Planets Archives

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.

March 18, 2024March 18, 2024 by Nancy Atkinson

Improving a 1960s Plan to Explore the Giant Planets

John Bodylski holds a balsa wood model of his proposed aircraft that could be an atmospheric probe. Directly in front of him is a fully assembled version of the aircraft and a large section of a second prototype at NASA’s Armstrong Flight Research Center in Edwards, California. Credit: NASA/Steve Freeman

In the 1960s, NASA engineers developed a series of small lifting-body aircraft that could be dropped into the atmosphere of a giant planet, measuring the environment as they glided down. Although it would be a one-way trip to destruction, the form factor would allow a probe to glide around in different atmospheric layers, gathering data and transmitting it back to a parent satellite. An updated version of the 1960s design is being tested at NASA now, and a drop-test flight from a helicopter is scheduled for this month.

February 14, 2024February 14, 2024 by Evan Gough

Radio Telescope Confirms Free-Floating Binary Planets in the Orion Nebula

Free-floating JuMBOs (Jupiter-Mass Binary Objects) don't conform to our present stellar and planetary formation theories. Credit: Gemini Observatory/Jon Lomberg

Planets orbit stars. That’s axiomatic. Or at least it was until astronomers started finding rogue planets, also called free-floating planets (FFPs). Some of these planets were torn from their stars’ gravitational grip and now drift through the cosmos, untethered to any star. Others formed in isolation.

Now, astronomers have discovered that some FFPs can orbit each other in binary relationships as if swapping their star for another rogue planet.

January 19, 2024January 19, 2024 by Carolyn Collins Petersen

Diamond Rain on Ice Giants Could Influence Their Magnetic Fields

Scientists created a model to explain how diamond rain falls inside Uranus and Neptune and messes with their magnetic fields. Courtesy SLAC.

Imagine Jupiter with a diamond core the size of Earth. That’s what science fiction author Arthur C. Clarke described in his novel (and movie) 2010: Odyssey 2. Now, imagine the same thing, but at Uranus and Neptune. In addition to a possible diamond core, diamond rain fills the interior. Scientists at the U.S. Department of Energy’s SLAC National Accelerator Laboratory think they know how these diamonds form on ice-giant planets.