History of Jupiter in Timeline

Jupiter, the fifth planet from the Sun, is the Solar System's largest. A gas giant, its mass exceeds 2.5 times that of all other planets combined, though it's still less than 1/1000th the Sun's mass. With a diameter eleven times Earth's, Jupiter orbits the Sun at 5.20 AU, taking 11.86 years. It's the third-brightest object in Earth's night sky, observed since prehistory, and named after the Roman chief deity, Jupiter.

1906: Discovery of first Trojan asteroid

In 1906, Max Wolf discovered the first Trojan asteroid, 588 Achilles, associated with Jupiter.

1932: Identification of ammonia and methane in Jupiter's spectra

In 1932, Rupert Wildt identified absorption bands of ammonia and methane in the spectra of Jupiter, contributing to the understanding of its atmospheric composition.

1938: Observation of White Ovals

In 1938, three long-lived anticyclonic features called "white ovals" were observed on Jupiter.

1939: Formation of White Ovals

In 1939, three smaller white oval-shaped storms formed in Jupiter's atmosphere, later contributing to the creation of Oval BA.

1940: Formation of White Ovals

In 1940, three smaller white oval-shaped storms formed in Jupiter's atmosphere, later contributing to the creation of Oval BA.

1955: Discovery of radio wave emissions from Jupiter

In 1955, Bernard Burke and Kenneth Franklin discovered that Jupiter emits bursts of radio waves at a frequency of 22.2 MHz. The period of these bursts matched the rotation of the planet.

1973: Pioneer Missions Flyby of Jupiter

Beginning in 1973, the Pioneer missions performed planetary flyby maneuvers that brought them within the observation range of Jupiter, obtaining the first close-up images of Jupiter's atmosphere and several of its moons.

1973: First automated spacecraft visit to Jupiter

In 1973, the space probe Pioneer 10 passed close enough to Jupiter to send back revelations about its properties and phenomena, marking the first automated spacecraft visit to the planet.

1973: First Robotic Probe Visits to Jupiter

Since 1973, Jupiter has been visited by nine robotic probes: seven flybys and two dedicated orbiters. These missions provided valuable data and images of the planet and its moons.

1976: Adoption of the name Jupiter by the International Astronomical Union

In 1976, the International Astronomical Union formally adopted the name Jupiter for the planet. Since then, they have named its newly discovered satellites after the god's lovers, favourites, and descendants.

1979: Discovery of additional satellites before Voyager 1 flyby

Eight satellites were discovered before the flyby of the Voyager 1 probe in 1979, adding to the knowledge of Jupiter's moons.

1979: Discovery of Jupiter's planetary rings

In 1979, the Voyager 1 spacecraft discovered Jupiter's faint system of planetary rings. These rings consist mainly of dust and have three main segments: an inner torus of particles known as the halo, a relatively bright main ring, and an outer gossamer ring.

February 1992: Ulysses Solar Probe Flyby

In February 1992, the Ulysses solar probe performed a flyby maneuver of Jupiter to attain a polar orbit around the Sun. During this pass, the spacecraft studied Jupiter's magnetosphere.

July 1994: Collision of Comet Shoemaker–Levy 9 with Jupiter

In July 1994, the Comet Shoemaker–Levy 9 collided with Jupiter, an event closely observed by observatories worldwide and widely covered by the media.

1994: Impact of Comet Shoemaker-Levy 9

In 1994, the Comet Shoemaker–Levy 9 collided with Jupiter. The impacts were closely observed by observatories around the world, including the Hubble Space Telescope and Galileo spacecraft.

July 1995: Release of Atmospheric Probe from Galileo Spacecraft

In July 1995, a 340-kilogram titanium atmospheric probe was released from the Galileo spacecraft and entered Jupiter's atmosphere on December 7, collecting data for 57.6 minutes.

December 7, 1995: Galileo Mission Reaches Jupiter

On December 7, 1995, the Galileo mission reached Jupiter and became the first spacecraft to orbit the planet. It remained in orbit for over seven years, conducting multiple flybys of all the Galilean moons and Amalthea.

1997: Review of early impact observations

In 1997, a review of astronomical records from 1664 to 1839 determined that potential impact observations had little or no possibility of being actual impact events.

