Universe Today

November 13, 2024November 13, 2024 by Evan Gough

Lessons From Ancient Earth’s Atmosphere: From Hostile to Hospitable

Earth's ancient atmosphere was much different than now. How did it transition from hostile to hospitable? If scientists can figure that out, they'll be better able to understand exoplanets and their atmospheres. Image Credit: Tohoku University

Will we ever understand how life got started on Earth? We’ve learned much about Earth’s long, multi-billion-year history, but a detailed understanding of how the planet’s atmospheric chemistry evolved still eludes us. At one time, Earth was atmospherically hostile, and its transition from that state to a planet teeming with life followed a complex path.

November 13, 2024November 13, 2024 by Brian Koberlein

Astronomers Defy the Zone of Avoidance to Find Hundreds of New Galaxies

A rendered image of the Milky Way based on the Gaia EDR3 dataset. Credit: Wikipedia user Kevinmloch

There is a region of the sky where astronomers fear to look. Filled with dark clouds of dust, it hides an unseen mass. A mass so large it is pulling the Milky Way and other galaxies toward it…

November 12, 2024November 12, 2024 by Evan Gough

An Otherworldly Cloud Over New Zealand

Landsat 8’s Operational Land Imager captured this unique lenticular cloud that forms over the Otago region of New Zealand’s South Island. Image Credit: NASA/Lauren Dauphin; USGS

Filmmakers love New Zealand. Its landscapes evoke other worlds, which explains why so much of The Lord of the Rings was filmed there. The country has everything from long, subtropical sandy beaches to active volcanoes.

The country’s otherworldliness extends into its atmosphere, where a cloud nicknamed the “Taieri Pet” forms when conditions are right.

November 12, 2024November 12, 2024 by Mark Thompson

Early Black Holes Fed 40x Faster than Should Be Possible

This artist’s illustration shows a red, early-Universe dwarf galaxy that hosts a rapidly feeding black hole at its center. Using data from NASA's JWST and Chandra X-ray Observatory, a team of U.S. National Science Foundation NOIRLab astronomers have discovered this low-mass supermassive black hole at the center of a galaxy just 1.5 billion years after the Big Bang. It is accreting matter at a phenomenal rate — over 40 times the theoretical limit. While short lived, this black hole’s ‘feast’ could help astronomers explain how supermassive black holes grew so quickly in the early Universe.

The theory goes that black holes accrete material, often from nearby stars. However the theory also suggests there is a limit to how big a black hole can grow due to accretion and certainly shouldn’t be as large as they are seen to be in the early Universe. Black holes it seems, are fighting back and don’t care about those limits! A recent study shows that supermassive black holes are growing at rates that defy the limits of current theory. Astronomers just need to figure out how they’re doing it!

November 12, 2024November 12, 2024 by Evan Gough

A Spider Stellar Engine Could Move Binary Stars Halfway Across a Galaxy

Illustration of a millisecond pulsar consuming material from a companion star. Pulsars that evaporate their companions rather than consuming them could serve as stellar engines. Credit: NASA / GSFC SVS / Dana Berry

Eventually, every stellar civilization will have to migrate to a different star. The habitable zone around all stars changes as they age. If long-lived technological civilizations are even plausible in our Universe, migration will be necessary, eventually.

Could Extraterrestrial Intelligences (ETIs) use stars themselves as stellar engines in their migrations?

November 12, 2024November 12, 2024 by Andy Tomaswick

Scaling Propellant Production on Mars is Hard

Putting humans on Mars has been one of NASA’s driving missions for years, but they are still in the early stages of deciding what exactly that mission architecture will look like. One major factor is where to get the propellant to send the astronauts back to Earth. Advocates of space exploration often suggest harvesting the necessary propellant from Mars itself – some materials can be used to create liquid oxygen and methane, two commonly used propellants. To support this effort, a group from NASA’s COMPASS team detailed several scenarios of the infrastructure and technologies it would take to make an in-situ resource utilization (ISRU) system that could provide enough propellant to get astronauts back to a Mars orbit where they could meet up with an Earth return vehicle. However, there are significant challenges to implementing such a system, and they must be addressed before the 8-9-year process of getting the system up and running can begin.

