Category: 7. Science

Finding Earth-like planets is nearly impossible because stars drown them out in brightness. Conventional telescope designs fall short, but a proposed rectangular infrared telescope could solve this. It might reveal dozens of promising worlds within 30 light-years, paving the way to spotting signs of life.

Origins of Life and Water’s Role

Earth is the only place we know of that harbors life, and every living thing here depends on liquid water to power essential chemical reactions. Simple, single-celled organisms have been around for nearly as long as the planet itself, but it took about three billion years before more complex, multicellular organisms evolved. Humans, by comparison, have existed for only a tiny fraction of Earth’s history—less than one ten-thousandth of its age.

This timeline suggests that life could arise fairly often on planets where liquid water is present, but intelligent beings capable of exploring the cosmos may be far less common. If we hope to discover life beyond Earth, we may need to reach out to it directly.

Limits of Space Travel and Search Targets

The challenge is that space is unimaginably vast, and the laws of physics prevent us from moving or communicating faster than the speed of light. That restriction means only the nearest stars to our sun could realistically be explored within a human lifetime, even with robotic probes. Among those, the best candidates are stars that closely resemble our sun in size and temperature. Such stars live long enough and remain stable enough to allow complex life to develop.

Currently, astronomers have identified approximately 60 sun-like stars within a distance of roughly 30 light-years from Earth. Planets circling these stars that are similar in size and temperature to Earth, where both solid ground and liquid water might exist, are considered the most promising places to look.

The Overwhelming Brightness of Stars

Observing an Earth-like exoplanet separately from the star it is orbiting around is a major challenge. Even in the best possible scenario, the star is a million times brighter than the planet; if the two objects are blurred together, there is no hope of detecting the planet.

Optics theory says that the best resolution one can get in telescope images depends on the size of the telescope and the wavelength of the observed light. Planets with liquid water give off the most light at wavelengths around 10 microns (the width of a thin human hair and 20 times the typical wavelength of visible light). At this wavelength, a telescope needs to collect light over a distance of at least 20 meters to have enough resolution to separate the Earth from the sun at a distance of 30 light-years.

Additionally, the telescope must be in space, because looking through the Earth’s atmosphere would blur the image too much. However, our largest space telescope – the James Webb Space Telescope (JWST) – is only 6.5 meters in diameter, and that telescope was extremely difficult to launch.

Alternative Telescope Concepts and Challenges

Because deploying a 20-meter space telescope seems out-of-reach with current technology, scientists have explored several alternative approaches. One involves launching multiple, smaller telescopes that maintain extremely accurate distances between them, so that the whole set acts as one telescope with a large diameter. But, maintaining the required spacecraft position accuracy (which must be precisely calibrated to the size of a typical molecule) is also currently infeasible.

Other proposals use shorter wavelength light, so that a smaller telescope can be used. However, in visible light a sun-like star is more than 10 billion times brighter than the Earth. It is beyond our current capability to block out enough starlight to be able to see the planet in this case, even if, in principle, the image has high enough resolution.

One idea for blocking the starlight involves flying a spacecraft called a ‘starshade’ that is tens of meters across, at a distance of tens of thousands of miles in front of the space telescope, so that it exactly blocks the light from the star while the light from a companion planet is not blocked. However, this plan requires that two spacecraft be launched (a telescope and a starshade). Furthermore, pointing the telescope at different stars would entail moving the starshade thousands of miles, using up prohibitively large quantities of fuel.

A Bold New Design: The Rectangular Telescope

In our paper, we propose a more feasible alternative. We show that it is possible to find nearby, Earth-like planets orbiting sun-like stars with a telescope that is about the same size as JWST, operating at roughly the same infrared (10 micron) wavelength as JWST, with a mirror that is a one by 20 meter rectangle instead of a circle 6.5 meters in diameter.

With a mirror of this shape and size, we can separate a star from an exoplanet in the direction that the telescope mirror is 20 meters long. To find exoplanets at any position around a star, the mirror can be rotated so its long axis will sometimes align with the star and planet. We show that this design can in principle find half of all existing Earth-like planets orbiting sun-like stars within 30 light-years in less than three years. While our design will need further engineering and optimization before its capabilities are assured, there are no obvious requirements that need intense technological development, as is the case for other leading ideas.

Toward Earth 2.0: The Search for Life

If there is about one Earth-like planet orbiting the average sun-like star, then we would find around 30 promising planets. Follow-up study of these planets could identify those with atmospheres that suggest the presence of life, for example, oxygen that was formed through photosynthesis. For the most promising candidate, we could dispatch a probe that would eventually beam back images of the planet’s surface. The rectangular telescope could provide a straightforward path towards identifying our sister planet: Earth 2.0.

