The Cassini spacecraft from NASA managed to find interstellar dust near Saturn that appears to be originally from beyond the solar system. Scientists believe the particles of dust have traveled between stars before coming so close to us.
Many have long hoped that Cassini would detect interstellar dust ever since 2004. However, until now, no one knew whether the spacecraft would be able to do so. The findings published in the Science journal last week show that the instrument has discovered 36 microscopic interstellar particles of dust.
Prof. Dr. Mario Trieloff, who is an earth scientist working at the Heidelberg University, has explained that interstellar dust makes up a great percent of the unknown aspects of space since individual particles can be as small as two hundred nanometers in size and thus extremely hard to find.
Interstellar dust is the result of the death of stars, which is subsequently shot into space at great speeds. Because of this, they end up traveling through different solar systems without being affected by gravity. The ones found by Cassini were not on meteorites as they usually are. Instead, they crashed with the Cosmic Dust Analyzer of Cassini, when flying at 45,000 miles per hours.
The Cosmic Dust Analyzer is used to measure the size, chemical composition and speed of interstellar dust particles. Furthermore, it can also identify their orbits or trajectories.
According to Heisenberg grant scientist Dr. Frank Postberg from the Institute for Earth Sciences, scientists have previously expected interstellar dust with different compositions to have appeared after different origin processes. However, the data received from Cassini shows that all interstellar dust particles have almost the same composition. This happens because they pass through space at a speed that modifies them.
NASA has stated that
“The grains all had a surprisingly similar chemical make-up, containing major rock-forming elements like magnesium, silicon, iron and calcium in average cosmic proportions. Conversely, more reactive elements like sulfur and carbon were found to be less abundant compared to their average cosmic abundance.”
The space agency believes that there are active areas in space where stars die and are born. When this happens, they lead to shockwaves which in turn produce supernova explosions. These pass through the active areas and thus disperse dust particles, which are destroyed before reforming several times in space.
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