Shortly after astronomers detected asteroid 2024 YR4 on December 27th, 2024, they realized it posed no threat to Earth. But it still might impact the Moon in 2032. The impact debris could threaten satellites and trigger an extraordinarily stunning meteor shower.
During its commissioning phase, NASA's [*Polarimeter to Unify the Corona and Heliosphere*](https://ift.tt/o31gU5H) (PUNCH) mission captured high-resolution images of a [Coronal Mass Ejection](https://ift.tt/Dt5PZUd) (CME) in greater detail than was previously possible.
Solar sails are space's ultimate free ride, they get their propulsion from the Sun, so they don't need to carry propellant, but they come with their own challenges. A sail has a large surface area but a low mass, which creates a huge moment of inertia and makes it difficult to control, especially with reaction wheels. A team of engineers have cracked it though with "smart mirrors" that can instantly switch their reflectivity on command, transforming sunlight from an unruly force into a precision steering tool.
The early universe was shrouded in darkness. Just hundreds of millions of years after the Big Bang, a thick fog of hydrogen gas choked the cosmos, blocking light from traveling far. At some point, this gas became ionized, stripped of its electrons. Thanks to the James Webb Space Telescope, astronomers have identified the culprit: low-mass starburst galaxies emitting huge amounts of ultraviolet light. In just one patch of sky. They discovered 83 of these galactic powerhouses in one part of the sky at a time when the Universe was only 800 million years old.
An international team of astronomers using the [*Cosmology Large Angular Scale Surveyor*](https://ift.tt/6tOo2jE) (CLASS) [reported the first-ever measurement](https://ift.tt/O1K8Mhb) announced the first-ever detection of radiation from the cosmic microwave background (CMB) interacting with the first stars in the Universe.
We don't know what dark matter is, but that doesn't stop astronomers from using it to their advantage. Dark matter is part of what makes gravitational lensing so effective. Astronomers expect the Roman Space Telescope to find 160,000 gravitational lenses, and dark matter makes a crucial contribution to these lenses.
For most of us, dust is just something we have to clean up. For astronomers, interstellar dust is a hindrance when they want to study distant objects. However, recent James Webb Space Telescope (JWST) observations of a distant galaxy are changing that. This infrared-sensitive observatory is letting them find a way to use dust to understand the evolution of early galaxies. In addition, it uncovered a special property of that galaxy's ice-covered dust, indicating it could be similar to the materials that formed our Solar System.
