Tag: astronomy

Scientists and engineers are ready to fly an infrared mission called EXCITE (EXoplanet Climate Infrared TElescope) to the edge of space.

The NASA EXCITE mission is designed to study atmospheres around exoplanets, or worlds beyond our solar system, during circumpolar long-duration scientific balloon flights.

However, it must first complete a test flight during NASA’s fall 2024 scientific ballooning campaign from Fort Sumner, New Mexico.

“EXCITE can give us a three-dimensional picture of a planet’s atmosphere and temperature by collecting data the whole time the world orbits its star,” said Peter Nagler, the mission’s principal investigator at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

“Only a handful of these types of measurements have been done before. They require a very stable telescope in a position to track a planet for several days at a time.”

NASA EXCITE mission will reveal crucial details about distant planets

The NASA EXCITE mission will study hot Jupiters, giant gas exoplanets that complete an orbit once every one to two days and have temperatures in the thousands of degrees.

The worlds are tidally locked, which means the same side always faces the star.

The telescope will observe how heat is distributed across the planet, from the scalding hemisphere facing the star to the relatively cooler nightside.

It will also determine how molecules in a planet’s atmosphere absorb and emit light over the entire orbit, a process called phase-resolved spectroscopy.

This data can reveal the presence of compounds—like water, methane, carbon dioxide, and others—and how they circulate globally as the planet orbits its star.

“During its first science flight, EXCITE aims to fly for over a dozen days from the Columbia Scientific Balloon Facility’s site in Antarctica,” explained Kyle Helson, an EXCITE team member and a research scientist at the University of Maryland, Baltimore County and NASA Goddard.

“At the pole, the stars we’ll study don’t set, so our observations won’t be interrupted. We hope that the mission will effectively double the number of phase-resolved spectra available to the science community.”

Observing wavelengths with limited interruption

The EXCITE mission will fly to about 132,000 feet via a scientific balloon filled with helium, which puts it above 99.5% of Earth’s atmosphere.

At that altitude, the telescope will be able to observe multiple infrared wavelengths with little interference.

Lee Bernard, an EXCITE team member and a graduate research assistant at Arizona State University in Tempe, said: “The telescope collects the infrared light and beams it into the spectrometer, where it kind of goes through a little obstacle course.

“It bounces off mirrors and through a prism before reaching the detector. Everything must be aligned very precisely — just a few millimetres off centre, and the light won’t make it.”

The spectrometer rests inside a vessel called a cryostat situated behind the telescope. The cryostat cools the spectrometer’s detector — once a flight candidate from Webb’s NIRSpec (Near InfraRed Spectrograph)— to about 350 degrees below zero Fahrenheit so it can measure tiny intensity changes in the infrared light.

Tim Rehm, an EXCITE team member and a graduate research assistant at Brown University, concluded: “It’s great to see the EXCITE mission’s subsystems all assembled and working together. We’re excited to do this test flight, and we’re looking forward to all the future science flights we hope to have.”

A groundbreaking study has identified a novel approach to terraforming Mars, potentially increasing the planet’s temperature by over 50 degrees Fahrenheit.

Researchers from the University of Chicago, Northwestern University, and the University of Central Florida have suggested that engineered dust particles released into the Martian atmosphere could significantly warm the planet, creating conditions more suitable for microbial life—a critical step toward making Mars habitable for humans.

A significant leap in terraforming technology

This new method is over 5,000 times more efficient than previous strategies aimed at terraforming Mars, representing a major advancement in our ability to modify the Martian environment.

Unlike earlier proposals that relied on transporting materials from Earth or mining rare Martian resources, this approach utilises materials already abundant on the Red Planet, making it far more practical and feasible.

Although this method would take decades to implement fully, it offers a more realistic and achievable solution compared to earlier ideas.

The science of Martian warming

The dream of making Mars habitable has inspired scientists and visionaries for decades, but the planet’s average temperature of -80 degrees Fahrenheit has always posed a significant hurdle.

Previous proposals to terraform Mars involved releasing greenhouse gases into its atmosphere, but these methods required either importing vast amounts of material from Earth or extracting scarce substances from the planet—both expensive and technically challenging options.

The new approach, however, leverages the natural resources already present on Mars. Dust on the planet is rich in iron and aluminium, but these particles alone tend to cool the surface rather than warm it.

The researchers hypothesised that by engineering the dust particles into specific shapes, they could trap heat more effectively.

The team designed particles resembling tiny rods—similar in size to glitter—that could enhance Mars’ natural greenhouse effect by scattering sunlight back to the surface and trapping heat.

Implementing the strategy

The study suggests that releasing these engineered particles into Mars’ atmosphere at a rate of 30 litres per second could raise the planet’s temperature by more than 50 degrees Fahrenheit.

This warming effect could be observed within months, and crucially, it could be reversed if needed by halting the release of particles.

According to the team, while millions of tonnes of these particles would be required, the amount is still five thousand times less than what previous methods would have needed, making this approach far more feasible.

Challenges and future directions

Despite the promising findings, the researchers acknowledge that many questions remain unanswered.

A key concern is how long the engineered dust would remain in Mars’ atmosphere. As the planet warms, water vapour could condense around the particles, potentially leading to rain and other unpredictable climate changes.

