Space News & Blog Articles

Exploring exoplanet atmospheres in more detail was one task that planetary scientists anticipated during the long wait while the James Webb Space Telescope (JWST) was in development. Now, their patience is finally paying off. News about discoveries of exoplanet atmosphere using data from JWST seems to be coming from one research group or another almost every week, and this week is no exception. A paper published in Nature by authors from a few dozen institutions describes the atmospheric differences between the “morning” and “evening” sides of a tidally locked planet for the first time.

First, let’s clarify what the “morning” and “evening” sides mean. Tidally locked planets don’t spin, so one hemisphere constantly faces the planet’s star. As such, there is always a part of the planet where it appears to be “morning,” with the star barely peaking over the horizon. Alternatively, there’s a part of the planet where it seems to be “evening,” where the star is again just barely peaking over the horizon, but it would appear to be setting. 

Typically, on Earth, we would think of the morning side as the star peaking over the eastern side, whereas the evening side would see the star setting into the western sky. However, exoplanets sometimes rotate in the opposite direction from planets in our solar system, so that mental model doesn’t always work for them.

The JWST light curve for WASP-34b, clearly showing the dip in the star’s brightness as the planet passes in front of it.
Credit – NASA / ESA / CSA / R. Crawford (STScI)

It’s also important not to confuse the “morning” and “evening” sides with the “day” and “night” sides of the planet. On the day side, the full force of the star affects the planet, but on the night side, the star is never seen at all. The temperature differences on such a planet are massive, and cause much more extreme weather than anything we have experience with in our solar system.

Next time you’re visiting the seaside or a large lake, or even sipping a frosty glass of water, think about where it all originated. There are many pathways that water could have taken to the infant Earth: via comets, “wet asteroids”, and outgassing from early volcanism. Aster Taylor, a University of Michigan graduate student has another idea: dark comets. They’re something of a cross between asteroids and comets and could have played a role in water delivery to our planet.

Dark comets are small Solar System bodies. They have short rotational periods thanks to non-gravitational pushes by sublimation that creates jets. These mysterious objects probably make up more than half of all near-Earth objects.

Planetary scientists consider dark comets as a population of active asteroids. Yet, they aren’t in the same category as regular asteroids and comets. They’re on near-Earth orbits, so when one passes close to the Sun, it doesn’t grow a coma. That lack of a coma is why they’re called “dark comets.” Yet, their sublimation jets appear to be a response to radiation from the Sun. They’re likely rich in water ice so that raises an interesting question. Could these also have been a source of water for Earth in the distant past?

“We don’t know if these dark comets delivered water to Earth,” said Taylor. “But we can say that there is still debate over how exactly the Earth’s water got here,” Taylor said. “The work we’ve done has shown that this is another pathway to get ice from somewhere in the rest of the Solar System to the Earth’s environment.”

The story of how Earth got its water is still unfolding. One theory says infant Earth formed with molecular precursors to water. Another one says that water-laden asteroids and comets brought water to Earth during or just after formation. That’s interesting because most asteroids exist near the so-called “ice line”—a region well beyond Earth where liquids freeze. Something propelled them to the inner solar system. When they got close to the Sun, their ice sublimated. That’s actually what happens with a comet, too. So, maybe both comets and planetesimals were water-bearers during Earth’s formation. Volcanic activity could have released their trapped water as vapor.

The James Webb Space Telescope (JWST) has accomplished some spectacular feats since it began operations in 2021. Thanks to its sensitivity in the near- and mid-infrared wavelengths, it can take detailed images of cooler objects and reveal things that would otherwise go unnoticed. This includes the iconic image Webb took of Jupiter in August 2022, which showed the planet’s atmospheric features (including its polar aurorae and Great Red Spot) in a new light. Using Webb, a team of European astronomers recently observed the region above the Great Red Spot and discovered previously unseen features.

The team was led by Dr. Henrik Melin, an STFC JWST Fellow and Planetary Scientist from the University of Leicester. He was joined by researchers from the University of Reading, the Space Telescope Science Institute (STScI), the JAXA Institute of Space and Astronautical Science, the Center for Space Physics at Boston University, the Observatoire de Paris, the SETI Institute, NASA’s Jet Propulsion Laboratory, and multiple universities. The paper that describes their observations recently appeared in the journal Nature Astronomy.

