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Did Ancient Supernovas Change Earth’s Climate?

Visible, infrared, and X-ray image of Kepler’s supernova remnant located about 13,000 light-years away. The bubble of ionized gas is about 30 light-years across. Credit: NASA, ESA, R. Sankrit and W. Blair (Johns Hopkins University).

Supernovas are some of the most powerful and energetic events in the entire Universe. When a dying star explodes you wouldn’t want to be anywhere nearby—fresh elements are nice and all, but the energy and radiation from a supernova would roast any planets within tens if not hundreds of light-years in all directions. Luckily for us we’re not in an unsafe range of any supernovas in the foreseeable future, but there was a time not very long ago (in geological terms) that these stellar explosions occurred nearby (in astronomical terms) and in 2016 scientists found the “smoking gun” evidence at the bottom of the ocean.

What’s more, the arrival of the iron-rich fallout from those stellar explosions seems to coincide with ancient global temperature changes*, the most recent dated near the start of the last major ice age which brought lower sea levels, widespread glaciation…and eventually the rise of the first modern humans.

Read more at Universe Today here: Nearby Supernovas Showered Earth With Iron

*Note: the changes in climate referred to here are not the same as the climate change we are witnessing today. Not only are we now seeing rapid warming of land and sea temperatures globally, but today’s forcings are the result of increasing greenhouse gases like carbon dioxide in the atmosphere—not radioactive iron from exploding stars.

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Space Cell

Chandra image of the Tycho supernova remnant

I don’t usually post images from outside our solar system here on LITD, but this one was too good not to share! NASA’s Chandra X-ray observatory made this image of the Tycho supernova remnant, an object in our Milky Way galaxy about 13,000 light years from Earth, in the constellation Cassiopeia. In visible light it is just another star, in infrared light it appears as a bubble of red gas, but in X-ray wavelengths it becomes an exotic globular structure spanning 55 light years across, with both high- and low-energy x-rays (seen above as blue and red structures, respectively) combining to form something that looks more like a microscopic animal cell than the remains of an exploded star!

The star field background is seen in optical light wavelength.

One could almost image this being pondered by the crew of the original TV Enterprise, displayed upon the bridge viewscreen as Mr. Spock runs sensor scans on it and Lt. Uhura attempts communication. Maybe it would even respond in a sudden booming voice. Then again…maybe not. 😉

One of the most important discoveries this image has provided scientists is in regards to the high-energy (blue) x-ray stripes that can be seen at the lower right edge of the structure. These are particles that have been accelerated to speeds 100 times faster than has been achieved at the Large Hadron Collider at CERN! This may prove to be the answer to how ultra-high-energy cosmic rays are produced.

The supernova remnant is named after Danish astronomer Tycho Brahe, who reported it in 1572. It was so bright it was visible during the day without a telescope!

Read more about this discovery on the Chandra imaging site here.

Credit: X-ray: NASA/CXC/Rutgers/K.Eriksen et al.; Optical: DSS

Read on LightsInTheDark.com

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