The Stars in Other Galaxies are Generally Heavier Than the Milky Way’s Stars

The Fornax Galaxy Cluster is one of the closest of such groupings beyond our Local Group of galaxies. This new VLT Survey Telescope image shows the central part of the cluster in great detail. At the lower-right is the elegant barred-spiral galaxy NGC 1365 and to the left the big elliptical NGC 1399.

How many of what kinds of stars live in other galaxies? It seems like a simple question, but it’s notoriously hard to pin down, because astronomers have such a difficult time estimating stellar populations in remote galaxies. Now a team of astronomers has completed a census of over 140,000 galaxies and found that distant galaxies tend to have heavier stars.

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Even if you can’t see Auroras, You Can Sometimes Hear Them. Here’s What They Sound Like

Auroras are some of Earth’s most spectacular natural phenomena. Travelers come from far and wide to see the incredible Northern Lights and wonder at their beauty. Once thought to be magical in nature, most science fans understand that the lights are formed by the solar wind interacting with our magnetosphere. But did you know they also make sounds?

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NASA Will Rent Future Spacesuits From Longtime Supplier and Newcomer

Moonwalker wearing Collins Aerospace spacesuit
An artist's conception shows the spacesuit made by the Collins Aerospace team. (Collins Photo)

NASA has struck deals with two commercial teams to provide the spacesuits destined for use when astronauts return to the moon by as early as 2025 — and there’s an extra twist that might have sounded alien to the Apollo moonwalkers a half-century ago. This time, NASA won’t own the suits.

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Dark Stars: The First Stars in the Universe Could Have Been Powered by Annihilating Dark Matter

A recent survey has discovered the first stars of the Milky Way. Credit: Gabriel Pérez, SMM (IAC)

Dark matter doesn’t really do much of anything in the present-day universe. But in the early days of the cosmos there may have been pockets of dark matter with high enough density that they provided a source of heat for newly forming stars. Welcome to the strange and wonderful world of “dark stars.”

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Compare Sand Dunes Across the Solar System, From Venus to Pluto

"Furrowed" dunes around Mars South Pole. Credit: NASA/JPL-Caltech/University of Arizona

One of the most interesting things we can learn from studying the planets and bodies of our Solar System is how much they have in common. Mars has polar ice caps and features that formed in the presence of water. Venus is similar to Earth in size, mass, and composition and may have once been covered in oceans. And countless icy bodies in the Solar System experience volcanism and have active plate tectonics, except with ice and water instead of hot silicate magma. Another thing they have in common, which may surprise you, is sand dunes!

According to a new study by researchers from Monash University and the University of Pennsylvania, multiple planets in our Solar System have sand dunes on their surfaces – just in different forms! These features further indicate that the mechanisms for dune formation are ubiquitous throughout the Solar System. These findings could lead to new methods for assessing the surface conditions of planets and moons and could have significant implications for future robotic and crewed missions to study them up-close.

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Could we Detect Dark Matter’s Annihilation Within Globular Clusters?

Globular Cluster
A Hubble Space Telescope image of the typical globular cluster Messier 80, an object made up of hundreds of thousands of stars and located in the direction of the constellation of Scorpius. The Milky Way galaxy has an estimated 160 globular clusters of which one quarter are thought to be ‘alien’. Image: NASA / The Hubble Heritage Team / STScI / AURA. Click for hi-resolution version.

A team of astronomers studied two nearby globular clusters, 47 Tucanae and Omega Centauri, searching for signals produced by annihilating dark matter. Those the searches turned up empty, they weren’t a failure. The lack of a detection placed strict upper limits on the mass of the hypothetical dark matter particle.

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Why are Uranus and Neptune Different Colors? Haze

NASA’s Voyager 2 spacecraft captured these views of Uranus (on the left) and Neptune (on the right) during its flybys of the planets in the 1980s.

Way back in the late 1980s, the Voyager 2 spacecraft visited Uranus and Neptune. During the flybys, we got to see the first close-up views of those ice giants. Even then, planetary scientists noticed a marked color difference between the two. Yes, they both sport shades of blue. But, if you look closely at Uranus, you see a featureless pale blue planet. Neptune, on the other hand, boasts interesting clouds, dark banding, and dark spots that come and go. They’re all set against a darker blue backdrop.

So, why the difference? Planetary scientists have long suspected aerosols (droplets of gas that have liquids or dust suspended in them) in each atmosphere. But, according to a team of scientists studying the layers of the planets, the hazes those aerosols create may only be part of the story.

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Hubble Sees Two Spiral Galaxies Together

Two spiral galaxies, collectively known as Arp 303, are seen in this image from the Hubble Space Telescope. Credit: NASA, ESA, K. Larson (STScI), and J. Dalcanton (University of Washington); Image Processing: G. Kober (NASA Goddard/Catholic University of America).

Two peculiar spiral galaxies are in the latest image release from the Hubble Space Telescope. The two galaxies, collectively known as Arp 303, are located about 275 million light-years away from Earth. IC 563 is the odd-shaped galaxy on the bottom right while IC 564 is a flocculent spiral at the top left.

Fittingly, these two oddball galaxies are part of the Atlas of Peculiar Galaxies, which is a catalog of unusual galaxies produced by astronomer Halton Arp in 1966. He put together a total of 338 galaxies for his atlas, which was originally published in 1966 by the California Institute of Technology.

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ESA's Juice Mission is Fully Integrated and Ready for Testing. Soon it'll fly to Space on a Mission to Jupiter's Moons

Artist's impression of the Jupiter Icy Moons Explorer (JUICE) near Jupiter and one of its moons, Europa. Credit: ESA/AOES

Now less than one year until the projected launch date, ESA’s JUICE mission is in the final phases of development. The JUpiter ICy moons Explorer (JUICE) is now fully built with all ten instruments integrated into the spacecraft bus. Next comes all-up testing in a full flight configuration.

Launch is currently scheduled for April of 2023, with the mission slated to conduct detailed investigations of Jupiter and its system of moons, focusing on Europa, Callisto and especially Ganymede.

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Civilizations Don’t Even Need Space Ships to Migrate From Star System to Star System

This artist’s impression shows an example of a rogue planet with the Rho Ophiuchi cloud complex visible in the background. Rogue planets have masses comparable to those of the planets in our Solar System but do not orbit a star, instead roaming freely on their own. Image Credit: ESO/M. Kornmesser/S. Guisard

In about 5 billion years, the Sun will leave the main sequence and become a red giant. It’ll expand and transform into a glowering, malevolent ball and consume and destroy Mercury, Venus, Earth, and probably Mars. Can humanity survive the Sun’s red giant phase? Extraterrestrial Civilizations (ETCs) may have already faced this existential threat.

Could they have survived it by migrating to another star system without the use of spaceships?

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