Universe Today

June 9, 2021November 16, 2021 by Nancy Atkinson

Finally! New Pictures of Ganymede, Thanks to Juno

Ganymede seen by JunoCam. The image is derived from a raw PJ34 JunoCam image, decompanded and stretched in a linear way in order to remove dark and to improve contrast moderately. Credit : NASA / JPL / SwRI / MSSS / Gerald Eichstädt.

Well, hello there old friend! This week the Juno mission to the Jupiter system made the first close flyby of Jupiter’s giant moon Ganymede, and as you might guess, the images are spectacular. This is the first time we’ve seen a close-up view of the Solar System’s largest moon since the Galileo mission 20 years ago. Voyager gave us the first views of Ganymede 40 years ago. Now, planetary scientists will be able observe any changes in Ganymede’s surface over time.

But first, the image editing gurus back on Earth are having a go at the raw images sent back by Juno. Our lead image comes from Gerald Eichstädt, who worked his magic to bring out the details of Ganymede, and it’s a stunner.

June 8, 2021June 8, 2021 by Paul M. Sutter

Whether They’re Stellar-Mass or Supermassive, Black Holes Behave Pretty Much the Same Way

In anticipation of the first image of a black hole, Jordy Davelaar and colleagues built a virtual reality simulation of one of these fascinating astrophysical objects. Their simulation shows a black hole surrounded by luminous matter. This matter disappears into the black hole in a vortex-like way, and the extreme conditions cause it to become a glowing plasma. The light emitted is then deflected and deformed by the powerful gravity of the black hole.

Astronomers recently caught a supermassive black hole gulp down a star. It flared in exactly the same way as its smaller cousins do when those black holes have a snack. It just took longer and was a million times brighter.

June 8, 2021June 8, 2021 by Evan Gough

The Universe is Constantly Bathing you in Radiation. Incredibly, This Could be Used for Medical Diagnosis

A cluster of massive stars seen with the Hubble Space Telescope. The cluster is surrounded by clouds of interstellar gas and dust called a nebula. The nebula, located 20,000 light-years away in the constellation Carina, contains the central cluster of huge, hot stars, called NGC 3603. Recent research shows that galactic cosmic rays flowing into our solar system originate in clusters like these. Credits: NASA/U. Virginia/INAF, Bologna, Italy/USRA/Ames/STScI/AURA

Walk into any modern hospital, and you’ll find a medical imaging department. Medical imaging uses x-rays, magnetic resonance imaging (MRI), and other arcane-sounding methods like positron emission tomography (PET) to image the body’s interior for analysis and diagnosis. To a non-specialist, these techniques can sound almost otherwordly. But in one way or another, these technologies rely on natural phenomena, including radiation, to do their thing.

Now a new study suggests that the Universe’s naturally occurring radiation could be used in medical imaging and could be particularly useful when it comes to COVID-19. The type of radiation in question is cosmic rays.

June 8, 2021June 8, 2021 by Paul M. Sutter

Astronomers Confirm the Existence of Magnetic Waves in the Sun’s Photosphere

Sunspots and a detached prominence photographed on July 11, 2014. (© Alan Friedman, All Rights Reserved.)

For the first time astronomers have observed waves of magnetic energy, known as Alfvén waves, in the photosphere of the sun. This discovery may help explain why the solar corona is so much hotter than the surface.

June 7, 2021June 7, 2021 by Paul M. Sutter

Planets may Start Forming Before the Star is Even Finished

An illustration of a protoplanetary disk. The solar system formed from such a disk. Astronomers suggest this birthplace was protected by a larger filament of molecular gas and dust early in history. Credit: NASA/JPL-Caltech/T. Pyle (SSC)

Planets form from the accumulation of countless grains of dust swirling around young stars. New computer simulations have found that planets begin forming earlier than previously thought, when a planet’s star hasn’t even finished forming yet.

June 7, 2021June 7, 2021 by Alan Boyle

Scientist sees deep meaning in black holes after Event Horizon Telescope’s triumph

M87 black hole — This view of the M87 supermassive black hole in polarized light highlights the signature of magnetic fields. (Credit: EHT Collaboration)

Why are black holes so alluring?

