Asteroid Impact May Have Caused Megatsunami on Mars 3.4 Billion Years Ago

The Mars of the past was very different from the one NASA’s Viking 1 lander found when it made history as the first lander on the Red Planet in 1976. A new study suggests that Viking 1 landed at the margins of a megatsunami deposit from the planet’s earlier, wetter phase. Researchers say they have found the remains of a crater left 3.4 billion years ago when an asteroid impacted. It was this, they say, that produced a 250-meter wall of water that washed over the landscape and altered Viking 1’s landing zone.

When planning the Viking 1 landing, NASA chose a landing zone that scientists believed was an ancient outflow channel. However, the probe discovered a boulder-strewn surface lacking in any of the formations associated with flowing water. Scientists speculated that Viking 1 had landed atop debris ejected by nearby impacts, but the relative lack of craters and lava fragments was a problem. The research, led by Planetary Science Institute Senior Scientist Alexis Rodriguez, proposes an alternative explanation. A megatsunami resulting from the asteroid impact could have deposited the sediments on which Viking 1 landed 3.4 billion years later.

The study cites a newly discovered crater as evidence of these claims. The possible marine impact crater, dubbed Pohl by the team, is in the northern Martian lowlands, which was a shallow sea billions of years ago. The crater is 68 miles (110 kilometers) in diameter, indicating a 1.8-mile (3-kilometer) impactor. Simulations show the resulting wave may have been as much as 820 feet (250 meters) tall. The seismic shaking from the event may have been so intense that the ocean floor dislodged and contributed to the debris seen around the Viking 1 site.

In a previous study, Rodriguez proposed two ancient megatsunamis on Mars. The study posits that the Pohl crater caused the first of them as it shows evidence of ocean-generated formations — that means it formed during the time when the Martian lowlands were covered in water. This was a time when Mars was cooling rapidly, and the ocean may have been giving way to glaciers that eroded the crater rim. That could explain why it has gone unstudied all this time. The crater was spotted using data from the Mars Reconnaissance Orbiter’s HiRISE camera, which can capture images at 25cm per pixel.

The team calls for a more detailed examination of Pohl crater and the surrounding area. The most recent exploration of this region was Pathfinder in the late 1990s, but NASA does not currently have plans to send another rover to Mars. The next Martian operation is the joint ESA operation to collect samples from the Perseverance rove and return them to Earth. Those missions are expected to launch at the tail end of this decade.

Continue reading

Chromebooks Gain Market Share as Education Goes Online

Chromebook sales have exploded in the pandemic, with sales up 90 percent and future growth expected. This poses some challenges to companies like Microsoft.

Review: The Oculus Quest 2 Could Be the Tipping Point for VR Mass Adoption

The Oculus Quest 2 is now available, and it's an improvement over the original in every way that matters. And yet, it's $100 less expensive than the last release. Having spent some time with the Quest 2, I believe we might look back on it as the headset that finally made VR accessible to mainstream consumers.

AMD Smashes Revenue Records as Zen 3, Xbox Series X, PS5 Ramp Up

AMD's Q3 2020 results are in, and the results are excellent for the company, in every particular.

MSI’s Nvidia RTX 3070 Gaming X Trio Review: 2080 Ti Performance, Pascal Pricing

Nvidia's new RTX 3070 is a fabulous GPU at a good price, and the MSI RTX 3070 Gaming X Trio shows it off well.