Brian Koberlein, Author at Universe Today

August 23, 2023August 23, 2023 by Brian Koberlein

The Irony. ClearSpace-1 Couldn't Clean up Space Debris Because its Target Already Got hit by Space Debris, Creating Even More Space Debris.

Illustration of ClearSpace-1 capturing a piece of space debris. Credit: ClearSpace

We have a problem.

Ever since the launch of Sputnik 1 in 1957, we have been launching debris into space. Everything from space stations and large communication satellites to small CubeSats. With each launch, we also add things such as rocket parts and paint chips to the orbital pile. Right now there are more than a million objects orbiting Earth wider than a centimeter, and at least 130 million millimeter-sized objects. Most of it isn’t going to deorbit any time soon.

August 22, 2023August 22, 2023 by Brian Koberlein

When the Sun Dies, it Could Produce a Fantastic Ring in Space, Like This New Image From JWST

The Ring Nebula seen by JWST's Near-Infrared Camera (left) and Mid-Infrared Instrument (right). Credit: ESA/Webb, NASA, CSA, M. Barlow (University College London), N. Cox (ACRI-ST), R. Wesson (Cardiff University)

Planetary nebulae were first discovered in the 1700s. Legend tells us that through the small telescopes of the time, they looked rather planet-like, hence the name. Real history is a bit more fuzzy, and early objects categorized as planetary nebulae included things such as galaxies. But the term stuck when applied to circular emission nebulae centered around a dying star. As new observations show, planetary nebulae have a structure that is both simple and complex.

August 19, 2023August 19, 2023 by Brian Koberlein

A New Way to Measure the Expansion Rate of the Universe: Redshift Drift

Cosmological redshift depends upon a galaxy's distance. Credit: NASA/JPL-Caltech/R. Hurt (Caltech-IPAC)

In 1929 Edwin Hubble published the first solid evidence that the universe is expanding. Drawing upon data from Vesto Slipher and Henrietta Leavitt, Hubble demonstrated a correlation between galactic distance and redshift. The more distant a galaxy was, the more its light appeared shifted to the red end of the spectrum. We now know this is due to cosmic expansion. Space itself is expanding, which makes distant galaxies appear to recede away from us. The rate of this expansion is known as the Hubble parameter, and while we have a good idea of its value, there is still a bit of tension between different results.

August 18, 2023August 18, 2023 by Brian Koberlein

A New Simulation Reveals One Entire Stage of a Star's Life

The interior structure of our Sun. Credit: Kelvin Ma, via Wikipedia

Nuclear fusion is at the center of stellar evolution. Most of a star’s life is a battle between gravity and nuclear power. While we understand this process on a broad scale, many of the details still elude us. We can’t dive into a star to see its nuclear furnace, so we rely on complex computer simulations. A recent study has made a big step forward by modeling the entire fusion cycle of a single element.

August 17, 2023August 17, 2023 by Brian Koberlein

We Might Be Able to Measure Dark Energy Through the Milky Way's Collision With Andromeda

How the sky might look when the Andromeda galaxy approaches the Milky Way. Credit: NASA; ESA; Z. Levay and R. van der Marel, STScI; T. Hallas; and A. Mellinger

The Universe is expanding, and it’s doing so at an ever-increasing pace. Whether due to a dark energy field throughout the cosmos or due to a fundamental of spacetime itself, the cosmos is stretching the space between distant galaxies. But nearby galaxies, those part of our local group, are moving closer together. And how they are falling toward each other could tell us about the nature of cosmic expansion.

August 16, 2023August 16, 2023 by Brian Koberlein

New Horizons is So Far Away, it Can Measure the True Darkness of the Universe

Artist view of the New Horizons spacecraft against a sea of stars. Credit: Serge Brunier/Marc Postman/Dan Durda

Just how dark is the night sky?

If you step outside during a moonless night and look up, it probably doesn’t look that dark at all. Streetlights or nearby porch lights fill the air with a background glow, particularly if they happen to be bluish-white LEDs. Light pollution in your neighborhood is likely so bad that you can only see a few bright stars. Even in somewhat rural areas, our skies are so bright that the Milky Way isn’t really visible. In North America and Europe, only about a quarter of children have seen the Milky Way.

August 14, 2023August 14, 2023 by Brian Koberlein

Storms on Saturn Can Have Impacts That Last for Hundreds of Years

A giant storm rages on Saturn. Credit: NASA/JPL-Caltech/SSI

The Great Red Spot of Jupiter is a storm that has raged for hundreds of years. It was first observed by Gian Domenico Cassini in 1665, and except for a period between 1713 to 1830, it has been observed continuously ever since. Even if Cassini’s storm is not the one we see today, the current red spot has been around for nearly two centuries. While great storms appear now and then on Saturn and other gas planets, they don’t have the staying power of Jupiter’s great storm. Or so we thought.

August 13, 2023August 13, 2023 by Brian Koberlein

Vera Rubin Will Find Many More Interstellar Objects

Illustration of an interstellar object approaching our solar system. Credit: Rubin Observatory/NOIRLab/NSF/AURA/J. daSilva

Most of the comets we see in the sky were born in our solar system. They may have formed deep within the Oort cloud, and for some, it is their first visit to the inner solar system, but they are distinctly children of the Sun. We know of only two objects that came from beyond our solar system, Omuamua and Borisov. There are likely other interstellar objects visiting our solar system, we just haven’t found them. But that’s likely to change when Rubin Observatory comes online.

August 12, 2023August 12, 2023 by Brian Koberlein

Giant Tidal Waves are Crashing Onto the Surface of an Enormous Star

Illustration of waves breaking on a heartbeat star. Credit: Melissa Weiss, CfA

Binary star systems often appear as variable stars. When we can’t see the individual stars because they are either too close together or too far away, we can see the gradual brightening and dimming of a single point of light as the stars orbit each other. Sometimes if the stars are particularly close when they pass each other they can brighten in unusual ways. One example of this is known as a heartbeat star.

August 11, 2023August 11, 2023 by Brian Koberlein

Evidence for Modified Gravity Found in the Motions of Binary Stars

Artistic repesentation of a binary star system. Credit: NASA/JPL-Caltech

With our continued failure to discover dark matter particles, it’s worth considering alternatives. While dark matter is the most widely supported model, the alternatives fall into two broad paths. One is that we should look to extended models of general relativity, such as conformal gravity. The other argues we should modify the very nature of Newtonian dynamics. The first approach tends to be popular with theorists since it focuses on an abstract theory in the same vein as Einstein’s original ideas. The second, often known as Modified Newtonian Dynamics, or MoND, tends to be more popular with observational astronomers.