Astronomy

People who can run a mile in less than 4 minutes generally live almost five years longer than would otherwise be expected, challenging the idea that too much strenuous exercise is bad for the heart

People who can run a mile in less than 4 minutes generally live almost five years longer than would otherwise be expected, challenging the idea that too much strenuous exercise is bad for the heart

The NOAA has bumped up its geomagnetic storm watch for May 11 to a "rare" level as solar activity continues at high levels and at least four coronal mass ejections propel toward Earth.

There’s something poetic about humanity’s attempt to detect other civilizations somewhere in the Milky Way’s expanse. There’s also something futile about it. But we’re not going to stop. There’s little doubt about that.

One group of scientists thinks that we may already have detected technosignatures from a technological civilization’s Dyson Spheres, but the detection is hidden in our vast troves of astronomical data.

A Dyson Sphere is a hypothetical engineering project that only highly advanced civilizations could build. In this sense, ‘advance’ means the kind of almost unimaginable technological prowess that would allow a civilization to build a structure around an entire star. These Dyson Spheres would allow a civilization to harness all of a star’s energy.

A Civilization could only build something so massive and complex if they had reached Level II in the Kardashev Scale. Dyson Spheres could be a technosignature, and a team of researchers from Sweden, India, the UK, and the USA developed a way to search for Dyson Sphere technosignatures they’re calling Project Hephaistos. (Hephaistos was the Greek god of fire and metallurgy.)

They’re publishing their results in the Monthly Notices of the Royal Academy of Sciences. The research is titled “Project Hephaistos – II. Dyson sphere candidates from Gaia DR3, 2MASS, and WISE.” The lead author is Matías Suazo, a PhD student in the Department of Physics and Astronomy at Uppsala University in Sweden. This is the second paper presenting Project Hephaistos. The first one is here.

“In this study, we present a comprehensive search for partial Dyson spheres by analyzing optical and
infrared observations from Gaia, 2MASS, and WISE,” the authors write. These are large-scale astronomical surveys designed for different purposes. Each one of them generated an enormous amount of data from individual stars. “This second paper examines the Gaia DR3, 2MASS, and WISE photometry of ~5 million sources to build a catalogue of potential Dyson spheres,” they explain.

A Type II civilization is one that can directly harvest the energy of its star using a Dyson Sphere or something similar. Credit: Fraser Cain (with Midjourney)

Combing through all of that data is an arduous task. In this work, the team of researchers developed a special data pipeline to work its way through the combined data of all three surveys. They point out that they’re searching for partially-completed spheres, which would emit excess infrared radiation. “This structure would emit waste heat in the form of mid-infrared radiation that, in addition to the level of completion of the structure, would depend on its effective temperature,” Suazo and his colleagues write.

The problem is, they’re not the only objects to do so. Many natural objects do, too, like circumstellar dust rings and nebulae. Background galaxies can also emit excess infrared radiation and create false positives. It’s the pipeline’s job to filter them out. “A specialized pipeline has been developed to identify potential Dyson sphere candidates focusing on detecting sources that display anomalous infrared excesses that cannot be attributed to any known natural source of such radiation,” the researchers explain.

This flowchart shows what the pipeline looks like.

This flowchart from the research illustrates the pipeline the team developed to find Dyson Sphere candidates. Each step in the pipeline filters our objects that don’t match the expected emissions from Dyson Spheres. Image Credit: Suazo et al. 2024.

The pipeline is just the first step. The team subjects the list of candidates to further scrutiny based on factors like H-alpha emissions, optical variability, and astrometry.

368 sources survived the last cut. Of those, 328 were rejected as blends, 29 were rejected as irregulars, and 4 were rejected as nebulars. That left only 7 potential Dyson Spheres out of about 5 million initial objects, and the researchers are confident that those 7 are legitimate. “All sources are clear mid-infrared emitters with no clear contaminators or signatures that indicate an obvious mid-infrared origin,” they explain.

This pie chart shows the breakdown of the 368 sources that made it through the filter. Only 7 objects out of millions are labelled Dyson Sphere candidates. Image Credit: Suazo et al. 2024.

These are the seven strongest candidates, but the researchers know they’re still just candidates. There could be other reasons why the seven are emitting excess infrared. “The presence of warm debris disks surrounding our candidates remains a plausible explanation for the infrared excess of our sources,” they explain.

But their candidates seem to be M-type (red dwarf) stars, and debris disks around M-dwarfs are very rare. However, it gets complicated because some research suggests that debris disks around M-dwarfs form differently and present differently. One type of debris disk called Extreme Debris Disks (EDD) can explain some of the luminosity the team sees around their candidates. “But these sources have never been observed in connection with M dwarfs,” Suazo and his co-authors write.

