Universe Today

December 10, 2024December 10, 2024 by Andy Tomaswick

A Commercial Tie-Up Bring High-Energy Nuclear Electric Propulsion Closer to Reality

Rendering of a 40 MW VASIMR® Nuclear Electric Propulsion (NEP) human mission to Mars (Credit, Ad Astra Rocket Company)

Propulsion technologies are the key to exploring the outer solar system, and many organizations have been working on novel ones. One with a long track record is the Ad Astra Rocket Company, which has been developing its Variable Specific Impulse Magnetoplasma Rocket (VASIMR) system for decades. However, this type of electric propulsion system requires a lot of energy, so the company has opted for a unique tie-up for a power plant that could solve that problem – a nuclear reactor. Ad Astra has recently entered into a strategic alliance with the Space Nuclear Power Corporation, or SpaceNukes, responsible for developing the Kilopower reactor, a 1kW nuclear reactor for use in space missions.

December 10, 2024December 10, 2024 by Mark Thompson

New Technique for Spotting Dyson Rings Unveiled.

Artist's impression of a Dyson Sphere. The construction of such a massive engineering structure would create a technosignature that could be detected by humanity. Credit: SentientDevelopments.com/Eburacum45

Dyson spheres and rings have always held a special fascination for me. The concept is simple, build a great big structure either as a sphere or ring to harness the energy from a star. Dyson rings are far more simple and feasible to construct and in a recent paper, a team of scientists explore how we might detect them by analysing the light from distant stars. The team suggests they might be able to detect Dyson rings around pulsars using their new technique.

December 10, 2024December 10, 2024 by Brian Koberlein

High Velocity Clouds Comprise Less of the Milky Way’s Mass Than We Thought

Illustration of the stellar halo surrounding our Milky Way Galaxy. Credit: Melissa Weiss / Harvard & Smithsonian’s Center for Astrophysics

Sometimes in astronomy, a simple question has a difficult answer. One such question is this: what is the mass of our galaxy?

On Earth, we usually determine the mass of an object by placing it on a scale or balance. The weight of an object in Earth’s gravitational field lets us determine the mass. But we can’t put the Milky Way on a scale. Another difficulty with massing our galaxy is that there are two types of mass. There is the mass of dark matter that makes up most of the Milky Way’s mass, and there is all the regular matter like stars, planets, and us, which is known as baryonic matter.

December 9, 2024December 9, 2024 by Mark Thompson

Has the Universe Been Designed to Support Life? Now We Have a Way to Test it!

NASA's Hubble Space Telescope provided one of the deepest, most detailed visible views of the universe. The field is a very small sample of the heavens and it is observations like this that raise questions like those posed by the anthropic principle. Credit: R. Williams (STScI), the Hubble Deep Field Team and NASA/ESA

The anthropic principle states that the fundamental parameters of the Universe such as the strength of the fundamental forces, have been finely tuned to support life. Whether this is true or not or whether it is even worthy of scientific investigation has been hotly debated. A new paper proposes some ways that this may now be tested and perhaps brings the topic under scientific scrutiny for the first time.

December 9, 2024December 9, 2024 by Evan Gough

Webb Sees a Supercluster of Galaxies Coming Together

Using the NASA/ESA/CSA James Webb Space Telescope, an international team of astronomers have found new galaxies in the Spiderweb protocluster. Because Webb can see infrared light very well, scientists used it to observe regions of the Spiderweb that were previously hidden to us by cosmic dust, and to find out to what degree this dust obscures them. This image shows the Spiderweb protocluster as seen by Webb’s NIRCam (Near-InfraRed Camera). Image Credit: ESA/Webb, NASA & CSA, H. Dannerbauer

As a species, we’ve come to the awareness that we’re a minuscule part of a vast Universe defined by galaxy superclusters and the large-scale structure of the Universe. Driven by a healthy intellectual curiosity, we’re examining our surroundings and facing the question posed by Nature: how did everything get this way?

We only have incremental answers to that huge, almost infinitely-faceted question. And the incremental answers are unearthed by our better instruments, including space telescopes, which get better and more capable as time passes.

Enter the James Webb Space Telescope.

December 9, 2024December 9, 2024 by Evan Gough

Hubble Gets its Best Look At the First Quasar

3C 273 is the uninspiring name given to the very first quasar to be linked with a visual object. Prior to that, quasars were known only by their radio emissions. The Hubble recently took a new, better look at the quasar, seen in this image. Image Credit: NASA, ESA, and STScI

The term quasar comes from quasi-stellar objects, a name that reflected our uncertainty about their nature. The first quasars were discovered solely because of their radio emissions, with no corresponding visual objects. This is surprising since quasars blaze with the light of trillions of stars.

In recent observations, the Hubble examined a historical quasar named 3C 273, the first quasar to be linked with a visual object.

December 9, 2024December 9, 2024 by Brian Koberlein

Do We Really Know What Becomes a Type Ia Supernova?

Illustration of a Type Ia supernova. Credit: Kiso Observatory, The University of Tokyo

Lots of things out in the Universe can cause a supernova, from the gravitational collapse of a massive star, to the collision of white dwarfs. But most of the supernovae we observe are in other galaxies, too distant for us to see the details of the process. So, instead, we categorize supernovae by observed characteristics such as the light curves of how they brighten and fade and the types of elements identified in their spectra. While this gives us some idea of the underlying cause, there are still things we don’t entirely understand. This is particularly true for one particular kind of supernova known as Type Ia.

December 9, 2024December 9, 2024 by Andy Tomaswick

A Cheap Satellite with Large Fuel Tank Could Scout For Interplanetary Missions

A spacecraft that can provide the propulsion necessary to reach other planets while also being reproducible, relatively light, and inexpensive would be a great boon to larger missions in the inner solar system. Micocosm, Inc., based in Hawthorne, California, proposed just such a system via a NASA Small Business Innovation Research (SBIR) grant. Its Hummingbird spacecraft would have provided a platform to visit nearby planets and asteroids and a payload to do some basic scouting of them.

December 9, 2024December 11, 2024 by David Dickinson

Our Strategy to Catch the 2024 Geminid Meteors

Don’t let the bright Moon deter you from seeing the one of the best meteor showers of the year.

Update: Astronomer Gianluca Masi will carry the Geminid meteors live on December 13th, courtesy of the Virtual Telescope Project.

One of the best meteor showers of 2024 closes out the year this coming weekend. If skies are clear, watch for the Geminid meteors, peaking on the night of Friday into Saturday, December 13-14^th.

December 8, 2024December 8, 2024 by Brian Koberlein

Observations by DESI Open the Door to Modified Gravity Models

The relations between various approaches of modified gravity. Credit: J. M. Ezquiaga and M. Zumalacárregui (2018)

The standard theory of cosmology is based upon four things: the structure of space and time, matter, dark matter, and dark energy. Of these, dark energy is the one we currently understand the least. Within the standard model, dark energy is part of the structure of space and time as described by general relativity. It is uniform throughout the cosmos and expressed as a parameter known as the cosmological constant. But initial observations from the Dark Energy Spectroscopic Instrument (DESI) suggest the rate of comic expansion may vary over time. If further observations reinforce this, it could open up cosmological models to alternatives to general relativity known as modified gravity.