INFORMATION

The odds of a sizable asteroid striking Earth are small, but they’re never zero. Large asteroids have struck Earth in the past, causing regional devastation. A really large asteroid strike likely contributed to the extinction of the dinosaurs. So we shouldn’t be too surprised that astronomers have discovered an asteroid with a better than 1% chance of striking our world. Those odds are large enough we should keep an eye on them, but not large enough that we should start packing bags and fleeing to the hills. The rock, named 2024 YR4, is somewhere between 40 – 100 meters wide, which would make it a “city killer” asteroid. If it does strike Earth, it wouldn’t decimate human civilization and cause mass extinctions, but it could destroy a heavily populated area if it struck a city, or trigger a tsunami if it struck the ocean. It would back a punch similar to the 1908 Tunguska event in Northern Siberia. So what is the overall risk of 2024 YR4? The scale most commonly used for asteroid i...

Mars haunts us as a vision of a planet gone wrong. It was once warm and wet, with rivers flowing across its surface and (potentially) simple life residing in its water bodies. Now it’s dry and freezing. Could Earth suffer this fate? Are there innumerable other worlds throughout the Universe that were habitable for a period of time before becoming uninhabitable? To answer those questions, we have to answer one of the big questions in space science: What drove the changes on Mars? New research shows that hydrogen played a critical role in keeping ancient Mars warm for periods of time, as the planet’s temperature oscillated between warm and cold. The research is “ Episodic warm climates on early Mars primed by crustal hydration. ” It’s published in Nature Geoscience, and the lead author is Danica Adams, a postdoctoral fellow in the Department of Earth and Planetary Sciences at Harvard University. “Early Mars is a lost world, but it can be reconstructed in great detail if we ask the...

What would you do for fun on another planet? Go ballooning in Venus’ atmosphere? Explore the caves of Hyperion? Hike all the way around Mercury? Ride a toboggan down the slopes of Pluto’s ice mountains? Or watch clouds roll by on Mars? All those adventures, and more, are offered in a new book titled  “Daydreaming in the Solar System.”  But the authors don’t stop at daydreaming: York University planetary scientist  John E. Moores  and astrophysicist  Jesse Rogerson  also explain why the adventures they describe would be like nothing on Earth. In the latest episode of the  Fiction Science podcast , Moores says the idea behind the book was to tell “a little story that is really, really true to what the science is, and then give the reader an idea of what science there is that actually enables that story to take place.” Trips to other worlds have been the stuff of science fiction for more than a century — going back to Jules Verne’s  “From the ...

When astronomers detected the first long-predicted gravitational waves in 2015 , it opened a whole new window into the Universe. Before that, astronomy depended on observations of light in all its wavelengths. We also use light to communicate, mostly radio waves. Could we use gravitational waves to communicate? The idea is intriguing, though beyond our capabilities right now. Still, there’s value in exploring the hypothetical, as the future has a way of arriving sooner than we sometimes think. New research examines the idea and how it could be applied in the future. It’s titled “ Gravitational Communication: Fundamentals, State-of-the-Art and Future Vision, ” and it’s available on the pre-press site arxiv.org. The authors are Houtianfu Wang and Ozgur B. Akan. Wang and Akan are both with the Internet of Everything Group, Department of Engineering, University of Cambridge, UK. “Gravitational waves can maintain consistent signal quality over immense distances, making them suitable ...

New images from NASA’s Juno spacecraft make Io’s nature clear. It’s the most volcanically active world in the Solar System, with more than 400 active volcanoes. Juno has performed multiple flybys of Io, and images from its latest one show an enormous hotspot near the moon’s south pole. Juno was sent to Jupiter to study the giant planet, but that primary mission ended, and NASA extended the mission. Currently, it is performing flybys of three of the Galilean moons: Ganymede, Europa, and Io. We’ve reported on Juno’s Io flybys previously. In its latest flyby, the orbiter imaged a volcanic hotspot on the moon’s south pole larger than Lake Superior. The images are from Juno’s JIRAM (Jovian Infrared Auroral Mapper) instrument. According to NASA, the hot spot’s eruptions are six times more energetic than all of Earth’s power plants and its radiance measured well above 80 trillion watts. “The data supports that this is the most intense volcanic eruption ever recorded on Io.” Alessandro ...

