Carolyn Collins Petersen, Author at Universe Today

July 16, 2024July 16, 2024 by Carolyn Collins Petersen

More Than Half of Near Earth Objects Could Be “Dark Comets”

An artist's concept of a dark comet floating in space. Courtesy Nicole Smith.

Next time you’re visiting the seaside or a large lake, or even sipping a frosty glass of water, think about where it all originated. There are many pathways that water could have taken to the infant Earth: via comets, “wet asteroids”, and outgassing from early volcanism. Aster Taylor, a University of Michigan graduate student has another idea: dark comets. They’re something of a cross between asteroids and comets and could have played a role in water delivery to our planet.

July 14, 2024July 14, 2024 by Carolyn Collins Petersen

Webb Completes Its Second Year of Operations

This “penguin party” (called Arp 142) is loud! The distorted spiral galaxy at center, the Penguin, and the compact elliptical galaxy at left, the Egg, are locked in an active embrace. A new near- and mid-infrared image from the Webb Space Telescope, taken to mark its second year of science, shows that their interaction is marked by a faint upside-down U-shaped blue glow. The blue galaxy at upper right (near bright star) is a closer galaxie teeming with new stars. It's not part of the collision and lies closer to Earth than Arp 142.

What happens when a spiral and an elliptical galaxy collide? To celebrate the second anniversary of the “first light” for the Webb telescope, NASA released an amazing infrared view of two galaxies locked in a tight dance. They’re called the Penguin and the Egg and their dance will last hundreds of millions of years.

July 9, 2024July 9, 2024 by Carolyn Collins Petersen

Ancient People Saw a Kilonova Light up the Sky

A comparison between the observed XMM-Newton image of the kilonova 1181 with an IRAS-derived schematic of infrared contours (presumably of the dust ring) around the resulting white dwarf. This kilonova occurred when two white dwarfs collided and were observed in 1181. Courtesy Ko, et al, 2024.

What happens when aging white dwarf stars come together? Observers in feudal Japan in the year 1181 had a front-row view of the superpowerful kilonova created by such a merger. Their records show that a rare “guest star” flared up and then faded. It took until 2021 for astronomers to find the place in the sky where it occurred.

July 6, 2024July 6, 2024 by Carolyn Collins Petersen

Webb Looks at One of the Best Gravitationally Lensed Quasars Ever Discovered

A small image of a galaxy distorted by gravitational lensing into a dim ring. At the top of the ring are three very bright spots with diffraction spikes coming off them, right next to each other: these are copies of a single quasar in the lensed galaxy, duplicated by the gravitational lens. In the centre of the ring, the elliptical galaxy doing the lensing appears as a small blue dot. Courtesy: ESA/Webb, NASA & CSA, A. Nierenberg

It looks like a distant ring with three sparkly jewels, but the Webb telescope’s (JWST) most recent image is really the view of a distant quasar lensed by a nearby elliptical galaxy. The telescope’s Mid-Infrared Instrument (MIRI) looked at the faint apparition during a study of dark matter and its distribution in the Universe.

July 3, 2024July 6, 2024 by Carolyn Collins Petersen

More Evidence that the Kuiper Belt is Bigger Than We Thought

The Kuiper Belt was named in honor of Dutch-American astronomer Gerard Kuiper, who postulated a reservoir of icy bodies beyond Neptune. The first Kuiper Belt object was discovered in 1992. We now know of more than a thousand objects there, and it's estimated it's home to more than 100,000 asteroids and comets there over 62 miles (100 km) across. Credit: JHUAPL

As the New Horizons spacecraft continues its epic journey to explore the Kuiper Belt, it has a study partner back here on Earth. The Subaru Telescope on the Big Island of Hawaii is deploying its Hyper Suprime-Cam imager to look at the Kuiper Belt along the spacecraft’s trajectory. Its observations show that the Kuiper Belt extends farther than scientists thought.

July 2, 2024July 2, 2024 by Carolyn Collins Petersen

Mysterious Swirls on the Moon Could Be Explained by Underground Magma

This is an image of the Reiner Gamma lunar swirl on the Moon, supplied by NASA's Lunar Reconnaissance Orbiter. Credits: NASA LRO WAC science team

In the latest chapter of “The Mystery of the Lunar Swirls,” planetary scientists have a new theory to explain these odd markings on the Moon’s surface. It invokes underground magmas and strange magnetic anomalies.

June 30, 2024June 30, 2024 by Carolyn Collins Petersen

Galaxies Filled With Old Stars Seen Shortly After the Big Bang

Astronomers used JWST to investigate three mysterious objects in the very early Universe. These little red dots contain extremely ancient stars and supermassive black holes. Courtesy JWST/Penn State University.

How can young galaxies in the early Universe have ancient stars? That’s the question a team of astronomers set out to answer using JWST as a probe. They first spotted the massive objects in 2022 and are still working to explain what these things are.

June 29, 2024June 29, 2024 by Carolyn Collins Petersen

Earliest Supermassive Black Holes Were “Shockingly Normal”

Artist's impression of a quasar core. Quasars are powered by interactions between supermassive black holes and their accretion disks at the hearts of galaxies. JWST observed one in infrared light to reveal its feeding mechanism. Courtesy T. Mueller/MPIA.

The early Universe is a puzzling and—in many ways—still-unknown place. The first billion years of cosmic history saw the explosive creation of stars and the growth of the first galaxies. It’s also a time when the earliest known black holes appeared to grow very massive quickly. Astronomers want to know how they grew and why they feed more like “normal” recent supermassive black holes (SMBH).

June 28, 2024June 28, 2024 by Carolyn Collins Petersen

Seeing Both Sides of the Sun at the Same Time

Solar Orbiter's view of a solar outburst from AR3664 on May 21st, 2024. The views are in two different wavelengths of ultraviolet light. Courtesy: ESA & NASA/Solar Orbiter/EUI Team

As everybody who saw May’s spectacular auroral displays knows, the Sun is in its most active period in 11 years. The active region sunspot group that unleased the giant X-class flare rotated around the Sun, away from our direct view. But, that isn’t keeping the Solar Orbiter from spotting what’s happening with it and other active regions as they travel around on the Sun.

June 28, 2024June 28, 2024 by Carolyn Collins Petersen

Cepheid Variables are the Bedrock of the Cosmic Distance Ladder. Astronomers are Trying to Understand them Better

One of the brightest Cepheid variable stars, RS Puppis. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-Hubble/Europe Collaboration

One of the most fundamental questions astronomers ask about an object is “What’s its distance?” For very faraway objects, they use classical Cepheid variable stars as “distance rulers”. Astronomers call these pulsating stars “standard candles”. Now there’s a whole team of them precisely clocking their speeds along our line of sight.