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13 hours agoThe universe is expanding 'too fast' - and scientists have no idea why
The universe is expanding faster than predicted, indicating potential flaws in current cosmological models.
The UK is not well prepared for a severe space weather event, despite some investment in developing forecasting capabilities. The government does not yet understand the full range of possible impacts and cascading effects well.
Stellar activity such as solar storms and plasma turbulence from a star near a transmitting planet can broaden otherwise ultra-narrow signals. That spreads the power of any such transmission across more frequencies, the institute's scientists say, which makes it more difficult to detect using traditional narrowband searches.
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 sun is putting on a show. On Sunday the star unleashed several strong and bright solar flares, including one of the most powerful eruptions seen in decades. Far from the steadily glowing orb we sometimes picture, the sun's surface is made up of roiling plasma thrown about by twisting magnetic fields. When these fields snap, they can throw out huge bursts of energy and charged particles into spacea solar flare.
The sun's rhythmic rise and fall in the sky can make it easy to forget that our star is unpredictablea roiling, burbling mass of magnetically knotted plasma that governs the entire solar system. But a new video from the European Space Agency's (ESA's) Proba-3 mission that shows a string of fountainlike explosions on the sun offers a powerful reminder of our home star's active nature.
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 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."
Earlier this week, the Sun unleashed a powerful X-class solar flare, a major burst of electromagnetically charged particles that lit up the Earth's night sky as they entered our planet's atmosphere. The effect was stunning: a dazzling display of auroras reaching as far as southern California. Forecasters that it was one of the largest solar storms in decades, making for a particularly unique opportunity to watch the show unfold.
Auroras are nature's most special light show: when charged particles from the sun hit our atmosphere, they can generate bright colors that dance across the night sky near the Earth's poles. Auroras can come in various forms, including bands, rays, patches and more. But why auroras form these patterns is less clear. Now, researchers say they've identified the battery that powers at least one kind of auroraaurora arcs.
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 gas giant's shape and size, previously known only from data collected more than 45 years ago, have been updated at last. The biggest planet in the Solar System just got smaller and flatter. Access Nature and 54 other Nature Portfolio journals Get Nature+, our best-value online-access subscription Subscribe to this journal Receive 51 print issues and online access $199.00 per year only $3.90 per issue. Prices may be subject to local taxes which are calculated during checkout.