Deep Impact update

September 2005

Two months ago, much of the world stopped to watch Comet Tempel 1 plough into the Deep Impact spacecraft and the resulting spectacular release of a cloud of dust and gas. Some people watched through telescopes, and some watched the images sent back from the flyby spacecraft by television or computer. Whatever the form of observation, it is true that it was a Deep Impact felt around the world. For the past two, almost three months the science team has been hard at work studying the resulting data while the engineering team planned and performed a maneuver to put the spacecraft on a new path and into a safe sleep mode. If you missed any of this, you may want to take a look at our web site and read the newsletter below for new updates.
http://deepimpact.jpl.nasa.gov
http://deepimpact.umd.edu

Deep Impact probe hits comet
Mission aims to unlock secrets of origins of solar system

Monday, July 4, 2005; Posted: 8:23 a.m. EDT (12:23 GMT)

The "flyby" spacecraft photographed this image of Monday's collision.


"The image clearly shows a spectacular impact," Michael A'Hearn, the mission's scientist, said in a news release.

The Deep Impact spacecraft released the washing machine-size probe, known as the "impactor," on Sunday and then moved into position to watch the collision.

Images showed a huge explosion on the comet -- possibly the equivalent to five tons of TNT. The impactor was destroyed, as expected, but the Deep Impact ship survived to beam back images.

NASA scientists got word of their success at 1:57 a.m. ET, five minutes after the collision.

"This mission is truly a smashing success," said Andy Dantzler, director of NASA's solar system division, in a news release. "Tomorrow and in the days ahead, we will know a lot more about the origins of our solar system."

Icy dirt ball targeted
Comets are the trailblazers of the heavens -- rushing through space from the far reaches of the solar system and back toward the sun in long oval orbits.

They are made of ice, dust and gas left over from when the sun and the planets formed.

Scientists believe comets may hold the keys to the birth of the solar system and perhaps to the birth of life.

The target of Deep Impact was Tempel 1, a jet-black, pickle-shaped, icy dirt ball traveling at 6.3 miles per second.

Since its January 12 launch, NASA's Deep Impact spacecraft raced to catch up with Tempel 1 while observing it along its journey through the solar system.

At a cost of $330 million, Deep Impact is the eighth mission in NASA's Discovery Program, which supports low-budget science missions.

Among the program's other endeavors: the Near Shoemaker that landed a spacecraft on asteroid Eros; the Mars Pathfinder; and the solar wind collection spacecraft Genesis, which crashed into Earth when its parachutes failed to open on descent.

The Deep Impact spacecraft was composed of two probes mated together -- "flyby" and "impactor."

Flyby is about the size of a small car and monitored the impact. It carries two cameras -- a high-resolution one that was tightly focused on the crater and a medium-resolution one that's taking wider views.

Impactor was an 820-pound copper-fortified probe designed to produce maximum wallop when it hit the comet. It also carried a medium-resolution camera that recorded the probe's final moments before it collided with the comet.

Spectacular show ushers in Fourth of July
Staging the fireworks show began 24 hours before impact when mission scientists at NASA's Jet Propulsion Laboratory released impactor from flyby.

Scientists spent Sunday steering flyby into position for observing while aligning impactor for its rendezvous with Tempel 1.

Tempel 1 is traveling through space at about 23,000 mph (37,100 km/h) -- the equivalent of traveling from New York to Los Angeles, California, in less than 6.5 minutes.

At those speeds, impactor had to be in the right place at the right time to intercept the speeding snowball.

"It's a bullet trying to hit a second bullet with the third bullet," Rick Grammier, Deep Impact project manager at the Jet Propulsion Laboratory, said in June.

During its final two hours, impactor was on autopilot, maneuvering itself into the path of the comet.

Then, at about 1:52 am ET Monday, Tempel 1 slammed into impactor -- an event "all over in the blink of an eye," Grammier said.

Until its death, impactor recorded images and gathered data while flyby passed 310 miles (500 kilometers) away, observing the impact, the ejected material, and the structure and composition of the comet's interior. Most of the data will be stored on flyby and radioed back to Earth after the encounter.

Every space and ground-based telescope large enough to do the job was watching the event.

The Hubble, Chandra, Spitzer, Galex and SWAS space telescopes were all recording it. The Rosetta spacecraft, a European probe on its way to another comet, also observed.

On the ground, more than 100 professional astronomers at 60 observatories and a small army of amateur astronomers turned their telescopes in Tempel 1's direction.

The faraway comet