These are the science dispatches for the third week in July 2018, including the discovery of twelve new moons around Jupiter, including a real oddball. And fossil-hunters uncover the oldest preserved snake sealed in amber.
The discovery of 12 new moons around Jupiter brings its moon count to 79
Whilst most of the planets in our solar system have their own natural satellites, gas-giant Jupiter could be said to have more than its fair share. That is especially in consideration of the fact that astronomers have discovered 12 new Jovian moons, it was announced this week. One of the moons, labelled ‘oddball’ by its discoverers, may even shed light on the development of the early solar system.
The new moons were discovered by Scott. S. Shephard of the Carnegie Institute of Science and his team using the Blanco 4-meter telescope at Cerro Tololo Inter-American in Chile and operated by the National Optical Astronomical Observatory of the United States, whilst they were looking to the edge of the solar system for evidence of an elusive ninth planet. “Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant Solar System objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our Solar System,” said Sheppard in a Carnegie press release.
Nine of the new moons, part of an outer ‘swarm’ are in a retrograde orbit, opposite to the rotation of Jupiter. Taking roughly two years to orbit Jupiter, they are believed to be the remnants of larger bodies which broke apart on collision with asteroids, comets and other moons.
Two of the other moons discovered exist closer to Jupiter itself and are orbiting in prograde, in the same direction as the gas giant’s rotation. These prograde moons are also believed to be part of a larger body and take roughly a year to orbit the planet.
It was the final moon that has raised the most questions though. Labelled an ‘oddball’ by its discoverers, it possesses an orbit unlike any other Jovian moon and is also likely Jupiter’s smallest moon. This moon is further out than the prograde moons and has an orbit with a strong inclination. It takes a year and a half to orbit Jupiter and its orbital path takes it past the outer retrograde moons.
This means that collisions between this ‘oddball’ prograde moon and the outer retrograde moons are extremely likely. It’s this exact mechanism that likely formed the newly observed moons in the first place. “This is an unstable situation,” said Sheppard. “Head-on collisions would quickly break apart and grind the objects down to dust.”
Thus, the team believes that this ‘oddball’ moon may be the final remnant of a once-larger prograde-orbiting moon that formed some of the retrograde moon groupings during past head-on collisions. The name Valetudo has been proposed for it, after the Roman god Jupiter’s great-granddaughter, the goddess of health and hygiene.
Observations of these interactions may well give scientists a clue as to the solar system’s early development and how it has come to look the way it does now. For example, the fact that these smaller moons still exist around Jupiter suggests that they formed after planet formation took place, a period when the Sun was still surrounded by gas and dust clouds.
As the moons are more influenced by such gas and dust, if these smaller moons had formed whilst these clouds were still abundant, they would likely have been dragged down towards Jupiter’s surface. Thus their presence implies they formed after the surrounding gas and dust clouds were dissipated.
Researchers discover oldest recorded snake embryo preserved in amber
Researchers have discovered the remains of the earliest recorded snake, which would have slithered its way through the forests of Myanmar 99 million years ago. The specimen sealed in amber is a newly discovered species, named Xiaophis myanmarensis, and represents a significant development in the investigation of life in East-Asia and snake evolution in particular.
The discovery of the oldest baby snake ever discovered was announced in a paper published in Science Advances along with the co-discovery of fossilised scale samples from the same area which researchers believe also came from the Cretaceous period.
“It’s spectacular to have a baby snake in the fossil record because, of course, they’d be such tiny, delicate things,” says co-author of the study Michael Caldwell, a biology professor at the University of Alberta.
The 2016 discovery was made by a group of fossil-hunters who quickly contacted Chinese palaeontologist Lida Xing from the China University of Geosciences. The 1.8-inch specimen consists of a perfectly preserved spine and body but is, unfortunately, missing its head. It is remarkably similar to snakes found today and the study says it represents “greater ecological diversity among early snakes than previously thought.”
The new species was named Xiaophis myanmarensis in tribute to Xiao Jia, an amber specialist who was part of the initial team of fossil hunters. It was her donation of the sample that has allowed it to be studied further.