Astronomers | Pakistan

Astronomers have observed a planetary system that challenges current planet formation theories, with a rocky planet that formed beyond the orbits of its gaseous neighbours, possibly after much of the planet-forming material had been used up. The system, observed using the European Space Agency’s Cheops space telescope, consists of four planets — two rocky and two gaseous — orbiting a relatively small and dim star called a red dwarf about 117 light-years from Earth in the direction of the Lynx constellation. A light-year is the distance light travels in a year, 9.5 trillion kilometres. The star, named LHS 1903, is about 50 per cent as massive and 5pc as luminous as our sun. The order of the planets is what caught the attention of scientists. The innermost planet is rocky, the next two are gaseous and the fourth one, which current planetary formation theory suggests should be gaseous, instead is rocky. “The planet-formation paradigm states that planets close to their host star should form small and rocky, with ...

Astronomers said on Wednesday they had observed the moment when planets start forming around a distant star for the first time, revealing a process that sheds light on the birth of our own solar system. The new planetary system is forming around the baby star HOPS-315 — which resembles our own Sun in its youth — 1,300 light years from Earth in the Orion Nebula. Young stars are surrounded by massive rings of gas and dust called protoplanetary discs, which is where planets form. Inside these swirling discs, crystalline minerals that contain the chemical silicon monoxide can clump together. This process can snowball into kilometre-sized “planetesimals”, which one day grow into full planets. In our home Solar System, the crystalline minerals that were the starter dough for Earth and Jupiter’s core are believed to have been trapped in ancient meteorites. Now astronomers have spotted signs that suggest these hot minerals are starting to solidify in the disc surrounding HOPS-315, according to a new study in the jour...