Planets Archives

December 31, 2024December 31, 2024 by Matt Williams

A Young Exoplanet's Atmosphere Doesn't Match its Birthplace

The natal disk of PDS 70 with new planet PDS 70b (bright spot on the right). Credit: ESO/A. Müller et al.

If the modern age of astronomy could be summarized in a few words, it would probably be “the age of shifting paradigms.” Thanks to next-generation telescopes, instruments, and machine learning, astronomers are conducting deeper investigations into cosmological mysteries, making discoveries, and shattering preconceived notions. This includes how systems of planets form around new stars, which scientists have traditionally explained using the Nebular Hypothesis. This theory states that star systems form from clouds of gas and dust (nebulae) that experience gravitational collapse, creating a new star.

The remaining gas and dust then settle into a protoplanetary disk around the new star, which gradually coalesces to create planets. Naturally, astronomers theorize that the composition of the planets would match that of the disk itself. However, when examining a still-developing exoplanet in a distant star system, a team of astronomers uncovered a mismatch between the gases in the planet’s atmosphere and those within the disk. These findings indicate that the relationship between a protoplanetary disk and the planets they form might be more complicated.

December 30, 2024December 30, 2024 by Evan Gough

Saturn’s Rings Might Be Really Old After All

The Hubble Space Telescope captured this image of Saturn in February, 2023. Image Credit: STScI

Saturn’s rings are among the most glorious, stunning, and well-studied features in the Solar System. However, their age has been difficult to ascertain. Did they form billions of years ago when the planet and the Solar System were young? Or did they form in the last few hundred millions of years?

The latest new research shows that the iconic rings are, in fact, very old.

September 7, 2024September 7, 2024 by Carolyn Collins Petersen

There’s More Water Inside Planets Than We Thought

Planets with magma oceans like this one, GJ 1214b, could have most of their water beneath the surface, deep in their interiors. Image: NASA/JPL-Caltech/R. Hurt

When you walk across your lawn or down the street, you move on the surface of a surprisingly layered world. Some of those layers are rock, others are molten. A surprising amount of water is mixed into those layers, as well. It turns out that most planets have more of it “deep down” than we imagined.

July 18, 2024July 18, 2024 by Laurence Tognetti

Officially, Only the Sun Can Have Planets. Is it Time to Fix the Definition of “Planet”?

Color-enhanced image of Pluto obtained from NASA’s New Horizons spacecraft in July 2015. (Credit: NASA / Johns Hopkins University Applied Physics Laboratory (JHUAPL) / Southwest Research Institute (SwRI))

What is the true definition of a planet, and could there be a more refined definition in the future? This is what a recent study published in The Planetary Science Journal hopes to address as a team of researchers from the United States and Canada investigated the potential for a new definition of a “planet”. This study holds the potential to challenge the longstanding definition outlined by the International Astronomical Union (IAU), which established IAU Resolution B5 in 2006, resulting in demoting Pluto from a “planet” to a “dwarf planet”.

July 2, 2024July 2, 2024 by Evan Gough

Alpha Centauri Could Have a Super Jupiter in Orbit

This image of the sky around the bright star Alpha Centauri AB also shows the much fainter red dwarf star, Proxima Centauri, the closest star to the Solar System. The picture was created from pictures forming part of the Digitized Sky Survey 2. The blue halo around Alpha Centauri AB is an artifact of the photographic process, the star is really pale yellow in colour like the Sun. Image Credit: Digitized Sky Survey 2 Acknowledgement: Davide De Martin/Mahdi Zamani

The three-body problem is one of Nature’s thorniest problems. The gravitational interactions and resulting movements of three bodies are notoriously difficult to predict because of instability. A planet orbiting two stars is an example of the three-body problem, but it’s sometimes called a “restricted three-body problem.” In that case, there are some potential stable orbits for a planet.

A new study shows that the nearby Alpha Centauri AB pair could host a Super Jupiter in a stable orbit.

June 19, 2024June 19, 2024 by Evan Gough

If We Want To Find Life-Supporting Worlds, We Should Focus on Small Planets With Large Moons

A rocky planet with a large moon may have good potential to host life, given that the Moon controls essential aspects for life on Earth, including the length of the day, ocean tides, and stable climate. Image Credit: University of Rochester photo illustration by Michael Osadciw featuring Unsplash photography from Brad Fickeisen, Jaanus Jagomagi, and Engin Akyurt

There’s no perfect way of doing anything, including searching for exoplanets. Every planet-hunting method has some type of bias. We’ve found most exoplanets using the transit method, which is biased toward larger planets. Larger planets closer to their stars block more light, meaning we detect large planets transiting in front of their stars more readily than we detect small ones.

That’s a problem because some research says that life-supporting planets are more likely to be small, like Earth. It’s all because of moons and streaming instability.

May 6, 2024May 6, 2024 by Evan Gough

New Evidence for Our Solar System’s Ghost: Planet Nine

Artist's impression of Planet Nine as an ice giant eclipsing the central Milky Way, with a star-like Sun in the distance. Neptune's orbit is shown as a small ellipse around the Sun. The sky view and appearance are based on the conjectures of its co-proposer, Mike Brown.

Does another undetected planet languish in our Solar System’s distant reaches? Does it follow a distant orbit around the Sun in the murky realm of comets and other icy objects? For some researchers, the answer is “almost certainly.”

April 19, 2024April 19, 2024 by Evan Gough

The Giant Planets Migrated Between 60-100 Million Years After the Solar System Formed

The migration of the giant planets had a hand in shaping our Solar System, including Earth. New research shows the migration happened much earlier than thought. Image Credit: NASA

Untangling what happened in our Solar System tens or hundreds of millions of years ago is challenging. Millions of objects of wildly different masses interacted for billions of years, seeking natural stability. But its history—including the migration of the giant planets—explains what we see today in our Solar System and maybe in other, distant solar systems.

New research shows that giant planet migration began shortly after the Solar System formed.

April 1, 2024April 1, 2024 by Evan Gough

Where Are All These Rogue Planets Coming From?

An artist's illustration of a rogue planet, dark and mysterious. Image Credit: NASA

There’s a population of planets that drifts through space untethered to any stars. They’re called rogue planets or free-floating planets (FFPs.) Some FFPs form as loners, never having enjoyed the company of a star. But most are ejected from solar systems somehow, and there are different ways that can happen.

One researcher set out to try to understand the FFP population and how they came to be.

rogue

March 21, 2024March 21, 2024 by Evan Gough

One in Twelve Stars Ate a Planet

When a star eats a planet, it changes the star's metallicity. New research based on co-natal stars shows that one in twelve stars have eaten at least one planet. Image Credit: International Gemini Observatory/NOIRLab/NSF/AURA/M. Garlick/M. Zamani

That stars can eat planets is axiomatic. If a small enough planet gets too close to a large enough star, the planet loses. Its fate is sealed.

New research examines how many stars eat planets. Their conclusion? One in twelve stars has consumed at least one planet.