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By cabinsinthewoods

Was Earth Born With Life On It?

“By finding graphite deposits in zircons that are 4.1 billion years old, graphite deposits that show this carbon-12 enhancement, we now have evidence that life on Earth goes back at least 90% of Earth’s history, and possibly even longer! After all, finding the remnants of organic matter in a certain location means the organic matter is at least as old as the location it’s buried in, but it could still be even older. This is so early that it might make you think that perhaps this life didn’t originate here on Earth, but that Earth was born with life. And this could really, truly be the case.”

How old is life on Earth? If all you had to go on was the fossil record, you’d run into severe trouble once you went back more than one or two billion years, as all your rock would have metamorphosed, making examination and identification of fossils impossible. But recently, we’ve discovered another method: to measure the isotopic content of carbon deposits in ancient rock formations. The carbon-12 to carbon-13 ratio is a surefire signature of life, and tells us that life on Earth goes back at least 4.1 billion years: 90% of the age of our planet. Could this be the hint we’ve needed to conclude that life on Earth actually predates the Earth itself? It’s not quite certain, but the beauty of science is we can always test it and find out! Here’s how.

Water, Water Everywhere; We Track Drops to Drink!

When we think about what makes a planet habitable, we’re often talking about water. With abundant water in liquid, gas (vapor) and solid (ice) form, Earth is a highly unusual planet. Almost 70% of our home planet’s surface is covered in water!

But about 97% of Earth’s water is salty – only a tiny amount is freshwater: the stuff humans, pets and plants need to survive.

Water on our planet is constantly moving, and not just geographically. Water shifts phases from ice to water to vapor and back, moving through the planet’s soils and skies as it goes.

That’s where our satellites come in.

Look at the Midwestern U.S. this spring, for example. Torrential rain oversaturated the soil and overflowed rivers, which caused severe flooding, seen by Landsat.

Our satellites also tracked a years-long drought in California. Between 2013 and 2014, much of the state turned brown, without visible green.  

It’s not just rain. Where and when snow falls – and melts – is changing, too. The snow that falls and accumulates on the ground is called snowpack, which eventually melts and feeds rivers used for drinking water and crop irrigation. When the snow doesn’t fall, or melts too early, communities go without water and crops don’t get watered at the right time.

Even when water is available, it can become contaminated by blooms of phytoplankton, like cyanobacteria . Also known as blue-green algae, these organisms can make humans sick if they drink the water. Satellites can help track algae from space, looking for the brightly colored blooms against blue water.

Zooming even farther back, Earth’s blue water is visible from thousands of miles away. The water around us makes our planet habitable and makes our planet shine blue among the darkness of space.

Knowing where the water is, and where it’s going, helps people make better decisions about how to manage it. Earth’s climate is changing rapidly, and freshwater is moving as a result. Some places are getting drier and some are getting much, much wetter. By predicting droughts and floods and tracking blooms of algae, our view of freshwater around the globe helps people manage their water.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

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2024 September 8

M31: The Andromeda Galaxy Image Credit: Subaru (NAOJ), Hubble (NASA/ESA), Mayall (NSF); Processing & Copyright: R. Gendler & R. Croman

Explanation: The most distant object easily visible to the unaided eye is M31, the great Andromeda Galaxy. Even at some two and a half million light-years distant, this immense spiral galaxy – spanning over 200,000 light years – is visible, although as a faint, nebulous cloud in the constellation Andromeda. A bright yellow nucleus, dark winding dust lanes, and expansive spiral arms dotted with blue star clusters and red nebulae, are recorded in this stunning telescopic image which combines data from orbiting Hubble with ground-based images from Subaru and Mayall. In only about 5 billion years, the Andromeda galaxy may be even easier to see – as it will likely span the entire night sky – just before it merges with, or passes right by, our Milky Way Galaxy.

∞ Source: apod.nasa.gov/apod/ap240908.html

You never forget your first true love...

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