Impacts Archives

July 21, 2023July 21, 2023 by Evan Gough

Not All Craters are Circular. Sometimes They Look Like This

This unusual looking Martian crater was created when something impacted the planet's surface at an angle. Image Credit: NASA/JPL-Caltech/UArizona

Impact craters are nature’s signature from a more chaotic time in our Solar System’s history. A quick glance at the Moon’s disfigured surface makes that clear. Same with Mars, though a telescope is needed to examine it. Or better yet, an orbital spacecraft with a powerful camera.

The Mars Reconnaissance Orbiter and its HiRISE camera have been examining Mars’ surface for years, cataloguing the planet’s menagerie of impact craters. One of them, recently chosen as the HiRISE Picture of the Day (HIPOD,) looks like a Thunderbird. Or a dinosaur footprint left in the mud.

May 3, 2023May 3, 2023 by Evan Gough

Is This Nearby Asteroid a Chunk of the Moon?

Illustration of Asteroid (Artist’s Impression). Credit: N. Bartmann (ESA/Webb), ESO/M. Kornmesser and S. Brunier, N. Risinger

The Moon dominates our view of the night sky. But it’s not the only thing orbiting Earth. A small number of what scientists call quasi-satellites also orbit Earth.

One of them is called Kamo’oalewa, and it’s a near-Earth asteroid. It’s similar to the Moon in some respects. Could it be a chunk of the Moon?

March 19, 2023March 19, 2023 by Carolyn Collins Petersen

Watch the Chelyabinsk Meteor Breakup in this Detailed Simulation

The Chelyabinsk impactor vapor trail. — This image of a vapor trail was captured about 125 miles (200 kilometers) from the Chelyabinsk meteor event, about one minute after the house-sized asteroid entered Earth’s atmosphere. Credits: Alex Alishevskikh

The people of Chelyabinsk in Russia got the surprise of their lives on the morning of February 15, 2013. That’s when a small asteroid exploded overhead. The resulting shockwave damaged buildings, injured people, and sent a sonic boom thundering across the region.

February 24, 2023February 24, 2023 by Carolyn Collins Petersen

Recreating the Extreme Forces of an Asteroid Impact in the Lab

Barringer Meteor Crater in Arizona. Scientists studied the forces in the event that created this impact scar. Image credit: NASA

About 50,000 years ago, a nickel-iron meteorite some 50 meters across plowed into the Pleistocene-era grasslands of what is now Northern Arizona. It was traveling fast—about 13 kilometers per second. In just a few seconds, an impact dug out a crater just over a kilometer wide and spread rocks from the site for miles around.

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 13, 2022December 13, 2022 by Evan Gough

Asteroids Didn’t Create the Moon’s Largest Craters. Left-Over Planetesimals Did

The largest impact basin on the Moon is the South-Pole Aitken basin. It, and other impact basins, were created by planetesimals according to a new study. Image Credit: Moriarty et al., 2021.

The Moon’s pock-marked surface tells the story of its history. It’s marked by over 9,000 impact craters, according to the International Astronomical Union (IAU.) The largest ones are called impact basins, not craters. According to a new study, asteroids didn’t create the basins; leftover planetesimals did.

October 29, 2022October 29, 2022 by Carolyn Collins Petersen

InSight Felt the Ground Shake From a Meteorite Impact on Mars

Insight detected earthquake caused by impact that crated this crater. — Boulder-sized blocks of water ice lie around an crater blasted out by a meteoroid on December 24, 2021. NASA's InSight lander measured the earthquake the impact caused. Credit: NASA/JPL-Caltech/University of Arizona.

The Mars InSight lander might be nearing the end of its life on the Red Planet, but its scientific data are still shaking up the planetary science community. That’s because it detected another Marsquake on December 24, 2021. It was a major shaker and generated surface waves that rippled across the crust of the planet. The data from that quake allowed science team members to get a better idea of the Martian crust’s structure.

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.

September 29, 2022September 29, 2022 by Carolyn Collins Petersen

The Moon was Pummeled by Asteroids at the Same Time the Dinosaurs Died. Coincidence?

Earth and possibly its Moon were hit by impactors that killed off the dinosaurs — Artistic rendition of the Chicxulub impactor striking ancient Earth, with Pterosaur observing. Could pieces of the same impact swarm have hit the Moon, too? Credit: NASA

It only takes a quick look at the Moon to see its impact-beaten surface. There are craters everywhere. Some of those impact sites apparently date back to the same time some very large asteroids were whacking Earth. One of them formed Chixculub Crater under the Yucatan Peninsula. That impact set in motion catastrophic events that wiped out much of life on Earth, including the dinosaurs.

August 18, 2022August 18, 2022 by Carolyn Collins Petersen

Would We Have Continents Without Asteroid Impacts?

Early Earth was a wild and wooly place. In its first billion years, during a period called the Archean, our planet was still hot from its formation. Essentially, the surface was lava for millions of years. Asteroids bombarded the planet, and the place was still recovering from the impact that formed the Moon. Oceans were beginning to form as the surface solidified and water outgassed from the rock. The earliest atmosphere was actually rock vapor, followed quickly by the growth of a largely hot carbon dioxide and water vapor blanket. Earth was just starting land masses that later became continents. For decades, geologists have asked: what started continental formation?