The left-most picture here was taken by a ground-based telescope run by the University of Hawaii. In this image, Comet Linear appears as a diffuse, elongated cloud of debris without any visible nucleus. The image on the right was taken by the Hubble Space Telescope on the same day, August 5, 2000. Hubble's resolution was needed to show that the nucleus of the comet had actually fragmented into many pieces. Scientists call these leftover pieces "cometesimals". Hubble has found at least 16 of these "cometesimals", some of which are as wide as 330 feet across.
Click on image for full size
NASA, Harold Weaver (Johns Hopkins University), and the HST Comet LINEAR Investigation Team
The Amazing, Vanishing Linear!
News story originally written on May 25, 2001
Linear was discovered on September, 27 1999.
Linear has been a really interesting comet! First, Linear put on a great show for the Hubble Space Telescope. The Hubble was tracking the comet for just two days, July 5-7, 2000. On July 5, 2000, comet Linear blew off a piece of its crust. The Hubble telescope watched the comet brighten by an extra 50% in less than four hours. Then, when comet Linear came closest to the Sun on July 26, 2000 (still 114 million kilometers away though!), the comet nucleus broke apart! Now, comet Linear is little more than a trail of debris orbiting the Sun.
Astronomers have been studying the comet since last summer when it broke apart. Using different telescopes, astronomers have seen the leftover pieces of Linear. Some are as small as a piece of dust and some are as big as a football field! But astronomers haven't seen medium-size pieces - it's like they disappeared! In other words, researchers have found there is not as much material in the fragments as there was in Linear before it broke apart. The leftover material just wouldn't add up to a comet as large as Linear. Scientists need to study Linear's leftover pieces some more. It might turn out that they will find more medium-size pieces and it might be that they need to rethink the size of comet Linear.
Shop Windows to the Universe Science Store!
Our online store
on science education, classroom activities in The Earth Scientist
specimens, and educational games
You might also be interested in:
The Hubble Space Telescope (HST) was one of the most important exploration tools of the past two decades, and will continue to serve as a great resource well into the new millennium. The HST found numerous...more
It was another exciting and frustrating year for the space science program. It seemed that every step forward led to one backwards. Either way, NASA led the way to a great century of discovery. Unfortunately,...more
The Space Shuttle Discovery lifted off from Kennedy Space Center on October 29th at 2:19 p.m. EST. The weather was great as Discovery took 8 1/2 minutes to reach orbit. This was the United States' 123rd...more
A moon was discovered orbiting the asteroid, Eugenia. This is only the second time in history that a satellite has been seen circling an asteroid. A special mirror allowed scientists to find the moon...more
Will Russia ever put the service module for the International Space Station in space? NASA officials want an answer from the Russian government. The necessary service module is currently waiting to be...more
A coronal mass ejection (CME) happened on the Sun early last month. The material that was thrown out from this explosion passed the ACE spacecraft. The SWICS instrument on ACE has produced a new and very...more
J.S. Maini of the Canadian Forest Service called forests the "heart and lungs of the world." This is because forests filter air and water pollution, absorb carbon dioxide, release oxygen, and maintain...more