Nearby Supernovae Were Essential to Life on Earth

Distant past supernovae could be linked by cosmic ray particles to climate change on Earth and changes in biodiversity. Courtesy: Henrik Svensmark, DTU Space.
Distant past supernovae could be linked by cosmic ray particles to climate change on Earth and changes in biodiversity. Courtesy: Henrik Svensmark, DTU Space.

It’s almost impossible to comprehend a supernova explosion’s violent, destructive power. An exploding supernova can outshine its host galaxy for a few weeks or even months. That seems almost impossible when considering that a galaxy can contain hundreds of billions of stars. Any planet too close to a supernova would be completely sterilized by all the energy released, its atmosphere would be stripped away, and it may even be shredded into pieces.

But like many things in nature, it all comes down to dose.

A certain amount of supernova activity might be necessary for life to exist.

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The Early Earth was Really Horrible for Life

The Blue Marble image of Earth from Apollo 17. Credit: NASA

Earth has had a long and complex history since its formation roughly 4.5 billion years ago. Initially, it was a molten ball, but eventually, it cooled and became differentiated. The Moon formed from a collision between Earth and a protoplanet named Theia (probably), the oceans formed, and at some point in time, about 4 billion years ago, simple life appeared.

Those are the broad strokes, and scientists have worked hard to fill in a detailed timeline of Earth’s history. But there are a host of significant and poorly-understood periods in the timeline, lined up like targets for the scientific method. One of them concerns UV radiation and its effects on early life.

A new study probes the effects of UV radiation on Earth’s early life-forms and how it might have shaped our world.

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Chefs on the Moon Will be Cooking up Rocks to Make air and Water

Artist impression of a Moon Base concept. Credit: ESA – P. Carril

NASA has delayed their Artemis mission to the Moon, but that doesn’t mean a return to the Moon isn’t imminent. Space agencies around the world have their sights set on our rocky satellite. No matter who gets there, if they’re planning for a sustained presence on the Moon, they’ll require in-situ resources.

Oxygen and water are at the top of a list of resources that astronauts will need on the Moon. A team of engineers and scientists are figuring out how to cook Moon rocks and get vital oxygen and water from them. They presented their results at the Europlanet Science Congress 2021.

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A Billion Years From now There won’t be Much Oxygen in the Earth’s Atmosphere

The Blue Marble image of Earth from Apollo 17. Credit: NASA

Breathe it while you still can. A new research study forecasts the future of oxygen in the Earth’s atmosphere and finds grim news. As the sun continues to warm, carbon dioxide will bind to rocks. This will starve plants, and in as little as a billion years they won’t be able to produce enough oxygen to keep our planet habitable (for us).

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Earth’s Oxygen Could be Making the Moon Rust

Enhanced map of hematite (red) on Moon using a spheric projection (nearside only). Credit: Shuai Li

It takes oxygen to make iron rust. So when scientists discovered hematite spread widely through lunar high latitudes, they were surprised. How did that happen?

A new study suggests that oxygen from Earth could be playing a role in rusting the Moon.

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New Data Show How Phytoplankton Pumps Carbon Out of the Atmosphere at an Enormous Scale

One of the most fascinating things about planet Earth is the way that life shapes the Earth and the Earth shapes life. We only have to look back to the Great Oxygenation Event (GOE) of 2.4 billion years ago to see how lifeforms have shaped the Earth. In that event, phytoplanktons called cyanobacteria pumped the atmosphere with oxygen, extinguishing most life on Earth, and paving the way for the development of multicellular life.

Early Earth satisfied the initial conditions for life to appear, and now, lifeforms shape the atmosphere, the landscape, and the oceans in many different ways.

At the base of many of these changes is phytoplankton.

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Even if Exoplanets Have Atmospheres With Oxygen, it Doesn’t Mean There’s Life There

Artist’s impression of a sunset seen from the surface of an Earth-like exoplanet. Credit: ESO/L. Calçada

In their efforts to find evidence of life beyond our Solar System, scientists are forced to take what is known as the “low-hanging fruit” approach. Basically, this comes down to determining if planets could be “potentially habitable” based on whether or not they would be warm enough to have liquid water on their surfaces and dense atmospheres with enough oxygen.

This is a consequence of the fact that existing methods for examining distant planets are largely indirect and that Earth is only one planet we know of that is capable of supporting life. But what if planets that have plenty of oxygen are not guaranteed to produce life? According to a new study by a team from Johns Hopkins University, this may very well be the case.

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There Might be Enough Oxygen Below the Surface of Mars to Support Life

Artist's impression of water under the Martian surface. Credit: ESA/Medialab

The possibility that life could exist on Mars has captured the imagination of researchers, scientists and writers for over a century. Ever since Giovanni Schiaparelli (and later, Percival Lowell) spotted what they believed were “Martian Canals” in the 19th century, humans have dreamed of one day sending emissaries to the Red Planet in the hopes of finding a civilization and meeting the native Martians.

While the Mariner and Viking programs of the 1960s and 70s shattered the notion of a Martian civilization, multiple lines of evidence have since emerged that indicate how life could have once existed on Mars. Thanks to a new study, which indicates that Mars may have enough oxygen gas locked away beneath its surface to support aerobic organisms, the theory that life could still exist there has been given another boost.

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Weekly Space Hangout – February 3, 2017: Meredith Rawls & the LSST

Host: Fraser Cain (@fcain)

Special Guest: Meredith Rawls

Meredith is a Postdoctoral Researcher in the Department of Astronomy at the University of Washington. She writes software to prepare for the coming onslaught of data from the Large Synoptic Survey Telescope and studies weird binary stars. She is also the lead organizer of the ComSciCon-Pacific Northwest workshop for STEM graduate students in Seattle this March. Meredith holds degrees in physics and astronomy from Harvey Mudd College, San Diego State University, and New Mexico State University. When she’s not science-ing or telling people all about it, she plays viola, volunteers at summer camp, and advocates for more equity and less light pollution.

Guests:

Paul M. Sutter (pmsutter.com / @PaulMattSutter)
Kimberly Cartier ( KimberlyCartier.org / @AstroKimCartier )

Their stories this week:
Oxygen on the moon

Nearby “super-void” shapes galaxy motion

First science from Keck’s vortex coronograph

We use a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

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We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Universe Today, or the Universe Today YouTube page