Late Heavy Bombardment put under the microscope

https://www.nature.com/articles/d41586-018-01074-6

The article goes over the case against the cataclysm scenario, and it turns out the case isn’t as rock-solid (sorry, had to put a pun in here somehow) as previously thought. It turns out that what we previously thought was evidence for the Late Heavy Bombardment was actually a sampling error, as the article attests to in the quote below:

Yet just when the idea of the LHB finally seemed unimpeachable, holes began to appear. Apollo data and ‘crater counting’, which estimates the order in which craters were laid down on the basis of how they overlap, had indicated that three of the largest crater basins on the Moon’s near side — Imbrium, Nectaris and Serenitatis — might all be about 3.95 billion years old (see ‘Sampling the Moon’). But high-resolution maps from NASA’s Lunar Reconnaissance Orbiter, which started circling the Moon in 2009, spotted rays of debris extending from Imbrium5. This suggested that the impact that formed the crater might have knocked rocks into nearby Serenitatis, contaminating the Apollo samples picked up there. In 2010, a reanalysis of rocks thought to have been ejected from Nectaris indicated that they were also chemically and geologically similar to Imbrium material6. “We started realizing that maybe we were sampling Imbrium over and over,” says Zellner.

The article goes on further, saying that “we find no evidence of a large spike in impacts occurring around the 3.9 billion year mark” (slight paraphrasing). It also mentions the existence of crystals dated to 4.1 Ga that “demonstrate the existence of relatively calm pools of liquid water,” which would’ve been supposedly evaporated from the surface of the Earth from that period of if the LHB hypothesis is correct.

The article concludes by saying that at the most the evidence indicates a “more prolonged period of bombardment, as opposed to the sudden spike in impact events as predicted by the cataclysm hypothesis.” Others are skeptical of even that, instead believing that there was one single rapid spike that occurred very shortly after the solar system formed, whereas others believe there was no spike nor period of bombardment at all.

10 Mysteries of Titan

The excellent as always Mr John Michael Godier has come out with a new video, I suggest giving it a watch. Mr Godier here explains ten mysteries of Titan, the only moon in our solar system with a substantial atmosphere, and the only other terrestrial body in our solar system with surface liquids, specifically lakes and rivers of liquid methane. It’s also becoming more and more evident that prebiotic chemistry of sorts is occurring on Titan, and what’s happening their may hold clues for the origin of life here on earth as well, as the early earth is believed to have been very similar to Titan.

It’s even possible we may find life there, however such life would be totally alien to our own, utilizing an entirely different, and also entirely hypothetical, biochemistry than the water based one that is used on earth. Titan also quite likely has a subsurface ocean of liquid water, and that subsurface ocean may very well have hydrothermal vents, meaning that it’s quite likely that even if no life is found on Titan’s surface, that life may still be found on Titan irregardless of its surface conditions.

Formalhaut

PBS Space Time Video

In this PBS Space Time video the forming solar system of Formalhaut is explored, with lots of Lord of the Rings puns to go around ever since the now infamous “Eye of Sauron” photo was released. Interestingly the star is a member of a tristellar system, it’s stellar siblings are a red dwarf and a flare star respectively.

Formalhaut’s solar system is also (probably) home to two planets, a hot Jupiter and a probably terrestrial planet called “Dagon,” how’s that for a cool name? Interestingly enough the orbit of Dagon indicates it was formed further in, closer to Formalhaut proper, but was thrown out into its current orbit by a close encounter with the aforementioned hot Jupiter. Something similar is posited to have happened in our solar system early on with the gas giants, as they all formed relatively close together but something threw them further apart.

Formalhaut may very well be a glimpse into what would have happened during the formation of our own solar system, as it is a solar system in formation right now as we speak.