planet, called Gliese 486b (pronounced Glee-seh), is a ‘super-Earth’: that is, a rocky planet bigger than Earth but smaller than ice giants like Neptune and Uranus. It orbits a red dwarf star around 26 light-years away, making it a close neighbour — galactically speaking.
With a piping-hot surface temperature of 430 degrees Celsius, Gliese 486b is too hot to support human life. But studying its atmosphere could help us learn whether similar planets might be habitable for humans — or if they’re likely to hold other signs of life.
“This is the kind of planet we’ve been dreaming about for decades,” says Dr Ben Montet, an astronomer and Scientia Lecturer at UNSW Science and co-author of the study. “We’ve known for a long time that rocky super-Earths must exist around the nearby stars, but we haven’t had the technology to search for them until recently. This finding has the potential to transform our understanding of planetary atmospheres.”
Like Earth, Gliese 486b is a rocky planet — but that’s where the similarities end.
Our neighbour is 30 per cent bigger and almost three times heavier than Earth. It’s possible that its surface — which is hot enough to melt lead — may even be scattered with glowing lava rivers.
Super-Earths themselves aren’t rare, but Gliese 486b special for two key reasons: firstly, its heat ‘puffs up’ the atmosphere, helping astronomers take atmospheric measurements; and secondly, it’s a transiting planet, which means it crosses over its star from Earth’s perspective — making it possible for scientists to conduct in-depth analysis of its atmosphere.
“Understanding super-Earths is challenging because we don’t have any examples in our backyard,” says Dr Montet. “Gliese 486b is the type of planet we’ll be studying for the next 20 years.”
Lessons from the atmosphere
A planet’s atmosphere can reveal a lot about its ability to support life.
For example, a lack of atmosphere might suggest the planet’s nearby star is volatile and prone to high stellar activity — making it unlikely that life will have a chance to develop. On the other hand, a healthy, long-lived atmosphere could suggest conditions are stable enough to support life.
Both options help astronomers solve a piece of the planetary formation puzzle.
“We think Gliese 486b could have kept a part of its original atmosphere, despite being so close to its red dwarf star,” says Dr Montet. “Whatever we learn about the atmosphere will help us better understand how rocky planets form.”
As a transiting planet, Gliese 486b gives scientists two unique opportunities to study its atmosphere: first when the planet passes in front of its star and a fraction of starlight shines through its atmospheric layer (a technique called ‘transmission spectroscopy’); and then when starlight illuminates the surface of the planet as it orbits around and behind the star (called ‘emission spectroscopy’).
In both cases, scientists use a spectrograph — a tool that splits light according to its wavelengths — to decode the chemical makeup of the atmosphere.
“This is the single best planet for studying emission spectroscopy of all the rocky planets we know,” says Dr Montet. “It’s also the second-best planet to study transmission spectroscopy.”
Life on Gliese 486b
Gliese 486b is a great catch for astronomers — but you wouldn’t want to live there, says Dr Montet.
“With a surface of 430 degrees Celsius, you wouldn’t be able to go outside without some kind of spacesuit,” he says. “The gravity is also 70 per cent stronger than on Earth, making it harder to walk and jump. Someone who weighed 50 kilograms on Earth would feel like they weighed 85 kilograms on Gliese 486b.”
On the plus side, the quick transition of the planet around its star means that interstellar visitors would have a birthday every 36 hours.
They would just need to expect the party to be interrupted.
“The planet is really close to its star, which means you’d really have to watch out for stellar storms,” says Dr Montet. “The impacts could be as innocuous as beautiful aurorae covering the sky, or they could completely wipe out electromagnetic systems.”
But despite these dangers of living on Gliese 486b, Dr Montet says it’s too valuable a planet to cross off our interstellar bucket list just yet.
“If humans are able to travel to other star systems in the future, this is one of the planets that would be on our list,” he says. “It’s so nearby and so different than the planets in our own solar system.”
Narrowing the search for habitable planets
The study was part of the CARMENES project, a consortium of eleven Spanish and German research institutions that look for signs of low-mass planets around red dwarf stars.
Red dwarfs are the most common type of star, making up around 70 per cent of all stars in the universe. They are also much more likely to have rocky planets than Sun-like stars.
Based on these numbers, the best chance for finding life in the universe may be looking around red dwarfs, says Dr Montet — but this comes with a catch.
“Red dwarfs are known to have a lot of stellar activity, like flares and coronal mass ejections,” says Dr Montet. “This kind of activity threatens to destroy a planet’s atmosphere. “Measuring Gliese 486b’s atmosphere will go a long way towards deciding if we should consider looking for signs of life around red dwarfs.”
