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Euclid Begins its 6-Year Survey of the Dark Universe

ESA’s Euclid mission was launched in July 2023 and has already sent home test images showing that its instruments are ready to go. Now, the space telescope begins mapping huge swaths of the sky, focusing on an area for 70 minutes at a time. Throughout its 6-year mission, it will complete 40,000 of these “pointings”, eventually observing 1.5 billion galaxies in the sky. Astronomers will use this map to measure how dark matter and dark energy have changed over time.

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Another Clue Into the True Nature of Fast Radio Bursts

Astronomers have used two X-ray telescopes to study a neutron star and have discovered a link between it and mysterious fast radio bursts (FRBs). In October 2022, NASA’s NICER and NuSTAR missions watched a type of neutron star called a magnetar for hours and detected the release of energy from its surface as it glitched, suddenly spinning faster. At the same time, radio telescopes detected an FRB from the star. These two events are connected.

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Passing Stars Changed the Orbits of Planets in the Solar System

We’re light-years away from the closest stars, but in the billions of years of history in the Milky Way, our Sun has come much closer to other stars. For example, a star passes within 0.8 light-years every millions years and 0.16 light-years every 20 million years. These close passes have had a collective effect on the planets, shifting their orbits and helping to explain some of the eccentricities of the planets. Some of these might even have affected Earth’s climate.

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Measuring Distances in the Universe With Fast Radio Bursts

Astronomers still aren’t entirely sure what causes fast radio bursts, which can briefly release a galaxy’s worth of energy. However, they might have figured out how to use them to measure distances in the Universe. In a new paper, astronomers propose that fast radio bursts could be detected as they’re magnified by stellar microlenses. With about 30 microlensing events, they should be able to measure cosmic distances precisely.

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The Event Horizon Telescope Zooms in on a Black Hole's Jet

The Event Horizon Telescope has given us amazing views of the supermassive black holes at the hearts of M87 and the Milky Way. A new image from the EHT shows another black hole at the core of the radio galaxy 3C 84. Unlike the previous targets, 3C is one of the most active supermassive black holes in our vicinity, blasting enormous jets out into the cosmos. A series of images show the power of the EHT, resolving the region around the black hole where the jets form.

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Did the Galileo Mission Find Life on Earth?

Although it was bound for Jupiter, NASA’s Galileo spacecraft made flybys of Earth in 1990 and 1992 to get boosts in its velocity. Astronomers realized this would be an ideal opportunity to test if remote imaging of Earth would detect the presence of life. In a new paper, researchers examined over 1500 photometric measurements of Earth from Galileo, judging how well it could stand in for an inhabited exoplanet.

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Dust Ruins Another Way of Measuring Distance in the Universe

Astronomers are always searching for new ways to measure distance in the Universe, especially at the greatest distances where less is known. One method measures active galaxies blasting out ultraviolet and X-ray radiation. Another measure is X-ray radiation coming from the accretion disk around a quasar. Since both methods measure the same distance to a galaxy, they should match. But they don’t, and the culprit, once again, is dust absorbing and scattering UV and X-rays.

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Astronomers Measure the Mass of the Milky Way by Calculating How Hard it is to Escape

Several techniques have been developed to measure the mass of the Milky Way, providing a range of estimates. In a new paper, a team of researchers used data from ESA’s Gaia spacecraft to measure the escape velocity of the Milky Way at different distances from the galactic center and calculated its total mass, including the dark matter halo. Their measurement of 640 billion solar masses aligns with other estimates but is on the lower end.

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It's a Fine Line Between a Black Hole Energy Factory and a Black Hole Bomb

You might be surprised to learn there’s a way to extract enormous energy from a rapidly spinning black hole. Known as the “Penrose Process,” an advanced civilization would feed material into a black hole and extract energy as some of it is hurled into space. A new paper suggests that the process could be even more efficient, cycling the material back into the black hole for another round. Or maybe this will turn into an extremely powerful bomb.

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Nancy Grace Roman Could Find the First Stars in the Universe

The first stars in the Universe were made out of the primordial hydrogen and helium left over from the Big Bang. They were probably monsterous, with dozens or even hundreds of times the mass of the Sun. They lived short lives and then detonated as supernovae. Current telescopes will have a tough time spotting these stars, but a new paper suggests that the upcoming Nancy Grace Roman Telescope might have a clever trick to spot them.