You could cite plenty of reasons: They’re matter-gobbling monsters, making them the perfect plot device for a Disney movie. They warp spacetime, demonstrating weird implications of general relativity. They’re so massive that inside a boundary known as the event horizon, nothing — not even light — can escape its gravitational grip.

But perhaps the most intriguing feature of black holes is their sheer mystery. Because of the rules of relativity, no one can report what happens inside the boundaries of a black hole.

“We could experience all the crazy stuff that’s going on inside a black hole, but we’d never be able to tell anybody,” radio astronomer Heino Falcke said. “We want to know what’s going on there, but we can’t.”

Falcke and his colleagues in the international Event Horizon Telescope project lifted the veil just a bit two years ago when they released the first picture ever taken of a supermassive black hole’s shadow. But the enduring mystery is a major theme in Falcke’s new book about the EHT quest, “Light in the Darkness: Black Holes, the Universe, and Us” — and in the latest installment of the Fiction Science podcast, which focuses on the intersection of fact and science fiction.

June 7, 2021June 7, 2021 by Brian Koberlein

Researchers Simulate the Formation of the Oort Cloud

Illustration of the Oort cloud for our solar system. Credit: ESA/AOES Medialab

There is a cloud of debris surrounding our solar system. It’s known as the Oort cloud, and it is the source of most of the comets in our solar system. It was first proposed by Jan Oort, as a way to explain why there were so many long-period comets, and why they can appear from almost any direction. It’s estimated that there are about 100 billion small icy bodies in the Oort cloud, spread throughout a sphere about 50,000 AU from the Sun. Through our studies of comets we’ve learned a great deal about the Oort cloud, but we still don’t fully understand how it came to be.

June 7, 2021June 7, 2021 by Matt Williams

Time to Update Your Desktop Wallpaper With This Perfect Spiral Galaxy: NGC 691

This image features the spiral galaxy NGC 691, imaged in fantastic detail by Hubble’s Wide Field Camera 3 (WFC3). This galaxy is the eponymous member of the NGC 691 galaxy group, a group of gravitationally bound galaxies that lie about 120 million light-years from Earth. Objects such as NGC 691 are observed by Hubble using a range of filters. Each filter only allows certain wavelengths of light to reach Hubble’s WFC3. The images collected using different filters are then coloured by specialised visual artists who can make informed choices about which colour best corresponds to which filter. By combining the coloured images from individual filters, a full-colour image of the astronomical object can be recreated. In this way, we can get remarkably good insight into the nature and appearance of these objects. Links Video of the Eponymous NGC 691

In 1990, the field of astronomy was forever changed with the launch of the Hubble Space Telescope. While it was not the first space observatory, its unprecedented resolution and versatility allowed for the deepest and most detailed images of the Universe ever taken. The latest image to be released by the mission features the spiral galaxy NGC 691, which was captured in amazing detail by Hubble’s Wide Field Camera 3 (WFC3).

June 7, 2021June 7, 2021 by Nancy Atkinson

Clever Trick Used to Clean off InSight’s Solar Panels and Boost its Power

The Mars InSight lander poured martian regolith on its solar panels in a unique experiment, which worked! Credit: NASA

Ever have an idea that was so crazy that it just might work? A few weeks ago, members of the InSight Mars team came up with a crazy, counter-intuitive way to try to get dust off the lander’s solar panels: pour *more* dust on the panels.

Yes, that sounds crazy. But yes, it actually worked!

June 7, 2021June 7, 2021 by Paul M. Sutter

Star Formation Begins When Clouds of Gas Crash Into Each Other

another seyfert galaxy — The NASA/ESA Hubble Space Telescope has captured this vivid image of spiral galaxy Messier 77 — a galaxy in the constellation of Cetus, some 45 million light-years away from us. The streaks of red and blue in the image highlight pockets of star formation along the pinwheeling arms, with dark dust lanes stretching across the galaxy’s starry centre. The galaxy belongs to a class of galaxies known as Seyfert galaxies, which have highly ionised gas surrounding an intensely active centre.

To trigger star formation, you need to compress a lot of gas into not a lot of volume. To make a lot of stars at once, you need to really pack it in. Until now, astronomers haven’t been sure how to pull this off. But a collection of 20 papers outlines how to do it: make giant clouds of gas crash into each other.