Earth Archives

January 21, 2023January 21, 2023 by Andy Tomaswick

A new Propulsion System Could Levitate Vehicles in the Earth’s Upper Atmosphere

Sometimes it’s hard to remember that NASA also does atmospheric research too. While typically thought of as the province of the National Oceanic and Atmospheric Administration (NOAA), America’s space agency also has a vested interest in exploring our atmosphere and in the technologies that enable us to do so. As such, its NASA Institute for Advanced Concepts (NIAC) program provided a Phase I grant to a team from the University of Pennsylvania to develop a novel type of propulsion using only light to collect data in the Earth’s challenging-to-explore mesosphere.

January 20, 2023January 20, 2023 by Evan Gough

Light Pollution is Obscuring the Night Sky. RIP Stargazing

A startling analysis from Globe at Night — a citizen science program run by NSF’s NOIRLab — concludes that stars are disappearing from human sight at an astonishing rate. Image Credit: NOIRLab/NSF/AURA, P. Marenfeld

A citizen science initiative called Globe at Night has some sobering news for humanity. Our artificial light is drowning out the night sky for more and more people. And it’s happening more rapidly than thought.

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January 18, 2023January 18, 2023 by Evan Gough

Could Next-Generation Telescopes See That Earth Has Life?

In this image, Earthshine lights up the dark portion of the lunar surface. Image Credit: NASA

While the Earth absorbs a lot of energy from the Sun, a lot of it is reflected back into space. The sunlight reflected from Earth is called Earthshine. We can see it on the dark portion of the Moon during a crescent Moon. The Farmer’s Almanac said it used to be called “the new Moon in the old Moon’s arms.”

Earthshine is one instance of planetshine, and when we look at the light from distant exoplanets, we’re looking directly at their planetshine without it bouncing off another object.

If distant astronomers were looking at Earthshine the way we look at exoplanet shine, would the light tell them our planet is rippling with life?

December 29, 2022December 29, 2022 by Evan Gough

Should Planetary Defence Take Center Stage?

This illustration shows NASA's NEO Surveyor against an infrared observation of a starfield made by the agency's WISE mission. NEO Surveyor is the first purpose-built space telescope that will advance NASA’s planetary defense efforts by finding and tracking hazardous near-Earth objects. Credit: NASA/JPL-Caltech/University of Arizona

Throughout the Solar System, planets and moons bear the scars of a past fraught with collisions. The Moon, Mercury, and Mars are so scarred from these impacts that craters overlap one another on their surfaces. Earth was subject to the same bombardment, though most of its impact scars disappeared over time due to active geology.

But some are still visible, and we know how catastrophic some of these impacts were for life.

December 15, 2022December 16, 2022 by Evan Gough

Earth’s Water is 4.5 Billion Years Old

A new research article shows that Earth's water is as old as the Solar System, and has been present as the Sun grew and the planets formed. Image Credit: NASA/JPL

The origin of Earth’s water has been an enduring mystery. There are different hypotheses and theories explaining how the water got here, and lots of evidence supporting them.

But water is ubiquitous in protoplanetary disks, and water’s origin may not be so mysterious after all.

December 10, 2022December 10, 2022 by Scott Alan Johnston

To Fight Climate Change, We Could Block the Sun. A Lightweight Solar Sail Could Make it Feasible

Can we build an enormous umbrella to dim the Sun? Such a feat would be a megaproject on a scale like no other. It would take at least 400 dedicated rocket launches a year, for ten years (There have been 172 rocket launches by all nations so far in 2022). The project would weigh in at 550,000 tons: at its lightest. And it would be an ecological experiment that puts us all – the entire planet – in the petri dish, with high risk and high reward. But could such a project actually reverse climate change and bring us back from the brink of global disaster?

The answer seems to be yes, it could work. But there are consequences, and with the planet at stake, it seems wise to examine them before committing to such a thing.

November 30, 2022November 30, 2022 by Evan Gough

Should We Build a Nature Reserve on Mars?

There are 8 billion of us now. The UN says when the population peaks around the year 2100, there’ll be 11 billion human souls. Our population growth is colliding with the natural world on a greater scale than ever, and we’re losing between 200 and 2,000 species each year, according to the World Wildlife Federation.

An Engineer from the UK says that one way to mitigate the damage from the clash between humanity and nature is to create more habitat. We could do that by building Terran ecosystem preserves on Mars.

November 28, 2022November 28, 2022 by Nancy Atkinson

OK, Artemis. Now You’re Just Showing Off. A Stunning View of the Moon Eclipsing Earth From the Orion Spacecraft

Screenshot of the Moon eclipsing Earth, via NASA's livestream from Orion.

Have you ever seen a lunar eclipse of the Earth from the far side of the Moon? Now we have.

On Monday (November 28, 2022) NASA’s Orion spacecraft streamed back live video showing the Earth and Moon right next to each other, followed by a stunning view of the Moon eclipsing the Earth.

What a time to be alive! Image editor Kevin Gill might have said it best:

November 24, 2022November 24, 2022 by Evan Gough

What’s the Best Mix of Oceans to Land for a Habitable Planet?

A new study asks what ratio of land to ocean is best for habitability? Image Credit: Reto Stöckli, Render by Robert Simmon. Based on data from the MODIS Science Team

Earth is about 29% land and 71% oceans. How significant is that mix for habitability? What does it tell us about exoplanet habitability?

November 22, 2022November 22, 2022 by Evan Gough

Volcanoes are the worst. They’ve caused extinctions on Earth, and probably killed Venus

This is a computer-generated, three-dimensional perspective of the surface of Venus showing Maat Mons. It's Venus's highest volcano and is 8 kilometres (5.0 mi) high. The viewpoint is located 634 kilometers (393 miles) north of Maat Mons at an elevation of 3 kilometers (2 miles) above the terrain. Lava flows extend for hundreds of kilometers across the fractured plains shown in the foreground, to the base of Maat Mons. The vertical scale in this perspective has been exaggerated 10 times. Credits: NASA/JPL

Is there anything good about volcanoes? They can be violent, dangerous, and unpredictable. For modern humans, volcanoes are mostly an inconvenience, sometimes an intriguing visual display, and occasionally deadly.

But when there’s enough of them, and when they’re powerful and prolonged, they can kill the planet that hosts them.