Sun-gazing missions SOHO and STEREO watched the return of comet 96P/Machholz when it entered their fields of view between Oct. 25-30. It is extremely rare for comets to be seen simultaneously from two different locations in space, and these are the most comprehensive parallel observations ever taken of this comet.
A small, recently discovered asteroid -- or perhaps a comet -- appears to have originated from outside the solar system, coming from somewhere else in our galaxy. If so, it would be the first "interstellar object" to be observed and confirmed by astronomers.
Scientists, working closely with amateur astronomers, have spotted the dusty tails of six exocomets -- comets outside our solar system -- orbiting a faint star 800 light years from Earth.
Last year, a fountain of dust was spotted streaming from Rosetta's comet, prompting the question: how was it powered? Scientists now suggest the outburst was driven from inside the comet, perhaps released from ancient gas vents or pockets of hidden ice.
The missing link in our understanding of planet formation has been revealed by the first ever spacecraft to orbit and land on a comet, say scientists.
Observations made with the Atacama Large Millimeter/submillimeter Array (ALMA) and ESA's Rosetta mission, have revealed the presence of the organohalogen Freon-40 in gas around both an infant star and a comet. Organohalogens are formed by organic processes on Earth, but this is the first ever detection of them in interstellar space. This discovery suggests that organohalogens may not be as good markers of life as had been hoped, but that they may be significant components of the material from which planets form.
Scientists analysing the final telemetry sent by Rosetta immediately before it shut down on the surface of the comet last year have reconstructed one last image of its touchdown site.
NASA's Hubble Space Telescope has photographed the farthest active inbound comet ever seen, at a whopping distance of 1.5 billion miles from the Sun (beyond Saturn's orbit). Slightly warmed by the remote Sun, it has already begun to develop an 80,000-mile-wide fuzzy cloud of dust, called a coma, enveloping a tiny, solid nucleus of frozen gas and dust. These observations represent the earliest signs of activity ever seen from a comet entering the solar system's planetary zone for the first time.
Astronomers have observed the intriguing characteristics of an unusual type of object in the asteroid belt between Mars and Jupiter: two asteroids orbiting each other and exhibiting comet-like features, including a bright coma and a long tail. This is the first known binary asteroid also classified as a comet.
Astronomers have focused the Hubble Space Telescope on an exoplanet that had already been seen losing its atmosphere, which forms an enormous cloud of hydrogen, giving the planet the appearance of a giant comet. During earlier observations, it was not possible to cover the whole cloud, whose shape was predicted by numerical simulations. Thanks to these new observations, the scientists have finally been able to confirm the initial predictions.