#planet-mass-measurement

#planet-mass-measurement

Hubble captured the planet's reflected visible light and highlighted Saturn's iconic yellow hues, which are, in part, a product of the sunlight-reflecting ammonia crystals and hydrocarbons such as methane in its atmosphere.

Discovered in December 2024, asteroid 2024 YR4 was briefly considered the most dangerous asteroid in decades after scientists initially estimated it had a 3.1% chance of colliding with the Earth in 2032. Closer observations quickly ruled out a city killer scenario, but instead astronomers calculated there was a 4.3% chance that the moon lay in the path of impact.

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.

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.

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.

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.

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.

A dead star 730 light years away appears to be forming a powerful structure around itself - and despite their best efforts, astronomers aren't sure how. The cosmic corpse, designated RXJ0528+2838, is an incredibly dense stellar remnant known as a white dwarf, with a Sun-like star orbiting around it. This binary arrangement isn't uncommon throughout the universe, but what is strange is the structure surrounding the former body: a highly energetic and luminescent cloud known as a nebula,

With Webb, we are able to see farther than humans ever have before, and it looks nothing like what we predicted, which is both challenging and exciting,

A bright star in a nearby galaxy has essentially vanished. Astronomers believe that it died and collapsed in on itself, transforming into the eerie cosmic phenomenon known as a black hole. "It used to be one of the brightest stars in the Andromeda galaxy," says Kishalay De, an astronomer with Columbia University and the Flatiron Institute. "Today, it is nowhere to be seen, even with the most sensitive telescopes."

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 population of super-Earths and sub-Neptunes, and the origin of the radius valley that separates these two classes of planets, is best explained by cores that are made of an Earth-like composition without a substantial amount of accreted ice8,9,10,11. For sub-Neptunes, the hydrogen-rich envelope overlies the rocky core for billions of years, whereas for super-Earths, the envelope may be retained for about 100 Myr (refs. ).

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.

V1298 Tau is a young (10-30 Myr), approximately solar-mass star (1.10 ± 0.05  M⊙ ) in the Taurus star-forming region2,4,5,6,7,8. Observations by NASA's Kepler space telescope in its extended K2 mission9 revealed transits of the star by four different planets, each larger than Neptune2,3. The V1298 Tau planets occupy a sparsely populated region of the observed exoplanet period versus radius plane. As a young system of large planets, it provides a crucial snapshot of planetary architecture

I think the first thing to remember is: We are right at the beginning of this adventure. There's so much excitement that every little signal - every "wiggle" in a spectrum - gets people saying, "Oh! That might be life!" And then, on the other side, other people respond with, "I don't see enough wiggles, so there's probably not even an atmosphere. Dead planet. Move on." Both reactions are too fast.