Carolyn Collins Petersen

Carolyn Collins Petersen is a long-time science writer and former astronomy researcher. She writes about astronomy and space exploration and has written 8 books, including the recently released 2nd edition of her Astronomy 101 book, countless articles, more than 60 documentaries for planetarium star theaters, and exhibits for Griffith Observatory, NASA/JPL, the California Academy of Sciences, the Shanghai Astronomical Museum, and the Lowell Observatory Dark Sky Planetarium. She is CEO of Loch Ness Productions. You can email Carolyn here.

Recent Articles

Is a Sea Change Coming for New Horizons Heliospheric Science?

September 02, 2026

If you visit the New Horizons mission website frequently, you'll notice that the spacecraft continues to generate excellent science as it plows its way through the Kuiper Belt. It recently woke up from its latest hibernation period in good health and is transmitting data it gathered back to Earth. The spacecraft, in addition to studying the Jupiter system in 2007, the Pluto system in 2015, and the Kuiper Belt Object Arrokoth in early 2019, has been doing some other fascinating solar system science since then thanks to two mission extensions in 2016 and 2023. Now, as a result of budget cuts at NASA, an important part of the NH science mission could end as early as October of this year.
What Can Happen When a Rapidly Spinning Star Meets a Black Hole?

August 31, 2026

Astrophysicists at Syracuse University in New York think they've found a hitherto-hidden explanation for strange activity during so-called repeating partial Tidal Disruption Events (rpTDEs). These are interactions between a supermassive black hole and a star that wanders too close for comfort, but not close enough to get swallowed up.
Gardening the Moon's Cosmic Archives

August 30, 2026

When a meteoroid hits the Moon's surface, it does more than just dig up a little dirt. It actually excavates a little bit of cosmic history that recorded a long-ago supernova explosion. Scientists at the University of Hawaii Institute of Geophysics and Planetology have come up with a way to decode that history and learn something about such energetic events in the Universe.
A Tool for Measuring the Mass of the Stars, Galaxies, and the Universe Gets a Tweak

August 30, 2026

How do scientists know the mass of the Universe? Measuring it has traditionally relied on knowing how many stars there are in galaxies, as well as clouds of gas and dust, and associated dark matter. Astronomers generally use the mass of the brightest stars to estimate the mass of an entire galaxy. That means the rest of a galaxy's stars and its dark matter are essentially invisible. For decades, astronomers estimated the number of small, unseen stars in clusters and galaxies using a mathematical rule that assumed stars formed in roughly the same mass proportions everywhere in the Universe. That tool is called the initial mass function (IMF). It describes how many stars of each size there are in a given cluster or galaxy. However, there are challenges with the way it's currently applied because of assumptions it contains.
Ancient Dust Grains Hold Magnetic Clues to the Sun's Birth

August 30, 2026

Those little dust grains that fall to Earth during meteor showers or end up as part of larger meteorites found on Earth may hold surprising clues to the formation of the Sun. That's because they record the state of the magnetic field in the protostellar nebula from which Earth (and ultimately the planets) formed.
A Distant Stream of Stars May Offer New Clues to Dark Matter

August 25, 2026

Dark matter continues to challenge astronomers as they work to solve the mystery of this so-far-unseen material that permeates the Universe. It's not that the stuff doesn't exist. It does, but we just can't see it. The only way it can be detected is by its gravitational effects on ordinary matter. A team of researchers led by University of Copenhagen PhD student Julie Kiel Holm has found a stream of stars stretching out more than 3,000 light-years from a globular cluster that appears to have been shaped by dark matter in a distant galaxy.
Pluto Planetary Science is the Gift that Keeps on Giving

August 19, 2026

Something's wetting the surface of dwarf planet Pluto along the northern edge of Sputnik Planitia, and planetary scientists have found a good explanation for it. A recent study of new Horizons images taken during the 2015 flyby revealed evidence that liquid nitrogen is rising up through cracks in Sputnik Planitia. That's the giant heart-shaped glacial basin we see in all the Pluto images taken by the spacecraft.
Solar Magnetic Field Braids May Have a Previously Hidden Cause

August 12, 2026

Scientists using the Daniel K. Inouye Solar Telescope (DKIST) in Hawai'i have found a mechanism occurring on the Sun's surface that they think is heating our star's outer atmosphere. The process, called a Kelvin-Helmholtz Instability (KHI), could well be the root cause of a phenomenon called flux braiding that builds up and moves around on the Sun and heats the coronasphere. This discovery may well also explain the fundamental physics of similar activity at other stars.
How to Find Lunar Ice? Moonquakes to the Rescue!

