The modern robotic investigation of comets began with a spacecraft from the European Space Agency (ESA) named Giotto. Giotto captured in 1986 the first close-up images of a cometary nucleus and a wealth of other data. ESA is marking the 20th anniversary of Giotto’s successful flyby of Comet Halley on the eve of a NASA press conference regarding science results from the Stardust mission. Twenty years after Giotto, our knowledge about comets, those cold remnants of our solar system’s formation, is undergoing a revolution.

By 1986, six spacecraft were ready for an unprecedented scientific investigation of Comet Halley as it returned to the inner solar system. Due to budget cuts, NASA’s ambitious plans to study Comet Halley were reduced to long distance observations using the International Sun-Earth Explorer 3 (ISEE-3) spacecraft (renamed Interplanetary Comet Explorer (ICE)) already in operations. Meanwhile, after flying by Venus, the Russian Space Research Institute (IKI) spacecrafts VEGA-1 and VEGA-2 were directed toward Comet Halley. Japan’s Institute of Space and Aeronautical Science, which in 2003 became part of Japan Aerospace Exploration Agency (JAXA), used their existing SAKIGAKE (MS-T5) spacecraft for long distance observations and launched SUISEI (PLANET-A), a spacecraft specifically built to study Comet Halley. ESA’s Giotto spacecraft rounded out “Halley Armada.”

Named after the painter of “Adoration of the Magi” which includes a representation of a comet widely believed to be based on Comet Halley, Giotti flew closer to the comet than any of the other spacecraft. The dramatic images and other data returned revealed that Halley was not a round and icy “snow ball” as expected but instead an irregular and dark “dirt ball.” Jets of ice and gas volatiles erupted from the sun-heated surface of the nucleus, creating the bright and extensive coma and tail visible from the Earth.

This first close-up look at a comet revolutionized our understanding of the objects. Since then, several other robotic missions have provided even more highly detailed images and data. Tomorrow, scientists will hold a press conference to report the first science results from their analysis of the first pristine cometary material returned to Earth for extensive analysis. What we learn from the Stardust mission will no doubt radically advance our knowledge.

In twenty years, from the first close-up images of a comet to the first cometary material returned for study, we have learned more about the formation of our solar system and perhaps even the history of life on Earth than in all the thousands of years of comet observation that preceded the Space Age. From Giotto to Stardust in the blink of an eye.

More Information

• ESA Press Release - “Giotto’s brief encounter“
• Halley Armada:
  • Interplanetary Comet Explorer (ICE)
  • SUISEI (PLANET-A)
  • SAKIGAKE (MS-T5)
  • VEGA-1 and VEGA-2
  • Giotto
• Stardust
  • Press Conference, Monday, March 13, 2006 - “NASA ANNOUNCES FIRST STARDUST COMET SAMPLE RESULTS” | Announcement | NASA TV

The sample-return capsule from the Stardust spacecraft landed early this morning in Utah, after gliding through the darkness across the West Coast of the United States. Inside the capsule is valuable cargo: the first cometary and interstellar material to be returned to the Earth for study.

NASA TV covered the landing live while helicopters at the Utah Test and Training Range in western Utah, USA positioned themselves for retrieval in a holding area. As the capsule streaked over Oregon it became the fastest human-made object to descend through the atmosphere, at nearly 29,000 miles per hour (12.8 kilometers per second.) In just seconds it moved out of Oregon and over Nevada and was picked up by infrared ground tracking instruments.

At 10,000 feet above the Earth’s surface, the main parachute deployed, to applause from ground crews. The capsule’s UHF beacon was successfully picked up to help the helicopters with their retrieval. The capsule rapidly decelerated in speed and began drifting to the surface before landing at an estimated 10 miles per hour. Touchdown occurred at approximately 3:10 a.m. Mountain Standard Time. Landing coordinates came immediately and the helicopters quickly began their search in the dark for the capsule.

The search lasted approximately 42 minutes before official confirmation came that the capsule had been located.

