Stemming from the Greek word for "wanderers," planets have long captured humanity's attention as they moved across the sky against a backdrop of fixed stars. Planets are distinct from stars in that they have no internal source of radiation and typically orbit stars. While our solar system has eight planets, astronomers continue to discover more throughout the universe as technology advances. Find out more about your favorite or least familiar planet with our collection of the internet's best resources on planets.
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Beyond challenging Earth-centric views upon their discovery in 1610, the Galilean moons were also later analyzed to contribute to early astrometry and astronomical interferometry. Measurements of eclipses were also used to estimate the speed of light.
As seen from space, Jupiter’s most striking feature is an anticyclone 30% larger than Earth, with winds twice the speed of Category 5 hurricanes. The descent into the storm brings enough pressure to strip atoms of their electrons.
The continent-sized cyclones at Jupiter’s poles generate strong winds and ammonia-laden storms. The spacecraft has also collected data on Jupiter’s unique magnetic field, which resembles a blend of Earth’s and Uranus/Neptune's.
The auroras flicker faster and brighter than those seen on Earth. This contrasts with earlier predictions that the lights would fade slowly over several minutes, providing insights into how Jupiter’s magnetosphere operates.
Scientists from the University of Zurich and NCCR PlanetS proposed the mechanism after using computer modeling to replicate Jupiter’s formation to match its observed concentration of heavy elements. The work may help understand how Jupiter-like exoplanets exist near host stars.
Since solar winds remove gases from protoplanetary disks within millions of years of a star’s birth, models needed to provide a mechanism to jump-start Jupiter’s formation and growth. The solution involved incorporating pebbles of matter into the disk.
One theory of Jupiter’s formation involves the planet spiraling inwards from the asteroid belt, gathering material and disrupting the initial formation of terrestrial planets. Saturn’s gravitational pull would then reverse its course.
Discovered in 1995, hot Jupiters are a class of exoplanets—planets orbiting stars other than the sun—with size and mass similar to Jupiter. They are most commonly found orbiting metal-rich stars and have become essential for testing theories of planetary system formation.
Using the JunoCam, scientists have observed several of Jupiter's features, including cyclones, the Great Red Spot, and cloud bands and zones. The mission's effectiveness has resulted in its extension from July 2021 to September 2025.
Despite decreasing in size, the anticyclone remains larger than Earth, rotating with winds up to 933 km/h. Its longevity may be because it is trapped between two opposite-flowing jet streams, which act like two conveyor belts.
From roughly 60 miles above the Earth's surface to farther than light has traveled during the entire age of the universe, space has captured human imagination for millennia. Explore the final frontier with the best resources curated from across the internet.