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3 lobes and a moon for asteroid Nysa?
The German-French astronomer Hermann Goldschmidt discovered asteroid Nysa (pronounced NYE-suh) back on May 27, 1857. It became the 44th known minor planet. Now, nearly 170 years later, we are still discovering the true nature of this rocky world in the asteroid belt.
On July 29, 2026, Lowell Observatory said astronomers using the Large Binocular Telescope in Arizona and the Very Large Telescope in Chile have discovered that this world is likely made of three bodies that have stuck together.
What’s more, their observations also revealed a tiny moon circling the asteroid.
Nysa is unusual
Astronomers have previously found a number of asteroids that look like two rocky bodies collided and stuck together. These binary asteroids include Donaldjohanson and Torifune.
But Nysa – named after the mythical mountainous land of Nysa from Greek mythology – would be the first known trinary asteroid.
Lead author Kate Minker of Lowell Observatory in Flagstaff, Arizona, said:
The images reveal a remarkably unusual object. The most likely explanation is that Nysa is either a contact trinary, consisting of three connected components, or an extremely irregular coherent body unlike anything we’ve previously observed.
The researchers published their peer-reviewed paper on arXiv on July 28, 2026. It’s been accepted for publication by the journal Astronomy & Astrophysics. Al Conrad of the Large Binocular Telescope Observatory said:
In this paper, we’re finally unmasking the asteroid’s true nature, long after it was discovered.
Asteroid 44 Nysa
The new images of Nysa appear to show two depressions that wrap around the asteroid. These would be the connection points between the three previously separate objects. The astronomers call these colli, or neck-like connections between separate lobes.
Nysa’s composition suggests it formed close to the sun. Nysa is an E-type asteroid because it’s rich in a mineral called enstatite. That’s a mineral that reflect a lot of light, making Nysa one of the brightest asteroids. It shines at around magnitude 6.75. That’s within reach of a pair of 7×50 binoculars.
So how did it get its unique shape? Astronomers think it might have formed during a collision, even before it reached the asteroid belt. Three of the scattered pieces then slowly gravitated back together and stuck. Another possibility is the asteroid could have formed after a hit-and-run from another asteroid. These collisions can offer astronomers a peek at the conditions of the early solar system.
A mini moon for Nysa
The new imagery also shows a pretty clear moon orbiting the asteroid. It even has its own designation: S/2026 (44) 1. The researchers estimate the moon to be around a half mile (a little more than 1 km) in diameter. It has a separation from Nysa of about 100 miles (160 km). Nysa itself has a diameter of about 46 miles (75 km).
Bottom line: The asteroid Nysa might be the first-known three-lobed body. And the new observations also reveal a tiny moon orbiting the asteroid.
Source: Unmasking (44) Nysa: Evidence for a trilobate structure
Via University of Arizona
Via Lowell Observatory