Brian Koberlein, Author at Universe Today

October 14, 2024October 14, 2024 by Brian Koberlein

Can an Asteroid's Movements Reveal a New Force in the Universe?

Illustration of the asteroid Bennu. Credit: NASA Jet Propulsion Laboratory

There are four fundamental forces in the Universe. These forces govern all the ways matter can interact, from the sound of an infant’s laugh to the clustering of galaxies a billion light-years away. At least that’s what we’ve thought until recently. Things such as dark matter and dark energy, as well as a few odd interactions in particle physics, have led some researchers to propose a fifth fundamental force. Depending on the model you consider, this new force could explain dark matter and cosmic expansion, or it could interact with elemental particles we haven’t yet detected. There are lots of theories about this hypothetical force. What there isn’t a lot of is evidence. So a new study is looking for evidence in the orbits of asteroids.

October 11, 2024October 11, 2024 by Brian Koberlein

A Black Hole has Destroyed a Star, and Used the Wreckage to Pummel Another Star

Illustration of a tidal disruption event. Credit: NASA/CXC/SAO and Soheb Mandhai/The Astro Phoenix

When a supermassive black hole consumes a star, it doesn’t just swallow it whole. It shreds the star, ripping it apart bit by bit before consuming the remains. It’s a messy process known as a tidal disruption event (TDE). Astronomers occasionally catch a glimpse of TDEs, and one recent one has helped solve a mystery about a type of transient X-ray source.

October 10, 2024October 10, 2024 by Brian Koberlein

Most Mars Meteorites Came From Five Craters

A digital-image mosaic of Mars’ Tharsis plateau shows the extinct volcano Arsia Mons. Credit: NASA/JPL/USGS

Meteorites strike Earth every day. It’s estimated that about 100 – 300 metric tonnes of material strike our planet every year. Most of it consists of sand-grain sized dust that burns up in the atmosphere, but each year a few thousand will reach Earth’s surface.

October 4, 2024October 4, 2024 by Brian Koberlein

The Sun Unleashes its Strongest Flare This Cycle

Image of the October 3, 2024 X9 flare seen in extreme ultraviolet light. Credit: NASA/SDO

Yesterday the Sun released a huge solar flare, and it’s heading toward Earth! It’s nothing to worry about since it’s nowhere near as large as the Carrington Event of 1859, but it is large enough to give us some amazing aurora.

October 3, 2024October 3, 2024 by Brian Koberlein

Gravitational Lens Confirms the Hubble Tension

Webb image showing the appearances of a lensed supernova. Credit: NASA, ESA, CSA, STScI

We’ve known the Universe is expanding for a long time. The first solid paper demonstrating cosmic expansion was published by Edwin Hubble in 1929, based on observations made by Vesto Slipher, Milton Humason, and Henrietta Leavitt. Because of this, the rate of cosmic expansion is known as the Hubble constant, or Hubble parameter, H₀. From this parameter, you can calculate things such as the age of the Universe since the Big Bang, so knowing the value of H₀ is central to our understanding of modern cosmology.

October 2, 2024October 2, 2024 by Brian Koberlein

Bernard's Star Has a Planet (Again)!

This artist’s impression shows Barnard b, a sub-Earth-mass planet that was discovered orbiting Barnard’s star. Credit: ESO/M. Kornmesser

The thing about exoplanets is that astronomers don’t see them the way most people think they do. Part of the reason for that is the way we announce them. Whenever an interesting exoplanet is discovered, the press release usually has colorful artwork showing oceans, mountains, and clouds. Something visually captivating like the image above. But the reality is that we have only imaged a few exoplanets directly, and even then, they appear only as small fuzzy blobs. Most of the known exoplanets were discovered by the transit method, where the star dims slightly as the planet passes in front of it. So what astronomers actually see is a periodic flickering of starlight.

September 28, 2024September 28, 2024 by Brian Koberlein

How Does the Milky Way Compare to Other Galaxies?

A mosaic of the images of 378 satellites across 101 Milky Way-like systems. Credit: Yao-Yuan Mao (Utah), with images from the DESI Legacy Surveys Sky Viewer

The Milky Way is special because it is our home. No matter where we are on Earth we can see its arc of light overhead if the night is dark enough. But how similar is our galaxy to others? Is it an unusual spiral galaxy, or is it rather typical in the cosmos?

September 27, 2024September 27, 2024 by Brian Koberlein

Martian Clay Could Be Hiding the Planet's Atmosphere

An illustration comparing modern Mars (left) with early Mars (right). Credit: NASA’s Goddard Space Flight Center

Ages ago in its youth, Mars appeared much like Earth. It was a warm planet with lakes, rivers, and vast seas. It had a thick atmosphere with clouds and rain. One major difference is that the atmosphere was rich with carbon dioxide instead of oxygen. Then about 3.5 billion years ago much of the atmosphere disappeared, and we haven’t understood how. A new study in Science Advances suggests that the waters of Mars may have been the key, and much of the ancient atmosphere may be locked in the surface of the red planet.

September 26, 2024September 26, 2024 by Brian Koberlein

Dark Matter Could a Have Slight Interaction With Regular Matter

A comparison of non-interacting and interacting dark matter. Credit: Gabriel Pérez

The reason we call dark matter dark isn’t because it’s some shadowy material. It’s because dark matter doesn’t interact with light. The difference is subtle, but important. Regular matter can be dark because it absorbs light. It’s why, for example, we can see the shadow of molecular clouds against the scattered stars of the Milky Way. This is possible because light and matter have a way to connect. Light is an electromagnetic wave, and atoms contain electrically charged electrons and protons, so matter can emit, absorb and scatter light. Dark matter isn’t electrically charged. It has no way to connect with light, and so when light and dark matter meet up they simply pass through each other.

September 25, 2024September 25, 2024 by Brian Koberlein

Biosignatures Can be Made in the Lab. No Life Needed.

The most likely way we will discover life on a distant exoplanet is by discovering a biosignature. This can be done by looking at the atmospheric spectra of a world to discover the spectral pattern of a molecule that can only be created through biological processes. While it sounds straightforward it isn’t. The presence of simple molecules such as water and oxygen don’t prove life exists on a planet. It’s true that Earth’s atmosphere is oxygen rich thanks to life, but geological activity can also produce large quantities of oxygen. And as a new study shows, some molecules we’ve long thought to be biological in origin may not be.