SCIENCE* LAB SCREECH : ASTEROID ELEKTRA

 

Astronomical Quartet

Yet another hanger-on for the asteroid 130

We already knew the asteroid 130 Elektra was special. Astronomers previously discovered it had two moons, making it a rare triple asteroid system.

NOW a third moon may have been found, making it even more uncommon - the first known quadruple asteroid in the solar system.

Elektra was first discovered in 1873, orbiting in the asteroid belt between Mars and Jupiter. Oblong-shaped and 160 miles, or about 260 kilometers, across on its longest side, it is a relatively large asteroid and completes an orbit of the sun every five years.

In 2003, the first moon was discovered orbiting Elektra, and in 2014 a second.

The discoveries were interesting, but not unusual - more than 150 asteroids are known to have one or two moons, in the same way planets can have moon that are gravitationally bound to them.

BUT until now, no asteroid had been found to have three moons, though astronomers expect to find more.

Anthony Berdue, a postdoctoral researcher at the National Astronomical Research Institute of Thailand, and his colleagues used images from the Very Large Telescope in northern Chile to take a closer look at Elektra, and they have found evidence for a previously hidden moon inside the orbits of the other two. [Jonathan O'Callaghan]