From an Aussie backyard to NASA
The findings were made possible using data from NASA’s all-sky survey called the Transiting Exoplanet Survey Satellite (TESS) mission and telescopes in Spain, USA, Chile and Hawaii.
Almost 70 people were involved in the study, including two Australians: Dr Montet from UNSW Science, and Thiam-Guan (TG) Tan, a citizen astronomer who built an observatory in his own backyard in Perth. Mr Tan helped confirm the planet by observing a transit of Gliese 486b.
“I built my observatory more than 10 years ago to see if I could participate in the search for planets,” says Mr Tan. “It has been very satisfying to be able to confirm that a bloke in a backyard can contribute to significant discoveries, such as Gliese 486b.”
In addition to Gliese 486b, Mr Tan has helped discover more than 70 planets using his observatory.
“It’s an interesting time in astronomy,” says Dr Montet. “TESS is producing all of this data, but it’s more information than any person or group can look at. “Citizen scientists have an opportunity to get involved in testing astronomical data, whether it’s confirming a planet sighting or looking for transiting planets. These kinds of collaborations between professional and amateur astronomers are really helping advance the scientific field.”
People interested in getting involved in astronomical research can look at the Planet Hunters website, says Dr Montet. TESS data is made available to the community only two months after its collection.
“The easiest way to get involved is to create an account and start looking at TESS data,” he says. “You don’t even need a fancy telescope. “Who knows — you might even be able to find the next Earth-sized planet.”
Effective temperatures of red supergiants estimated from line-depth ratios of iron lines in the YJ bands, 0.97–1.32 μm
by Daisuke Taniguchi, Noriyuki Matsunaga, Mingjie Jian, Naoto Kobayashi, Kei Fukue, Satoshi Hamano, Yuji Ikeda, Hideyo Kawakita, Sohei Kondo, Shogo Otsubo, Hiroaki Sameshima, Keiichi Takenaka and Chikako Yasui in Monthly Notices of the Royal Astronomical Society
Red supergiants are a class of stars that end their lives in supernova explosions. Their life cycles are not fully understood, partly due to difficulties in measuring their temperatures. For the first time, astronomers develop an accurate method to determine the surface temperatures of red supergiants.
Stars come in a wide range of sizes, masses and compositions. Our sun is considered a relatively small specimen, especially when compared to something like Betelgeuse which is known as a red supergiant. Red supergiants are stars over nine times the mass of our sun, and all this mass means that when they die they do so with extreme ferocity in an enormous explosion known as a supernova, in particular what is known as a Type-II supernova.
Type II supernovae seed the cosmos with elements essential for life; therefore, researchers are keen to know more about them. At present there is no way to accurately predict supernova explosions. One piece of this puzzle lies in understanding the nature of the red supergiants that precede supernovae.
Despite the fact red supergiants are extremely bright and visible at great distances, it is difficult to ascertain important properties about them, including their temperatures. This is due to the complicated structures of their upper atmospheres which leads to inconsistencies of temperature measurements that might work with other kinds of stars.
“In order to measure the temperature of red supergiants, we needed to find a visible, or spectral, property that was not affected by their complex upper atmospheres,” said graduate student Daisuke Taniguchi from the Department of Astronomy at the University of Tokyo. “Chemical signatures known as absorption lines were the ideal candidates, but there was no single line that revealed the temperature alone. However, by looking at the ratio of two different but related lines — those of iron — we found the ratio itself related to temperature. And it did so in a consistent and predictable way.”
Taniguchi and his team observed candidate stars with an instrument called WINERED which attaches to telescopes in order to measure spectral properties of distant objects. They measured the iron absorption lines and calculated the ratios to estimate the stars’ respective temperatures. By combining these temperatures with accurate distance measurements obtained by the European Space Agency’s Gaia space observatory, the researchers calculated the stars luminosity, or power, and found their results consistent with theory.
“We still have much to learn about supernovae and related objects and phenomena, but I think this research will help astronomers fill in some of the blanks,” said Taniguchi. “The giant star Betelgeuse (on Orion’s shoulder) could go supernova in our lifetimes; in 2019 and 2020 it dimmed unexpectedly. It would be fascinating if we were able to predict if and when it might go supernova. I hope our new technique contributes to this endeavor and more.”
Hemispheric Tectonics on LHS 3844b
by Tobias G. Meier, Dan J. Bower, Tim Lichtenberg, Paul J. Tackley, Brice-Olivier Demory in The Astrophysical Journal
On Earth, plate tectonics is not only responsible for the rise of mountains and earthquakes. It is also an essential part of the cycle that brings material from the planet’s interior to the surface and the atmosphere, and then transports it back beneath the Earth’s crust. Tectonics thus has a vital influence on the conditions that ultimately make Earth habitable.
