geology Archives

February 21, 2023February 22, 2023 by Laurence Tognetti

Meteorites are Contaminated Quickly When They Reach Earth

Image of an Earth-altered sample of the Winchcombe meteorite; scale bar in micrometers. (Credit: University of Glasgow)

On Earth, geologists study rocks to help better understand the history of our planet. In contrast, planetary geologists study meteorites to help better understand the history of our solar system. While these space rocks put on quite the spectacle when they enter our atmosphere at high speeds, they also offer insights into both the formation and evolution of the solar system and the planetary bodies that encompass it. But what happens as a meteorite traverses our thick atmosphere and lands on the Earth? Does it stay in its pristine condition for scientists to study? How quickly should we contain the meteorite before the many geological processes that make up our planet contaminate the specimen? How does this contamination affect how the meteorite is studied?

January 30, 2023January 31, 2023 by Laurence Tognetti

Scientists Examine Geological Processes of Monad Regio on Neptune’s Largest Moon, Triton

Global color mosaic of Neptune's largest moon, Triton, taken by NASA's Voyager 2 in 1989. (Credit: NASA/JPL-Caltech/USGS)

In a recent study submitted to the journal Icarus, a team of researchers at the International Research School of Planetary Science (IRSPS) located at the D’Annunzio University of Chieti-Pescara in Italy conducted a geological analysis of a region on Neptune’s largest moon, Triton, known as Monad Regio to ascertain the geological processes responsible for shaping its surface during its history, and possibly today. These include what are known as endogenic and exogenic processes, which constitute geologic processes occurring internally (endo-) and externally (exo-) on a celestial body. So, what new insights into planetary geologic processes can we learn from this examination of Monad Regio?

January 6, 2023January 6, 2023 by Evan Gough

Perseverance is Putting its Samples Onto the Surface of Mars, So a Future Helicopter can Pick Them Up

This image shows the location where NASA's Perseverance will begin depositing its first cache of samples. NASA's Perseverance Mars rover captured it on Dec. 14, 2022, the 646th Martian day, or sol, of the mission. This enhanced color image was taken by the rover's Mastcam-Z camera and is not representative of the way the scene would look to the human eye. Image Credit: NASA/JPL-Caltech/ASU/MSSS

At this point in its mission, NASA’s Mars Perseverance Rover has collected almost 50% of its samples. The rover is now building its first sample ‘depot’ on the surface of Mars. The depot is a flat, obstacle-free area with 11 separate landing circles, one for each sample tube and one for the lander.

A future mission will retrieve these samples by helicopter.

November 3, 2022November 3, 2022 by Evan Gough

Scientists Piece Together the Shoreline of an Ancient Ocean on Mars

Stitched together from 28 images, this view from NASA's Curiosity Mars rover was captured after the rover ascended the steep slope of a geologic feature called "Greenheugh Pediment." In the distance at the top of the image is the floor of Gale Crater, which is near a region called Aeolis Dorsa that researchers believe was once a massive ocean. The layered structure of the rocks indicated they were created by waterborne sediment. Credit: NASA/JPL-Caltech/MSSS.

Scientists have long suspected that Mars was once warm and wet in its ancient past. The Mars Ocean Hypothesis says that the planet was home to a large ocean around 4 billion years ago. The ocean filled the Vastitas Borealis basin in the planet’s northern hemisphere. The basin is 4–5 km (2.5–3 miles) below Mars’ mean elevation.

A new topographic map of Mars reinforces the hypothesis and adds more detail.

October 3, 2022October 3, 2022 by Evan Gough

Scientists Have Been Underestimating the Asteroid That Created the Biggest Known Crater on Earth

South Africa's Vredefort Crater is Earth's largest impact crater. New Research clarifies the power of the impact and its catastrophic effects. Image Credit: NASA Earth Observatory image by Lauren Dauphin / University of Rochester illustration by Julia Joshpe

Ancient impacts played a powerful role in Earth’s complex history. On other Solar System bodies like the Moon or Mercury, the impact history is preserved on their surfaces because there’s nothing to erase it. But Earth’s geologic activity has erased the evidence of impact craters over time, with some help from erosion.

