Hubble Fellow Scott Sheppard is quoted in a Space.com article entitled, “Neptune May Have Thousands of Escorts.” So far, five of these bodies—known as Trojans—have been found at Neptune’s Lagrange points—where the gravity of the planet and that of the Sun interact to create an area of gravitational stability. The first Neptune Trojan was discovered in 2001 as part of the NASA- funded Deep Ecliptic Survey. A further three Neptune Trojans between 37 and 87 miles in diameter have since been identified by Sheppard and Chadwick Trujillo of the Gemini Observatory, using the 6.5-meter Magellan telescope at the Las Campanas Observatory in Chile.

Despite their diminutive size and brightness, the Neptune Trojans quickly betrayed their existence by their distinct motion against background stars. The most recent Trojan discovered by Sheppard and Trujillio is moving at an unusual inclination of 25 degrees relative to the plane of the solar system.

Sheppard commented, “The sky we covered searching for Neptune Trojans was all within 1.5 degrees of the ecliptic. High inclination objects will spend the majority of their time off the ecliptic. Thus, detecting a high inclination Trojan in our survey suggests there is a large population of such objects. In fact, the high-inclination objects appear to outnumber the low-inclination objects by a ratio of four to one.”

For more information, see the online article.