Carolyn Collins Petersen, Author at Universe Today

April 12, 2023April 12, 2023 by Carolyn Collins Petersen

Not Snowball Earth, More of a Slushball Earth

DNDXCB View of Earth 650 million years ago during the Marinoan glaciation. the idea of Slushball Earth may change how we view that past ice age. Credit: University of St. Andrews. — Artist's impression of Earth 650 million years ago during the Marinoan glaciation. Credit: University of St. Andrews.

Our planet hasn’t always been the warm, inviting place we know today. At least five times in its history, Earth froze over, locked in the grip of an ice age. Scientists sometimes refer to these periods as “Snowball Earth.” The popular idea is that everything was covered with ice, making life difficult, if not impossible. But, there’s new evidence that during at least one of these icy periods, parts of Earth’s surface could have been more like a giant mushy ball of slush.

April 10, 2023April 10, 2023 by Carolyn Collins Petersen

It’s Time for Supernova Remnant Cassiopeia A to Get the JWST Treatment

Cassiopeia A (Cas A) is a supernova remnant. It has been observed many times. This new image uses data from Webb’s Mid-Infrared Instrument (MIRI) to reveal Cas A in a new light. Credits: NASA, ESA, CSA, D. D. Milisavljevic (Purdue), T. Temim (Princeton), I. De Looze (Ghent University). Image Processing: J. DePasquale (STScI)

Ready for another stunning image from JWST? How about a peek inside a supernova remnant? Not just any stellar debris, but a highly detailed view of the leftovers from the explosion that created Cassiopeia A. The latest image is giving astronomers an up-close and personal look at what happened to a supermassive star some 11,000 light-years away from us. It may also help answer questions about the existence of cosmic dust, particularly in the early Universe.

April 6, 2023April 6, 2023 by Carolyn Collins Petersen

Do Repeating Radio Signals Indicate an Exoplanet with a Magnetosphere?

An artist's conceptual rendering of interactions between a prospective exoplanet and its star. Plasma emitted from the star is deflected by the exoplanet's magnetic field (and magnetosphere) then interacts with the star's magnetic field, resulting in an aurora on the star and the emission of radio waves. Credit: National Science Foundation/Alice Kitterman — An artist's conceptual rendering of interactions between a prospective exoplanet and its star. Plasma emitted from the star is deflected by the exoplanet's magnetic field then interacts with the star's magnetic field, resulting in an aurora on the star and the emission of radio waves. Credit: National Science Foundation/Alice Kitterman

There’s an interesting problem in exoplanet studies: how to tell if a planet has a magnetosphere. It’s not like we can visibly see it unless we find a different way of looking. A pair of scientists may have found one. They used radio telescopes to track emissions given off by magnetic star-planet interactions. These happen when a planet with a magnetic field plows through star stuff caught its star’s magnetic field.

April 4, 2023April 4, 2023 by Carolyn Collins Petersen

Global Sea Levels Rose by 0.27 cm from 2021 to 2022

An aerial view of the icebergs near Kulusuk Island, off the southeastern coastline of Greenland, a region that is exhibiting an accelerated rate of ice loss. The water runs off into the ocean and is contributing to sea level rise. Credits: NASA Goddard Space Flight Center

It probably comes as no surprise to people living in low-lying coastal regions, but sea waters are rising by large, measurable amounts. That assessment comes from NASA, which has analyzed 30 years of sea-level satellite measurements. The news is not good. Since 1993, the seas rose by a total of 9.1 centimeters. Two years ago, it went up by 0.27 centimeters.

March 31, 2023March 30, 2023 by Carolyn Collins Petersen

Now We Know How a Solar Storm Took Out a Fleet of Starlinks

A view of an auroral storm from the ISS. Aurorae are one effect of solar storms like the one that took out 39 Starlink satellites in 2022. Credit: NASA/ESA/Tim Peake — A view of an auroral storm from the ISS. Credit: NASA/ESA/Tim Peake

On March 23rd, sky observers marveled at a gorgeous display of northern and southern lights. It was reminder that when our Sun gets active, it can spark a phenomenon called “space weather.” Aurorae are among the most benign effects of this phenomenon.

March 30, 2023March 30, 2023 by Carolyn Collins Petersen

Plans are Underway to Build a 30 Cubic Kilometer Neutrino Telescope

Underwater neutrino detectors take advantage of location to track these fast particles. This is an artist's impression of a KM3NeT installation in the Mediterranean. Chinese scientists hope to build a bigger underwater "neutrino telescope" in the next few years. Courtesy Edward Berbee/Nikhef.

How do astronomers look for neutrinos? These small, massless particles whiz through the universe at very close to the speed of light. They’ve been studied since the 1950s and detecting them provides work for a range of very interesting observatories.

March 28, 2023March 28, 2023 by Carolyn Collins Petersen

Are We Alone? The Answer Might Be in Space Dust That’s All Around Us

When an asteroid hit the Yucatan peninsula 65 million years ago it through Earth debris to space. Could that debris carry evidence of life? And, could such an event at an alien planet carry evidence of its life to us on dust particles generated in the impact? Image courtesy Don Davis.

When it comes to looking for extraterrestrial life “out there” astronomers scan distant planets. They also look for technosignatures at alien worlds. What if the answer they seek is dust blowing on the interstellar winds?

March 27, 2023March 27, 2023 by Carolyn Collins Petersen

Why Does ‘Oumuamua Follow Such a Bizarre Orbit? Hydrogen Outgassing

An artist’s depiction of the interstellar comet ‘Oumuamua, as it warmed up in its approach to the sun and outgassed hydrogen (white mist), which slightly altered its orbit. The comet, which is most likely pancake-shaped, is the first known object other than dust grains to visit our solar system from another star. (Image credit: NASA, ESA and Joseph Olmsted and Frank Summers of STScI)

Nothing excites space enthusiasts like a good alien mystery. The interstellar visitor ‘Oumuamua presented one as it moved through the inner solar system in 2017. At least one scientist has insisted that this pancake-shaped object is an alien spacecraft. That’s because of the way it accelerated away from the Sun as it passed through. However, a number of planetary scientists say its activity might be more comet-like—something fairly common in the solar system.

March 25, 2023March 25, 2023 by Carolyn Collins Petersen

Don’t Take Batteries to the Moon or Mars, 3D Print Them When you Get There

Artist's impression of astronauts on the lunar surface, as part of the Artemis Program. How will they store power on the Moon? 3D printed batteries could help. Credit: NASA

When the Artemis astronauts and future explorers go to the Moon and Mars, they’ll need power. Lots of it. Of course, they’ll use solar panels to generate the juice they need for habitats, experiments, rovers, and so on. But, they’ll need batteries for power storage. Those things weigh a lot and cost a fortune to send up from Earth. So, why not simply 3D print their own when they get there?

March 22, 2023March 22, 2023 by Carolyn Collins Petersen

Did Supernovae Help Push Life to Become More Diverse?

Distant past supernovae could be linked by cosmic ray particles to climate change on Earth and changes in biodiversity. Courtesy: Henrik Svensmark, DTU Space.

Life on Earth has been around for a long time—at least 3.8 billion years. During that time, it evolved significantly. Why has biodiversity here changed so much? A new study proposes a startling idea. Some major diversity changes are linked to supernovae—the explosions of massive stars. If true, it shows that cosmic processes and astrophysical events can influence the evolution of life on our planet.