A team of astronomers have discovered a rather curious exoplanetary system that has two gas giant planets that are messing up each other’s orbit! On of them is 3.8 times the mass of Jupiter and completes an orbit every 82 days, the other is just 1.4 Jupiter masses. Hiding in the wings is another mini-Neptunian world. The two gas giants are locked into a 2:1 orbital resonance and, as a result of their gravitational interactions, the orbit of the more massive can vary by up to 4 days! Exoplanets are alien worlds that orbit around stars beyond our Solar System. They vary by size, mass, composition and environment and studying them provides insight into not only planetary formation but also the liklihood for the presence of alien life! Like all bodies that orbit a common host; moons around a planet or planets around a star, their orbits can become linked in what has become known as a resonance. This artist’s illustration shows the Neptune-like exoplanet GJ 3470b, which has an atmospher...

Saturn’s moon Titan is perhaps one of the most fascinating moons in the Solar System. It’s the second largest of all the moons in our planetary neighbourhood and is the only one with a significant atmosphere. It’s composed of 95% nitrogen and 5% methane and is 1.5 times as dense as the Earth’s atmosphere. The methane in the atmosphere of Titan is what puzzles scientists. It should have all be broken up within 30 million years causing the atmosphere to freeze but it hasn’t! There must be an internal process replenishing it, but what is it? Titan is the largest moon of Saturn and second only in size to Ganymede, the largest moon of Jupiter. The surface of Titan is covered with dunes, icy mountains, and liquid hydrocarbon lakes—primarily composed of methane and ethane. Beneath its icy crust, scientists believe a vast subsurface ocean of water exists, raising the possibility of microbial life. NASA’s Cassini-Huygens mission provided detailed insights into Titan’s climate, seasonal change...

On Thursday January 30th, astronauts Suni Williams and Butch Wilmore are doing a 6.5-hour spacewalk outside the International Space Station. Among other goals, they’ll be collecting surface samples from the station to analyze for the presence of microbes. The ISS “surface swab” is part of the ISS External Microorganisms project. It was developed to understand how microorganisms are transported by crew members to space. It also seeks to understand what happens to those “mini-critters” in the space environment. The “bugs” that the two astronauts bring back in for analysis will come from areas on the space station near life-support system vents. The idea is to figure out if the station releases those microbes through the vents. Scientists also want to know the size of the release population, and where else they show up on the station. The Microbes Experiment Researchers seek to understand how microbes exist and thrive in space and planetary environments. At the moment, the best analo...

When an exoplanet is discovered, scientists are quick to describe it and explain its properties. Now, we know of thousands of them, many of which are members of a planetary system, like the well-known TRAPPIST-1 family of planets. Patterns are starting to emerge in these exoplanetary systems, and in new research, a team of scientists says it’s time to start classifying exoplanet systems rather than just individual planets. The paper is “ Architecture Classification for Extrasolar Planetary Systems, ” and it’s available on the pre-print site arxiv.org. The lead author is Alex Howe from NASA’s Goddard Space Flight Center. The authors say it’s time to develop and implement a classification framework for exoplanet systems based on our entire catalogue of exoplanets. “With nearly 6000 confirmed exoplanets discovered, including more than 300 multiplanet systems with three or more planets, the current observational sample has reached the point where it is both feasible and useful to buil...

Exoplanets have captured the imagination of public and scientists alike and, as the search continues for more, researchers have turned their attention to the evolution of metallicity in the Milky Way. With this answer comes more of an idea about where planets are likely to form in our Galaxy. They have found that stars with high-mass planets have higher metallicity than those with lower amounts of metals. They also found that stars with planets tend to be younger than stars without planets. This suggests planetary formation follows the evolution of a galaxy with a ring of planet formation moving outward over time.  The search for exoplanets has largely been one of surveying nearby stars.  That generally means we are exploring stars in our region of the Galaxy. As technology develops, our ability to detect them improves and to date, nearly 6,000 planets have been discovered around other stars. A number of different techniques have been used to find them such as the transit me...

Exoplanet exploration has taken off in recent years, with over 5500 being discovered so far. Some have even been in the habitable zones of their stars. Imaging one such potentially habitable exoplanet is the dream of many exoplanet hunters, however, technology has limited their ability to do that. In particular, one specific piece of technology needs to be improved before we can directly image an exoplanet in the habitable zone of another star – a starshade. Christine Gregg, a researcher at NASA Ames Research Center, hopes to contribute to the effort of developing one and has received a NASA Institute for Advanced Concepts (NIAC) grant as part of the 2025 cohort to work on a star shade that is based on a special type of metamaterial. To understand the goal of Dr. Gregg and her team, it’s best first to understand what starshades do and what’s holding them back from being deployed. A starshade is designed to float in tandem with a space telescope and block out the light from a specific...