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Gizmorama - November 27, 2017

Good Morning,


NASA has its eye on an unusual comet. It's unlike anything they have ever seen.

Learn about this and more interesting stories from the scientific community in today's issue.

Until Next Time,
Erin


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*-- NASA telescope tracks oddball comet 45P --*

Fresh observations of comet 45P suggest the icy orb is an oddball, boasting a chemical composition unlike any comet studied thus far.

Researchers at NASA's Infrared Telescope Facility in Hawaii tracked the comet as it whizzed past Earth earlier this year. Scientists hoped to glean new details about the ices that form Jupiter-family comets.

As comets barrel toward the sun, some of their ices melt and gases trapped in the comet's nucleus are released into the comet's thin atmosphere. Scientists used IRTF instruments to measure nine gases released by comet 45P. The iSHELL high-resolution spectrograph can pick up the infrared chemical fingerprints of a handful of gases all at once.

Some gases released by comets can form the molecular building blocks that sparked life, including sugars and amino acids, which is why some planetary scientists believed comets delivered the biochemical spark that begat life on Earth.

Gases trapped in the nucleus of comets also serve as a kind of window to the past. The nucleus preserves the chemical conditions of the early solar system, when many comets were first formed.

Researchers were particularly keen on detecting carbon monoxide and methane, a pair of gases difficult to detect in Jupiter-family comets.

Their analysis showed 45P is depleted of almost all of its carbon monoxide. The gas easily escapes into space during a comet's trip near the sun, so the discovery wasn't all that surprising. What was surprising, however, was that scientists measured high levels of methane.

Methane also escapes easily into the comet's atmosphere, or coma, and then space. A comet low in CO should be low in CH4 too.

Scientists suggest a couple of scenarios for the anomaly. They say it's possible the methane is trapped in a different type of ice that doesn't melt as easily. Or, they hypothesized, the CO reacted with hydrogen to form methanol. Observations show 45P has higher concentrations of frozen methanol than other Jupiter-family comets.

Such a reaction reveals the challenge of studying a comet's chemical composition. Researchers have to try to figure out to what extent newer chemical reactions have augmented the comet's time capsule qualities.

"Comet scientists are like archaeologists, studying old samples to understand the past," Boncho Bonev, an astronomer at American University, said in a news release. "We want to distinguish comets as they formed from the processing they might have experienced, like separating historical relics from later contamination."

Researchers hope analysis of forthcoming short-period comet flybys will provide context to their 45P observations, which they detailed in the Astronomical Journal.

"This research is groundbreaking," said Faith Vilas, the solar and planetary research program director at the National Science Foundation. "This broadens our knowledge of the mix of molecular species coexisting in the nuclei of Jovian-family comets, and the differences that exist after many trips around the sun."



*-- Space dust could carry life from planet to planet --*

Astrobiologists suggest the building blocks of life could be carried between worlds by streams of space dust. In fact, life-giving dust may have delivered the biological particles that first sparked life on Earth.

Researchers at the University of Edinburgh argue interplanetary dust could collide with tiny organisms or biological particles in Earth's upper atmosphere with enough energy to kick them into space. These organisms or life-bearing particles could be carried from planet to planet, or possibly even to another solar system.

Scientists detailed their hypothesis in a new study, recently published in the journal Astrobiology.

Previous studies have shown a variety of microorganisms can survive in space, including the small, resilient micro-animals known as tardigrades, or water bears. The outside and inside of the International Space Station, for example, host diverse microbial communities.

Edinburgh scientists calculated that small particles suspended more than 93 miles above Earth's surface could be knocked into space by dust streams traveling 43 miles per second. The same mechanics could potentially propel a water bear into interplanetary space.

"The proposition that space dust collisions could propel organisms over enormous distances between planets raises some exciting prospects of how life and the atmospheres of planets originated," Arjun Berera, professor of physics and astronomy at Edinburgh, said in a news release. "The streaming of fast space dust is found throughout planetary systems and could be a common factor in proliferating life."

***

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