
Up close with comets —
Color filters help create this vivid image of Comet ISON, captured by NASA's Hubble Space Telescope on April 30.

Up close with comets —
The Hubble Space Telescope took this picture of Comet ISON on April 10, 2013, when the comet was slightly closer than Jupiter's orbit, or about 386 million miles from our sun.

Up close with comets —
In November, Comet ISON is expected to dive into the sun's atmosphere. Rolando Ligustri used a telescope at the CAST Observatory in Italy to capture this image of it on February 28.

Up close with comets —
Comet PanSTARRS put on a show in both the Northern Hemisphere and Southern Hemispheres earlier this year. This image was taken by amateur astronomer Terry Lovejoy on February 12, 2013, from Brisbane, Australia. He used a QHY9 camera and an 8" telescope with 5 minutes exposure.

Up close with comets —
In 1986, the European spacecraft Giotto became one of the first spacecraft to encounter and photograph the nucleus of a comet. This photo shows Comet Halley's nucleus. The debris from the nucleus creates the trail of debris responsible for the Orionids meteor shower each October and the Eta Aquariids in May.

Up close with comets —
On July 3, 2005, NASA's Deep Impact fly-by spacecraft dropped its "impactor" probe into the path of Comet Tempel 1. There was a bright flash as the probe hit the comet. The images were beamed around the world in near real time on NASA TV and over the Internet. Orbiting telescopes watched from space and astronomers on the ground captured images, too.

Up close with comets —
NASA's Deep Impact mission's impactor probe snapped this picture 90 seconds before the probe was pummeled by Comet Tempel 1 on July 4, 2005.

Up close with comets —
Comet Wild 2's nucleus was photographed by NASA's Stardust spacecraft as it flew past in January 2004 and collected samples from the comet's coma. The spacecraft's return capsule ferried the samples back to Earth on January 15, 2006.

Up close with comets —
After returning the world's first particles from a comet, the Stardust capsule was packed up and shipped to the Smithsonian. The mission's principal investigator was surprised by the size and composition of the particles captured in the capsule's aerogel-lined collector.

Up close with comets —
This close-up view of Comet Hartley 2 was taken by NASA's EPOXI mission during a fly-by of the comet on November 4, 2010.

Up close with comets —
Comet Siding Spring looks like a red blaze in the sky in this infrared image taken on January 10, 2010, from NASA's Wide-field Infrared Survey Explorer (WISE).

Up close with comets —
This image of Comet NEAT was taken at Kitt Peak National Observatory near Tucson, Arizona, on May 7, 2004.

Up close with comets —
Comet Linear was photographed by a camera on the European Space Agency's Rosetta space probe on April 30, 2004. Rosetta is on its way to study Comet 67-P/Churyumov-Gerasimenko. On June 8, 2011, Rosetta was placed in hibernation. It will wake up when it reaches the comet in mid-2014, when it will drop a small lander onto the comet's surface.

Up close with comets —
One of the most famous comets is Hale-Bopp. It was discovered independently on July 23,1995, by Alan Hale in New Mexico and by Thomas Bopp in Arizona. It was one of the brightest comets in decades and was visible to the naked eye for several months.

Up close with comets —
Comet Lovejoy stunned scientists in December 2011 when it flew through the hot atmosphere of the sun and emerged intact. The comet was discovered by amateur astronomer Terry Lovejoy of Australia.