The team conducted integral field spectroscopy (IFS) of Jupiter’s Great Red Spot using Webb’s Near-InfraRed Spectrograph (NIRSpec) in July 2022. This process involves dissecting an astronomical image into multiple spatial components and dispersing them with a spectrograph to provide spatially resolved information. Their observations were made as part of an Early Release Science program titled “ERS Observations of the Jovian System as a Demonstration of JWST’s Capabilities for Solar System Science.”

Interestingly, the discovery was completely unexpected, as the team attempted to study Jupiter’s upper atmosphere in more detail. Compared to Jupiter’s bright aurorae, the glow from the planet’s ionosphere is weak, making it difficult for ground-based telescopes to conduct detailed observations of this region. Scientists have been especially interested in studying Jupiter’s ionosphere since it is where Jupiter’s atmosphere and magnetic field begin to interact. It is within this layer that Jupiter’s polar aurorae can be seen, which are fueled by material ejected by Io’s many active volcanoes.

Closer to the equator, the structure of the planet’s upper atmosphere is influenced by incoming sunlight. Because Jupiter receives only 4% as much sunlight as Earth, astronomers expected this region of the atmosphere to be homogenous. However, the team was surprised that this region contained intricate wave patterns, including dark arcs, bright spots, and other structures. As Dr. Melin explained in an ESA press release:

Pulsars are the remnants of the explosion of massive stars at the end of their lives. The event is known as a supernova and as they rapidly spin they sweep a high energy beam across the cosmos much like a lighthouse. The alignment of some pulsar beams mean they sweep across Earth predictably and with precise regularity. They can be, and often are used as timing gauges but a team of astronomers have found subtle timing changes in some pulsars hinting at unseen mass between pulsars and telescopes—possibly dark matter entities.

The discovery in 1967 of pulsars has revolutionised our understanding of stellar evolution. The are formed during the collapse of supermassive stars at the end of their life. As the fusion in the core ceases, the inrushing stellar material crashing down onto the core compresses it to incredible density. The material that once made up the star is, through this process compressed into a sphere just a few tens of kilometres across. Pulsars are closely related to neutron stars which are formed though the same process and it is believed, the only difference is that one has a highly energetic beam that flashes across the Earth and one doesn’t. 

A team studying pulsars has recently detected hints of potential dark matter objects through changes in pulsar timing events as they rotate. Professor John LoSecco from the University of Notre Dame, presented at the National Astronomy Meeting at the University of Hull and emphasised the precision of pulsar-based timekeeping. “Science has advanced with precise time measurement methods,” he noted, comparing Earth’s atomic clocks with pulsars in space. While gravitational effects on light have been understood for over a century, their applications in uncovering hidden masses remain largely unexplored until now.

Professor LoSecco and the team noted tiny deviations in the pulsar timing, suggesting that radio waves may be getting redirected around an unseen mass located somewhere between the pulsar and the telescope. LoSecco theorised that the masses could potentially be dark matter! 

By examining the delays and analysing the radio pulse arrivals (which were typically accurate to within a nanosecond) they explored the pathway of radio signals within the latest Parkes Pulsar Timing Array survey. Other telescopes involved in this initiative were the Effelsberg, Nançay, Westerbork, Green Bank, Arecibo, Parkes, and the Lovell telescope in Cheshire. Using this and Parkes data, the pulse arrival times were analysed.

James Webb Space Telescope (JWST) has done it again. A team of astronomers have used it to map the weather on a pair of brown dwarf stars. Infrared light was analysed from the pair and its variation over time was measured. The team were able to generate a 3D picture of the weather and discovered gasses in the atmosphere like water vapour, methane and carbon dioxide. Swirling clouds of hot sand were also found with temperatures reaching as high as 950 C!

Weather on worlds beyond our solar system, is likely to be diverse and extreme. Some, like hot Jupiters (worlds that orbit close to their star and have high temperatures) or even brown dwarfs (failed stars) have temperatures high enough to vaporise metals with winds moving at thousands of kilometres per hour. Others, tidally locked planets, show strong contrasts between their hot, sunlit side and cold, dark side, creating intense atmospheric circulation. Advanced telescopes like JWST and space missions are revealing these weather systems, improving our understanding of planetary science. 

The team studied brown dwarfs, that are part of a binary system known as WISE 1049AB, the brightest and closest of their type to Earth. Brown dwarfs are celestial objects that bridge the gap between the largest planets and the smallest stars, typically ranging from 13 to 80 times the mass of Jupiter. They lack sufficient mass for sustained hydrogen fusion in the core but emit infrared radiation due to residual heat and fusion of deuterium and lithium. The WISE 1049AB system is about six light years away. 

