Carolyn Collins Petersen

Superdense Star Factories Tell a Tale of Starbirth in the Early Universe

June 20, 2025

The early Universe was a busy place some 13 billion years ago. That's when countless young galaxies began to evolve and birthed stars at a prodigious rate. The hearts of those very distant galaxies show turbulent, lumpy disks studded with even thicker clumps of dust and gas that spawned huge batches of stars. Astronomers want to understand what's driving the clumping, so they've turned to recent surveys of closer galaxies in the "local Universe" that contain similar lumpy regions.

Astronomers are Closing in on the Source of Galactic Cosmic Rays

June 17, 2025

In 1912, astronomer Victor Hess discovered strange, high-energy particles called "cosmic rays." Since then, researchers have hunted for their birthplaces. Today, we know about some of the cosmic ray "launch pads", ranging from the Sun and supernova explosions to black holes and distant active galactic nuclei. What astronomers are now searching are sources of cosmic rays within the Milky Way Galaxy. One such source is a pulsar wind nebula sending high-energy particles out to space.

Distant Galaxy Has Similar Icy Dust to the Milky Way. So, Similar Planets?

June 12, 2025

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.

Webb Watches Haze Rise and Fall in Pluto's Atmosphere

June 04, 2025

When the New Horizons spacecraft swept past Pluto and Charon in 2015, it revealed two amazingly complex worlds and an active atmosphere on Pluto. Those snapshots redefined our understanding of the system. Now, new observations using the James Webb Space Telescope taken over the space of a week, show that Pluto's atmosphere is completely different from any other one in the Solar System.

Finding a Better Way to Distinguish Life from Non-Life

May 31, 2025

The search for life on other worlds needs a way to sift through the chemistry of their atmospheres. If another species observed Earth to search for life, they'd look for "smoking gun" chemistry in the atmosphere. That includes looking for oxygen, since it is created through photosynthesis by plants and some bacteria. So, the key is to look for life-dependent chemical "signals" at exoplanets.

Strange Object is Releasing Regular Blasts of Both X-Rays and Radio Waves

May 29, 2025

Just when astronomers think they're starting to understand stellar activity, something strange grabs their attention. That's the case with a newly discovered stellar object called ASKAP J1832-0911. It lies about 15,000 light-years from Earth and belongs to a class of stellar objects called "long-period radio transients." That means it emits radio waves that vary in their intensity on a schedule of only 44 minutes per cycle. It does the same thing in X-ray intensities, which is the first time anybody's seen such a thing coupled with long-period radio transits.

Webb Reveals that Europa's Surface is Constantly Changing

May 29, 2025

You'd think that icy worlds are frozen in time and space because they're - well - icy. However, planetary scientists know that all worlds can and do change, no matter how long it takes. That's true for Europa, one of Jupiter's four largest moons. Recent observations made by the James Webb Space Telescope (JWST) zero in on the Europan surface ices and show they're constantly changing.

Will Europa Become a New Habitable World When the Sun Becomes a Red Giant?

May 27, 2025

People always want to know what will happen to Earth when the Sun eventually swells up as a red giant. For one thing, the expanding Sun will turn the inner planets into cinders. It will almost certainly spell the end of life on our planet. Mars might become more temperate and hospitable to life. In addition, it could well be a boon for the gas giant Jupiter and its moons. That's because the habitable zone of the Solar System will move outward from where it is now, to a spot encompassing the Jovian system and forcing changes on all of those worlds.

Is the World Ready for a Catastrophic Solar Storm?

May 21, 2025

Some 13,000 years ago, the Sun emitted a huge belch of radiation that bombarded Earth and left its imprint in ancient tree rings. That solar storm was the most powerful one ever recorded. The next strongest was the 1839 Carrington Event. It was spurred by a huge solar flare that triggered a powerful geomagnetic storm at Earth. The resulting "space weather" disrupted telegraph communications around the world. Today, as we move through this year's "solar maximum", a period of solar activity that occurs every 11 years, scientists want to prepare governments for the effects of severe solar storms.

How Many Rogue Planets are in the Milky Way? The Roman Space Telescope Will Give Us an Answer

May 08, 2025

Over the past decade or so, astronomers have speculated about the characteristics of rogue planets in the Milky Way Galaxy. These "free-floating" worlds don't orbit stars, but instead roam the spaceways. They're hard to spot with current technology, but the upcoming Nancy Grace Roman Space Telescope (Roman) will be a perfect instrument to find them and give insights into the history and features they may have in common with Solar System worlds.

