Space

Health & Medicine

Readers ponder the randomness of DNA errors

Readers sent feedback on cellular slip-ups, moon mayhem and more.

Science & Society

The first Cassini to explore Saturn was a person

Cassini, the spacecraft about to dive into Saturn, was named for the astronomical pioneer who first perceived the gap between the planet’s famous rings.

Planetary Science

Watery exoplanet’s skies suggest unexpected origin story

Compared with Neptune, HAT-P-26b’s atmosphere has few heavy elements, suggesting it formed differently than the ice giants in Earth’s solar system.

Planetary Science

Oxygen on comet 67P might not be ancient after all

Molecular oxygen detected around comet 67P may not be a relic of the solar system’s birth. Instead, it may be generated by interactions of water, the solar wind and the comet’s surface.

Planetary Science

Mars may not have been born alongside the other rocky planets

Mars formed farther away from the sun than its present-day orbit, not near the other terrestrial planets, new research suggests.

Planetary Science

Here’s how an asteroid impact would kill you

Most deaths caused by an asteroid impact would result from shock waves and winds generated from the blast, rather than effects such as earthquakes and tsunamis, new simulations show.

Astronomy

Read up on solar eclipses before this year’s big event

Three new books chronicle the science, history and cultural significance of total solar eclipses.

Planetary Science

Cassini’s ring dive offers first close-up of Saturn’s cloud tops

Cassini has completed its first dive between Saturn and its rings. Along the way, it snapped stunning pics of the planet’s atmosphere.

Astronomy

No long, twisted tail trails the solar system

The bubble that envelops the planets and other material in the solar system does not have a tail, new observations show.

Physics

Gamma-ray evidence for dark matter weakens

Excess gamma rays are still unexplained, but they might not come from dark matter.

Planetary Science

In ‘grand finale,’ Cassini spacecraft sets off on collision course with Saturn

The Cassini spacecraft will plunge into Saturn’s atmosphere and disintegrate on Sept. 15, but is slated to do some solid science before its demise.

Planetary Science

Bubbles may put mysterious fizz in Titan’s polar sea

Nitrogen bubbles may be the source of the “magic island” on Saturn’s moon Titan.