Until now, researchers have found no evidence of global tectonic activity on planets outside our solar system. A team of researchers led by Tobias Meier from the Center for Space and Habitability (CSH) at the University of Bern and with the participation of ETH Zurich, the University of Oxford and the National Center of Competence in Research NCCR PlanetS has now found evidence of the flow patterns inside a planet, located 45 light-years from Earth: LHS 3844b.
An extreme contrast and no atmosphere
“Observing signs of tectonic activity is very difficult, because they are usually hidden beneath an atmosphere,” Meier explains. However, recent results suggested that LHS 3844b probably does not have an atmosphere. Slightly larger than Earth and likely similarly rocky, it orbits around its star so closely that one side of the planet is in constant daylight and the other in permanent night — just like the same side of the Moon always faces the Earth. With no atmosphere shielding it from the intense radiation, the surface gets blisteringly hot: it can reach up to 800°C on the dayside. The night side, on the other hand, is freezing. Temperatures there might fall below minus 250°C. “We thought that this severe temperature contrast might affect material flow in the planet’s interior,” Meier recalls.
To test their theory, the team ran computer simulations with different strengths of material and internal heating sources, such as heat from the planet’s core and the decay of radioactive elements. The simulations included the large temperature contrast on the surface imposed by the host star.
Flow inside the planet from one hemisphere to the other
“Most simulations showed that there was only upwards flow on one side of the planet and downwards flow on the other. Material therefore flowed from one hemisphere to the other,” Meier reports. Surprisingly, the direction was not always the same. “Based on what we are used to from Earth, you would expect the material on the hot dayside to be lighter and therefore flow upwards and vice versa,” co-author Dan Bower at the University of Bern and the NCCR PlanetS explains. Yet, some of the teams’ simulations also showed the opposite flow direction. “This initially counter-intuitive result is due to the change in viscosity with temperature: cold material is stiffer and therefore doesn’t want to bend, break or subduct into the interior. Warm material, however, is less viscous — so even solid rock becomes more mobile when heated — and can readily flow towards the planet’s interior,” Bower elaborates. Either way, these results show how a planetary surface and interior can exchange material under conditions very different from those on Earth.
A volcanic hemisphere
Such material flow could have bizarre consequences. “On whichever side of the planet the material flows upwards, one would expect a large amount of volcanism on that particular side,” Bower points out. He continues “similar deep upwelling flows on Earth drive volcanic activity at Hawaii and Iceland.” One could therefore imagine a hemisphere with countless volcanoes — a volcanic hemisphere so to speak — and one with almost none.
“Our simulations show how such patterns could manifest, but it would require more detailed observations to verify. For example, with a higher-resolution map of surface temperature that could point to enhanced outgassing from volcanism, or detection of volcanic gases. This is something we hope future research will help us to understand,” Meier concludes.
Bernese space exploration: With the world’s elite since the first moon landing
When the second man, “Buzz” Aldrin, stepped out of the lunar module on July 21, 1969, the first task he did was to set up the Bernese Solar Wind Composition experiment (SWC) also known as the “solar wind sail” by planting it in the ground of the moon, even before the American flag. This experiment, which was planned and the results analysed by Prof. Dr. Johannes Geiss and his team from the Physics Institute of the University of Bern, was the first great highlight in the history of Bernese space exploration.
Ever since Bernese space exploration has been among the world’s elite. The numbers are impressive: 25 times were instruments flown into the upper atmosphere and ionosphere using rockets (1967–1993), 9 times into the stratosphere with balloon flights (1991–2008), over 30 instruments were flown on space probes, and with CHEOPS the University of Bern shares responsibility with ESA for a whole mission.
Correlation Based Imaging for Rotating Satellites
by Matan Leibovich, George Papanicolaou, Chrysoula Tsogka in SIAM Journal on Imaging Sciences
Litter is not only a problem on Earth. According to NASA, there are currently millions of pieces of space junk in the range of altitudes from 200 to 2,000 kilometers above the Earth’s surface, which is known as low Earth orbit (LEO). Most of the junk consists of objects created by humans, like pieces of old spacecraft or defunct satellites. This space debris can reach speeds of up to 18,000 miles per hour, posing a major danger to the 2,612 satellites that currently operate at LEO. Without effective tools for tracking space debris, parts of LEO may even become too hazardous for satellites.
