Nearly 4.5 million years ago, two enormous, blazing stars swung close to the solar system. They did not touch the sun, but they came close enough to leave a permanent mark on the thin mist of gas that ...

Massive stars have a layered structure, similar to an onion. The outermost layers predominantly comprise the lightest elements; as the layers move inward, the elements become heavier and heavier until ...

Nearly 4.5 million years ago, two enormous, blazing stars swung close to the solar system. Chevron reacts to Trump's Venezuela plan Wisconsin judge convicted of obstructing arrest of immigrant resigns ...