November 12, 2024November 13, 2024 by David Dickinson

Is an ‘Off-Year’ Leonid Outburst in the Cards For November?

The 1999 Leonids seen from NASA's airborne Leonid MAC campaign. Credit: NASA/Ames Research/ISAS/Shinsuke Abe/Hajime Yuno.

There are good reasons to keep an eye on the Leonid meteors this year.

It’s still one of the coolest things I ever saw. I was in the U.S. Air Force in the 90s, and November 1998 saw me deployed to the dark skies of Kuwait. That trip provided an unexpected treat, as the Leonid meteors hit dramatic storm levels on the morning of the 17^th. Meteor came fast and furious towards local sunrise, often lighting up the desert floor like celestial photoflashes in the sky.

Once every 33 years or so, the ‘lion roars,’ as Leonid meteors seem to rain down from the Sickle asterism of the constellation Leo. And while the last outbreak was centered around the years surrounding 1999, there’s some interesting discussion about possible encounters with past Leonid streams in 2024.

November 12, 2024November 12, 2024 by Mark Thompson

Reaction Engines Goes Into Bankruptcy, Taking the Hypersonic SABRE Engine With it

Scale model. Skylon is a British design for an unmanned Single Stage to Orbit (SSTO) spaceplane designed to reach Earth orbit where it would deploy and retrieve satellites. It was intended to be completely reusable, with the objective of cutting the cost of launches dramatically. It was envisaged that some 30 Skylon vehicles would be built, and operated by commercial companies, and it was planned that Skylon could be adapted for carrying passengers, or ‘space tourists’. At the heart of the Skylon concept were its two innovatory Synergestic Air Breathing and Rocket Engines (SABREs) which were designed to draw oxygen directly from the atmosphere. Skylon is one example of several SSTO launcher concepts considered worldwide in the 1990s.

Rarely does something get developed which is a real game changer in space exploration. One example is the Skylon reusable single-stage-to-orbit spaceplane. Powered by the hypersonic SABRE engine it operates like a jet engine at low altitude and more like a conventional rocket at high altitude. Sadly, ‘Reaction Engines’ the company that designs the engines has filed for bankruptcy.

November 11, 2024November 12, 2024 by Matt Williams

Project Hyperion is Seeking Ideas for Building Humanity’s First Generation Ship

Project Hyperion is the first design competition for a generation ship. Credit: Maciej Rebisz/Michel Lamontagne

The dream of traversing the depths of space and planting the seed of human civilization on another planet has existed for generations. For long as we’ve known that most stars in the Universe are likely to have their own system of planets, there have been those who advocated that we explore them (and even settle on them). With the dawn of the Space Age, this idea was no longer just the stuff of science fiction and became a matter of scientific study. Unfortunately, the challenges of venturing beyond Earth and reaching another star system are myriad.

When it comes down to it, there are only two ways to send crewed missions to exoplanets. The first is to develop advanced propulsion systems that can achieve relativistic speeds (a fraction of the speed of light). The second involves building spacecraft that can sustain crews for generations – aka. a Generation Ship (or Worldship). On November 1st, 2024, Project Hyperion launched a design competition for crewed interstellar travel via generation ships that would rely on current and near-future technologies. The competition is open to the public and will award a total of $10,000 (USD) for innovative concepts.

November 11, 2024November 11, 2024 by Evan Gough

How Did Supermassive Black Holes Get So Big, So Early? They Might Have Had a Head Start

An artist's illustration of a supermassive black hole (SMBH.) The JWST has revealed SMBHs in the early Universe that are much more massive than our scientific models can explain. Could primordial black holes have acted as "seeds" for these massive SMBHs? Image Credit: ESA

Supermassive Black Holes (SMBHs) can have billions of solar masses, and observational evidence suggests that all large galaxies have one at their centres. However, the JWST has revealed a foundational cosmic mystery. The powerful space telescope, with its ability to observe ancient galaxies in the first billion years after the Big Bang, has shown us that SMBHs were extremely massive even then. This contradicts our scientific models explaining how these behemoths became so huge.

How did they get so massive so early?