Category Astronomy/Space

Highly Porous Rocks Responsible for Bennu’s Surprisingly Craggy Surface

The asteroid Bennu
OSIRIS-REx mission scientists thought sampling a piece of Bennu would be like a walk on the beach, but the surprisingly craggy surface proved to be more of a challenge.NASA/Goddard/University of Arizona

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...

Read More

Late-time Small-body Asteroid Disruptions can Protect the Earth

The hydro simulation in Spheral that provided the basis for the analysis: 1 Megaton at a few meters standoff distance from a 100-meter diameter asteroid (with Bennu shape). Colors denote velocities. The legend is cm/us, which is equivalent to 10 km/s

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...

Read More

New Measurement Method promises Spectacular Insights into the Interior of Planets

High-resolution spectroscopy will enable unique insights into chemistry happening deep inside planets.
Foto: HZDR / U. Lehmann

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...

Read More

Extreme Exoplanet Even More Exotic than Originally thought

The fiery exoplanet WASP-76b – a so-called hot Jupiter, where it rains iron – may be hotter than previously thought.

Considered an ultra-hot Jupiter – a place where iron gets vaporized, condenses on the night side and then falls from the sky like rain — the fiery, inferno-like WASP-76b exoplanet may be even more sizzling than scientists had realized.

An international team, led by scientists at Cornell University, University of Toronto and Queen’s University Belfast, reports the discovery of ionized calcium on the planet – suggesting an atmospheric temperature higher than previously thought, or strong upper atmosphere winds.

The discovery was made in high-resolution spectra obtained with Gemini North near the summit of Mauna Kea in Hawaii.

Hot Jupiters are named for their h...

Read More