Scientific discoveries often come from surprising places. Lonnie Shekhtman of NASA:
Look up to the night sky just before dawn, or after dusk, and you might see a faint column of light extending up from the horizon. That luminous glow is the zodiacal light, or sunlight reflected toward Earth by a cloud of tiny dust particles orbiting the Sun. Astronomers have long thought that the dust is brought into the inner solar system by a few of the asteroid and comet families that venture in from afar.
But now, a team of Juno scientists argues that Mars may be the culprit.
It’s an amazing story that involves a mission to Jupiter getting pelted by high-speed dust particles and an instrument meant to be measuring one thing that ended up measuring something quite different. The result, it seems, is that Mars dust pollutes our part of the solar system, so much so that at the right time of day you can see it.
—Linked by Jason Snell