1998: Merging of two white ovals

In 1998, two of Jupiter's white ovals merged, marking a significant change in the planet's atmospheric features.

1999: Discovery of numerous small outer moons

Since 1999, the discovery of numerous small outer moons has complicated the previous classification of Jupiter's moons.

2000: Oval BA Formation

In 2000, Oval BA was formed when it absorbed the third white oval.

2000: Formation of Oval BA

In 2000, an atmospheric feature formed in Jupiter's southern hemisphere, similar in appearance to the Great Red Spot but smaller. This "Oval BA" was created when smaller, white oval-shaped storms merged.

2000: Cassini Probe Flyby

In 2000, the Cassini probe flew by Jupiter on its way to Saturn, and provided higher-resolution images of the planet.

September 21, 2003: Destruction of the Galileo Orbiter

On September 21, 2003, the Galileo orbiter was deliberately steered into Jupiter, destroying the spacecraft to avoid any possibility of it crashing into and contaminating the moon Europa.

2005: Cancellation of NASA's JIMO Mission

In 2005, funding difficulties caused NASA's JIMO (Jupiter Icy Moons Orbiter) mission to be cancelled.

2007: New Horizons Probe Flyby

In 2007, the New Horizons probe flew by Jupiter for a gravity assist en route to Pluto. The probe's cameras measured plasma output from volcanoes on Io and studied all four Galilean moons in detail.

2008: Computer simulations regarding Jupiter's impact on comets

In 2008, computer simulations suggested that Jupiter does not cause a net decrease in the number of comets that pass through the inner Solar System, as its gravity perturbs their orbits inward roughly as often as it accretes or ejects them.

April 2011: ESA Ends Partnership with NASA on EJSM/Laplace Mission

In April 2011, the ESA formally ended the partnership with NASA on the EJSM/Laplace mission due to budget issues at NASA.

2015: Great Red Spot shrinks

As of 2015, the Great Red Spot was measured at approximately 16,500 by 10,940 kilometres, and was decreasing in length by about 930 km per year.

July 4, 2016: Juno Mission Arrives at Jupiter

On July 4, 2016, NASA's Juno mission arrived at Jupiter with the goal of studying the planet in detail from a polar orbit.

August 27, 2016: First Flyby and Images of Jupiter's North Pole by Juno

On August 27, 2016, the Juno spacecraft completed its first flyby of Jupiter and sent back the first-ever images of Jupiter's north pole.

2016: Babylonians used trapezoidal rule for integrating the velocity of Jupiter

A 2016 paper reports that trapezoidal rule was used by Babylonians before 50 BC for integrating the velocity of Jupiter along the ecliptic.

April 2017: Discovery of the Great Cold Spot

In April 2017, a "Great Cold Spot" was discovered in Jupiter's thermosphere at its north pole. This feature is a large area that is significantly cooler than the surrounding material and has persisted for over 15 years.

July 2018: End of Juno's Budgeted Mission Plan

Juno completed 12 orbits before the end of its budgeted mission plan in July 2018.

2020: Provisional launch date for ESA/NASA's EJSM/Laplace

Around 2020, the provisional launch date of a joint NASA/ESA mission called EJSM/Laplace.

July 2021: NASA Extends Juno Mission Operations Plan

In June 2018, NASA extended the Juno mission operations plan to July 2021.

October 2021: Juno mission measures the depth of the Great Red Spot

In October 2021, a Juno flyby mission measured the depth of Jupiter's Great Red Spot, determining it to be around 300–500 kilometers.

April 14, 2023: Launch of the European Space Agency's Jupiter Icy Moon Explorer (JUICE)

On April 14, 2023, the European Space Agency's Jupiter Icy Moon Explorer (JUICE) was launched to study Jupiter's icy moons.

October 14, 2024: Launch of NASA's Europa Clipper Mission

On October 14, 2024, NASA's Europa Clipper mission was launched, aiming to study the moon Europa.

September 2025: Planned End of Juno Mission

In January 2021, the Juno mission was extended to September 2025. When Juno reaches the end of the mission, it will perform a controlled deorbit and disintegrate into Jupiter's atmosphere.