Europa and other ocean worlds in our solar system have recently attracted much attention. They are thought to be some of the most likely places in our solar system for life to have developed off Earth, given the presence of liquid water under their ice sheathes and our understanding of liquid water as one of the necessities for the development of life.

Various missions are planned to these ocean worlds, but many suffer from numerous design constraints. Requirements to break through kilometers of ice on a world far from the sun will do that to any mission. These design constraints sometimes make it difficult for the missions to achieve one of their most important functions—the search for life. But a team of engineers from NASA's Jet Propulsion Laboratory think they have a solution—send forth a swarm of swimming microbots to scour the ocean beneath a main "mothership" bot.

One of the most likely forms of the mothership bot for this mission is the Subsurface Access Mechanism for Europa—SESAME.

In May 2020, some unusual rocks containing distinctive greenish crystals were found in the Erg Chech sand sea, a dune-filled region of the Sahara Desert in southern Algeria.

On close inspection, the rocks turned out to be from outer space: lumps of rubble billions of years old, left over from the dawn of the solar system.

They were all pieces of a meteorite known as Erg Chech 002, which is the oldest volcanic rock ever found, having melted long ago in the fires of some now-vanished ancient protoplanet.

In new research published in Nature Communications, we analyzed lead and uranium isotopes in Erg Chech 002 and calculated it is some 4.56556 billion years old, give or take 120,000 years. This is one of the most precise ages ever calculated for an object from space—and our results also cast doubt on some common assumptions about the early solar system.

The secret life of aluminum

About 4.567 billion years ago, our solar system formed from a vast cloud of gas and dust.