There’s a new record for the shortest time measurement: how long it takes light to cross a hydrogen molecule

HD+ molecular ions (yellow and red pairs of dots: proton and deuteron) suspended in an ultra-high vacuum between atomic ions (blue dots). Credit: HHU / Alighanbari, Hansen, Schiller
HD+ molecular ions (yellow and red pairs of dots: proton and deuteron) suspended in an ultra-high vacuum between atomic ions (blue dots). Credit: HHU / Alighanbari, Hansen, Schiller

To measure small differences in time, you need a really tiny clock, and researchers in Germany have discovered the smallest known clock: a single hydrogen molecule. Using the travel of light across the length of that molecule, those scientists have measured the smallest interval of time ever: 247 zeptoseconds. Don’t know what a “zepto” is? Read on…

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It’s still possible to detect the site of the 2017 kilonova explosion

A team of European researchers, using data from the X-shooter instrument on ESO’s Very Large Telescope, has found signatures of strontium formed in a neutron-star merger. This artist’s impression shows two tiny but very dense neutron stars at the point at which they merge and explode as a kilonova. In the foreground, we see a representation of freshly created strontium. Image Credit: ESO/L. Calçada/M. Kornmesser

It’s been over a thousand days since the historic kilonova observation, and yet the region continues to emit X-rays, long after models predicted they should have faded away. What’s going on?

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The galaxy with 99.99% dark matter isn’t so mysterious any more

Artist rendering of the dark matter halo surrounding our galaxy. For quasars, the dark matter halos are much more massive. Credit: ESO/L. Calçada
Artist rendering of the dark matter halo surrounding our galaxy. Credit: ESO/L. Calçada

The dwarf galaxy known as Dragonfly 44 caused a stir recently: apparently it had way, way more dark matter than any other galaxy. Since this couldn’t be explained by our models of galaxy formation, it seemed like an oddball. But a new analysis reveals that Dragonfly 44 has much less dark matter than previously thought. In short: it’s totally normal.

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Do Ripples on the Surface of the Sun tell us that a Flare is Coming?

Credit: NSF

Flares from the sun are some of the nastiest things in the solar system. When the sun flares, it belches out intense X-ray radiation (and sometimes even worse). Predicting solar flares is a tricky job, and a new research paper sheds light on a possible new technique: looking for telltale ripples in the surface of the sun minutes before the blast comes.

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How to See What’s on the Other Side of a Wormhole Without Actually Traveling Through it

Wormholes are incredibly fascinating objects, but also completely hypothetical. We simply don’t know if they can truly exist in our universe. But new theoretical insights are showing how we may be able to detect a wormhole – from a spray of high-energy particles emitted at the moment of its formation.

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Matter makes up exactly 31.5±1.3% of the Universe

dark matter shown in blue
This image from the NASA/ESA Hubble Space Telescope shows the galaxy cluster MACS J0416. This is one of six clusters that was studied by the Hubble Frontier Fields programme, which yielded the deepest images of gravitational lensing ever made. Scientists used intracluster light (visible in blue) to study the distribution of dark matter within the cluster.

Weighing the universe is a tricky task, but a team of astronomers have used a clever technique to measure how many galaxy clusters are in the cosmos, and from there come up with a total amount of matter. The answer: 31.5±1.3% of all the energy in the universe.

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The Solar System has a second plane where objects orbit the Sun

Artist's impression of the ecliptic plane (yellow), and the recently-discovered "empty" ecliptic (blue) in our solar system. (Credit: NAOJ)

Almost all the objects orbiting the sun live in a particular plane, called the ecliptic plane. But a recent analysis of long-period comets reveals a second home, a so-called “empty ecliptic”. And it may be populated with comets dragged there by none other than the gravity of the Milky Way galaxy.

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What Decides the Shape of Planetary Nebulae? Whatever’s Orbiting a Star When it Dies

This Picture of the Week from the NASA/ESA Hubble Space Telescope shows NGC 5307, a planetary nebula which lies about 10000 light years from Earth. It can be seen in the constellation Centaurus (The Centaur), which can be seen primarily in the southern hemisphere.  A planetary nebula is the final stage of a Sun-like star. As such, planetary nebulae allow us a glimpse into the future of our own Solar System. A star like our Sun will, at the end of its life, transform into a red giant. Stars are sustained by the nuclear fusion that occurs in their core, which creates energy. The nuclear fusion processes constantly try to rip the star apart. Only the gravity of the star prevents this from happening.  At the end of the red giant phase of a star, these forces become unbalanced. Without enough energy created by fusion, the core of the star collapses in on itself, while the surface layers are ejected outward. After that, all that remains of the star is what we see here: glowing outer layers surrounding a white dwarf star, the remnants of the red giant star’s core.  This isn’t the end of this star’s evolution though — those outer layers are still moving and cooling. In just a few thousand years they will have dissipated, and all that will be left to see is the dimly glowing white dwarf.

Planetary nebulae are some of the most beautiful objects in the galaxy, spanning a variety of shapes and sizes. They’re created in the death throes of stars like the sun, and new research sheds light into how they get their distinctive and unique shapes. The answer: anything unlucky enough to orbit that dying star.

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Astronomers think they’ve found an exoplanet in a galaxy 23 million light-years away

Artist's impression of of Kepler-1649c orbiting around its host star. Credit: NASA’s Ames Research Center/Daniel Rutter

Using a variety of techniques astronomers have successfully identified thousands of exoplanets, which are planets orbiting stars outside of our own solar system. But a new research paper introduces a breakthrough: the first detection of an exoplanet not just in another solar system, but in an entirely different galaxy sitting millions of light years away.

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Solar Cycle 25 has arrived. Here’s what to expect from the Sun in the coming months and years

The sun goes through a regular 11-year cycle, swinging between periods of dormancy and periods of activity. Scientists from NASA and NOAA have just announced that the sun has just passed its minimum, and will be ramping up in activity over the next few years, meaning that we have entered a new round of the never-ending solar cycle.

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