A New Way to Detect Daisy Worlds

Daisy Worlds are planets where the biosphere regulates the environment to keep it habitable. Earth is one, sort of. Can we use information theory to identify agnostic biosignatures from these living worlds? Image Credit: NASA

The Daisy World model describes a hypothetical planet that self-regulates, maintaining a delicate balance involving its biogeochemical cycles, climate, and feedback loops that keep it habitable. It’s associated with the Gaia Hypothesis developed by James Lovelock. How can we detect these worlds if they’re out there?

By looking closely at information.

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Two Supermassive Black Holes on the Verge of a Merger

A pair of monster black holes swirl in a cloud of gas in this artist’s concept of AT 2021hdr. Credit: NASA/Aurore Simonnet (Sonoma State University)

In March 2021, astronomers observed a high-energy burst of light from a distant galaxy. Assigned the name AT 2021hdr, it was thought to be a supernova. However, there were enough interesting features that flagged as potentially interesting by the Automatic Learning for the Rapid Classification of Events (ALeRCE). In 2022, another outburst was observed, and over time the Zwicky Transient Facility (ZTF) found a pattern of outbursts every 60–90 days. It clearly wasn’t a supernova, but it was unclear on what it could be until a recent study solved the mystery.

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Interferometry Will Be the Key to Resolving Exoplanets

The setting Sun dips below the horizon of the Pacific Ocean, bathing the Paranal platform in light in this amazing aerial image from the Atacama Desert in northern Chile. The Cerro Paranal mountain top is home to the world’s most advanced ground-based facility for astronomy, hosting the four 8.2-metre Unit Telescopes of the Very Large Telescope, four 1.8-metre Auxiliary Telescopes and the VLT Survey Telescope (VST) — all of which are visible in this image. The 4.1-metre Visible and Infrared Survey Telescope for Astronomy (VISTA), also housed at Cerro Paranal, is hidden out of frame.

When it comes to telescopes, bigger really is better. A larger telescope brings with it the ability to see fainter objects and also to be able to see more detail. Typically we have relied upon larger and larger single aperture telescopes in our attempts to distinguish exoplanets around other stars. Space telescopes have also been employed but all that may be about to change. A new paper suggests that multiple telescopes working together as interferometers are what’s needed. 

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A New Mission To Pluto Could Answer the Questions Raised by New Horizons

Pluto may have been downgraded from full-planet status, but that doesn’t mean it doesn’t hold a special place in scientist’s hearts. There are practical and sentimental reasons for that – Pluto has tantalizing mysteries to unlock that New Horizons, the most recent spacecraft to visit the system, only added to. To research those mysteries, a multidisciplinary team from dozens of universities and research institutes has proposed Persephone – a mission to the Pluto system that could last 50 years.

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Astronomers Map the Shape of a Black Hole's Corona for the First Time

Illustration of material swirling around a black hole highlights the corona, that shines brightly in X-ray light. Credit: NASA/Caltech-IPAC/Robert Hurt

If you were lucky enough to observe a total eclipse, you are certain to remember the halo of brilliant light around the Moon during totality. It’s known as the corona, and it is the diffuse outer atmosphere of the Sun. Although it is so thin we’d consider it a vacuum on Earth, it has a temperature of millions of degrees, which is why it’s visible during a total eclipse. According to our understanding of black hole dynamics black holes should also have a corona. And like the Sun’s corona, it is usually difficult to observe. Now a study in The Astrophysical Journal has made observations of this elusive region.

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Yes, Virginia, The Universe is Still Making Galaxies

Scientists are getting their first look with the NASA/ESA/CSA James Webb Space Telescope’s powerful resolution at how the formation of young stars influences the evolution of nearby galaxies. The spiral arms of NGC 7496, one of a total of 19 galaxies targeted for study by the Physics at High Angular resolution in Nearby Galaxies (PHANGS) collaboration, are filled with cavernous bubbles and shells overlapping one another in this image from Webb’s Mid-Infrared Instrument (MIRI). These filaments and hollow cavities are evidence of young stars releasing energy and, in some cases, blowing out the gas and dust of the interstellar medium they plough into. Until Webb’s high resolution at infrared wavelengths came along, stars at the earliest point of their lifecycle in nearby galaxies like NGC 7496 remained obscured by gas and dust. Webb’s specific wavelength coverage (7.7 and 11.3 microns), allows for the detection of polycyclic aromatic hydrocarbons, which play a critical role in the formation of stars and planets. In Webb’s MIRI image, these are mostly found within the main dust lanes in the spiral arms. In their analysis of the new data from Webb, scientists were able to identify nearly 60 new, undiscovered embedded cluster candidates in NGC 7496. These newly identified clusters could be among the youngest stars in the entire galaxy. At the centre of NGC 7496, a barred spiral galaxy, is an active galactic nucleus (AGN). An AGN is a supermassive black hole that is emitting jets and winds. The AGN glows brightly at the centre of this Webb image. Additionally, Webb’s extreme sensitivity also picks up various background galaxies,far distant from NGC 7496, which appear green or red in some instances. NGC 7496 lies over 24 million light-years away from Earth in the constellation Grus.In this image of NGC 7496, blue, green, and red were assigned to Webb’s MIRI data at 7.7, 10 and 11.3, and 21 microns (the F770W, F1000W and F1130W, and F2100W filters, respectively

