Himalia group facts for kids

This diagram compares the orbital elements and relative sizes of the members of the Himilia group. The horizontal axis illustrates their average distance from Jupiter, the vertical axis their orbital inclination, and the circles their relative sizes.

This diagram illustrates all the irregular satellites of Jupiter. The Himalia group is bunched together near the top of the diagram. An object's position on the horizontal axis indicates its distance from Jupiter. The vertical axis indicates its inclination. Eccentricity is indicated by yellow bars illustrating the object's maximum and minimum distances from Jupiter. Circles illustrate an object's size in comparison to the others.

The Himalia group is a family of moons that orbit the giant planet Jupiter. These moons are not perfectly round, and they all travel in a similar path around Jupiter. Scientists believe they all came from the same original space rock.

These moons are called "prograde" because they orbit Jupiter in the same direction that Jupiter spins. The group is named after its largest member, Himalia.

Here are the moons known to be part of the Himalia group, listed from closest to farthest from Jupiter:

• Leda
• Himalia (the biggest moon in the group)
• Lysithea
• Elara

Another moon, named S/2000 J 11, might also be part of this group. Its path around Jupiter seems similar. However, its exact orbit is not fully known yet.

The International Astronomical Union (IAU) is the group that names planets, moons, and other space objects. For moons in the Himalia group, they make sure the names always end with the letter -a.

What Makes the Himalia Group Special?

The moons in the Himalia group share similar features in their orbits. An orbit is the path a moon takes around a planet.

Distance from Jupiter

These moons orbit Jupiter at a distance of about 11,150,000 to 11,750,000 kilometers. To give you an idea, that's more than 11 million kilometers away from Jupiter!

Orbital Tilt and Shape

The path of these moons is also tilted. This tilt, called inclination, is between 26.6 and 28.3 degrees compared to Jupiter's equator. Their orbits are also not perfect circles. The shape of their orbit, called eccentricity, varies from slightly oval to more stretched out.

Moon Colors and Origin

All the moons in the Himalia group look grey. They are similar in color to C-type asteroids. These are asteroids that are rich in carbon.

Scientists think that the Himalia group moons might be pieces of a larger asteroid. This original asteroid likely came from the Asteroid belt, which is between Mars and Jupiter. When this asteroid got too close to Jupiter, Jupiter's strong gravity might have pulled it apart.

The original asteroid was probably about 89 kilometers wide. Himalia, the largest moon in the group, makes up about 87% of the original asteroid's mass. This suggests that the asteroid broke apart without too much force.

See also

In Spanish: Grupo de Himalia para niños