Reference: “The case for a rectangular format space telescope for finding exoplanets” by Heidi Jo Newberg, Leaf Swordy, Richard K. Barry, Marina Cousins, Kerrigan Nish, Sarah Rickborn and Sebastian Todeasa, 30 June 2025, Frontiers in Astronomy and Space Sciences.
DOI: 10.3389/fspas.2025.1441984

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Star’s Tumultuous Core Uncovered Before Supernova Blast

by Clarence Oxford

Los Angeles CA (SPX) Sep 01, 2025

New results from NASA’s Chandra X-ray Observatory reveal that Cassiopeia A’s progenitor star violently reshaped its interior just hours before it exploded. This previously hidden stellar upheaval helps explain the asymmetry of the remnant and may even have triggered the supernova itself.

Cassiopeia A, one of the most studied remnants in the night sky, began as a massive star that lived for more than a million years. As with other massive stars, its interior formed onion-like layers of hydrogen, helium, carbon, and heavier elements. When iron accumulated at the core, it collapsed under its own weight, initiating the explosion about three centuries ago.

Chandra’s X-ray data, combined with advanced simulations, revealed that part of the silicon-rich inner layer broke outward into a neon-rich layer in the star’s final hours. This disruption forced silicon to move outward and neon to move inward, leaving clear evidence in Cas A’s debris field: regions with abundant silicon but little neon adjacent to areas with the opposite composition.

“These findings show a violent event where the barrier between layers disappears,” said Kai Matsunaga of Kyoto University, a co-author of the study. The survival of these unmixed regions confirms predictions from detailed models of stellar interiors near collapse.

The consequences of this rearrangement are profound. It likely produced Cas A’s lopsided shape and gave a strong recoil to the surviving neutron star, which now speeds away from the explosion site. Moreover, the turbulence from these late-stage flows may have amplified the supernova shock wave itself.

“Perhaps the most important effect of this change in the star’s structure is that it may have helped trigger the explosion itself,” noted co-author Hiroyuki Uchida of Kyoto University. Lead author Toshiki Sato of Meiji University added, “Each time we closely look at Chandra data of Cas A, we learn something new and exciting.”

Research Report:Inhomogeneous stellar mixing in the final hours before the Cassiopeia A supernova

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Chandra X-ray Center

Stellar Chemistry, The Universe And All Within It

New detectors aim to capture lighter forms of dark matter

by Clarence Oxford

Los Angeles CA (SPX) Sep 01, 2025

The search for elusive dark matter has gained a new tool, now operating deep within the French Alps. An international team, including Johns Hopkins University scientists, has deployed an ultrasensitive detector designed to probe particles far lighter than those targeted in decades of past experiments.

Researchers believe dark matter makes up about 85 percent of the universe, yet no direct laboratory evidence has been found. The new technology expands the search, either paving the way for the first detection or eliminating entire categories of theories that have remained untested.

“Dark matter is one of the most important ingredients that shape our universe and also one of the greatest cosmological mysteries,” said Danielle Norcini, assistant professor of physics and astronomy at Johns Hopkins. “Our prevailing theories about the nature of dark matter aren’t yielding results, even after decades of investigation. We need to broaden our search, and now we can.”

Traditional dark matter detectors rely on heavier atoms such as xenon or argon, attempting to catch recoils when weakly interacting massive particles (WIMPs) collide with nuclei. But after forty years of searching, no such signals have appeared, suggesting that lighter, weaker particles may be the real culprits.

The new devices, called silicon skipper CCDs, can register signals from single electrons, enabling searches for dark matter similar in size to an electron rather than a nucleus. This shift allows scientists to pursue particles described as “WIMPier than the WIMPs.”

To minimize interference, the instruments operate inside the Laboratoire Souterrain de Modane, located two kilometers underground in the French Alps. There, the surrounding rock shields cosmic rays, while layers of ancient lead and specially grown copper reduce background radiation.

“Trying to lock in on dark matter’s signal is like trying to hear somebody whisper in a stadium full of people,” Norcini explained. “While we haven’t discovered dark matter yet, our results show that our detector works as designed, and we are starting to map out this unexplored region.”

Following the successful proof-of-concept with eight skipper CCDs, the team plans to expand to 208 sensors. The scaled-up version, known as DAMIC-M, will become the most sensitive instrument dedicated to finding this lighter class of dark matter.

Research Report:Probing Benchmark Models of Hidden-Sector Dark Matter with DAMIC-M

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Johns Hopkins University

Stellar Chemistry, The Universe And All Within It

ESA and JAXA weigh joint effort for Apophis flyby mission

by Erica Marchand

Paris, France (SPX) Sep 01, 2025

ESA and the Japan Aerospace Exploration Agency (JAXA) are moving closer to a joint mission to the asteroid Apophis, which will pass Earth at a record-setting distance in 2029.

The proposed Rapid Apophis Mission for Space Safety (Ramses) would rendezvous with the 375 m asteroid and monitor how Earth’s gravity alters its physical state during the flyby. Scientists expect the close passage to provide unique insights into planetary defense strategies.

ESA intends to seek approval for Ramses at its November 2025 Ministerial Council, with a launch targeted for 2028. Preparatory work is already in progress to keep the mission viable ahead of the decision.

