New Exoplanet Confirmed as the Youngest Known World at Less Than 1 Million Years Old

Astronomers have confirmed a new exoplanet called Elias 2-24 b, a roughly Jupiter-mass world that is less than one million years old. The discovery makes it the youngest known exoplanet and offers researchers a rare opportunity to study a giant planet during the earliest stages of its development.

Located about 450 light-years from Earth, Elias 2-24 b orbits the young star Elias 2-24. The planet was found inside a gap in the star’s protoplanetary disk, where gas and dust provide the material from which planets form.

The discovery was published on September 16, 2026, in The Astrophysical Journal Letters.

Elias 2-24 b Sets a New Age Record

Elias 2-24 b is significantly younger than the previous record holders.

NASA reports that the previous youngest known planets were a four-way tie involving worlds orbiting PDS 70 and WISPIT 2, all of which were more than five million years old.

Feature	Elias 2-24 b
Estimated age	Less than 1 million years
Mass	Roughly Jupiter-mass
Distance	About 450 light-years
Host star	Elias 2-24
Location	Gap in protoplanetary disk
Current stage	Actively accreting material

Because the planet is extremely young, its exact mass is difficult to determine. Researchers therefore describe it as roughly Jupiter-mass rather than assigning a precise value.

Found in Archived Keck Observatory Data

The discovery came from a new analysis of previously collected observations.

A research team led by Andrea Bernardi, a doctoral candidate at Universidad Diego Portales in Chile, examined archival observations from the W. M. Keck Observatory in Hawaii.

Researchers identified a faint object in observations from 2018 and used additional observations from 2020 to track its movement. Its motion was consistent with an object orbiting Elias 2-24 rather than a background object or imaging artifact.

Keck’s NIRC2 instrument uses a coronagraph to block much of the bright light from the host star, making it possible to detect faint objects nearby. Observations from ALMA and the European Southern Observatory’s Very Large Telescope also contributed to the investigation.

The New Exoplanet Was Found Inside a Disk Gap

The planet’s location provides an important clue about its formation.

Young stars are surrounded by protoplanetary disks containing gas and dust. Developing planets interact with this material and can create gaps in the disk along their orbits.

Astronomers had already observed a prominent gap in the disk surrounding Elias 2-24. Finding a planet inside the gap strengthens the connection between these disk structures and developing planets.

Elias 2-24 b Is Still Growing

Most exoplanets observed today are much older than Elias 2-24 b. By the time many planets are detected, the disks from which they formed have already disappeared.

Elias 2-24 b remains embedded in its original environment and is actively accreting material from the surrounding disk.

This makes the planet an unusually valuable target for studying how giant planets gain mass and develop during their earliest stages.

Why the Discovery Challenges Planet-Formation Models

The planet’s age raises questions about how quickly giant planets can form.

Current models suggest that forming a Jupiter-sized planet at a distance comparable to Jupiter’s orbit can take roughly five million years. Elias 2-24 b appears to have reached roughly Jupiter-like mass in less than one million years.

The discovery therefore challenges some existing assumptions about the timescale of giant-planet formation. Researchers say current models may still be missing processes that allow planets to grow rapidly.

However, the finding does not disprove established planet-formation theories. Instead, it provides a very young system that can help scientists test and refine those models.

What Scientists Can Learn From Elias 2-24 b

The new exoplanet could help astronomers investigate:

• How quickly giant planets can gain mass.
• How growing planets interact with protoplanetary disks.
• How planets create gaps in disks.
• How young giant planets develop their atmospheres.
• Whether existing models can explain rapid planetary growth.

Future observations could provide more information about the planet’s mass, atmosphere, temperature and continuing accretion.

NASA’s Roman Telescope Could Find More Young Worlds

The discovery comes as NASA’s Nancy Grace Roman Space Telescope begins its mission.

Roman launched on August 30, 2026, and is currently undergoing commissioning. Its coronagraph is designed to suppress starlight and improve the ability to directly observe faint objects close to bright stars.

Once Roman begins science operations, its capabilities could help astronomers search for additional young planets and examine planetary systems at earlier stages of development.

Finding more examples could help researchers determine whether extremely rapid giant-planet formation is unusual or more common than currently understood.

FAQs

What is the new exoplanet discovered by astronomers?

The newly confirmed planet is Elias 2-24 b, a roughly Jupiter-mass world about 450 light-years from Earth.

How old is Elias 2-24 b?

It is estimated to be less than one million years old, making it the youngest known exoplanet.

Is Elias 2-24 b still forming?

Yes. Observations indicate that it is still actively accreting material from the protoplanetary disk around its host star.

How was the planet discovered?

Researchers found it in archival Keck Observatory observations and tracked its movement using observations from 2018 and 2020.

Why is Elias 2-24 b important?

Its extreme youth allows astronomers to study a giant planet while it is still embedded in the environment where it formed, providing valuable information about planetary growth.

Conclusion

The discovery of Elias 2-24 b gives astronomers a rare opportunity to study a giant planet at an extremely early stage.

At less than one million years old, the roughly Jupiter-mass world is still embedded in its surrounding disk and actively accreting material. Its position inside a disk gap also offers important evidence for understanding the relationship between developing planets and their environments.

The new exoplanet does not resolve every question about planet formation, but it provides an unusually young laboratory for testing existing theories. Future observations from facilities such as NASA’s Roman Space Telescope could reveal more about how rapidly giant planets form and evolve.