Earth's Oceans Delivered by Comets?

Using the powerful Herschel Space Telescope, scientists have found evidence that the water in Earth's oceans could have been delivered by comets rather than asteroids. 

What's the Latest Development?


During observations made with the powerful Herschel Space Telescope last year, astronomers found frozen water on a comet called Harltey 2. More recent analysis shows that the molecular composition of the comet's water—specifically, its deuterium-to-hydrogen ratio—matches that of Earth's. The Hartley 2 comet comes from the Kupiter belt, a band of space rocks much larger than our solar system's asteroid belt. Scientists will now look to other comets in the Kupiter belt to see if their composition is similar to Hartley 2. 

What's the Big Idea?

Water has been found on six comets prior to Hartley 2 but never before has the chemical composition of the water matched that of Earth's oceans. What's more, "the handful of water-bearing comets previously discovered, the researchers believe, came from the Oort cloud, a band of comets about a light-year away from the sun." The Kupiter belt, which scientists believe Hartley 2 calls home, is 1,000 times closer to Earth and could explain the difference in chemical compositions. 

'Upstreamism': Your zip code affects your health as much as genetics

Upstreamism advocate Rishi Manchanda calls us to understand health not as a "personal responsibility" but a "common good."

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  • Upstreamism tasks health care professionals to combat unhealthy social and cultural influences that exist outside — or upstream — of medical facilities.
  • Patients from low-income neighborhoods are most at risk of negative health impacts.
  • Thankfully, health care professionals are not alone. Upstreamism is increasingly part of our cultural consciousness.
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Videos
  • Oumuamua, a quarter-mile long asteroid tumbling through space, is Hawaiian for "scout", or "the first of many".
  • It was given this name because it came from another solar system.
  • Some claimed Oumuamua was an alien technology, but there's no actual evidence for that.

Banned books: 10 of the most-challenged books in America

America isn't immune to attempts to remove books from libraries and schools, here are ten frequent targets and why you ought to go check them out.

Nazis burn books on a huge bonfire of 'anti-German' literature in the Opernplatz, Berlin. (Photo by Keystone/Getty Images)
Culture & Religion
  • Even in America, books are frequently challenged and removed from schools and public libraries.
  • Every year, the American Library Association puts on Banned Books Week to draw attention to this fact.
  • Some of the books they include on their list of most frequently challenged are some of the greatest, most beloved, and entertaining books there are.
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