Space Rocks May Have 

Bounced Off Baby Earth

Squabbling

Sibling planets may have hurled space rocks when they were young.

Simulations Suggest

That space rocks the size of baby planets struck both the newborn Earth and Venus

But

Many of the rocks that only grazed Earth went on to hit — and stick — to Venus.

That Difference

In early impacts could help explain why Earth and Venus are such different worlds today, 

Planetary Scientist Shigeru Ida

“The pronounced differences between Earth and Venus, in spite of their similar orbits and masses, has been one of the biggest puzzles in our solar system,”

Scientists Have

Typically thought that there are two ways that collisions between baby planets can go.

The Objects

Could graze each other and each continue on its way, in a hit-and-run collision.

Or

Two protoplanets could stick together, or accrete, making one larger planet.

Pulsar Planets Are 

Incredibly Rare