Now that the sample-return capsule has landed safely on Earth and been retrieved, it will be transported to Stardust Laboratory at Johnson Space Center in Houston, Texas, USA where the exacting process of retrieving the individual grains from the aerogel tray can begin. A six-month effort of retrieval, documentation and early scientific analysis will be followed by the release of particles to the general science community for further research.

Last year’s Deep Impact mission to Comet Tempel 1 revealed just how little we know about the small bodies of our solar system. Comets might be more “snowy dirtballs” than “dirty snowballs” or they may instead have more variable compositions than previously understood. Images returned of Comet Wild 2 by Stardust during their January 2004 encounter revealed numerous crater-like features that have likely been modified by gas outbursts from the comet.

More Information

• Stardust – NASA’s Comet Sample Return Mission
• More Stardust Sample-Return Capsule Landing Images
• January 15, 2006 Press Release: NASA/JPL - “NASA’s Comet Tale Draws to a Successful Close in Utah Desert“

The first mission to return cometary material to the Earth is now in its final hours of the mission. The Stardust spacecraft, visitor to Asteroid 5535 Annefrank and Comet Wild 2, crossed the orbit of the Moon yesterday morning and successfully deployed the sample-return capsule toward the Earth later that evening. The capsule is expected to streak across the western United States early this morning before landing in the Utah Test and Training Range.

During its close flyby of Comet Wild 2, particles from the dusty coma of the comet impacted Stardust’s aerogel sample collectors. One side of the array was used to collect dust from the comet, while the other side was used to collect interstellar dust. The array was then stored within the sample-return capsule for eventual return to the Earth.

Stardust’s successful collection of dust particles from Comet Wild 2 could lead to a revolution in our understanding of the small bodies in our solar system. Small bodies in our solar system include objects like comets, asteroids, and the Kuiper Belt bodies of which Pluto is a likely member. Theory suggests that these small bodies are pristine remnants from the formation of our solar system that perhaps also played a role in seeding the early Earth with water and organic materials necessary for the development of life.

The cometary and interstellar dust particles captured by Stardust will undergo a variety of tests that can only be performed in advanced laboratories here on the Earth. Stardust itself will fire its thrusters to put it into orbit around the Sun.

Live coverage of the event will be provided by NASA TV.

More Information

• Stardust – NASA’s Comet Sample Return Mission
• January 14, 2006 Press Release: NASA/JPL - “NASA’S STARDUST PASSES MOON, JUST HOURS AWAY FROM EARTH RETURN“

Humanity improves the vision it turns on the universe in two ways: seeing farther than before and resolving greater detail. 2005 was a year of much more detail, of blurry bodies resolving into dynamic worlds and undiscovered objects in our own backyard suddenly coming into view. Augmented by robotic surrogates, adaptive optics, new remote sensing capabilities, and intelligent data-mining agents, here are the discoveries made or announced in 2005 that transformed our view of our solar system.

Spirit and Opportunity on Mars

Never before have robots on the surface of another world traveled so far or functioned for so long. Despite signs of old age, the Mars Exploration Rovers Spirit and Opportunity continue to explore Mars.

Spirit climbed a mountain, observed dust devils, and returned panoramas of Gusev Crater from its high vantage point. Opportunity spotted a meteorite, survived getting stuck in a dune, and returned images of a variety of outcrops on its way to new craters for exploration.

The 10th Planet

It was not a hoax, a conspiracy theory, or pseudoscience, but a soap opera of events that led to the announcement earlier this year of the tenth planet in our solar system, 2003 UB313. After being scooped by another team on an transneptunian object slightly smaller than Pluto, Michael E. Brown of the California Institute of Technology, Chad Trujillo of the Gemini Observatory, and David Rabinowitz of Yale University were forced to confirm that discovery and then announce one of their own: Planet X.

