Earth Archives

August 9, 2023August 9, 2023 by Laurence Tognetti

Interpreting Dune Patterns: Insights from Earth and Mars

Examples of active dune fields within Nili Patera on Mars. Dunes like these were examined for this study in hopes of giving scientists better insights into how their interactions are influenced by a planet’s climate. (Credit: NASA/JPL-Caltech/Univ. of Arizona)

A recent study published in the journal Geology attempts to interpret the patterns of dunes, which are sand mounds frequently formed by aeolian (wind) processes and range in size from small ripples observed on beaches to massive structures observed in the desert. Specifically, the researchers focused on patterns of dune crestlines, which are the top of the dunes. Different dune crestline patterns might appear as mundane features, but their formations are often the result of a myriad of influences, including climate change, surface processes, and atmospheric phenomena.

August 4, 2023August 4, 2023 by Andy Tomaswick

Light Pollution from Skyglow Changes Bird Behavior

In the astronomy community, we typically this of light pollution as an overall negative. Much research points out its negative effect on our sleep and even our observational equipment. It also significantly impacts wildlife; however, according to a new paper from some Belgian, Swiss, and German researchers, not all of that impact is negative.

June 29, 2023June 29, 2023 by Evan Gough

Light Pollution is Out of Control

The Earth at night. What will it look like 100 years from now? Image credit: NASA-NOAA

Concern over global light pollution is growing. Astronomers are noticing its growing effect on astronomical observations, just as predicted in prior decades. Our artificial light, much of which is not strictly necessary, is interfering with our science.

But there’s more than just scientific progress at stake. Can humanity afford to block out the opportunities for wonder, awe, and contemplation that the night sky provides?

June 23, 2023June 23, 2023 by Andy Tomaswick

The Earth’s Rotational Pole has Shifted from All the Groundwater We’ve Pumped Out

Earth is, in many ways, a water world. Around two-thirds of its surface is covered in water, and the oceans that provide that cover make up over 96% of all water on Earth, according to the US Geological Survey. Glaciers and ice caps make up another 1.74%, but groundwater is the third most plentiful source at 1.69% of all water available on Earth. That’s an astonishing 23.4 million cubic kilometers of the stuff, dwarfing the mere 176,000 cubic kilometers contained in all the lakes in the world. But that does not mean the total amount of groundwater is unlimited, and removing it can have a lasting impact on more than just the people who use it for bathing and drinking. A new study points to how humans pumping out groundwater impacts Earth’s rotation.

June 21, 2023June 21, 2023 by Nancy Atkinson

The Most Intense Lightning Ever Seen Came From Last Year's Tonga Volcano Eruption

The Tonga Hunga volcanic eruption sent a tsunami across the Pacific. Air pressure disturbances from the tsunami distorted GPS signals. GOES imagery courtesy NOAA,NESDIS. — The Tonga Hunga volcanic eruption as seen by a GOES satellite. Credit: NOAA,NESDIS.

The enormous undersea volcano that erupted in Tonga last year was record-breaking in many regards. It generated the highest-ever recorded volcanic plume, it triggered a sonic boom that circled the globe twice, and was the most powerful natural explosion in more than a century.

Now, scientists studying the eruption say the volcanic plume created record-breaking amounts of volcanic lightning, the most intense lightning rates ever documented in Earth’s atmosphere. While the ash obscured the view, satellites and ground-based radio antennas with specialized instrument could peer through the ash and see every stage of the unfolding eruption. Over 200,000 lightning flashes were detected in the volcanic plume, more than 2,600 flashes every minute.

June 16, 2023June 16, 2023 by Evan Gough

Earth Might Have Formed in Just a Few Million Years

Planets form by accreting material from a protoplanetary disk. New research suggests it can happen quickly, and that Earth may have formed in only a few million years. Credit: NASA/NASA/JPL-Caltech

Earth formed about 4.6 billion years ago. That simplistic statement is common, and it’s a good starting point for understanding our planet and our Solar System. But, obviously, Earth didn’t form all at once. The process played out for some period of time, and the usual number given is about 100 million years.

New research suggests that Earth formed more quickly than that in only a few million years.

June 15, 2023June 15, 2023 by Evan Gough

Did Life Need Plate Tectonics to Emerge?

New research indicates that mobile plate tectonics—thought to be necessary for the creation of a habitable planet—was not occurring on Earth 3.9 billion years ago. Image Credit: University of Rochester illustration / Michael Osadciw

It’s widely accepted that Earth’s plate tectonics are a key factor in life’s emergence. Plate tectonics allows heat to move from the mantle to the crust and plays a critical role in cycling nutrients. They’re also a key part of the carbon cycle that moderates Earth’s temperature.

But new research suggests that there was no plate tectonic activity when life appeared sometime around 3.9 billion years ago. Does this have implications for our search for habitable worlds?

June 9, 2023June 9, 2023 by Evan Gough

Geoengineering is Shockingly Inexpensive

Geoengineering isn't a quick fix for our climate crisis, and it's also expensive. Image Credit: University of Leeds

Despite decades of warnings and international climate agreements, global carbon emissions are still rising. Carbon emissions seem like an unstoppable juggernaut as energy-hungry humans keep breeding and pursuing more affluent lifestyles. Reducing emissions won’t be enough to confront the climate crisis; we need additional solutions.

Geoengineering, also called climate engineering, could be the solution we seek. But is it financially feasible?

June 8, 2023June 9, 2023 by Nancy Atkinson

Phew, California’s Largest Reservoir is Nearly Full

Shasta Lake, California’s largest reservoir, filled to nearly 100 percent capacity, seen on May 29, 2023 as seen by the Operational Land Imager (OLI) on the Landsat 9 satellite. Credit: US Geological Survey/NASA Earth Observatory/Lauren Dauphin.

California residents will be glad to know their reservoirs are nearly full again after years of drought. New satellite photos show the levels of Shasta Lake, California’s largest reservoir, going from 31% capacity last November to nearly 100% in May 2023. The reservoir was filled with heavy rains and a significant mountain snowpack that melted into the nearby rivers.

This is the highest levels this lake has seen in over four years, following years of persistent and extreme drought in the US southwest. Scientists are working on ways to recharge ground reservoirs with any excess water, to minimize the effect of the next inevitable drought.

June 7, 2023June 7, 2023 by Evan Gough

Is it Time for a New Definition of “Habitable?”

This artist’s impression shows the planet Proxima b orbiting the red dwarf star Proxima Centauri, the closest star to the Solar System. The double star Alpha Centauri AB also appears in the image between the planet and Proxima itself. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface. Credit: ESO/M. Kornmesser

Things tend to move from the simple to the complex when you’re trying to understand something new. This is the situation exoplanet scientists find themselves in when it comes to the term ‘habitable.’ When they were discovering the first tranche of exoplanets, the term was useful. It basically meant that the planet could have liquid water on its surface.

But now that we know of over 5,000 confirmed exoplanets, the current definition of habitable is showing its age.