45 Eugenia facts for kids

45 Eugenia is a large asteroid found in the Main Belt between Mars and Jupiter. It is special because it was one of the first asteroids discovered to have its own moon. It is also only the second known asteroid to have two moons orbiting it, making it a "triple asteroid."

How Was 45 Eugenia Discovered?

Eugenia was found on June 27, 1857, by a scientist named Hermann Mayer Salomon Goldschmidt. He was an artist and astronomer who discovered many asteroids.

Naming 45 Eugenia

This asteroid was named after Empress Eugénie, who was the wife of Napoleon III, the French Emperor. This was a big deal because it was the first time an asteroid was named after a real person. Before Eugenia, asteroids were usually named after characters from old myths and legends.

What Is 45 Eugenia Like?

Eugenia is a very big asteroid. It is about 214 kilometers (133 miles) wide. Imagine a rock that's wider than many cities!

Color and Composition

Eugenia is an F-type asteroid. This means it is very dark, even darker than soot. It is mostly made of materials like carbonate.

Is It Solid or Rubble?

Scientists think Eugenia might not be a solid rock. Its density is very low. This suggests it could be a "rubble pile." A rubble pile asteroid is like a giant collection of rocks and dust that are loosely held together by gravity. It might have been broken apart by a crash and then slowly pulled back together.

How Does 45 Eugenia Spin?

Eugenia spins around quite fast. One full spin takes about 5.7 hours. It also has an interesting tilt. Its axial tilt is about 117 degrees. This means it spins "backwards" compared to most planets.

Does 45 Eugenia Have Moons?

Yes, 45 Eugenia has two known moons! This makes it a very interesting object for astronomers to study.

Petit-Prince: Eugenia's First Moon

In November 1998, astronomers found a small moon orbiting Eugenia. They used a powerful telescope in Hawaii called the Canada-France-Hawaii Telescope. This was the first time a moon orbiting an asteroid was found using a telescope on Earth.

The moon was named Petit-Prince. This name honors Empress Eugénie's son, the Prince Imperial. Petit-Prince is much smaller than Eugenia, only about 13 kilometers (8 miles) wide. It takes about five days to orbit around Eugenia.

S/2004 (45) 1: Eugenia's Second Moon

Later, scientists found a second, even smaller moon orbiting Eugenia. This moon is estimated to be about 6 kilometers (3.7 miles) wide. It orbits closer to Eugenia than Petit-Prince does.

This second moon was discovered by looking at images taken in 2004. These images were from the VLT in Chile. The discovery was announced in 2007 by a team of scientists led by Franck Marchis.

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