Dawn Spacecraft Achieves Orbit Around Dwarf Planet Ceres

PASADENA (CBSLA.com) — A Jet Propulsion Laboratory-managed spacecraft made history Friday as the first mission to achieve orbit around a dwarf planet.

The ion-powered Dawn spacecraft was captured by the gravitational pull of Ceres – located between Mars and Jupiter – at 4:30 a.m., according to JPL.

"Since its discovery in 1801, Ceres was known as a planet, then as an asteroid and later a dwarf planet," according to Marc Rayman, Dawn's chief engineer and mission director at JPL. "Now, after a journey of 3.1 billion miles and 7.5 years, Dawn calls Ceres home."

With this achievement, Dawn also reached another space milestone as the first craft to orbit two extraterrestrial bodies in the same mission. Dawn orbited the asteroid Vesta for 14 months in 2011-12. Vesta and Ceres are the largest bodies in the solar system's main asteroid belt between Mars and Jupiter.

Dawn was launched in 2007 and is powered by a fuel-saving propulsion system. With electrically charged ions that are propelled through metal grids at high speed, "we can achieve fantastically high velocity," Rayman said.

"Being able to orbit two distant extraterrestrial destinations would be impossible without ion propulsion," he said.

Ceres was discovered by Sicilian astronomer Father Giuseppe Piazzi in 1801, which led to the discovery of more objects in the region that later became known as asteroids.

"Both Vesta and Ceres were on their way to becoming planets, but their development was interrupted by the gravity of Jupiter," according to Carol Raymond, deputy project scientist at JPL. "These two bodies are like fossils from the dawn of the solar system, and they shed light on its origins."

She said Vesta and Ceres are "samples of the building blocks that have formed Venus, Earth and Mars," noting that bodies similar to Vesta likely contributed to Earth's core, while "Ceres-like bodies may have provided our water."

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