That leaves the team with three questions: “Are our candidates strange young stars whose flux does not vary with time? Are these stars’ M-dwarf debris disks with an extreme fractional luminosity? Or something completely different?”

This figure from the research shows the seven candidates plotted on a colour-magnitude diagram. It indicates that all seven are M-dwarfs. Image Credit: Suazo et al. 2024.

“After analyzing the optical/NIR/MIR photometry of ~5 x 106 sources, we found 7 apparent M dwarfs exhibiting an infrared excess of unclear nature that is compatible with our Dyson sphere models,” the researchers write in their conclusion. There are natural explanations for the excess infrared coming from these 7, “But none of them clearly explains such a phenomenon in the candidates, especially given that all are M dwarfs.”

The researchers say that follow-up optical spectroscopy would help understand these 7 sources better. A better understanding of the H-alpha emissions is especially valuable since they can also come from young disks. “In particular, analyzing the spectral region around H-alpha can help us ultimately discard or verify the presence of young disks,” the researchers write.

“Additional analyses are definitely necessary to unveil the true nature of these sources,” they conclude.

The post Astronomers are on the Hunt for Dyson Spheres appeared first on Universe Today.

A new visualization from NASA takes the viewer on a one-way journey into a black hole.

The post Video: Plunge into a Black Hole appeared first on Sky & Telescope.

Astrobiology is the field of science that studies the origins, evolution, distribution, and future of life in the Universe. In practice, this means sending robotic missions beyond Earth to analyze the atmospheres, surfaces, and chemistry of extraterrestrial worlds. At present, all of our astrobiology missions are focused on Mars, as it is considered the most Earth-like environment beyond our planet. While several missions will be destined for the outer Solar System to investigate “Ocean Worlds” for evidence of life (Europa, Ganymede, Titan, and Enceladus), our efforts to find life beyond Earth will remain predominantly on Mars.

If and when these efforts succeed, it will have drastic implications for future missions to Mars. Not only will great care need to be taken to protect Martian life from contamination by Earth organisms, but precautions must be taken to prevent the same from happening to Earth (aka. Planetary Protection). In a recent study, a team from the University of New South Wales (UNSW) in Sydney, Australia, recommends that legal or normative frameworks be adopted now to ensure that future missions do not threaten sites where evidence of life (past or present) might be found.

The study was led by Clare Fletcher, a Ph.D. student with the Australian Centre for Astrobiology (ACA) and Earth and Sustainability Science Research Centre at UNSW. She was joined by Professor Martin Van Kranendonk, a researcher with the ACA and the head of the School of Earth and Planetary Sciences at Curtin University, and Professor Carol Oliver of the School of Biological, Earth & Environmental Sciences at UNSW. Their research paper, “Exogeoconservation of Mars,” appeared on April 21st in Space Policy.

The search for life on Mars can be traced to the late 19th and early 20th centuries when Percival Lowell made extensive observations from his observatory in Flagstaff, Arizona. Inspired by Schiaparelli’s illustrations of the Martian surface (which featured linear features he called “canali”), Lowell recorded what he also believed were canals and spent many years searching for other indications of infrastructure and an advanced civilization. During the ensuing decades, observatories worldwide observed Mars closely, looking for indications of life and similarities with Earth.

However, it was not until the Space Age that the first robotic probes flew past Mars, gathering data directly from its atmosphere and taking close-up images of the surface. These revealed a planet with a thin atmosphere composed predominantly of carbon dioxide and a frigid surface that did not appear hospitable to life. However, it was the Viking 1 and 2 missions, which landed on Mars in 1976, that forever dispelled the myth of a Martian civilization. But as Fletcher told Universe Today via email, the possibility of extant life has not been completely abandoned:

“It’s my personal belief that it is unlikely we will find evidence of extant (current) life on Mars, as opposed to evidence of past life on Mars. If we were to find extant life on Mars that could be proven to be endemic to Mars and not contamination from Earth, some think it might be found underground in lava tubes, for example, and some think the ice caps or any possible source of liquid water might be suitable places.”

Ironically, it was the same missions that discredited the notion of there being life on Mars that revealed evidence that water once flowed on its surface. Thanks to the many orbiter, lander, and rover missions sent to Mars since the turn of the century, scientists theorize that this period coincided with the Noachian Era (ca. 4.1 – 3.7 billion years ago). According to the most recent fossilized evidence, it was also during this period that life first appeared on Earth (in the form of single-celled bacteria).

