Category Astronomy/Space

The findings include signs of flash flooding that carried huge boulders downstream into the lakebed. The first scientific analysis of images taken by NASA’s Perseverance rover has now confirmed that Mars’ Jezero crater — which today is a dry, wind-eroded depression — was once a quiet lake, fed steadily by a small river some 3.7 billion years ago.

The images also reveal evidence that the crater endured flash floods...

Using data from NASA OSIRIS-REx mission, scientists concluded that asteroids with highly porous rocks, such as Bennu, should lack fine-grained material on their surfaces.

Scientists thought asteroid Bennu’s surface would be like a sandy beach, abundant in fine sand and pebbles, which would have been perfect for collecting samples.Past telescope observations from Earth’s orbit had suggested the presence of large swaths of fine-grain material called fine regolith that’s smaller than a few centimeters.

But when the spacecraft of NASA’s University of Arizona-led OSIRIS-REx asteroid sa...

If an asteroid is determined to be on an Earth-impacting trajectory, scientists typically want to stage a deflection, where the asteroid is gently nudged by a relatively small change in velocity, while keeping the bulk of the asteroid together.

A kinetic impactor or a standoff nuclear explosion can achieve a deflection. However, if the warning time is too short to stage a successful deflection, another option is to couple a lot of energy to the asteroid and break it up into many well-dispersed fragments...

At the heart of planets, extreme states are to be found: temperatures of thousands of degrees, pressures a million times greater than atmospheric pressure. They can therefore only be explored directly to a limited extent — which is why the expert community is trying to use sophisticated experiments to recreate equivalent extreme conditions...