JAXA has now formally requested government funding to join Ramses. Planned Japanese contributions include the spacecraft’s solar arrays, an infrared imaging system, and the use of an H3 launch vehicle for a rideshare option.

The collaboration builds on the agencies’ experience with Hera, ESA’s first planetary defense mission currently en route to asteroid Didymos. Both sides have held technical discussions to align contributions and mission design.

“Our experience working with our JAXA colleagues, first on the Hera mission and now on Ramses, has been excellent. We truly feel like one globally integrated team with a common goal,” said Paolo Martino, Ramses mission manager. “We would be glad to face the challenge of reaching Apophis together.”

“ESA welcomes JAXA’s increasing interest in participating in the Ramses mission. International collaboration lies at the heart of planetary defence, and we are very happy to see Europe and Japan continue to strengthen their partnership in this field,” said Holger Krag, Head of ESA’s Space Safety Programme.

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Planetary Defence

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Warped planet forming discs challenge long held models of planetary birth

by Sophie Jenkins

London, UK (SPX) Sep 01, 2025

Scientists studying the origins of planetary systems have found that protoplanetary discs are often warped, overturning the traditional view of smooth, flat discs. The findings, published in the Astrophysical Journal Letters, show that these subtle tilts can significantly influence how planets grow and establish orbits.

The research team, using the Atacama Large Millimetre/submillimetre Array (ALMA) as part of the exoALMA programme, discovered that many discs tilt by just half a degree to two degrees. These small misalignments resemble the inclinations between planets in our Solar System, suggesting that planetary birth environments may be more chaotic than once believed.

“Our results suggest that protoplanetary discs are slightly warped. This would be quite a change in how we understand these objects and has many consequences for how planets form. Particularly interesting is that the couple of degree warping is similar to the differences in inclination between our own Solar System planets,” said Dr Andrew Winter of Queen Mary University of London.

Dr Myriam Benisty of the Max Planck Institute for Astronomy added, “exoALMA has revealed large scale structures in the planet forming discs that were completely unexpected. The warp-like structures challenge the idea of orderly planet formation and pose a fascinating challenge for the future.”

The team analysed Doppler shifts in radio emissions from carbon monoxide gas, mapping motion within the discs with high precision. Careful modelling showed different regions of each disc tilted relative to one another, exposing the warps. These distortions can explain spiral patterns, turbulence, temperature variations and other large-scale gas motions observed across the discs.

Researchers believe the warps may be linked to how much material the young star accretes at its centre, pointing to a connection between stellar feeding and planet-forming regions. They could also result from gravitational forces of unseen stellar companions or dynamic interactions in the gas and dust.

The discovery provides new insight into how turbulence and mass transport in discs shape planetary formation. It challenges the notion of serene, flat nurseries for new worlds and offers a more dynamic blueprint for the creation of diverse planetary systems.

Research Report:exoALMA XVIII. Interpreting large scale kinematic structures as moderate warping

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Queen Mary University of London

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Gaia uncovers vast networks of stellar clusters across the Milky Way

by Erica Marchand

Paris, France (SPX) Sep 01, 2025

Gaia, the European Space Agency’s star-mapping mission, has redrawn our understanding of stellar communities in the Milky Way. After more than a decade of observations, the spacecraft revealed that clusters of stars are not isolated but instead linked in extended chains that stretch across vast galactic distances.

Launched in 2013 and operating until early 2025, Gaia has already transformed astronomy by charting the positions, motions, and brightness of billions of stars with unprecedented accuracy. Its data show that star clusters evolve dynamically, dissolve into their surroundings, and leave long tidal tails of stars and gas behind.

Gaia’s findings confirm that open clusters and stellar associations, once thought to exist separately, are often part of much larger families. These stellar chains display structures such as filaments, strings, and streams that persist for millions of years. The results also shed light on how star formation is triggered, shaped, and dispersed by stellar feedback and galactic forces.

The mission’s measurements have allowed astronomers to map dark molecular clouds, star-forming nurseries, and nearby stellar associations such as Orion OB1 and Scorpius-Centaurus. Gaia has also redefined large-scale structures like the Gould Belt, showing it to be part of elongated gas spurs and waves that thread the Milky Way’s disc.

Beyond cluster discovery, Gaia uncovered extensive tidal tails around clusters like the Hyades and Coma Berenices. These immense trails, stretching thousands of light-years, record the ongoing disruption of clusters as they interact with molecular clouds, spiral arms, and dark matter.

“Gaia’s datasets are significantly more detailed and precise than any that have come before. It’s no exaggeration to say that the mission has brought about a revolution in Milky Way astronomy, especially when it comes to star clusters,” said Johannes Sahlmann, ESA Project Scientist for Gaia.

Although Gaia has completed its observing phase, most of its data are still awaiting release. The next major catalogues, Data Release 4 and 5, will arrive in 2026 and 2030 respectively, promising further discoveries that will continue to reshape our view of the galaxy.

More information on Gaia’s contributions to mapping the Milky Way can be found at ESA’s Gaia mission site.

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Gaia

Stellar Chemistry, The Universe And All Within It