Could Sweating Spacecraft Make Re-Entry Easier?

May 07, 2025

When ISS astronauts return home, they have a hot ride back to Earth's surface. It's been that way since the beginning of human spaceflight to orbital space and beyond. The incoming vehicle uses friction with Earth's atmosphere to slow down to a safe landing speed. The "hot ride" part comes because that friction builds up high temperatures on the spacecraft's "skin". Without protection, the searing heat of atmospheric re-entry could destroy it. This same heating happens to incoming meteoroids as they whip through Earth's atmosphere.

Juno Continues to Teach us About Jupiter and Its Moons

May 01, 2025

The Juno spacecraft circling in Jovian space is the planetary science gift that just keeps on giving. Although it's spending a lot of time in the strong (and damaging) Jovian radiation belts, the spacecraft's instruments are hanging in there quite well. In the process, they're peering into Jupiter's cloud tops and looking beneath the surface of the volcanic moon Io.

A Dark Nebula with a Starry Background

April 28, 2025

Star birth is a process hidden inside dense crèches of gas and dust. Yet, if you know what to look for, you can see the products of this essential cosmic process across the sky. The Circinus West molecular cloud is a starbirth crèche some 2,500 light-years away. It boasts everything from dark nebulae to protostellar objects and newborn stars to the faint ghosts of stars that have already died.

Hubble Spots a Magnetar Zipping Through the Milky Way

April 26, 2025

Magnetars are among the rarest - and weirdest - denizens of the galactic zoo. They have powerful magnetic fields and may be the source of fast radio bursts (FRBs). A team of astronomers led by European Space Agency researcher Ashley Chrimes recently used the Hubble Space Telescope to track one of these monsters called SGR 0501+4516 (SGR0501, for short, and SGR stands for Soft Gamma Repeater). It's whipping through the Milky Way at a rate that could be as high as 65 kilometers per second. The big challenge was to find its birthplace and figure out its origin.

Jupiter's Atmosphere is a Wild Place

April 22, 2025

The weather gets a little wild and weird on Jupiter. How wild? Spacecraft instruments have measured strong winds, tracked fierce lightning, and found huge methane plume storms rising from deep beneath the clouds. How weird? Think: mushballs raining down like hailstones. They're made of ammonia and water encased in a water ice shell. According to planetary scientists, these mushballs plunge through the Jovian atmosphere. What's more, they probably form on the other gas and ice giants, too.

Astronomers Watch a Black Hole Wake Up in Real Time

April 19, 2025

You never know when a central supermassive black hole is going to power up and start gobbling matter. Contrary to the popular view that these monsters are constantly devouring nearby stars and gas clouds, it turns out they spend part of their existence dormant and inactive. New observations from the European Space Agency's XMM-Newton spacecraft opened a window on the "turn on event" for one of these monsters in a distant galaxy.

Failing to Find Life Tells Us a Lot About Life in the Universe

April 14, 2025

The search for life involves the most sophisticated observational machines known to humanity. They peer out across the light-years, looking for some proof - any proof - that other life exists, out there. What if, despite all our efforts, those observations turn up NO evidence of life elsewhere in our Milky Way Galaxy?

The Solar Wind Crashes Into Jupiter a Few Times Every Month

April 08, 2025

In the great tug-of-war between the Sun and its planets, Jupiter, Saturn, and Uranus are much more susceptible to solar activities than scientists thought. Jupiter itself has an interesting reaction as it gets pummeled several times a month by solar wind bursts. They compress its magnetosphere and create a huge "hot spot" with temperatures over 500C.

Many Protoplanetary Disks Aren't Much Bigger Than Earth's Orbit

March 30, 2025

When it comes to the planets produced in protoplanetary disks, size matters, but not the way you might think. That's the conclusion a group of astronomers found when they aimed the Atacama Large Millimeter Array in Chile at hundreds of these disks around young stars in the southern constellation Lupus. They used the observatory in 2023 and 2024 to focus on the disks and supplemented that with archival data.

Webb Sees a Young Star Create a Cosmic Tornado

March 27, 2025

Way back in 2006, the Spitzer Space Telescope (SST) took an infrared look at a strange object called Herbig-Haro 49/50. It's a jet flowing away from a hot young star. The Spitzer image showed a fuzzy blob at the end of the jet. Was it part of the jet, or something more distant? Recently, the James Webb Space Telescope (JWST) focused its infrared eye on the same object and sent home a fantastic snapshot of this cosmic tornado. It also answered the question about the blob: it turns out to be a distant galaxy, itself bursting with hot young stars.

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