The Latest Breaking News from the International Astronomical Union

Betelgeuse has a companion star, Siwarha. Astronomers confirm the dying red giant isn't alone. Here's what it means

Betelgeuse's companion star discovered explained its variable brightness. Astronomers have confirmed Betelgeuse, a famous night sky star, has a hidden companion. This small, hot star, named Siwarha, has been orbiting Betelgeuse for generations. Using advanced telescopes, scientists captured the sharpest image of Siwarha, confirming its existence. Siwarha's presence may influence…

The Economic Times · Jul 29

Pluto and the Love, Hate, Longing: What Our Relationship With a Demoted Planet Says About Us

We Gave It a Name, So It Became OursPluto was discovered in 1930 by Clyde Tombaugh, a 24-year-old farm boy from Kansas working at the Lowell Observatory. An 11-year-old British girl named Venetia Burney suggested the name. Her grandfather passed it along. The International Astronomical Union accepted it. And just…

Times Life · Jun 25

A philosopher’s take on NZ’s bill to define who counts as a woman or man

In August 2006, at the general assembly of the International Astronomical Union in Prague, astronomers voted on a new definition of a planet, and Pluto was demoted.

The Conversation · Jun 9

Saturn now has 274 moons – but exactly what makes something a moon remains unclear

Earlier this week, Saturn gained a whopping 128 new official moons, as the International Astronomical Union recognised discoveries from a team of astronomers led by Edward Ashton at the Academia Sinica in Taiwan. The sixth planet from the Sun now has a grand total of 274 moons, the most of…

The Conversation · Mar 14, 2025

Is Pluto a planet or not? Who cares! Our love for the King of the Kuiper Belt is stronger than ever 95 years later

On the 95th anniversary of its discovery, Pluto remains one of the most beloved and enigmatic worlds in our solar system, whether you call it a planet or not.

Space · Feb 18, 2025

Strange 'quasi-moon' of Earth gets named Cardea, after goddess of door hinges

A quasi-moon of Earth has been given a name. It's Cardea, after the goddess of door hinges.

Space · Jan 22, 2025

Strange "quasi-moon" of Earth will get one of these 7 names

A panel of experts has picked seven finalists for the name of asteroid (164207) 2004 GU9, a "quasi-moon" of Earth. You can vote for your favorite through Jan. 1, 2025.

Space · Dec 2, 2024

The Pluto problem: Is it time to rethink our definition of a planet?

In 2006, the International Astronomical Union (IAU) famously demoted Pluto to a dwarf planet. Things have been a bit of a mess since then — so is it time to redefine the planet?

Space · Oct 22, 2024

Pluto mission: South African astronomers join forces with NASA to learn more about the dwarf planet

When the International Astronomical Union announced in 2006 that Pluto was being demoted from its status as the Sun’s ninth planet, many astronomers and non-experts alike were shocked.

The Conversation · Sep 9, 2024

Earth has 7 strange quasi-moons — and you could name one of them

The International Astronomical Union has partnered with the Radiolab podcast to present a quasi-moon-naming contest.

Space · Jul 6, 2024