Universe Today

January 4, 2024January 4, 2024 by Evan Gough

This Globular Cluster is Plunging Toward the Milky Way’s Centre

The galactic cenre is dominated by powerful tidal forces. What happens to globular clusters that get too close? Image Credit: Spitzer Space Telescope/NASA/JPL-Caltech

Globular clusters (GCs) are spherical groups of stars held together by mutual gravity. Large ones can have millions of stars, and the stars tend to be older and have lower metallicity. The Milky Way contains more than 200 globulars, possibly many more, and most of them are in the galaxy’s halo, the outer reaches of the galaxy.

But they’re not all in the halo, and astronomers are keen to find ones nearest the galactic centre. Now, researchers have found one GC that’s plunging toward the Milky Way’s Centre.

January 4, 2024January 4, 2024 by Brian Koberlein

Want to Find Life? See What's Missing in an Atmosphere

Illustration potentially habitable worlds. Credit: Christine Daniloff, MIT; iStock

The world runs on carbon. Not just fossil-fuel-driven human society, but all life on Earth. Carbon-based organic molecules are a part of every living thing on Earth. Along with oxygen, nitrogen, and water, carbon is a necessary ingredient for life as we know it. So one way to look for life on other worlds could be to look for carbon in its atmosphere. But a new study shows that it’s actually a lack of carbon that could be the best clue to life on another world.

January 4, 2024January 4, 2024 by Nancy Atkinson

Astronomers Test an Exoplanet Instrument on Jupiter

NASA’s Juno spacecraft captured this view of Jupiter during the mission’s 40th close pass by the giant planet on Feb. 25, 2022. The large, dark shadow on the left side of the image was cast by Jupiter’s moon Ganymede. Image data: NASA/JPL-Caltech/SwRI/MSSS Image processing by Thomas Thomopoulos

The European Southern Observatory’s Very Large Telescope (VLT) has a high-resolution spectrograph called ESPRESSO, designed specifically to detecting and characterize exoplanets. Astronomers recently ran a test with the instrument, studying the atmosphere and winds of Jupiter. They used a technique called Doppler velocimetry to measure the reflection of light from the Sun in the planet’s clouds, allowing for instantaneous measurement of the clouds’ wind speeds. The technique has also been used on Venus and will guide the future study of exoplanets.

January 3, 2024January 3, 2024 by Scott Alan Johnston

Iron Snow Could Explain the Magnetic Fields at Worlds Like Ganymede

Iron snow in the core of Ganymede. Credits: Image by Ludovic Huguet and map texture from NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington

Jupiter’s largest moon, Ganymede, features a surprisingly strong magnetic field for its size. Tidal effects from Jupiter continually stretch and squeeze the moon, keeping its core warm and driving the magnetic field. But the exact geological processes occurring within the core are not fully understood. Now, a new experimental study has put one of the leading models of core dynamics to the test: the formation of crystalized ‘iron snow’.

January 3, 2024January 3, 2024 by Mark Thompson

China’s FAST Observatory is Playing a Key Role in the Search for Aliens

Some years ago I rememeber running the SETI at Home screensaver and would watch it for hours to see if any peaks appeared naively thinking they might be signals from an alien civilisation! There is no doubt that the search for extraterrestrials (ET) has captivated the minds of many people across the years. The search has of course to date, been unsuccesful despite multiple observations that seem to suggest the conditions for life across the cosmos may actually be more common than we first thought. Now Chinese agencies are funding projects to use the Five Hundred Meter Aperture Spherical Telescope (FAST) to conduct searches for alien signals.

January 3, 2024January 3, 2024 by Evan Gough

Ingenuity’s 69th Flight is its Farthest So Far

Ingenuity captured this image of Mars on December 2nd 2023 (Sol 990) with its high-resolution colour camera. Image Credit: NASA/JPL-Caltech

When NASA decided to send the little Ingenuity rotorcraft to Mars on the belly of the Perseverance rover, they weren’t certain of success. Nothing like it had ever been attempted in Mars’ extremely thin atmosphere. Mission planners hoped and planned for a total of five flights, enough for a technology demonstration.

But now, as almost everyone knows, Ingenuity has wildly exceeded NASA’s initial expectations.

January 3, 2024January 3, 2024 by Evan Gough

Juno Makes its Closest Flyby of Io

NASA's Juno spacecraft captured this image of Jupiter's volcanic moon Io. Image Credit: NASA / JPL-Caltech / SwRI / MSSS / Kevin Gill

NASA’s Juno spacecraft has been getting closer and closer to Jupiter’s volcanic moon Io with each recent orbit. Juno is in its 57th orbit of Jupiter, and on December 30th, Juno came to within 1500 km (930 miles) of Io’s surface. It’s been more than 20 years since a spacecraft came this close.

January 3, 2024January 3, 2024 by Evan Gough

The Oldest Known Spiral Galaxy Has Ripples Like the Surface of a Pond

This simulation illustrates a galaxy disk being disturbed, leading to the propagation of a seismic ripple throughout the disk. (Credit: Bland-Hawthorn and Tepper-Garcia, University of Sydney).

Astronomers have detected pond-like ripples across the gaseous disk of an ancient galaxy. What caused the ripples, and what do they tell us about the distant galaxy’s formation and evolution? And whatever happened, how has it affected the galaxy and its main job: forming stars?

January 3, 2024January 3, 2024 by Brian Koberlein

The Most Massive Neutron Stars Probably Have Cores of Quark Matter

Illustration of a quark core in a neutron star. Credit: Jyrki Hokkanen, CSC - IT Center for Science

Atoms are made of three things: protons, neutrons, and electrons. Electrons are a type of fundamental particle, but protons and neutrons are composite particles made of up and down quarks. Protons have 2 ups and 1 down, while neutrons have 2 downs and 1 up. Because of the curious nature of the strong force, these quarks are always bound to each other, so they can never be truly free particles like electrons, at least in the vacuum of empty space. But a new study in Nature Communications finds that they can liberate themselves within the hearts of neutron stars.

January 3, 2024January 3, 2024 by Nancy Atkinson

Watch a Full Martian Day, From Dawn to Dusk

Curiosity’s rear Hazcam captured the shadow of the back of the rover in this 12-hour view looking toward the floor of Gale Crater. A variety of factors caused several image artifacts, including a black speck, the distorted appearance of the Sun, and the rows of white pixels that streak out from the Sun. NASA/JPL-Caltech

On November 8th, NASA’s Curiosity Rover paused its incessant science work and just watched the day unfold on Mars. The rover used its black-and-white Hazard-Avoidance Cameras (Hazcams) to watch an entire 12-hour day on Mars as the shifting Sun cast shadows across the Martian landscape. NASA chose this day because of the Mars solar conjunction when the Sun interferes with communications with the Red Planet, meaning the rover doesn’t do any roving about. The timelapse comprises 25 frames from both the front and rear Hazcams.