Carolyn Collins Petersen, Author at Universe Today

December 12, 2022December 12, 2022 by Carolyn Collins Petersen

Black Holes Shouldn’t be Able to Merge, but Dozens of Mergers Have Been Detected. How Do They Do It?

black holes in a globular cluster — This is an artist’s impression created to visualize the concentration of black holes at the center of globular cluster NGC 6397. Credit: ESA/Hubble, N. Bartmann

Who knows what lurks in the hearts of some globular clusters? Astronomers using a collection of gravitational wave observatories found evidence of collections of smaller black holes dancing together as binaries in the hearts of globulars. What’s more, they’ve detected an increased number of gravitational wave events when some of these stellar-mass black holes crashed together.

December 9, 2022December 9, 2022 by Carolyn Collins Petersen

Comets Leave Dusty Trails That Surround the Solar System

Could the solar system be enveloped in a shell of faintly glowing dust from comets? Courtesy NASA/ESA/STSci

Comets are messy things. They scatter bits of dust as they travel through the solar system. If Earth happens to encounter one of those cometary dust trails, we get to see a meteor shower.

December 6, 2022December 6, 2022 by Carolyn Collins Petersen

Evidence of a Megatsunami on Mars

Mars panorama of an plain scoured by an ancient megatsunami. The image comes from Viking 1. Courtesy NASA.

Things were pretty wet back on Mars about three and a half billion years ago. You wouldn’t know that by looking at the planet today. But, would you believe a megatsunami happened there? It turns out that not one, but two of these rogue waves happened there some 3.4 billion years ago.

December 5, 2022December 5, 2022 by Carolyn Collins Petersen

Ground Telescopes can Adapt to Satellite Megaconstellations if They get Accurate Telemetry Data

starlink satellite streaks — An image of the NGC 5353/4 galaxy group made with a telescope at Lowell Observatory in Arizona, USA on the night of Saturday 25 May 2019. The diagonal lines running across the image are trails of reflected light left part of a Starlink satellite constellation.

The growing population of communication satellites such as Starlink and OneWeb is posing challenges for Earth-based astronomy facilities. Since such constellations will not be going away soon, astronomers want to find ways to work around the issue.

It’s not going to be easy, considering that thousands and thousands of low-Earth satellites (LEOsats) could potentially be placed in low-Earth orbit in the next few years. So, what are the solutions?

November 30, 2022November 30, 2022 by Carolyn Collins Petersen

With a Small Network of Satellites Around Mars, Rovers Could Navigate Autonomously

small satellites at Mars — An artist's concept for a smallsat constellation around Mars for polar exploration. Courtesy Serena Molli.

When it comes to “on the ground” exploration of Mars, rovers make pretty good advance scouts. From Pathfinder to Perseverance, we’ve watched as these semi-autonomous robots do what human explorers want to do in the future. Now, engineers are studying ways to expand rover exploration on Mars. One thing they’re thinking about: communication satellite constellations for Mars surface navigation.

November 30, 2022November 30, 2022 by Carolyn Collins Petersen

Mauna Loa is Erupting for the First Time in 40 Years. Here’s What it Looks Like From Space.

Fissure 3 of the current Mauna Loa eruption on the Big island of Hawaii. Courtesy USGS.

A sleeping giant of a volcano woke up this past week on the Big Island of Hawaii. Mauna Loa, which last erupted in the early 1980s, has been rattling the island with earthquakes for weeks. Finally, on November 27th, the mountain opened up. Not only did residents see this eruption, but NASA and NOAA satellites captured an infrared view of it.

November 29, 2022December 5, 2022 by Carolyn Collins Petersen

BlueWalker 3 is a Cellphone Tower in Space and One of the Brightest Objects Ever Launched. Astronomers Aren’t Happy.

It seems our nighttime skies are hosting another new communications network. In recent years, we’ve seen Starlink trains of satellites moving against the backdrop of stars, and more OneWeb satellites will soon be heading to orbit. Now, it’s BlueWalker 3, a prototype test satellite for a new communications constellation aimed at cell phones. Think of it as the first of many “cell towers in space” providing communications access for people around the globe.

November 28, 2022November 28, 2022 by Carolyn Collins Petersen

The Second-Closest Supermassive Black Hole Might be in a Nearby Dwarf Galaxy

Leo 1 dwarf spheroidal galaxy has a supermassive black hole — Leo I appears as a faint patch to the right of the bright star, Regulus. Astronomers say it appears to have a supermassive black hole Credit: Scott Anttila Anttler

There’s a little galaxy in the Milky Way’s cosmic neighborhood called Leo 1. It’s a dwarf spheroidal that lies less than a million light-years away from us. Surprisingly, it has a supermassive black hole about the same mass as Sagittarius A* in our galaxy. That’s unusual in several ways, and astronomers want to know more about it.

November 23, 2022November 23, 2022 by Carolyn Collins Petersen

JWST Detects Signs of Active Chemistry and Clouds in the Atmosphere of Exoplanet WASP-39 b

NASA’s JWST data just keeps on delivering amazing discoveries. Back in July, it observed the exoplanet WASP-39 b and found fingerprints of atoms and molecules and active chemical reactions in its clouds. Now, a team of scientists extends that discovery with a much deeper analysis of the data.

November 22, 2022November 22, 2022 by Carolyn Collins Petersen

The Milky Way’s Stellar Halo Isn’t a Sphere After All

stellar halo around the milky way — The Milky Way's anatomy includes a rounded stellar halo That view is changing with new data. Image courtesy ESA.

Our galaxy’s stellar halo is giving astronomers some new food for thought. It turns out everyone thought the halo was spherical. But, it’s not. That’s news to everyone who said it was spherical. According to a new measurement done by a team at Harvard-Smithsonian Center for Astrophysics, it has a tilted, oblong football shape. This all tells astronomers an interesting tale about our galaxy’s ancient history.