Brian Koberlein, Author at Universe Today

October 2, 2022October 2, 2022 by Brian Koberlein

The Milky Way is Surrounded by a Vast Graveyard of Dead Stars

Distribution of stellar remains in the Milky Way. Credit: University of Sydney

Everything dies in the end, even the brightest of stars. In fact, the brightest stars are the ones that live the shortest lives. They consume all the hydrogen they have within a few million years, then explode as brilliant supernovae. Their core remains collapse into a neutron star or black hole. These small, dark objects litter our galaxy, like a cosmic graveyard.

September 30, 2022September 30, 2022 by Brian Koberlein

A Dwarf Galaxy Passed Close to the Milky Way and Left Ripples in its Wake

Artist's view of ripples on the edge of the Milky Way. Credit: NASA JPL-Caltech R. Hurt (SSC Caltech)

When you imagine the collision of galaxies, you probably think of something violent and transformational. Spiral arms ripped apart, stars colliding, cats and dogs living together, mass hysteria. The reality is much less dramatic. As a recent study shows, our galaxy is in a collision right now.

September 28, 2022September 28, 2022 by Brian Koberlein

Jupiter’s Atmosphere is Surprisingly Hot

Temperature measurements of Jupiter's upper atmosphere. Credit: James O’Donoghue

Jupiter is a big planet, but it’s still a planet. That means it doesn’t heat itself through fancy mechanisms like nuclear fusion. Its interior is heated through its own weight, squeezing the interior through hydrostatic equilibrium, and its surface is heated mostly by the Sun. Since Jupiter only gets about 4% of the light per square meter that Earth gets, you’d expect its upper atmosphere to be pretty cold. Traditional models estimate it should be about -70 degrees Celsius. But recent measurements show the upper atmosphere is over 400 degrees Celsius, and in the polar regions as much as 700 degrees Celsius. In the words of Ruby Rhod from the movie The Fifth Element, “It’s Hot Hot Hot!”

September 25, 2022September 25, 2022 by Brian Koberlein

Life can Thrive Around Even the Smallest Stars

A starlight simulator (left) and when illuminated (right). Credit: La Rocca, et al

Photosynthesis is probably the most important chemical reaction for life on Earth. It is the process plants use to transform sunlight into energy it can use. Through it, plants can produce carbohydrates they can use (and we can eat when we harvest plants), generating oxygen as a by-product. Photosynthesis is why Earth’s atmosphere is about 20% oxygen. No photosynthesis, no life on Earth as we know it.

September 24, 2022September 24, 2022 by Brian Koberlein

The Moon’s Poles Have “Wandered” Over Billions of Years

A gravity map of the Moon with (left) and without (right) many craters. Credit: Smith, et al

Until 1959, humans had only seen one side of the Moon. The Moon is tidally locked with Earth, and so we can only see one side from the Earth’s surface. It took the soviet Luna 3 spacecraft to capture a blurry image for humans to get their first glimpse of the lunar far side. Because of this, many people imagine that the Moon has always been this way. But as a recent study shows, that isn’t quite true.

September 21, 2022September 21, 2022 by Brian Koberlein

It Appears That Enceladus is Even More Habitable Than we Thought

Phosphorus is likely abundant in the waters of Enceladus. Credit: Southwest Research Institute

The problem with looking for life on other worlds is that we only know of one planet with life. Earth has a wondrous variety of living creatures, but they all evolved on a single world, and their heritage stems from a single tree of life. So astrobiologists have to be both clever and careful when looking for habitable worlds, even when they narrow the possibilities to life similar to ours.

September 17, 2022September 17, 2022 by Brian Koberlein

A new way to Discover Planets? Astronomers Detect an Exoplanet by Seeing its Trojan Belts

Artist view of a planet and protoplanetary disk around a young star. Credit: M.Weiss/Center for Astrophysics | Harvard & Smithsonian

Although we have found thousands of exoplanets in recent years, we really only have three methods of finding them. The first is to observe a star dimming slightly as a planet passes in front of it (transit method). The second is to measure the wobble of a star as an orbiting planet gives it a gravitational tug (Doppler method). The third is to observe the exoplanet directly. Now a new study in the Astrophysical Journal Letters has a fourth method.

September 13, 2022September 14, 2022 by Brian Koberlein

On its Hunt for Dark Energy, a Telescope Stopped to Look at the Lobster Nebula

The Lobster Nebula NGC 6357 as seen by the Dark Energy Camera. Credit: CTIO/NOIRLab/DOE/NSF/AURA

If you thought dark matter was difficult to study, studying dark energy is even more challenging. Dark energy is perhaps the most subtle phenomenon in the universe. It drives the evolution of the cosmos, but its effects are only seen on intergalactic scales. So to study dark energy in detail, you need a great deal of observations of wide areas of the sky.

September 11, 2022September 11, 2022 by Brian Koberlein

If Jupiter's Orbit got Weirder, it Would Actually Make Earth More Habitable

Io Eclipse on Jupiter from Juno Perijove 22 - NASA/JPL/Kevin Gill

Earth is not just habitable, it’s unusually habitable. It’s rather wet for a planet so close to its Sun, it’s geologically active, and it has a stable orbit, all of which are necessary for life as we know it. But there are also secondary advantages, such as not being constantly bombarded by large asteroids, and having a rotational axis that is fairly stable. This is due in part thanks to the planet Jupiter. The giant planet has helped clear the solar system of asteroid debris and may have helped stabilize the orbits of the inner planets. So life is good. But a new study shows that if Jupiter had a different orbit, life could be even better.

August 24, 2022August 24, 2022 by Brian Koberlein

Colliding Black Holes Provide Another way to Measure Distance in the Universe

A simulation of two merging black holes. Credit: Simulating eXtreme Spacetimes (SXS) Project

We know the universe is expanding, and we have a pretty good idea of how fast it’s expanding, but we don’t know the rate exactly. That’s because of the different methods we have to measure the rate of cosmic expansion keep giving us slightly different results. It’s a nagging problem that bugs astronomers, so while they have worked to ensure current methods are accurate, they have also looked to new ways to measure cosmic expansion. One of these new ways involves gravitational waves.