A new satellite has been added to Jupiter: How was it discovered? By whom?

Astronomy enthusiasts discover a new small satellite around Jupiter

This is the first time in history that a new small satellite around Jupiter has been discovered by amateur astronomers.

In 1974, NASA's Pioneer 11 looked down at Jupiter's north pole (Image source: NASA Ames)

In a major first, an amateur astronomer has discovered an unknown satellite of Jupiter after carefully studying old astronomical images.

"I am proud to say that this is the first planetary satellite discovered by an amateur," said Li Kai (Satellite Seeker) in an article detailing the discovery published in Sky & Telescope on July 8.

Jupiter may have dozens or even hundreds of satellites orbiting it that have not yet been discovered. The giant planet's strong gravity field allows it to capture a lot of space debris into orbit. The previous number of Jupiter's satellites was 79, and this number is still growing. The latest one is this one discovered by astronomy enthusiast Li Kai, which is also the latest addition to the Jupiter satellite group Garni.

Garni and the other members of the group are irregular space rocks. According to NASA, they orbit in the opposite direction of Jupiter's orbit - a phenomenon called "retrograde motion" and orbit Jupiter at a very high orbital inclination. Garni is the largest of the Garni group of moons, with an average radius of 14 miles (23 kilometers). It is also the parent rock of the new moon discovered this time and 22 other unknown members. Astronomers believe that Garni is an asteroid captured by Jupiter's gravity, and the Garni group members are the fragments left after the asteroid experienced a cosmic collision.

From bottom to top, the bright spots in the image represent the Moon, Venus, and Jupiter; the curved horizon at the top is the crescent Earth. This view was taken by astronaut Scott Kelly from the International Space Station in 2015. (Image credit: NASA/Scott Kelly)

Li discovered the new satellite while observing online data. The data set was collected by researchers at the University of Hawaii using the 3.6-meter Canada-Hawaii Telescope (CFHT). Li paid special attention to images from February of that year, when the satellites appeared brightest. This is actually caused by the astronomical phenomenon of "opposition", which is when the sun and another specific planet appear on opposite sides of the earth in space. Our earth was located at the midpoint of the straight line between the sun and Jupiter in February 2003, so astronomers on earth could clearly see the Jupiter system illuminated by the sun.

Li Kai also used observation data from another telescope, the Subaru Telescope, to establish a 22-day arc trajectory for the star. This arc trajectory shows that the quasi-satellite is very likely to be subject to the gravity of Jupiter. With this line, they can also use other data to find and verify the existence of this satellite.

In the Sky & Telescope article, Li Kai called this exciting discovery "a summer hobby before returning to school."

The space rock is now named EJc0061, but it has no official name yet. Later, the satellite's official name will end with the letter "e", just like Carme. NASA officials explained in an introduction to Carme's naming that "this naming is in accordance with the International Astronomical Union (IAU) policy for naming retrograde satellites."

Related knowledge

Jupiter is the fifth planet from the sun and the largest planet in the solar system. It has 80 satellites. Astronomers discovered this planet very early. The Romans called it Jupiter after their god. Ancient China called Jupiter Suixing or Taisui because it takes about 12 years to orbit the celestial sphere, which is the same as the earthly branches. This is why the Suixing calendar was created.

Jupiter has 80 confirmed natural satellites, making it the second-largest satellite system of any planet in the Solar System. [1][2] The four largest, collectively known as the Galilean satellites, were discovered by Galileo Galilei in 1610, the first celestial bodies discovered (other than the Moon) that did not orbit the Sun. Since the late 19th century, more and smaller satellites of Jupiter have been discovered and named after the lovers, admirers, and daughters of Jupiter (or Zeus, the equivalent), king of the Roman gods.

Eight of Jupiter's satellites are regular satellites, orbiting in almost perfectly circular prograde orbits with an inclination of nearly zero relative to Jupiter's equatorial plane. The four Galilean satellites are the most massive, with masses large enough to form a nearly spherical shape. The remaining four regular satellites are much smaller, orbit closer to Jupiter, and are the main source of dust in Jupiter's rings. The remaining satellites are all irregular satellites, with prograde and retrograde orbits, farther from Jupiter, and very high orbital inclinations and eccentricities. These satellites are likely to be objects that once orbited the Sun and were later captured by Jupiter. Since 2003, a total of 23 irregular satellites have been discovered but not named.

BY: Doris Elin Urrutia

FY: Jiandibai

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