#comet-perplexity

#comet-perplexity

We found that life is more likely to survive an asteroid impact, so it's definitely still a real possibility that life on Earth could have come from Mars. Maybe we're Martians! The idea that life could have spread through the solar system or even the universe on rocks is known as the lithopanspermia hypothesis.

The first time that University of Oxford astronomer Lyla Jung saw the cosmic configuration on her monitor, she almost didn't believe it was real. But it wasand Jung and her colleagues went on to identify one of the largest rotating structures ever found in space: a chain of galaxies embedded in a spinning cosmic filament 400 million light-years from Earth. The finding, published in Monthly Notices of the Royal Astronomical Society, may give astronomers new insights into galaxies' formation, evolution and diversity, Jung says.

Chances to see 4 bright planets with your own eyes occur every few years on average, so it's not once in a lifetime. Even so, the planets are best observable just after sunset, so this is one of the most convenient opportunities for several years.

This system is truly extraordinary. We're seeing the radio equivalent of a laser halfway across the universe. Fundamentally, masers and lasers are focused beams of light in the same frequency. In the realm of astrophysics, these can arise from clouds of dust being excited into a higher energy state from the light emitted by other sources, like stars and black holes.

Looking skyward fills us with wonder. Off-world, the Sun, planets, stars, and galaxies all await. Our Solar System encompasses our own cosmic backyard. Farther away, stars and star clusters abound within the Milky Way. Hundreds of billions of stars exist just within our home galaxy. Inside our Local Group, only Andromeda surpasses us in mass, size, and stars. More than 5 million light-years away, galaxies abound in groups and clusters.

The universe is exploding. Or parts of it are. The night sky may seem calm, even serene, but that masks events of a catastrophic and nearly unimaginable scale. Across the galaxy and even the cosmos itself, immense outbursts of energy occur that could easily vaporize our planet. Happily, space is vast, and the terrible distance between these events and us diminishes what we see to a faint glowusually.

Okay, first thing first: the universe is in fact expanding. We've known this for more than a century now, and it's the basis for modern cosmology. This idea is called the big bang modelwhich is an unfortunate name because it brings to mind a cosmos expanding like an explosion, with galaxies moving away from each other through space like shrapnel. But in fact space itself is expanding, and that's different.