Cool strikes

Stonehenge’s central stone, is named the Altar Stone, might well perhaps even hang had Scottish and no longer Welsh origins, researchers sing. The discovering means that Gradual Neolithic groups had lengthy-distance connections, Bruce Bower reported in “Stonehenge’s roots lengthen to Scotland” (SN: 9/7/24 & 9/21/24, p. 10).

Reader Ralph Bradburd wondered if a glacier, no longer other folks, might well perhaps hang at the least partly transported the Altar Stone from Scotland to southern England, where Stonehenge is found.

That difficulty is worth brooding about but is unlikely, says geoscientist Anthony Clarke of Curtin University in Perth, Australia. Ice sheet reconstructions show that glaciers moved northward from the Grampian Mountains in central Scotland in opposition to the Orcadian Basin within the northeast, where the Altar Stone is thought to hang come from, he says. So glacial dash up there don’t hang brought the Altar Stone south to Stonehenge.

What’s extra, there might be tiny proof of rocks deposited by glaciers, is named glacial erratics, in central southern Britain, Clarke says. And namely, erratics from Scotland hang no longer been discovered shut to Stonehenge.

Up within the air

Cloud-forming aerosols shall be solid for the length of stratospheric air intrusion events, in which Earth’s jet streams cause stratospheric air to dip into the underlying troposphere, Carolyn Gramling reported in “Earth’s jet streams sow cloud seeds” (SN: 9/7/24 & 9/21/24, p. 12).

Reader James W. Benefiel asked whether it’s extra seemingly for clouds to map when water vapor within the upper troposphere condenses on particles.

Right here’s if truth be told a known mechanism for the formation of cloud condensation nuclei, the petite particles that water droplets condense onto and that are the genesis of clouds, Gramling says. Such particles can map where convective clouds, similar to thunderstorm clouds, carry gases or petite particles from Earth’s surface high into the ambiance, where water vapor can condense onto them.

What this original seek suggests is an fully diversified chemical direction of for cloud formation, which entails ozone from the stratosphere, Gramling says. Stratospheric air intrusion events had been already a known phenomenon. Now researchers hang linked such events to a bump within the formation of cloud condensation nuclei. The scientists propose that the blending of stratospheric ozone with tropospheric moisture, catalyzed by sunlight, might well perhaps also broaden the production of free hydroxyl radicals, which would perhaps react with diversified molecules to manufacture the cloud-forming particles.

Given the frequency of stratospheric air intrusion events, this mechanism shall be a serious provide of cloud nuclei, Gramling says. Nonetheless real how grand is soundless unknown.

Friend or foe?

A chemical diagnosis means that the asteroid that killed the dinosaurs came from beyond Jupiter, Carolyn Gramling reported in “Dinosaur killer’s starting set aside revealed” (SN: 9/7/24 & 9/21/24, p. 7).

The anecdote sparked a packed with life discussion on Reddit about whether Jupiter shields Earth from asteroid and comet collisions.

Reddit user DonManuel wrote that Jupiter’s failure to give protection to Earth from the dino-killer exhibits “how critical the protection of Jupiter if truth be told is for all times on Earth.” Nonetheless user Astromike23 wrote that the premise that Jupiter shields Earth from impacts is a delusion.

Indeed, Jupiter’s role as a planetary protector is no longer so sure-slash. The planet’s mighty gravitational pull can influence the orbits of nearby objects, which is also a double-edged sword for Earth.

A tiny bit learn imply Jupiter might well perhaps also defend Earth and neighboring planets from impacts by pulling passing asteroids and comets in opposition to itself or flinging them out of the photo voltaic blueprint fully. Nonetheless diversified learn suggests Jupiter can furthermore slingshot asteroids and comets into the inner photo voltaic blueprint and put up a collision direction with Earth or its neighbors. Jupiter might well perhaps also even entice objects that wouldn’t most steadily scoot Earth, rising the chance for collision.