The planetary body larger than Pluto and much further away from the sun was actually discovered during a reanalysis of data from October 21, 2003. Dr. Brown and his team then went back through even older observations to see if the object had shown up before but simply been missed. Sure enough, they came across an observation of 2003 UB313 made in 1989.

The story did not end there. Allegations of fraud were made against the other team, who may have used Dr. Brown’s own work as their own. Meanwhile, the debate over the definition of “planet” was reignited, with Dr. Brown strongly defending the use of that label for his discovery. For many planetary scientists, Pluto is not a planet, but simply a large member of the Kuiper Belt, a region of small objects outside the orbit of Neptune. Dr. Brown and others argue that Pluto should retain its classification as a planet simply for cultural reasons. And if Pluto remains a planet, then any object discovered to be larger than Pluto and orbiting the Sun should also be classified as a planet. Thus, Dr. Brown concluded, 2003 UB313 must be considered the 10th planet.

2003 UB313 has a surface of methane ice, just like Pluto. With the recent discovery of a companion moon scientists hope to nail down the mass and size of both objects. A decision over the classification of 2003 UB313 is still forthcoming.

The Plumes of Enceladus

A tiny moon orbiting Saturn in the frigid outer solar system should be silent and long dead. Most of Saturn’s moons are in fact just that. A series of discoveries by the Cassini spacecraft in 2005 limited this to a generalization forever by returning spectacular images of ice plumes erupting from the surface of Enceladus. The mystery, of course, is where the energy comes from to drive this activity. There is heat inside of Enceladus, heat that makes the tiger stripes near its south pole warmer than the rest of the moon, heat that causes material to vaporize or erupt from this region, resulting in kilometers-high plumes that help support a tentative but oxygen-rich local atmosphere and provide the material to constantly replenish one of Saturn’s rings.

Pulling Back the Shroud of Titan

Cassini provided humans their first glimpse of the surface of Titan late last year. The view left scientists scratching their heads. Then, on January 14, 2005 ESA’s Huygens probe descended through the thick orange smog of Titan’s atmosphere to reveal terrains that were surprisingly Earth-like, with river channels and shore lines suggesting large volumes of liquid at work. When Huygens landed it continued capturing images from the surface, including an orange-hued view of its surroundings.

Not only does the surface of Titan show the signs of active reworking by liquid, but the atmosphere is full of methane, a relatively unstable gas that would not show up in the atmosphere if it were not constantly replenished. What Huygens did not provide was images of standing liquid on the surface, long suspected as the methane reservoir. After Huygens landed it began to settle into the soil and recorded a rise of methane, presumably liquid methane that was vaporized by the heat of entry. The pebbles surrounding the landing site were well-rounded, a sign of fluvial processes here on the Earth. The highlands, where the channels start, were light, while the channel beds and sea-like lowlands were stained dark. This comes from hydrocarbons that snow from the atmosphere and are carried downstream.

Where, then, is the liquid? Huygens had stopped broadcasting from the surface of Titan, but Cassini continues to encounter Titan, with the capability to pry beneath the thick atmosphere by using various remote sensing wavelengths including radar. During one flyby, Cassini captured an image of what appears to be a lake. During another, a volcano. Persistent methane clouds have been detected.

Scientists hypothesize that Huygens landed during a dry season, or perhaps during low tide. Titan might experience monsoonal seasons with periodic torrential liquid methane rains followed by little activity. The surface is obviously quite young, but many more observations by Cassini will be necessary before scientists feel confident in their understanding of the processes at work.

All but one of Cassini’s moon flybys over the next two and a half years will be of Titan. These flybys will be at altitudes of 2000 kilometers (1300 miles) or lower to provide even more detailed data about the surface of Titan.

Deep Impact

We bombed the hell out of a comet and learned that what we thought we knew about these objects was wrong.

On July 03, 2005 Deep Impact encountered Comet Tempel 1. When the event was over, Comet Tempel 1 had a new crater and a rising plume of debris from colliding with the Deep Impact impactor. The parent probe captured images and other data of the impact that are still be analyzed.

