Universe Today

September 19, 2023September 19, 2023 by Evan Gough

Galaxies Breathe Gas, and When They Stop, No More Stars Form

Artist concept of how a galaxy might accrete mass from rapid, narrow streams of cold gas. These filaments provide the galaxy with continuous flows of raw material to feed its star-forming at a rather leisurely pace. Credit: ESA–AOES Medialab

For most of the history of astronomy, all we could see were stars. We could see them individually, in clusters, in nebulae, and in fuzzy blobs that we thought were clumps of stars but were actually galaxies. The thing is, most of what’s out there is much harder to see than stars and galaxies. It’s gas.

Now that astronomers can see gas better than ever, we can see how galaxies breathe it in and out. When they stop breathing it, stars stop forming.

September 19, 2023September 19, 2023 by Brian Koberlein

Polar Ring Galaxies Are Bizarre and Rare. Astronomers Just Found Two More

A galaxy with a polar ring of hydrogen gas, known as a polar ring galaxy. Credit: Jayanne English, Nathan Deg & WALLABY Survey, CSIRO/ASKAP, NAOJ/Subaru Telescope

Galaxies come in a range of shapes, from elegant spirals to egg-shaped ellipticals. We often categorize galaxies by their shape, which was traditionally done based on what we could observe in the visual spectrum. But as we expanded astronomy into radio, infrared, ultraviolet, and x-ray light, learned that often galaxies have structures invisible to our eyes. Take, for example, an odd type of galaxy known as polar ring galaxies (PRGs).

September 19, 2023September 19, 2023 by Nancy Atkinson

Spacecraft Could be Equipped With Tiny Thrusters That Use Water for Propellant

A micro thruster developed at Imperial College is only 1 mm long. Credit: Imperial College/ESA

Engineers working with the European Space Agency have developed a new thruster design smaller than the tip of your finger. Despite its small size, this mini-thruster designed for CubeSats appears to be highly efficient without the use of toxic chemicals.

September 18, 2023September 18, 2023 by Carolyn Collins Petersen

A Collision Between Gigantic Galaxy Clusters. Too Big, Too Early

Hubble Space Telescope image of the El Gordo galaxy cluster. This and other gigantic galaxy clusters are challenging the most common theory of the evolution of structure in the Universe. Credit: NASA, ESA, and J. Jee (University of California, Davis)

Just when cosmologists have a workable theory for when and how galaxy collisions happened in the early Universe, something challenges it. In this case, the challenger is a collision of two massive galaxy clusters that combined to form a gigantic galaxy cluster.

September 18, 2023September 18, 2023 by Brian Koberlein

An Ambitious New Technology Might be Needed to See Other Earths

How a starshade would reveal exoplanets. Credit: NASA/JPL

The race is on to discover truly habitable Earth-like worlds. While we are starting to observe the atmospheres of large potentially habitable planets such as Hycean worlds with the telescopes we currently have, the most significant breakthroughs will likely come with the development of advanced specialized telescopes. These new designs will likely use a starshade to hide the glare of a star and allow us to directly observe its exoplanets. But will that be enough to study distant terrestrial planets?

September 18, 2023September 18, 2023 by Evan Gough

When did the First Continents Appear in the Universe?

Continents might be necessary for life, especially complex life. This image shows super-continent Pangaea during the Permian period (300 - 250 million years ago). Credit: NAU Geology/Ron Blakey

On Earth, continents are likely necessary to support life. Continents ‘float’ on top of the Earth’s viscous mantle, and heat from the planet’s core keeps the mantle from solidifying and locking the continents into place.

The core is hot because of the presence of radioactive elements that came from neutron star collisions. It should be possible to calculate when the first continents formed in the Universe.

So that’s what one researcher did.

September 18, 2023September 18, 2023 by Evan Gough

It’s Like Looking at the Infant Sun: Webb Captures Image of an Energetic Young Star

NASA’s James Webb Space Telescope’s high resolution, near-infrared look at Herbig-Haro 211 reveals exquisite detail of the outflow of a newly forming young star, an infantile analogue of our Sun. Image Credit: ESA/Webb, NASA, CSA, Tom Ray (Dublin)

Ever wondered what our young Sun might have looked like in its infancy some five billion years ago?

The audacious JWST has captured an image of a very young star much like our young Sun, though the star itself is obscured. Instead, we see supersonic jets of gas. Young stars can blast out jets of material as they form, and the jets light up the surrounding gas. The luminous regions created by the jets as they slam into the gas are called Herbig-Haro Objects.

September 18, 2023September 18, 2023 by Nancy Atkinson

SpaceX Test Fires a Raptor Engine, Simulating a Lunar Landing

A Raptor Vacuum engine was successfully cold-started during a test in August 2023. Via SpaceX.

When NASA astronauts return to the surface of the Moon in the Artemis III mission, the plan is to use a modified SpaceX Starship as their lunar lander. NASA announced last week that SpaceX has now demonstrated an important capability of the vacuum-optimized Raptor engine that will be used for the lander: an extreme cold start.

A test last month successfully confirmed the engine can be started in the frigid conditions of space, even when the vehicle has spent an extended time in space, where temperatures will drop lower than a shorter low-Earth orbit mission. The Raptor vacuum engine was chilled to mimic conditions after a long coast period in space, and then was successfully fired.

September 17, 2023September 17, 2023 by Laurence Tognetti

Helicopters Could Map the Magnetic Fields on Mars

Artist illustration of how a magnetic field could have looked on ancient Mars. (Credit: NASA/JPL-Caltech)

A recent study published in The Planetary Science Journal examines how helicopters equipped with a magnetometer could be used to conduct magnetic field investigations within the crust of Mars, providing important insights into the present characteristics and early evolution of the Red Planet. This study comes as NASA’s Ingenuity helicopter continues breaking records and making history as the first powered aerial explorer on another planet, along with the recently expired NASA InSight lander using its own magnetometer to measure the crustal magnetic field.

September 17, 2023September 17, 2023 by Scott Alan Johnston

A Collection of New Images Reveal X-Rays Across the Universe

NASA/CXC/SAO, JPL-Caltech, MSFC, STScI, ESA/CSA, SDSS, ESO.

One of the miracles of modern astronomy is the ability to ‘see’ wavelengths of light that human eyes can’t. Last week, astronomers put that superpower to good use and released five new images showcasing the universe in every wavelength from X-ray to infrared.

Combining data from both Earth- and ground-based telescopes, the five images reveal a diverse set of astronomical phenomena, including the galactic centre, the death throes of stars, and distant galaxies traversing the cosmos.