Universe Today

November 15, 2024November 15, 2024 by Brian Koberlein

A New Look a the Most Ancient Light in the Universe

The South Pole Telescope observes the southern winter sky. Credit: Aman Chokshi

In the earliest moments of the Universe, the first photons were trapped in a sea of ionized gas. They scattered randomly with the hot nuclei and electrons of the cosmic fireball, like tiny boats in a stormy sea. Then, about 370,000 years after the big bang, the Universe cooled enough for the photons to be free. After one last scattering, they could finally ply interstellar space. Some of them traveled across 14 billion years of space and time to reach Earth, where we see them as part of the cosmic microwave background. The remnant first light of creation.

November 15, 2024November 14, 2024 by Paul M. Sutter

Space Tourism: The Good, The Bad, The Meh

The Polaris Dawn crew (left to right): Anna Menon, Scott Poteet, Jared Isaacman, and Sarah Gillis. Credit: Polaris Program/John Kraus

Space tourism here is here to stay, and will likely remain a permanent fixture of near-Earth activities for the foreseeable future. But is it worth it?

November 14, 2024November 14, 2024 by Matt Williams

New Study Examines Cosmic Expansion, Leading to a New Drake Equation

An illustration of cosmic expansion. Credit: NASA's Goddard Space Flight Center Conceptual Image Lab

In 1960, in preparation for the first SETI conference, Cornell astronomer Frank Drake formulated an equation to calculate the number of detectable extraterrestrial civilizations in our Milky Way. Rather than being a scientific principle, the equation was intended as a thought experiment that summarized the challenges SETI researchers faced. This became known as the Drake Equation, which remains foundational to the Search for Extraterrestrial Intelligence (SETI) to this day. Since then, astronomers and astrophysicists have proposed many updates and revisions for the equation.

This is motivated by ongoing research into the origins of life on Earth and the preconditions that led to its emergence. In a recent study, astrophysicists led by Durham University produced a new model for the emergence of life that focuses on the acceleration of the Universe’s expansion (aka. the Hubble Constant) and the number of stars formed. Since stars are essential to the emergence of life as we knot it, this model could be used to estimate the probability of intelligent life in our Universe and beyond (i.e., in a multiverse scenario).

November 14, 2024November 14, 2024 by Alan Boyle

Pentagon’s Latest UFO Report Identifies Hotspots for Sightings

Map showing distribution of UAP reports — This map from the Pentagon's All-Domain Anomaly Resolution Office shows the global distribution for reports relating to unidentified anomalous phenomena in 2023-2024, with red and orange areas representing higher concentrations. (DoD / AARO Graphic)

The Pentagon office in charge of fielding UFO reports says that it has resolved 118 cases over the past year, with most of those anomalous objects turning out to be balloons. But it also says many other cases remain unresolved.

This year’s legally mandated report from the Department of Defense’s All-Domain Anomaly Resolution Office, or AARO, also identifies areas of the world that seem to be hotspots for sightings of unidentified flying objects. Such objects have been re-branded as unidentified anomalous phenomena, or UAPs.

Today’s report come just one day after a House subcommittee hearing about UAPs, during which witnesses — and some lawmakers — voiced concerns about potential alien visitations and undisclosed efforts to gather evidence. In contrast, the Pentagon’s report for the 2023-2024 time period states that, “to date, AARO has discovered no evidence of extraterrestrial beings, activity or technology.”

November 14, 2024November 14, 2024 by Evan Gough

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.

November 14, 2024November 14, 2024 by Brian Koberlein

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.

November 14, 2024November 14, 2024 by Mark Thompson

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.

November 14, 2024November 14, 2024 by Andy Tomaswick

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.

November 14, 2024November 14, 2024 by Brian Koberlein

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.

November 14, 2024November 14, 2024 by Paul M. Sutter

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.