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 the planet Mars may be the culprit.
An instrument aboard the Juno spacecraft serendipitously detected dust particles slamming into the spacecraft during its journey from Earth to Jupiter. The impacts provided important clues to the origin and orbital evolution of the dust, resolving some mysterious variations of the zodiacal light.