First-Ever Quadruple Asteroid

Astronomers discovered a third moon orbiting the main-belt asteroid (130) Elektra. This is the first quadruple asteroid ever found.

• Elektra is a large main-belt asteroid. It was first discovered by Litchfield Observatory astronomer Christian Peters on February 17, 1873.
• Elektra has an effective diameter of 199 km and an estimated mass of 7*1018
• First moon of Elektra was discovered in 2003 by Dr. William Merline and his team. It was discovered using “Keck II telescope” at the Mauna Kea Observatory.

First Moon of Elektra

• First moon of Elektra is designated as S/2003 (130) 1 or S1.
• It has a diameter of 6 km. It orbits 1,300 km away from the parent asteroid, with a period of 5.3 days.

Second Moon of Elektra

• Second moon of Elektra is designated as S/2014 (130) 1 or S2.
• It was discovered on December 6, 2014 by Dr. Bin Yang and his team, using SPHERE facility on ESO’s Very Large Telescope.
• It has a diameter of around 2 km.
• It orbits 500 km away from Elektra, once every 1.2 days.