Also one of Garys links. At www.dailymail.co.uk/sciencetech/article-9078899/ … we learn that a meteor that exploded in earth's atmosphere back in 2008 was once part of a much larger space rock, that contained a surprising amount of water. The term asteroid is used loosely as I suppose the parent body could have been a comet. Meteors originate from larger bodies – even moons and planets. The object that exploded over the Nubian Desert in what is modern Sudan was around 13 feet in diameter and exploded quite close to the ground, even if it was chondrite, or stony in composition. It created a fireball that lit up the sky as bright as the full moon, in an area of the earth's surfce not overduly troubled by street lights and neon signs. The study was published in Nature Astronomy this month, December of 2020.
The media this week was mostly intrigued by a conjunction of Saturn with Jupiter, calling it the Christmas star – as it is the week leading up to Christmas day. See for example https://spaceweather.com [December 20th to 22nd] and https://phys.org/news/2020-12-jupiter-saturn-merging-night-sky-1.html … but over here in Blighty it was mostly too cloudy and wet to see much. We did, in compensation, have images posted on the TV news, in newspapers, and at various internet links, including the two above. The two planets were actually 400 million miles apart, give or take the odd yard or foot. The alignment only existed from an earth based position. In a clear sky and looking at it with the naked eye it may very well have been a luminous double but the images tell a different story, and spoil the broth.
At https://phys.org/news/2020-12-rosetta-stone-planet-formation.html … the Rosetta Stone of planet formation. Surprisingly, little is known of the composition and nature of the planet and star forming disks of dust and gas, in spite of the authoritative claims otherwise. The knowledge of the process is assumption led, assumption fueled, and assumption interpolated. It discusses the recent offerings via Europe's Very Large Telescope Array, SPHERE.