Did The Solar System Once Collide With An Interstellar Cloud?
Headlines:
• NASA's Parker Solar Probe has been exploring the Sun's polar regions, revealing new insights into the Solar System's magnetic field. • The Solar Wind is a stream of charged particles emitted by the Sun, affecting the Earth's magnetic field and influencing our planet's climate. • Scientists have discovered a new planet orbiting a nearby star, which may have the potential to support ⁙⁙⁙. • The Andromeda Galaxy, our closest galactic neighbor, "is approaching the Milky Way at a speed of 250,"000 miles per hour. • Astronomers have detected a massive galaxy collision that could have implications for the formation of planets. • The Hubble Space Telescope has captured stunning images of distant galaxies and stars... shedding light on the history of the universe. • Scientists are working to develop a new propulsion system to explore the Solar System and beyond. • The European Space Agency (ESA) is planning to launch a mission to study the formation of the Solar System. • Researchers are investigating the possibility of extraterrestrial ⁙⁙⁙ in the polar regions of Mars. These bullet points are based on real news headlines and are categorized under the subject of space exploration and the Solar System.Astronomers have proposed a rather uncomfortable past for our solar system and our planet — as well as an alternative explanation for a radioactive anomaly on Earth.
Something strange happened to our solar system a few million years ago. Every time scientists analyze Antarctic ice cores, deep sea sediments, ferromanganese crusts, or even samples of lunar rock, they find something that shouldn't be there: a radioactive isotope of iron, known as iron-60.
On June 10th in Nature Astronomy , Merav Opher (Boston University), Avi Loeb (Harvard), and Josh Peek (Space Telescope Science Institute) proposed a different idea: What if iron-60 peaked not because of specific supernovae but because something temporarily weakened the magnetic structure that protects the solar system?
The heliosphere is a giant magnetic bubble that shields Earth and the other planets from the charged particles that permeate the space between stars, known as the interstellar medium. Despite its name, though, the heliosphere isn't a sphere — the Sun's motion through the interstellar medium causes it to have a comet-like shape, compressed in the direction of movement, with a longer tail extending behind it.
The constant flow of the solar wind currently pushes the closer boundary of this magnetic structure far beyond Pluto's orbit (which extends at most 49 astronomical units, or a.u., from the Sun), out to around 120 a.u. The Voyager 1 and 2 probes crossed this outer boundary of the heliosphere in 2012 and 2018, respectively.(In the other direction, the heliosphere's boundary is much farther away.)
The interstellar medium contains vast clouds of dense, cold dust, and the nearest of these clouds currently lie several dozen light-years away. In the past, Opher and her colleagues propose, one of them might have encountered the solar system, collapsing the heliosphere to a fraction of its current size.
The consequences for our planet may have been dramatic. "Earth and all the planets were exposed to massive amounts of hydrogen, increased radiation, and interstellar dust," Opher explains. Global temperatures may have dropped, starting a prolonged cold phase — perhaps even causing the most recent ice age.
Comments
Post a Comment