NASA's Dawn spacecraft became the first mission to achieve orbit around a dwarf planet last week when it was captured by Ceres’ gravity at 4:39 a.m. PST (7:39 a.m. EST) on Friday.

"Since its discovery in 1801, Ceres was known as a planet, then an asteroid and later a dwarf planet," said Marc Rayman, Dawn chief engineer and mission director at JPL, in a prepared statement. "Now, after a journey of 3.1 billion miles (4.9 billion kilometers) and 7.5 years, Dawn calls Ceres, home."

The Dawn mission will allow Jet Propulsion Laboratory scientists "to look back in time to see how terrestrial planets are put together," director of NASA’s Planetary Science Division Jim Green said during a media briefing about the achievement.

The spacecraft’s last leg to the largest unexplored world in the inner solar system unveiled some unexplained surprises that have scientists baffled. A mysterious bright point was spotted when Dawn captured the sharpest images ever of the dwarf planet in January. Then a second unexplained bright spot residing alongside the first luminous anomaly appeared in images taken late last month.

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Unfortunately, we’ll have to wait until mid-April to find out what the mysterious areas are as the spacecraft's trajectory is swinging it around the dark side of Ceres at the moment. The first science orbit is expected to be April 23 with an altitude of 8,400 miles above Ceres, while the final orbit will be 230 miles above the surface.

With an average diameter of 590 miles (950 kilometers), Ceres is the largest body in the asteroid belt located between Mars and Jupiter. Dawn will remain in its orbit for 16 months as scientists study its surface.

"We feel exhilarated," said Chris Russell, principal investigator of the Dawn mission. "We have much to do over the next year and a half, but we are now on station with ample reserves, and a robust plan to obtain our science objectives."

Dawn’s orbit around Ceres makes it the first mission to orbit two extraterrestrial targets. The spacecraft previously explored the giant asteroid Vesta, the second largest body in the asteroid belt, from 2011 to 2012.

Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Jenna Pitcher is a freelance journalist writing for IGN. You can follow her on Twitter