Artist’s impression of Mars during the Noachian Era. Credit: Ittiz/Wikipedia Commons

Our current astrobiology efforts on behalf of NASA and other space agencies are focused on Mars precisely for this reason: to determine if life emerged on Mars billions of years ago and whether or not it co-evolved with life on Earth. This includes the proposed Mars Sample Return (MSR) mission that will retrieve the drill samples obtained by the Perseverance rover in the Jezero Crater and return them to Earth for analysis. In addition, NASA and China plan to send crewed missions to Mars by 2040 and 2033 (respectively), including astrobiology studies.

These activities could threaten the very abodes where evidence of past life could be found or (worse) still exists. “Human activities might threaten sites like this in part due to possible microbial contamination,” said Fletcher. “Evidence of life (past and extant) also has greater scientific value when in its palaeoenvironmental context, so any human activities that might damage the evidence of life and/or its surrounding environmental context pose a risk. This could be something innocuous, like debris falling in the wrong spot, or something more serious, like driving over possibly significant outcrops with a rover.”

Conservation measures must be developed and implemented before additional missions are sent to Mars. Given humanity’s impact on Earth’s natural environment and our attempts to mitigate this through conservation efforts. In particular, there have been numerous cases where scientific studies were conducted without regard for the heritage value of the site and where damage was done because of a lack of proper measures. These lessons, says Fletcher, could inform future scientific efforts on Mars:

“It’s important that we learn from what has been considered “damaging” on Earth and take this into consideration when exploring Mars. If a site is damaged beyond being able to be studied in the future, then we limit what can actually be learned from a site. When considering Mars missions cost billions of dollars and are to meet specific scientific goals, limiting the information being learned from a site is incredibly detrimental. My recommendations are that of my paper: interdisciplinary cooperation, drawing on experience and knowledge from Earth, creating norms and a code of practice (part of my PhD work), and working towards creating legislation for these issues.”

Artist’s rendition of NASA’s Dragonfly on the surface of Titan. Credit: NASA/Johns Hopkins APL/Steve Gribben

The need for exogeoconservation is paramount at this juncture. In addition to Mars, multiple astrobiology missions will travel to the outer Solar System this decade to search for evidence of life on icy moons like Europa, Ganymede, Titan, and Enceladus. This includes the ESA’s JUpiter ICy moons Explorer (JUICE) mission, currently en route to Ganymede, and NASA’s Europa Clipper and Dragonfly missions that will launch for Europa and Titan in October 2024 and 2028 (respectively). Therefore, the ability to search for extant or past life without damaging its natural environment is an ethical and scientific necessity.

“I hope this paper is very much a starting point for anyone working in Mars science and exploration, as well as anyone thinking about space policy and exogeoconservation,” said Fletcher. “My goal was to start drawing attention to these issues, and that way start a generation of researchers and practitioners focused on exogeoconservation of Mars.”

Further Reading: Space Policy

The post We Need to Consider Conservation Efforts on Mars appeared first on Universe Today.

Surprising recent measurements hint that the universe isn’t expanding in the way we had thought, and it could be explained by still-theoretical dark radiation

Surprising recent measurements hint that the universe isn’t expanding in the way we had thought, and it could be explained by still-theoretical dark radiation

Sierra Space's first Dream Chaser space plane has finished rigorous environmental testing in Ohio and is being prepped for the journey to its Florida launch site.

This image of the Andromeda galaxy uses data from NASA’s retired Spitzer Space Telescope. Multiple wavelengths are shown, revealing stars (in blue and cyan), dust (red), and areas of star formation.

Primordial black holes left over from the Big Bang and no wider than a dime could be a prime target for NASA's Nancy Grace Roman Telescope after it launches in 2026.

Lucasfilm Animation's second Star Wars anthology series often wows, but neither the tales chosen nor the structure feel like a good fit for the format.

Last week, the chief scientist of the James Webb Space Telescope, Jane Rigby, was awarded the 2024 Medal of Freedom.

A sunspot so big it rivals the gigantic sunspot responsible for the Carrington Event in 1859 has unleashed another X-class solar flare. Watch the eruption here and find out how to see the sunspot for yourself.

An analysis of a mathematical economic game suggests that even learning from past mistakes will almost never help us optimise our decision-making – with implications for our ability to make the biggest financial gains

An analysis of a mathematical economic game suggests that even learning from past mistakes will almost never help us optimise our decision-making – with implications for our ability to make the biggest financial gains

It's been four years since it was made, but if you could smell it, you'd find it still retains the whiff of a DoubleTree Cookie. The first food item baked in space is now at the Smithsonian.

The Red Planet launches large bursts of plasma into space from its upper atmosphere, much like the sun’s coronal mass ejections, despite not having a global magnetic field

The Red Planet launches large bursts of plasma into space from its upper atmosphere, much like the sun’s coronal mass ejections, despite not having a global magnetic field

China launched its first Long March 6C rocket, helping the nation further its goal of launching 100 orbital missions this year.