Universe Today

December 12, 2024December 12, 2024 by Brian Koberlein

Early Earth's Oceans of Magma Accelerated the Moon's Departure

Illustration of the exoplanet Corot-7b, which may have lava oceans. Credit: ESO/L. Calçada

The Earth and Moon have been locked in a gravitational dance for billions of years. Each day, as the Earth turns, the Moon tugs upon the oceans of the world, causing the rise and fall of tides. As a result, the Earth’s day gets a little bit longer, and the Moon gets a little more distant. The effect is small, but over geologic time it adds up. About 620 million years ago, a day on Earth was only 22 hours long, and the Moon was at least 10,000 km closer than it is now.

December 11, 2024December 11, 2024 by Matt Williams

Could the ESA’s PLATO Mission Find Earth 2.0?

Artist's impression of the ESA's PLATO mission. Credit: ESA/ATG medialab

Currently, 5,788 exoplanets have been confirmed in 4,326 star systems, while thousands more candidates await confirmation. So far, the vast majority of these planets have been gas giants (3,826) or Super-Earths (1,735), while only 210 have been “Earth-like” – meaning rocky planets similar in size and mass to Earth. What’s more, the majority of these planets have been discovered orbiting within M-type (red dwarf) star systems, while only a few have been found orbiting Sun-like stars. Nevertheless, no Earth-like planets orbiting within a Sun-like star’s habitable zone (HZ) have been discovered so far.

This is largely due to the limitations of existing observatories, which have been unable to resolve Earth-sized planets with longer orbital periods (200 to 500 days). This is where next-generation instruments like the ESA’s PLAnetary Transits and Oscillations of stars (PLATO) mission come into play. This mission, scheduled to launch in 2026, will spend four years surveying up to one million stars for signs of planetary transits caused by rocky exoplanets. In a recent study, an international team of scientists considered what PLATO would likely see based on what it would see if observing the Solar System itself.

December 11, 2024December 11, 2024 by Mark Thompson

Zap! A Black Hole Scores a Direct Hit With its Jet

NASA/CXC/SAO/D. Bogensberger et al; Image Processing: NASA/CXC/SAO/N. Wolk;

Most galaxies are thought to play host to black holes. At the center of Centaurus A, a galaxy 12 million light years away, a jet is being fired out into space. Images that have been captured by NASA’s Chandra X-ray observatory show that the high energy particles have struck a nearby object creating a shockwave. The target is thought to be a giant star, maybe even a binary system, where the collision and turbulence has increased density in the region.

December 11, 2024December 11, 2024 by Evan Gough

Does Life Really Need Planets? Maybe Not

Newly discovered Earth-size planet TOI 700 e orbits within the habitable zone of its star in this illustration. New research questions whether planets are necessary for life. Image Credit: NASA/JPL-Caltech/Robert Hurt

Do we have a planetary bias when it comes to understanding where life can perpetuate? It’s only natural that we do. After all, we’re on one.

However, planets may not be necessary for life, and a pair of scientists from Scotland and the USA are inviting us to reconsider the notion.

December 11, 2024December 11, 2024 by Brian Koberlein

Tidal Steams of Interstellar Objects May Flow Through the Milky Way Like Braided Rivers

How tidal disruption can create a stream of interstellar objects. Credit: NAOC / Y. Zhang

We know that interstellar objects occasionally visit our solar system. So far, we have only discovered two interstellar objects (ISOs), but that’s mainly because we can only distinguish them from solar system bodies by their orbital motion, and that takes a series of observations over time. The two we have discovered, ?Oumuamua and Borisov, were only noticed because they had highly unusual orbits that moved through the inner solar system. But when sky survey telescopes such as the Vera Rubin Observatory come online, we will likely find new interstellar objects all the time. It’s estimated that several ISOs enter the solar system every year, and there could be hundreds of them passing by at any given time. But that raises an interesting question about how these objects arrive. Do they enter our solar system randomly from all directions, or do they appear in clusters a few at a time?

December 10, 2024December 10, 2024 by Mark Thompson

An Interstellar Visitor Helped Shape the Orbits of the Planets.

This artist’s impression illustrates an interstellar object rapidly approaching our Solar System. The object, ejected from its home planetary system long ago, traveled through interstellar space for billions of years before briefly passing through our cosmic neighborhood. Rubin Observatory will reveal many of these previously unknown interstellar visitors. Alt-Text: An artist’s impression of a small, rocky interstellar object hurtling from the upper right toward the inner Solar System. The orbits of the four inner planets (Mercury, Venus, Earth, Mars) are fully visible, drawn as teal concentric circles around the bright ball of the Sun at the center. We see the orbits from a slightly elevated angle, so that the circular paths appear oval. The black background is sprinkled with points of starlight. The interstellar object looks like an elongated potato above the Sun, streaming toward the Sun from the upper right, with a short tail of gas and dust trailing behind.

The orbits of the planets around the Sun have been the source for many a scientific debate. Their current orbital properties are well understood but the planetary orbits have evolved and changed since the formation of the Solar System. Planetary migrations have been the most prominent idea of recent decades suggesting that planetary interactions caused the young planets to migrate inwards or outwards from their original positions. Now a new theory suggests 2-50 Jupiter mass object passing through the Solar System could be the cause.

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.