JPL Scientists Celebrate Success of Deep Impact Mission

Three days after Deep Impact scientists at the Jet Propulsion Laboratory in La Cañada Flintridge successfully impacted the comet Tempel 1, they were dancing - literally - in the streets.

“I got a call from [JPL] media that five comets were headed for JPL,” Don Yeomans, Deep Impact co-investigator said of Bill Haley’s original comets, who played for employees at JPL on July 5.

The Comets are the five surviving members of the original Comets. They had scientists up and rockin’ to their hits, including “Rock Around the Clock” and “Shake Rattle & Roll.”

The scientists from Deep Impact mission had something to dance about after their success at impacting a comet 83 million miles from Earth.

Deep Impact, which launched on Jan. 12, is a mission of two parts: a VW Bug-sized flyby probe to shoot pictures and carry the second part, and a coffee table-sized iron impactor. Its mission to comet Tempel 1 is to find what is inside a comet, possibly to find the “building blocks of life.” After flying for 173 days and covering 268 million miles, at 83 million miles away from Earth, it moved into the path of comet Tempel 1. On July 2, at 11:07 p.m., the impactor was released in the comet’s path, and the flyby maneuvered 310 miles away to take pictures of the upcoming impact.

After three targeting maneuvers, the impactor began its final descent into the comet. Scientists had originally planned for the impactor to take photos of the comet up to 30 seconds before the impact; however, the spacecraft exceeded expectations by sending back photos three seconds before impact. The impactor hit the comet at 6.3 miles per second, shooting particles out into space, at 10:52:24 p.m. (PDT). At that speed, one worry was how impacting the comet may throw it out of its main orbit. Though the kinetic energy is equal to 5 tons of dynamite, the impactor only changes Tempel 1’s speed by 0.014 inches per hour.

With the impactor gone, the flyby shot pictures of the impact site and the sun lit particles for 13 minuets, until it turned around to protect itself from the ejecta - the flying particles released by the impactor.

Telescopes from all over the world were aimed at Temple 1 to observe the impact. A large flash was seen by the flyby spacecraft and other observers. That flash, according to JPL’s Bill Blume, mission design lead for Deep Impact said happened because of the heat generated on impact. The iron impactor vaporized along with pieces of the comet, turning them into liquid rock and metal. Like on Earth, with lava or smelting iron, it is heated into a more liquid state that gives off light without fire.

The mission had a large interest around the world. JPL reported that their Web site received 1 billion hits during the time of impact.

“We want to keep people excited about it,” said Pete Schultz, co-investigator from Brown University. To help that interest continue, JPL/NASA will be publishing up-to-date pictures of their findings on their Web site at www.nasa.gov/deepimpact.

Scientist continue to look at data, but it will take time.

“The more we find, the more we process,” said Schultz, regarding the data that is streaming into JPL from the flyby and observation telescopes. “We are looking at several points of view. Scientist have yet to find the crater they assume was created by the impact.

“There is a lot of debris [from the impact],” said Schultz.

Now the research goes to the scientists and many team members, like Shadan Ardalan, are preparing to go on to the next project.

“I was pulled from Cassini [Saturn Mission],” said Ardalan. He admits that it is sad leaving a project. His first mission with JPL was Galileo.

“I think of it [Galileo] often, and I think of it fondly,” said Ardalan of his time on the mission. He feels that it is important to explore space and to get answers of where we come from. “We are a species of explorers by nature.” Ardalan compares looking at the 4-billion-year old comet to a history lesson. “We study history in part to learn how to behave in the future,” said Ardalan, who added that we look at Venus and Mars and wonder, “Could Earth suffer that same fate?”