What we learned:

• Comets vary greatly among each other in their surface terrain.
• These surface terrains can be quite complex.
• Some comets are loosely packed, held together by gravity.
• Comets may be compositionally quite complex.

Deep Impact detected the presence of water vapor and carbon dioxide gas after impact, while the Spitzer Space Telescope detected “clays; iron-containing compounds; carbonates, the minerals in seashells; crystallized silicates, such as the green olivine minerals found on beaches and in the gemstone peridot; and polycyclic aromatic hydrocarbons, carbon-containing compounds found in car exhaust and on burnt toast” according to September 07, 2005 press release from NASA and the Jet Propulsion Laboratory.

The parent probe continues to function and was placed into a new orbit that will allow mission scientists to return to Comet Tempel 1 or encounter a different comet in a few years.

More Information

• Spirit and Opportunity on Mars
  • Mars Exploration Rovers
• The Tenth Planet
  • Science Paper (PDF) - “DISCOVERY OF A PLANETARY-SIZED OBJECT IN THE SCATTERED KUIPER BELT” M. E. Brown, C. A. Trujillo, and D. L. Rabinowitz
  • NASA Press Release, July 29, 2005 - “Planetary Scientists Discover Tenth Planet“
  • California Institute of Technology, Division of Geological and Planetary Sciences - Dr. Michael E. Brown
• The Plumes of Enceladus
  • Cassini-Huygens Website
    • Saturn’s Moons section
    • Enceladus Information
• Pulling Back the Shroud of Titan
  • Cassini-Huygens Website
    • Saturn’s Moons section
    • Titan Information
• Deep Impact
  • Press Release – NASA/JPL-Caltech - “How to Make Comet Soup“
  • Deep Impact - NASA
  • Deep Impact - Jet Propulsion Laboratory

When the world’s foremost expert on impact cratering mentions that his preconceived notions about comets have changed at least twice in the past week, it is time to rewrite the book on the subject. Dr. H. Jay Melosh, professor and a member of the Deep Impact science team, spoke before a packed crowd Saturday night, July 09, 2005, during a presentation at the University of Arizona entitled “Deep Impact: The first look inside a comet”.

“We did it!” Melosh exclaimed to loud applause. The Impactor spacecraft successfully separated from the Flyby spacecraft and collided with Comet Tempel 1 late Sunday, July 03, 2005 (Pacific Daylight Time.) Flyby captured the impact using its High and Medium Resolution Imagers and returned these spectacular images, along with data from a suite of other instruments, to the Earth over the next few days.

Melosh provided early results from analysis of this data. The surface of the comet consists of fine particles, similar in consistency to talcum powder. This dusty material was thrown out into space by the impact, resulting in a brilliant veil that hid some of the details behind it, including the plume of material rising from the impact site. While many people are eager to hear the size of the resulting crater, Melosh said much more work will need to be done before that can be determined, partly because of the material that obscured the impact site. It is not clear if images were taken of the crater. Flyby passed over the site quickly before it had to turn its cameras away to protect them from stray particles. When it was out of danger Flyby turned back around to capture the comet silhouetted by the still-growing plume of material.

One of the last images Flyby took of Comet Tempel 1 continued to show material reflecting sunlight. A false-color image using different colors to depict brightness levels indicates the bright plume and sunward facing side of the comet (in white) and the side facing away from the sun (in black). The other colors show the extent of the plume of material that spread out into space.

While he was not willing to provide detailed information about the crater size, Melosh said “think big.” What he could reveal was that the impact went deep, suggesting that comets are structurally weak. Impactor itself vaporized almost immediately upon impact, resulting in a bright split-second flash. The energy it imparted to the comet surface continued to travel in a shockwave that evacuated the crater, resulting in a gigantic explosion of material into space and the disturbance of surface material as the crater began to grow in diameter.

