Dust from the great beyond

Interstellar grains seen by the Cassini spacecraft lend support to the old panspermia hypothesis.
By Dirk Schulze-Makuch
April 21, 2016

After analyzing ten years of data from the Cassini spacecraft that’s been orbiting Saturn since 2004, a team of scientists led by Nicolas Altobelli of the European Space Agency in Madrid, Spain, reports finding dust that came from outside our solar system. Along with millions of ice-rich dust particles shed by Saturn’s moons, Cassini’s Cosmic Dust Analyzer detected a grand total of 36 grains that the scientists could trace back to the local interstellar cloud. That cloud is an almost empty bubble of gas through which our solar system is currently moving.
The small interstellar dust grains were zipping past Saturn at speeds of over 72,000 kilometers per hour (44,000 mph), which explains how they avoided becoming gravitationally trapped by the sun. This marks the first time scientists have been able to analyze material from outside our solar system. Intriguingly, the Cassini Cosmic Dust Analyzer saw the same kind of chemical and mineralogical make-up in the interstellar grains as it did in the local dust.
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Impact on Jupiter caught by amateur astronomers

Something just struck Jupiter, and two amateur astronomers captured it on video

Two amateur astronomers in different countries captured space images that astronomers say depicts an amazing cosmic event: something basically crashing into the planet Jupiter.
Experts say it wasn’t aliens, alas, but space debris–either an asteroid or a comet. It’s cool but not too terribly surprising, because Jupiter is the largest planet in our solar system, with the most mass.


Space station experiment identifies microbes that can survive unprotected in space

by Will Parker
Scientists conducting a series of experiments on the International Space Station say that some micro-organisms can survive for long periods exposed to the hostile environment of outer space. The findings, published in the Astrobiology Journal, lend weight to the concept of panspermia, where life on Earth emerged from bacterial colonies transported on comets and asteroids.
The experiments were designed to see whether bacterial hitchhikers on spacecraft were hardy enough to survive in space and contaminate other planets. Currently, spacecraft landing on Mars or other planets where life might exist must meet requirements for a maximum allowable level of microbial life (known as bioburden). These acceptable levels were based on studies of how various life forms survive exposure to the rigors associated with space travel.
“If you are able to reduce the numbers to acceptable levels, a proxy for cleanliness, the assumption is that the life forms will not survive under harsh space conditions,” explains NASA’s Kasthuri J. Venkateswaran. But that assumption may not hold up, as it seems some microbes are hardier than expected.

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