How Giant Planets Are Born: Clues from Distant Stars

By Space.Fan Editorial DeskSeptember 27, 2026 at 2:02 PM UTC

Scientists have found that giant planets often build themselves like snowballs, pulling in material from their surroundings.

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The Drop

Astronomers have taken a close look at two s that host their own s. By using a powerful instrument called GHOST on the Gemini telescope, the team measured the chemical makeup of these s. They looked for sixteen different elements, including carbon, oxygen, and iron. This is a very precise way to see exactly what the s are made of. Knowing what the s are made of helps us understand the environment where their s were born. By comparing the s to their s, scientists found that the s have higher amounts of certain elements than their host s. This tells us a lot about how these worlds formed long ago. It suggests that the s grew through a process called core-accretion. This is like a snowball effect where a rocky core forms first, and then it gains more weight by pulling in gas and dust from the area around the . This study confirms that these giant s grew up in a very specific way, distinct from how some other types of s might form.

Why It Matters

This research is important because it acts like a missing piece in a puzzle of how ary systems grow. By showing that these s have more heavy elements than their s, scientists have strong proof that they grew from smaller solid building blocks. This helps rule out other theories where s might form instantly from a large collapse of gas. It gives astronomers a better blueprint for how the diverse family of s across our galaxy came to be.

The Catch

While these results are strong, they depend on how we model the temperature and pressure of s. The researchers found that different methods of measuring a 's heat can lead to slightly different answers, which shows that our tools for looking at very distant objects are still evolving. We are looking at a small sample of only two s, so there is still much more work to do to see if this is true for every giant in space.

Put That in Perspective

Scientists have been trying to solve the mystery of planet formation for decades. Early models were mostly based on our own solar system, but direct imaging of distant systems like AF Lep and Epsilon Indi gives us a chance to see how different stars build their own families of planets. Future research will likely focus on observing even more systems to see if this snowball growth pattern is common across the universe.

Source September 27, 2026

Aneesh Baburaj, Quinn M. Konopacky, Christopher A. Theissen, Jerry W. Xuan, Roman Gerasimov, Kielan K. W. Hoch

Northwestern University, University of California San Diego, California Institute of Technology, University of Notre Dame, Space Telescope Science Institute·The Astronomical Journal·10.3847/1538-3881/ae9afe