Although some of this activity was obscured by the plume and fine surface material, instruments onboard Flyby monitored the event in electromagnetic wavelengths that can see through dust. Scientists are busily examining the data and hope to share more results over the next few weeks.

Melosh hinted that current models for comets are wrong, but would not say how, since much more analysis and peer-review is necessary before reaching any conclusions. Deep Impact provided the highest resolution images ever of a comet, revealing complex and mysterious surface features, including round depressions that resemble impact craters, smooth regions that may indicate surface resurfacing, crevasses and steep slopes. Early compositional analysis of spectra taken during the event indicates the presence of water, CO2, and CO ices on the comet, according to Melosh.

Flyby has been redirected back toward the Earth, in preparation for a possible mission extension. While the spacecraft survived the encounter with Tempel 1 apparently unscathed and with half of its fuel unused, Flyby will require the gravitational help of the planet Earth to send it to another destination. Scientists are considering a return to Tempel 1 to capture new images of the impact area, or an encounter with another comet, both not expected to take place for another five years.

More Information

• The Lunar and Planetary Laboratory Public Outreach Program
  • Deep Impact: The first look inside a crater
• Deep Impact Image Viewer
• Deep Impact - NASA
• Deep Impact - Jet Propulsion Laboratory
• Deep Impact Amateurs Observers’ Program

The Frontier Channel is proud to announce a brand new format for the RADIO Frontier Channel podcast. Because science and technology news is usually better presented visually, I will begin adding a presentation of images and movies you can click through while listening to the podcast. “Episode 09 - Let’s Bomb the Hell out of a Comet” is the first episode to presented in this format.

How does it work? If you subscribe to the show with a podcast client (such as iTunes, iPodder, iPodderX, or Doppler) start listening to the episode in your favorite music player. Then in your web browser head on over to the show notes for that episode on the RADIO Frontier Channel site. Find the presentation link under the “Show Notes” heading. Clicking on the link will take you to the first slide (don’t worry, it is a regular web page and doesn’t require any special software to view.) Each page will be clearly labeled with the slide number. During the podcast I will tell you when it is time to click on the “Next Slide” link. Navigation is easy (”Previous Slide” | “Back to Show Notes” | “Next Slide”.)

If you like to listen to the podcast right in your web browser, open up one tab to start playing the podcast, and a second tab to follow along in the visual presentation. If your web browser does not support tabs, just open two separate browser windows: one for the podcast and one for the visual presentation.

For “Episode 09 - Let’s Bomb the Hell out of a Comet” I have provided eleven slides of some of the best Deep Impact mission images released so far by NASA, including images of the spectacular impact that took place late Sunday night, July 03, 2005. I have even included a short film of the impact created from several images taken by the Flyby spacecraft. I tried to keep each slide clutter and text-free (except for appropriate credits) so that the image or movie is the main focus. Listen to the podcast for a description of each one, including some sound bites from NASA’s coverage of the event that will help put it all in perspective. If you would like to skip directly to the first slide of the Deep Impact Presentation, click here.

Below is the “Episode 09 - Let’s Bomb the Hell out of a Comet” show notes description:

“Welcome to a very special “Let’s Bomb the Hell out of a Comet” edition of RADIO Frontier Channel. I am your host, Richard Leis. Deep Impact’s coffee table-sized Impactor smashed into the nucleus of Comet Tempel 1 late Sunday night and the images received so far have been spectacular. The traffic to the Deep Impact website yesterday proves yet again that people love a summer blockbuster, but this time reality proved itself to have better special effects than any movie. Join me for an audio tour of the event and follow along with a visual presentation on the RADIO Frontier Channel website, including some of the best images taken by Deep Impact during the mission. Head on over to radio.frontierchannel.tv, click on the Episode 09 “Show Notes” link, and then click on the “Deep Impact Presentation” link. We will start with Slide 1 and I will let you know during the podcast when to move on to the next slide.”