The astronomers observed the light output and how it changed over time to develop a picture of cloudy regions as they rotated into and out of view. This was then visualised as light curves – plots showing how the brightness of each object varies over time. Using this information allowed them to create 3D image of the weather on the objects covering a span of five to seven hours, one day on the brown dwarfs. Not only did they capture and plot light curves but to understand the chemical composition of the atmosphere they explored the different wavelengths of light that were being emitted.

The 3D weather information could help develop a better understanding of brown dwarfs and how they can provide insight into the missing link between planets and stars. The latest study takes previous research work which focussed largely on snapshots of the atmosphere on just one side and expands upon them. Trying to improve the model of atmospheric changes is challenging though because brown dwarfs rotate quickly and the weather can change swiftly. 

Astronauts sometimes struggle to consume enough nutritious food on the ISS because it tastes bland. But astronaut food is of high quality and designed to be palatable and to meet nutrition needs. What’s the problem?

NASA has two facilities devoted to astronaut food: the Space Food Systems Laboratory at Johnson Space Center in Houston and the Space Food Research Facility, also in Texas. Both facilities support the production and development of astronaut food— including menus, packaging, and hardware—for all of NASA’s space programs. There’s even an Advanced Food Research Team looking ahead to future space missions that will travel beyond the ISS and Low-Earth Orbit (LEO).

Astronauts have a variety of foods available to them. Foods range from freeze-dried or dehydrated foods like scrambled eggs and mashed potatoes to “canned” type foods like ravioli and meatloaf to irradiated foods like smoked turkey. They even have unprepared foods like nuts and granola bars.

But despite these dedicated efforts to provide a variety of quality foods with enjoyable tastes, astronauts regularly report that their food tastes bland in space.

Researchers at the Royal Melbourne Institute of Technology (RMIT) University are using Virtual Reality to research the cause of this problem. They’ve published a study in the International Journal of Food Science and Technology that presents their results. Its title is “Smell Perception in Virtual Spacecraft? A Ground-Based Approach to Sensory Data Collection.” The lead researcher is Julia Low from the School of Science at RMIT.

The crew of NASA’s first Mars habitat simulation, CHAPEA 1, exited their Earth-based environment after 378 days on July 6 at 5 p.m. EDT. Greeted by friends, family, mission team members and project directors, the crew of four expressed gratitude and optimism about their time in isolation and the data collected, which will contribute to the future goal of putting boots on Mars.

The egress event at the Johnson Space Center was initiated by Deputy Director Steve Koerner, who expressed sincere gratitude to the team and their families and highlighted the crucial data gathered over the course of the project. The four crew members included Mission Commander Kelly Haston, Flight Engineer Ross Brockwell, Medical Officer Nathan Jones, and Science Officer Anca Selariu. NASA astronaut and Deputy Director of Flight Operations Kjell Lindgren ceremonially opened the habitat door, officially bringing the team out of isolation.

Koerner remarked on the mission’s significance: “Mars is our goal. As global interests and capabilities in space continue to expand, America is poised to lead.” The mission, primarily focused on nutrition-based science but included cross-disciplinary experiments that simulated various aspects of life on Mars. “They’ve been separated from their families, placed on a carefully prescribed meal plan, and undergone a lot of observation. By growing and harvesting their own vegetables, dealing with communication delays and conducting simulated Mars walks, this team has helped us obtain crucial information as we prepare to return to the moon and on to Mars,” Koerner added.

Principal Investigator Grace Douglas reiterated her thanks on behalf of NASA to the team and their families for their incredible sacrifice. “This project has enabled the collection of thousands of data points, yielding a unique and valuable integrated dataset in a Mars-realistic simulation. These data will provide unprecedented insight into how engineers, scientists, and astronauts can work together to achieve mission objectives while maintaining health and performance for the success of future human missions to Mars.”

Douglas also thanked the science, engineering, and mission control teams who worked tirelessly to support the crew and ensure data integrity for mission success. The development of this analogue mission was a unique challenge for the engineering teams. Director of Engineering Julie Kramer White noted, “From working with the teams to outfit the habitat, whether it was Mars walks, robotic operations, or habitat maintenance—planned and unplanned—the analogues are crucial in understanding what it’s going to take and if our architectures will work when plans meet reality.”