In a paper, Matan Leibovich (New York University), George Papanicolaou (Stanford University), and Chrysoula Tsogka (University of California, Merced) introduce a new method for taking high-resolution images of fast-moving and rotating objects in space, such as satellites or debris in LEO. They created an imaging process that first utilizes a novel algorithm to estimate the speed and angle at which an object in space is rotating, then applies those estimates to develop a high-resolution picture of the target.
Leibovich, Papanicolaou, and Tsogka used a theoretical model of a space imaging system to construct and test their imaging process. The model depicts a piece of fast-moving debris as a cluster of very small, highly reflective objects that represent the strongly reflective edges of an item in orbit, such as the solar panels on a satellite. The cluster of reflectors all move together with the same speed and direction and rotate about a common center. In the model, multiple sources of radiation on the Earth’s surface — such as the ground control stations of global navigation satellite systems — emit pulses that are reflected by target pieces of space debris. A distributed set of receivers then detects and records the signals that bounce off the targets.
The model focuses on sources that produce radiation in the X-band, or from frequencies of 8 to 12 gigahertz. “It is well known that resolution can be improved by using higher frequencies, such as the X-band,” Tsogka said. “Higher frequencies, however, also result in distortions to the image due to ambient fluctuations from atmospheric effects.” Signals are distorted by turbulent air as they travel from the target to receivers, which can make the imaging of objects in LEO quite challenging. The first step of the authors’ imaging process was thus to correlate the data taken at different receivers, which can help reduce the effects of these distortions.
The diameter of the area encompassed by the receivers is called the physical aperture of the imaging system — in the model, this is about 200 kilometers. Under normal imaging conditions, the physical aperture’s size determines the resolution of the resulting image; a larger aperture begets a sharper picture. However, the quick movement of the imaging target relative to the receivers can create an inverse synthetic aperture, in which the signals that were detected at multiple receivers as the target moved throughout their field of view are synthesized coherently. This configuration can effectively improve the resolution, as if the imaging system had a wider aperture than the physical one.
Objects in LEO can spin on timescales that range from a full rotation every few seconds to every few hundred seconds, which complicates the imaging process. It is thus important to know — or at least be able to estimate — some details about the rotation before developing the image. The authors therefore needed to estimate the parameters related to the object’s rotation before synthesizing the data from different receivers. Though simply checking all of the possible parameters to see which ones yield the sharpest image is technically feasible, doing so would require a lot of computational power. Instead of employing this brute force approach, the authors developed a new algorithm that can analyze the imaging data to estimate the object’s rotation speed and the direction of its axis.
After accounting for the rotation, the next step in the authors’ imaging process was to analyze the data to develop a picture of the space debris that would hopefully be as accurate and well-resolved as possible. One method that researchers often employ for this type of imaging of fast-moving objects is the single-point migration of cross correlations. Though atmospheric fluctuations do not usually significantly impair this technique, it does not have a very high resolution. A different, commonly-used imaging approach called Kirchhoff migration can achieve a high resolution, as it benefits from the inverse synthetic aperture configuration; however, the trade-off is that it is degraded by atmospheric fluctuations. With the goal of creating an imaging scheme that is not too heavily affected by atmospheric fluctuations but still maintains a high resolution, the authors proposed a third approach: an algorithm whose result they call a rank-1 image. “The introduction of the rank-1 image and its resolution analysis for fast-moving and rotating objects is the most novel part of this study,” Leibovich said.
To compare the performance of the three imaging schemes, the authors gave simulated data of a rotating object in LEO to each one and compared the images that they produced. Excitingly, the rank-1 image was much more accurate and well-resolved than the result of single-point migration. It also had similar qualities to the output of the Kirchhoff migration technique. But this result was not entirely surprising, given the problem’s configuration. “It is important to note that the rank-1 image benefits from the rotation of the object,” Papanicolaou said. Though a rotating object generates more complex data, one can actually incorporate this additional information into the image processing technique to improve its resolution. Rotation at certain angles can also increase the size of the synthetic aperture, which significantly improves the resolution for the Kirchhoff migration and rank-1 images.
Further simulations revealed that the rank-1 image is not easily muddled by errors in the new algorithm for the estimation of rotation parameters. It is also more robust to atmospheric effects than the Kirchhoff migration image. If receivers capture data for a full rotation of the object, the rank-1 image can even achieve optimal imaging resolution. Due to its good performance, this new imaging method could improve the accuracy of imaging LEO satellites and space debris. “Overall, this study shed light on a new method for imaging fast-moving and rotating objects in space,” Tsogka said. “This is of great importance for ensuring the safety of the LEO band, which is the backbone of global remote sensing.”
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