After listening to the show and looking at the images and movies, let me know what you think. Contact information is provided on the show notes page and in the podcast. I hope merging podcast audio with visual presentations will provide listeners a much better way to experience the thrill of science and technology at the frontier. If you have any suggestions for improvements, please let me know!

RADIO Frontier Channel Podcast

Episode 09 - Let’s Bomb the Hell out of a Comet - listen to the podcast and follow along with the Deep Impact Presentation

Deep Impact Flyby took a look back at the devastation it wrought on Comet Tempel 1 and snapped a spectacular image of impact ejecta streaming out into space in a column that has grown much larger in dimension than the comet nucleus itself. While images and other data continues to stream to the Earth from Flyby, scientists are examining the data already received, including temperature readings of the nucleus before impact and spectral readings that will provide the composition of the comet.

At this morning’s Post-Impact Briefing held at NASA’s Jet Propulsion Laboratory in Pasadena, California, USA, scientists displayed new images of the comet and preliminary scientific results. Principal Investigator Dr. Mike A’Hearn noted that Comet Tempel 1 was shaped more like “a loaf of bread or a muffin” than the various fruits people have previously suggested in analogy. Dr. A’Hearn said that this loaf has a lot of topographic relief, craters that may have been formed by natural impacts, and intriguing bright spots. Scientists have spotted evidence for layering of material on the comet and regions of smooth areas that are unexplained.

Dr. Pete Schultz, the Co-Investigator from Brown University, described the impact itself and the search for the resulting crater. He presented an animation created from images taken by Flyby of the event. There was a brief incandescent flash of light as volatile gases were vaporized when Impactor first made contact with the cometary surface, followed by a split second pause before a huge explosion of material erupted from the rapidly-forming crater. This plume of ejecta cast a growing shadow on the surface. A cloud of dust kicked up by the collapsing crater wall was also spotted in images. The new crater was obscured by dust and gas from the eruption, but scientists will try to enhance likely images of the region in search of the crater. They do not expect to have preliminary results until later this week.

Flyby “is in great shape,” according to Rick Grammier, Deep Impact Project Manager at JPL. Flyby will continue to capture images and other data about Tempel 1. When its primary mission ends and all the data has been returned to the Earth, the spacecraft will enter a sun-safe mode with only critical systems functioning until a potential extended or different mission has been chosen and funded.

Earlier figures for traffic to the Deep Impact website indicate a billion hits, far more than the traffic the Cassini-Huygens and Mars Exploration Rovers websites experienced at their peak, combined. Planetary science mission sites often become the new record-holders for all-time traffic numbers in the first few days of their mission, beginning with the 100 million hits over three days seen by the NASA’s Mars Pathfinder Rover site in 1997. While website hit statistics do not indicate the exact number of individual visitors, they do indicate the popularity of a site.

More Information

• Deep Impact Image Viewer
• Deep Impact - NASA
• Deep Impact - Jet Propulsion Laboratory
• Deep Impact Amateurs Observers’ Program

Members of the Deep Impact team spoke to reporters early this morning about the success of their mission to Comet Tempel 1. About ten percent of the data has been downloaded from Flyby with the remaining portion to be downloaded over the next 24 hours. The team continues to clean up the raw data to produce useful products for the media, the public, and the scientific community.

During the press conference, team members presented an animation created from images taken by Impactor prior to hitting the comet. The animation begins with the comet as a distant bright orb that rapidly grows in size until the final image of what appears to be surface boulders or rocks taken just three seconds prior to impact. The audience reaction? Loud exclamations, gasps, and applause.

The resulting ejecta cone from the impact exploded out into space. Dr. Michael A’Hearn, Principal Investigator for the Deep Impact mission and Professor of Astronomy at the University of Maryland said that the ejecta cone grew to be larger in dimension than the comet nucleus itself and was still evolving at least 45 minutes after impact. Ground and space-based telescopes, including Hubble, recorded a rapid increase in brightness of the comet. Scientists will take a close look at images and spectra of the ejecta material to determine the composition of Tempel 1.

