Space News & Blog Articles

Using in-situ propellant has been a central pillar of the plan to explore much of the solar system. The logic is simple - the less mass (especially in the form of propellant) we have to take out of Earth’s gravity well, the less expensive, and therefore more plausible, the missions requiring that propellant will be. However, a new paper from Donald Rapp, the a former Division Chief Technologist at NASA’s JPL and a Co-Investigator of the successful MOXIE project on Mars, argues that, despite the allure of creating our own fuel on the Moon, it might not be worth it to develop the systems to do so. Mars, on the other hand, is a different story.

Human beings are pretty familiar with the concept of "ice ages." Not only is their ample physical evidence to suggest that glacial periods occurred during the Pleistocene epoch - which lasted from ca. 2.58 million to 11,700 years ago, there are even Indigenous oral traditions that speak of lake formation and dramatic climate shifts in the distant past. Far from being mere myths, these traditions are considered preserved accounts that are corroborated by scientific findings. However, the cycles of glacial and interglacial periods that characterize the Pleistocene were merely the latest in a long line of historical shifts in Earth's climate.

Let’s rewind the clock back…oh, I don’t know, let’s say a hundred years. It was 1917, and Einstein had just developed his general theory of relativity. It was a masterpiece, giving us our modern day view of the gravitational force. And like anybody curious about gravity, Einstein decided to apply his new equations to the evolution of the universe.

All motion is relative. That simple fact makes tracking the motion of distant objects outside our galaxy particularly challenging. For example, there has been a debate among astronomers for decades about the path that one of our nearest neighbors, the Large Magellanic Cloud (LMC), took over the last few billion years. A new paper from Scott Lucchini and Jiwon Jesse Han from the Harvard Center for Astrophysics grapples with that question by using a unique technique - the paths of hypervelocity stars.

To be fair, all scientific models are in some sense wrong. They’re all approximations of reality. They’re all mathematical models that we use to describe and understand our observations and measurements. And like I said, the LCDM model has, over the course of almost a quarter century, proven to be enormously resilient, flexible, and powerful when describing broad swaths of nature.

Tracking down black holes at the center of dwarf galaxies has proven difficult. In part that is because they have a tendency to “wander” and are not located at the galaxy’s center. There are plenty of galaxies that might contain such a black hole, but so far we’ve had insufficient data to confirm their existence. A new paper from Megan Sturm of Montana State University and her colleagues analyzed additional data from Chandra and Hubble on a set of 12 potential Active Galactic Nuclei (AGN) galaxy candidates. They were only able to confirm three, which highlights the difficulty in isolating these massive wanderers.

Hawking radiation has never been proved, but it's generally thought to be real. Essentially, the argument is that when you combine black hole event horizons with quantum fuzziness, thermal energy can escape a black hole. We don't have a fully quantum theory of gravity, but we do have several semi-classical models that support the existence of Hawking radiation. And if Hawking radiation is true, then the interaction of black holes is governed by the laws of thermodynamics.

One of the things the James Webb Space Telescope revealed to us is a class of small, distant galaxies in the very early Universe. Their light has been stretched into the red after billions of years travelling in the expanding Universe, and they've been dubbed Little Red Dots (LRD). Initially, the JWST couldn't reveal their true nature because LRDs are near the limits of the powerful telescope's observational power. But we know they're there; the genie's out of the bottle.

Astronomers know that mergers play a huge role in galaxy growth. Right now, the Milky Way is slowly consuming the Large and Small Magellanic Clouds. The evidence is a stream of gas called the Magellanic Stream that's about 600,000 light-years long. The Milky Way (MW) is stripping this gas from the clouds, which don't have enough mass to retain it. They're losing the gravitational tug-of-war with the much more massive MW.

Our search for exoplanets is focused on Milky Way stars. It's been successful, with more than 6,000 detected so far. Scientists are even beginning to move beyond mere detections, and working on characterizing other characteristics of these planets, especially their atmospheres.

The details of a supernova explosion are still clouded in mystery and subject to vigorous debate. What exactly happens when they explode? What underlying mechanisms are involved? New observations of a supernova with the European Southern Observatory's Very Large Telescope are removing some of the mystery.

Last time I wrote about new data that overturns the standard cosmological model. Before anyone starts dusting off their fringe cosmological models, we should note what this new study doesn't overturn. It doesn't say the Big Bang model is wrong, nor does it say that the Universe isn't expanding or that Hubble's redshift-distance relation needs to be thrown out. It really only says that our Hubble constant model is wrong. But we already knew that thanks to a little thing known as the Hubble tension. These new results could solve that mystery as well.

The case for habitability in Enceladus' warm, ice-capped ocean is growing. Ever since Cassini found evidence of hydrothermal activity in the moon's ocean, and detected life's building blocks in the plumes of material ejected from the ocean, scientists have worked to put this data into context.

A trio of exoplanets may challenge what we know about planetary formation.

So if the standard model of cosmology is wrong, what alternative is there?

Nestled on a hillside in Guangdong Province near Zhaoqing City, the Jinlin crater managed to hide in plain sight until researchers identified it as an impact structure. Only about 200 confirmed impact craters exist worldwide, making each discovery scientifically valuable. But this one stands out for its exceptional size and youth.

Quasars acting as strong gravitational lenses are among the rarest finds in astronomy. Out of nearly 300,000 quasars catalogued in the Sloan Digital Sky Survey, only twelve candidates were identified, and just three confirmed. These systems are exceptionally valuable because they allow astronomers to precisely measure the mass of a quasar's host galaxy, something that is normally impossible given that the overwhelming brightness of the quasar itself drowns out its surroundings.

The James Webb Space Telescope didn't need much time to show us how wrong we were about the early Universe. Mere weeks after it began observations, it found galaxies in the very early Universe that were far more massive than our theories showed. These confounding images required an explanation.

NASA is facing increasingly sharp challenges as it pursues its goal of landing astronauts on the moon again before this decade is out — and as the space agency braces for another leadership change, it’s clear that the year ahead will also bring further challenges. How will NASA fare?

Carl Sagan, along with co-author Edwin Salpeter, famously published a paper in the 70s about the possibility of finding life in the cloud of Jupiter. They specifically described “sinkers, floaters, and hunters” that could live floating and moving in the atmosphere of our solar system’s largest planet. He also famously talked about how clouds on another of our solar system’s planets - Venus - obfuscated what was on the surface, leading to wild speculation about a lush, Jurassic Park-like world full of life, just obscured by clouds. Venus turned out to be the exact opposite of that, but both of those papers show the impact clouds can have on the Earth for life. A new paper by authors as the Carl Sagan Institute, led by Ligia Coelho of Cornell, argues that we should look at clouds as potential habitats for life - we just have to know how to look for it.

Measuring the Solar System's velocity through space sounds straightforward, but it represents one of the most challenging tests of our cosmological understanding. As our Solar System travels through the universe, this motion creates a subtle asymmetry, a "headwind" where slightly more distant galaxies appear in our direction of travel than behind us. The effect is extraordinarily faint and requires sensitive measurements to detect.