Earth’s complex history has elevated its status among its Solar System siblings and created a world that’s rippling with life. Ancient giant impacts have played a role in that history, bringing catastrophe and disruption and irrevocably changing the course of events. Deciphering the role these giant impacts played is difficult since the evidence is missing or severely degraded. So how do scientists approach this problem?

One crater at a time.

June 14, 2022June 14, 2022 by Evan Gough

A Geologic map of the Entire Moon has Been Released at 1:2,500,000-Scale

Chinese scientists took 10 years to create the most detailed map yet of the Moon. Image Credit: Jinzhu Ji et al. 2022.

Chinese scientists have created the most detailed map of the Moon yet. It took them 10 years and involved hundreds of researchers. The new map will be a boon to lunar exploration and for anyone who just wants to study our natural satellite in more detail.

April 1, 2022April 1, 2022 by Evan Gough

Pluto’s Surface was Shaped by Ice Volcanoes

New Horizons mission scientists have determined that cryovolcanic activity most likely created unique structures on Pluto not yet seen anywhere else in the solar system. Image Credit: NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute/Isaac Herrera/Kelsi Singer

For all of Earth’s geological diversity and its long history, the planet has never had ice volcanoes. But Pluto has. And that cryovolcanism has shaped some of the ice dwarf’s surface features.

The resulting structures are unique in the Solar System.

March 29, 2022March 29, 2022 by Evan Gough

This is Where the Mars Sample Return Mission Could be Landing

This image was acquired based on a hopeful scenario in which the Perseverance rover has an extended mission or two and travels outside of Jezero Crater to explore terrains to the west. In this scenario, the decision could be made to land the Mars Sample Return (MSR) mission here to pick up samples collected by Perseverance. MSR will probably not land here, but acquisition of a HiRISE stereo pair provides the data needed to assess the risk of landing. The cutout shows that there are diverse colors and textures, so this would be an interesting region to explore. Image Credit: NASA/JPL/UArizona

NASA’s Perseverance Rover is busy exploring Jezero Crater on Mars. Part of its mission is to collect samples for retrieval by a future mission. NASA and the ESA haven’t determined where the sample return mission will land yet.

That depends on the Perseverance mission and how it spends the rest of its time on Mars. But we know of one possible—albeit ambitious—landing spot: just west of Jezero Crater.

March 25, 2022March 25, 2022 by Evan Gough

These are Star Dunes on Mars, Formed When the Wind Comes From Many Different Directions

An amazing aspect of Mars that is captured in many HiRISE images is geologic diversity within a small area. This image, of a crater in the Tyrrhena Terra region, was targeted to look at the geologic aspects of possible clays detected with the CRISM instrument. Image Credit: NASA/JPL/UArizona

Missions to Mars are expensive, even orbiters. They’re there to do science, not take pretty pictures. But sometimes Mars’ beauty is captured inadvertently, usually with some science mixed in.

That’s the case with this picture of star dunes captured by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter.

March 7, 2022March 7, 2022 by Evan Gough

What’s it Like Inside a Super-Earth?

Artist’s impression of a Super-Earth orbiting a Sun-like star. Credit: ESO

We know a ton about the inside of Earth. We know it has both an inner core and an outer core and that the churning and rotation create a protective magnetosphere that shields life from the Sun’s radiative power. It has a mantle, primarily solid but also home to magma. We know it has a crust, where we live, and plate tectonics that moves the continents around like playthings.

But what about Super-Earths? We know they’re out there; we’ve found them. What do we know about their insides? Earth’s structure, and its ability to support life, are shaped by the extreme pressure and density in its interior. The pressure and temperature inside Super-Earths are even more powerful. How does it shape these planets and affect their habitability?