Thumbnail versions of images from Flyby’s Medium Resolution Instrument (MRI) were rapidly provided on the mission site, which slowed to a crawl during and after impact. Team members stated that the number of visitors to the website has outpaced the combined peak traffic to the Cassini-Huygens and Mars Exploration Rovers websites.

Still ahead for the Deep Impact mission team is another press conference at 11 a.m. Pacific Daylight Time today, completing the download of data from Flyby, and processing images from the High Resolution Instrument (HRI). These higher resolution images will take longer to process because of a flaw in the camera. The team was able to develop software to correct for this camera blurring, but the resulting deconvolution process will take more time. The images released so far have undergone little enhancement and team members during the press conference mentioned that the best was still yet to come.

Flyby survived the encounter with Comet Tempel 1 with no apparent damage. It will continue to monitor the comet, although it is now facing the opposite side from the impact location and rapidly receding. Team members were reluctant to discuss future scenarios for Flyby, but if the spacecraft remains in good condition, it could potentially be targeted at another comet for exploration.

More Information

• Dr. Michael A’Hearn - Deep Impact Principal Investigator and Professor of Astronomy at the University of Maryland
• Deep Impact Image Viewer
• Deep Impact - NASA
• Deep Impact - Jet Propulsion Laboratory
• Deep Impact Amateurs Observers’ Program

In a brilliant explosion, Deep Impact’s impactor spacecraft smashed into Comet Tempel 1 around 10:52 p.m. Pacific Standard Time today. The control room at the Jet Propulsion Laboratory in Pasadena, Californa, USA went crazy with gasps, shouts and applause as the first images showing the impact appeared on their projector screen. The image taken by the flyby spacecraft (sailing by a safe distance from the comet) was right out of a science fiction movie, but with better special effects, showing a prominent plume of material erupting from the surface of the comet.

Just prior to impact, the impactor spacecraft itself sent back images of the comet rapidly filling its view. Comet Tempel 1 appears to have several shallow craters that may be caused by natural impacts or by active processes within the comet itself. Scientists are scrambling to analyze the wealth of date returned so far.

The flyby spacecraft is currently in shield mode, placing a shield between itself and the dangerous particles in the coma of the comet as it continues to take images of the impact area. Scientists are eager to pour over images of the crater formed by the impact, in hopes of learning about the internal structure and composition of Tempel 1. The data could provide clues about the formation of our solar system and other important questions. Did comets bring water to the inner planets? Are they the source of organic building blocks that eventually led to life on the Earth?

So far the comet remains too faint to see with the naked eye from the Earth. However, observatories around the world are expected to return images of a rapid brightening of the comet during impact. Please stay tuned to The Frontier Channel for first images as NASA releases them to the public (a barrage of visitors is currently slamming their web servers.)

More Information

• Deep Impact Image Viewer
• Deep Impact - NASA
• Deep Impact - Jet Propulsion Laboratory
• Deep Impact Amateurs Observers’ Program

There is not a lot of material in the coma of Comet Tempel 1, according to scientists after studying recent observations made by the Chandra X-ray Observatory. The space telescope saw a steady stream of X-rays from the interaction of the comet nucleus with the solar wind. However, the X-ray view could change during Tempel 1’s occasional outbursts, several of which have occurred in the past week. Images from Chandra might then show a forward arc of X-rays from coma material interacting with the solar wind.

Chandra and other space-based telescopes, including Hubble, are poised to capture images of Deep Impact’s impactor spacecraft slamming into Tempel 1. Each telescope offers its own suite of instruments tailored for specific regions of the electromagnetic spectrum, allowing a more complete picture of the impact event and its aftermath than could be provided by visible light images alone.

More Information

• Chandra X-ray Observatory
• Deep Impact Image Viewer
• Deep Impact - NASA
• Deep Impact - Jet Propulsion Laboratory
• Deep Impact Amateurs Observers’ Program