The spacecraft Dawn is finally reaching the end of its four-year journey toward the dwarf planet Ceres as part of a NASA project led by UCLA researchers.
After passing through the last of the asteroid belt between Jupiter and Mars, the spacecraft will capture high-resolution images to investigate how the solar system formed and how water is involved in the evolution of a planet.
“Asteroids are thought to provide the building blocks of the solar system, as they collide and form bigger bodies,” said Christopher Russell, the principal investigator of the Dawn mission and professor of geophysics and space physics at UCLA. “To understand other planets in our solar system, it is important to understand these building blocks.”
Russell came up with the plan for the mission in 1992. His innovative design utilizes a more fuel-efficient technique known as ion propulsion to power the spacecraft.
In 2000, the position of Vesta and Ceres changed so that they aligned and allowed for a spacecraft to visit one and then the other, doubling the value of the mission, Russell said.
After the discovery, NASA approved and funded Russell’s mission. And in 2007, UCLA researchers began working on the Dawn Mission at the Jet Propulsion Lab at the California Institute of Technology.
As the largest dwarf planet within the asteroid belt between Mars and Jupiter, Ceres is the second stop for Dawn. The spacecraft previously visited the second largest body, the asteroid Vesta, in 2011, where it stayed collecting data about the structure and composition of the asteroid until 2012. Dawn is now expected to arrive at Ceres on March 6, where it will collect images of canyons, mountains and craters.
Russell and his team, including three UCLA graduate students, have been working with NASA and other institutions from around the world. At UCLA, the team has been studying the data collected from Vesta and is currently awaiting new information from Ceres.
“Now is an interesting time because new data is starting to come back from the spacecraft, so people are busy interpreting and speculating on these remotely sensed images,” said Kynan Hughson, a geophysics and space physics graduate student working on the mission.
The UCLA team works to process and interpret images and to map out the planet’s features.
“On a day-to-day basis, we’re looking at 2D and 3D images taken from Vesta, mapping geological features trying to understand how Vesta formed,” said Jennifer Scully, a geology graduate student working on the project. “Working on an active mission has taught me to analyze data and to understand how data like this is collected.”
Ceres and Vesta, believed to have formed more than 4.6 billion years ago, could possibly tell us more about how our own solar system was formed, Russell said.
“This study matters because these asteroids formed early in the history of our solar system,” Scully said. “These are fossils of the beginning of the solar system, telling us about the bodies that would have formed our own Earth.”
These asteroids could also offer some explanation as to where the water on Earth came from. Russell initially chose these two bodies because Vesta is a dry, rocky body, whereas Ceres is a wet body believed to be about 40 percent water, he said. The contrasting bodies could provide information about where water comes from on planets.
Dawn is designed to collect information about the composition of the bodies, their gravitational pull on nearby planets like Mars and the levels of water on each body to compare them with other planets, such as Earth.
Data has shown that Ceres is much cooler than Vesta. This environment could possibly be capable of sustaining life.
“People get excited about water because it’s one of the ingredients for life as we know it,” Scully said. “It doesn’t mean that we are going to find life on Ceres, but it’s an interesting idea to speculate about where life comes from and the conditions it requires.”
The Dawn mission will conclude in July of this year, and Dawn will enter into permanent orbit, Russell said.