August 11, 2026

The surface of the Moon is a bleak and forbidding place that might be hiding a lot of water ice on and under the dusty landscape. However, most possible ice deposits don't just stand out in an image. You need specialized mapping to find traces of water ice. So, scientists have devised another way to find the Moon's frosty hidden reserves. They use seismic waves from moonquakes as locator beacons.
Scientists Watch as a Distant World's Atmosphere Shrinks and Thins

August 07, 2026

As dwarf planet Pluto moves along in its distant, high-obliquity 248-year orbit, its atmosphere is changing. That's because it's beginning to travel through colder, darker parts of the outer Solar System for the next 88 years. As a consequence, the mostly-nitrogen atmosphere is expected to grow gradually thinner and eventually freeze out over the coming decades. When that happens, the atmosphere will shrink.
Scientist Constructs "Big Picture" of Mars Water from Rover Data

August 05, 2026

Rover data from more than 20 years ago has revealed clues to the existence of liquid water on ancient Mars. The NASA Spirit Rover carried a specialized instrument called a Mössbauer Spectrometer that performed mineralogical analyses of soil, rock, and dust on the surface of the Red Planet at Gusev Crater. Individual measurements didn't always indicate definitive proof of water, but when scientist Paolo de Souza of Edith Cowan University in Australia examined years' worth of measurements together, a definite pattern began to show up in the existence of minerals that could only exist in the presence of water. His analysis shows that Mars used to sport a lot more water than scientists expected and that the data showing its existence was in the data all along.
Astronomers Measure the Long Reach of a Quasar

July 31, 2026

There are a number of things in the Universe that could wipe out life as we know it, but — for now, and for Earth — a blast from our galaxy's supermassive black hole isn't one of them. That's not to say that Sagittarius A* doesn't pose a danger. If it wakes up someday and blasts out a strong wind, that definitely could affect Earth. It could well have powered a quasar in the past, and could do so again.
It Took a Century, but Astronomers Imaged Betelgeuse's Companion

July 31, 2026

Most of us are familiar with Betelgeuse (also known as alpha Orionis), the bright shoulder star in the constellation Orion. It's a red supergiant star that lies somewhere between 400 and 550 light-years away from us and is quite bright. Betelgeuse contains about 14 times the mass of the Sun and is a fairly young star compared to ours. It appears to be no more than 10 million years old, which means that it evolved rapidly from a protostar to the red giant we see today. That lifecycle means Betelgeuse will explode as a supernova sometime in the relatively near future — say within the next 100,000 years.
What Killed Galaxies in the Early Universe?

July 30, 2026

Galaxies in the infancy of the Universe are the building blocks of more modern galaxies. They began as small "shreds" of material that coalesced over time to form larger ones. That's why astronomers use observatories such as the James Webb Space Telescope (JWST) to study the young Universe. The light from those early objects appears in the infrared part of the spectrum, which JWST is tuned to see.
Radio Array Detects Polarized Light From a GRB

July 30, 2026

On March 10, 2026, the Fermi telescope gamma-ray burst team reported the detection of a long-duration gamma ray burst that occurred when a star exploded inside a dense, highly magnetized cloud of hydrogen gas. That HII region is a bubble of ionized hydrogen created by winds from a massive young star. Astronomers immediately turned as many telescopes as possible to view the burst and its afterglow, including the NSF's Karl Jansky Very Large Array.
Tracking Satellites and Space Debris Using Radio Antennae

July 30, 2026

Every year, thousands and thousands of satellites get launched into orbit around our planet. The result is an increasingly congested "space" above Earth populated by equipment that provides services to the surface. At the same time, these satellites affect ground-based astronomy research and create potential for damage when they eventually fall through Earth's atmosphere to the ground. In addition, near-Earth space hosts old rocket bodies and other materials left in space by past missions.
A Wandering Black Hole Meets a Wandering Star

July 29, 2026

What happens when a black hole and a star meet in the middle of nowhere in a galaxy? It sounds like it could be a dramatic science fiction backdrop, with some hapless starship caught in the crunch. Actually, such encounters in real life are pretty rare. They happen maybe once every 100,000 years. But, when they <i>do</i> occur, the immense gravity of the supermassive black hole tears the star apart. It's an eerie-looking process. The star gets "spaghettified" — that is, pulled on one side by the black hole. That rips out a stream of gas from the star which eventually forms a disk around the black hole.
A Distant Primordial Object May Be a Newborn Little Red Dot

July 28, 2026

Little Red Dots are among the most intriguing discoveries made to date by the infrared-sensitive James Webb Space Telescope (JWST). They are distant, small objects that appear red in the JWST observations and they've only been known since 2024. More than 300 of them have been found as part of JWST's infrared surveys of the early Universe.
Black Hole Collisions Tell a Tale of Repeating Mergers

July 27, 2026

A black hole merger is one of the Universe's most energetic and massive events. During such a collision, two black holes orbit closer and closer until they collide and become a much more massive black hole. The event also gives off radiation and, as it happens, gravitational waves. They help tell the story of the two objects involved in the collision.
Should Scientists Have Research "Reserves" on the Moon?

July 24, 2026

The worlds of the Solar System offer up exciting and (so far) mostly pristine places for planetary scientists to study. As space missions continue to travel to Mars, Europa, asteroids, and other worlds, questions keep coming up about keeping them safe for continued exploration and observations.