“Climate feedback is really difficult to model accurately,” explained Edwin Kite, an associate professor of geophysical sciences at the University of Chicago and the corresponding author of the study.

“To implement something like this, we would need more data from both Mars and Earth, and we’d need to proceed slowly and reversibly to ensure the effects work as intended.”

Towards making Mars habitable

While this study focuses on terraforming Mars to create conditions suitable for microbial life and potentially growing crops, the researchers emphasise that generating a breathable atmosphere for humans is still a distant goal.

However, this innovative method could serve as a crucial first step toward future terraforming efforts.

As scientists continue to explore the potential for making Mars habitable, this study offers a significant leap forward, moving the vision of human colonisation of the Red Planet closer to reality.

The newly announced Ariel Data Challenge 2024, led by UCL researchers, is calling on data scientists, astronomers, and AI enthusiasts to help uncover the atmospheres of distant planets.

The competition, based on the European Space Agency’s Ariel space mission and featured at the NeurIPS 2024 machine learning conference, will tackle one of astronomy’s most complex and important data analysis problems—extracting faint exoplanet signals from noisy space telescope observations.

It offers participants a unique chance to contribute to cutting-edge research in the field of exoplanet atmospheres, with a prize pool of $50,000 USD.

Dr Caroline Harper, Head of Space Science, UK Space Agency, said: “Distant planets are likely to be more numerous in our galaxy than the stars themselves.

“The techniques developed through this prestigious competition could help open new windows for us to learn about the composition of their atmospheres and even their weather.”

The atmospheres of distant planets are unique

The discovery of distant planets has transformed our cosmic perspective, challenging conventional notions about the nature of the Solar System, the Earth’s uniqueness and the potential for life elsewhere.

Astronomers are aware of over 5,600 exoplanets as of today. However, detecting these worlds is only the initial step, as scientists seek to further comprehend and characterise their nature by studying their atmospheres.

The European Space Agency’s Ariel Space Mission, whose scientific leadership is provided by UCL’s Professor Giovanna Tinetti, will be launched in 2029 and will complete one of the largest-ever surveys of these planets by observing the atmospheres of around one-fifth of the known exoplanets.

Paul Eccleston, Ariel Mission Consortium Manager, RAL Space, commented: “The Ariel Data Challenge will be incredibly useful for building the payload structural model in the coming months.”

However, observing these atmospheres and deriving their properties is a formidable challenge. These atmospheric signals only account for a minute fraction of the starlight received from the planetary systems and are regularly corrupted by instrument noise.

The Ariel Data Challenge

The Ariel Data Challenge 2024 focuses on overcoming these noise sources, such as ‘jitter noise’ caused by spacecraft vibrations. This noise, along with other disturbances, complicates the analysis of spectroscopic data used to study the atmospheres of distant planets.

With support from the DiRAC HPC Facility, mission scientists have meticulously produced the most accurate representation of Ariel observations to date, based on Ariel’s payload design and incorporating representative noise effects from in-flight data obtained by the James Webb Space Telescope.

Scientists involved in the Ariel mission now seek novel methods to push the boundaries of current data analysis approaches – innovative solutions that can effectively suppress these noise sources and extract vital signals from exoplanet atmospheres.

The competition is open now until late October. Winners will be invited to present their solutions at the NeurIPS conference, with cash prizes available for the top six solutions.

A groundbreaking study has revealed that red dwarf stars can produce stellar flares that carry far-ultraviolet (far-UV) radiation levels much higher than previously believed.

This discovery suggests that the intense UV radiation from stellar flares could significantly impact whether planets around red dwarf stars can be habitable.

“Few stars have been thought to generate enough UV radiation through flares to impact planet habitability. Our findings show that many more stars may have this capability,” said astronomer Vera Berger, who led the study.

Led by current and former astronomers from the University of Hawaiʻi Institute for Astronomy (IfA), the research was recently published in Monthly Notices of the Royal Astronomical Society.

UV from stellar flares presents a double-edged sword

Berger and her team used archival data from the GALEX space telescope to search for stellar flares among 300,000 nearby stars.

“Combining modern computer power with gigabytes of decades-old observations allowed us to search for flares on thousands and thousands of nearby stars,” explained Michael Tucker, a PhD graduate of IfA and now a postdoctoral fellow at Ohio State University.

According to researchers, UV radiation from stellar flares can either erode planetary atmospheres, threatening their potential to support life or contribute to the formation of RNA building blocks, which are essential for the creation of life.

This study challenges existing models of stellar flares and exoplanet habitability. It shows that far-UV emission from flares is, on average, three times more energetic than typically assumed and can reach up to twelve times the expected energy levels.

Benjamin Shappee, an Associate Astronomer at IfA, commented: “A change of three is the same as the difference in UV in the summer from Anchorage to Honolulu, where unprotected skin can get a sunburn in less than ten minutes.”

Hidden causes of stronger UV emissions

The exact cause of this stronger far-UV emission remains unclear. The team believes it might be that flare radiation is concentrated at specific wavelengths, indicating the presence of atoms like carbon and nitrogen.

“This study has changed the picture of the environments around stars less massive than our Sun, which emit very little UV light outside of stellar flares,” concluded Jason Hinkle, a PhD candidate at IfA who co-authored the study.

The researchers said that more data from space telescopes is needed to study the UV light from stars, which is crucial for understanding the source of this emission.