Despite the fact that our universe is old, cold, and well past its prime, it’s not done making new galaxies yet.

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Our Breathtaking Cosmos: New Zealand Astrophotography Winners Announced

Overall "Trophy Winner," "Sky Fire" by Tom Rae. Credit and copyright: Tom Rae and the NZ Astrophotography Competition.

The New Zealand Astrophotography Competition showcases and recognizes some of the most stunning images of the southern hemisphere’s night sky. This year, photographers from across New Zealand have captured some incredibly breathtaking skyscapes such as amazing auroras, stunning images of our Solar System, and deep-sky marvels.

Universe Today was proud to be part of this year’s competition, as our own Fraser Cain was one of the judges.

The overall winner in the competition is a gorgeous view of the Aurora Australis, above, by photographer Tom Rae. Rae said he captured this image during the “once in a lifetime” geomagnetic storm in May of 2024, showing the Milky Way arching over the dramatic landscape of Aoraki Mount Cook National Park. This image also won the “Aurora” category.

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Why are Some Quasars So Lonely?

This image, taken by NASA’s James Webb Space Telescope, shows an ancient quasar (circled in red) with fewer than expected neighboring galaxies (bright spheres), challenging physicists’ understanding of how the first quasars and supermassive black holes formed. Credits:Credit: Christina Eilers/EIGER team

At the centre of most galaxies are supermassive black holes. When they are ‘feeding’ they blast out jets of material with associated radiation that can outshine the rest of the galaxy. These are known as quasars and they are usually found in regions where huge quantities of gas exist. However, a recent study found a higher than expected number of quasars that are alone in the Universe. These loners are not surrounded by galaxies nor a supply of gas. The question therefore remains, how are they shining so brightly. 

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Congressional Hearing Fuels Fresh Debate About UFOs

Tic Tac object on infrared sensor image
Infrared imagery captured by a Navy fighter jet in 2004 shows an anomalous "Tic Tac" object, highlighted by a red circle. (U.S. Navy Video)

An 11-page document that’s attributed to a Pentagon whistleblower has provided new cases in the controversy over unidentified anomalous phenomena — also known as UAPs, unidentified flying objects or UFOs.

The document, released today in conjunction with a House subcommittee hearing on UAPs, lays out details about what’s said to be a special access program called Immaculate Constellation. It accuses officials in the federal government’s executive branch of a “criminal conspiracy” that has been managing issues surrounding UAPs and evidence for non-human intelligence “without congressional knowledge, oversight or authorization for some time, quite possibly decades.”

Over the past few years, the Department of Defense has become more open to discussing UAP reports publicly, while insisting that there have been no substantiated reports of alien visitations. During today’s hearing, lawmakers called on the Pentagon to be more transparent in its investigations.

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New Study Examines How Extraterrestrial Civilizations Could Become “Stellarvores.”

Artist's impression of accretion in a binary system. Credit: ESO/L. Calçada

One of the most challenging aspects of astrobiology and the Search for Extraterrestrial Intelligence (SETI) is anticipating what life and extraterrestrial civilizations will look like. Invariably, we have only one example of a planet that supports life (Earth) and one example of a technologically advanced civilization (humanity) upon which to base our theories. As for more advanced civilizations, which statistically seems more likely, scientists are limited to projections of our own development. However, these same projections offer constraints on what SETI researchers should search for and provide hints about our future development.

In a series of papers led by the Blue Marble Space Institute of Science (BMSIS), a team of researchers examines what Earth’s level of technological development (aka. “technosphere”) will look like in the future. In the most recent installment, they offer a reinterpretation of the Kardashev Scale, which suggests that civilizations expand to harness greater levels of energy (planet, host star, and galaxy). Instead, they suggest that the Kardashev Scale establishes upper limits on the amount of stellar energy a civilization can harness (a “luminosity limit”) and that civilizations might circumvent this by harnessing stellar mass directly.

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