Universe Today
Mercury is Shrinking, But Faster Than Previously Thought
The rough, impact-debris-covered surface of Mercury has hidden the true rate at which Mercury has been shrinking, which scientists previously underestimated by 30%
Planetary Science
The study of planets and moons
Recent Articles
-
-
For Trans-Neptunian Objects, The Past Is Written On Their Surface
Some Trans-Neptunian Objects (TNOs) formed closer to the Sun and migrated to the outer solar system, while others formed there originally. A new study finds that "hot" and "cold" origin TNOs can be distinguished not only by their orbits, but also by their surface color.
-
Saturn's South Pole Features Newly Formed Atmospheric Decagon
The planet Saturn is arguably the most recognizable planetary object in the entire solar system because of its massive rings. Anytime a child is asked what their favorite planet is, the answer is often “The one with the rings!” But, while Saturn’s rings are its most striking feature, the famed planet has a myriad of other unique features that often get overlooked, specifically its polar activity. This includes a long-known rotating hexagon in its north polar region, but what kinds of activity could be occurring in Saturn’s southern polar region, and what could this teach scientists about planetary formation and evolution?
-
If Venus Had An Ancient Moon, It Was Doomed
Earth has a big beautiful Moon, while Venus, its 'sister planet', doesn't. Why is that? Did it ever have one? If it did, new research shows it was never going to last very long.
-
Don't Get Your Hopes Up for a City on the Moon
Bezos said we should move heavy industry to the Moon. Musk says we'll have sustainable lunar cities. We know there's ancient water ice in craters on the Moon's poles, but there's not enough water to support a city.
-
Venus Moon Would Have Been Doomed From The Start, Says New Paper
Venus likely never had a moon and even if it did, it would have soon been torn asunder by the planet’s own gravity, says prominent planetary astrophysicist.
-
What's Carving Active Gullies on Mars? It's Not Water
Scientists were shocked when they received the first images of Martian gullies. They were even more shocked as those gullies appeared to change over time. Their similarities to gullies seen on Earth were uncanny, but all of Earth’s gullies are formed by the water run-off, and Martian is too cold and has too sparse an atmosphere to have liquid water on its surface. Whatever has been causing those changing gullies couldn’t have been water, so what was it? A new paper from Apolline Leclef of the Institut d’Astrophysique Spatiale at Université Paris-Saclay and her colleagues, available in pre-print on arXiv, shows how they are likely caused by CO2 frost turning into a fluid.
-
A New Surface Atlas of Phobos Will Help JAXA's MMX Mission Collect its Samples
JAXA's Martian Moon eXploration (MMX) will be on its way to Mars and Phobos next month. It will collect samples from Phobos and return them to Earth. A new morphodynamic atlas of the small moon will help scientists collect and understand the samples.
-
Icy Exocomets Around a Distant Star Help Explain Earth's Water
Did icy comets deliver water to the young Earth? That idea won't go away. Now, astronomers at Lund University in Sweden have found evidence of exocomets orbiting a young star named PDS 70. The observations suggest that these comets are delivering water to that system's inner regions.
-
Scientists Are Still Trying To Understand How the Moon Formed
The Earth and the Moon have nearly identical isotopic compositions, and the Giant Impact Hypothesis strives to explain this. New research into the ancient impact shows how the temperature of both worlds, and how it affects the strength of the materials involved in the collision, shaped the outcome, including the isotopic compositions.
-
New Research Shows How Mercury's Crust Formed by Extreme Volcanism
Researchers have figured out how to use lunar samples to determine the nature of volcanic activity on ancient Mercury. It's all based on SiO2, or silicon dioxide. Its abundance in a planet's crust reveals a lot about magma and volcanic activity.
-
Is a Sea Change Coming for New Horizons Heliospheric Science?
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.
-
Mars's Interior is 400°C Hotter Under Southern Hemisphere
The planet Mars is a cold and dry world completely devoid of life, but billions of years ago things were much different. This is when Mars had a much warmer interior than it does today, resulting in active volcanism that replenished its atmosphere, a magnetic field that protected the planet from harmful solar and cosmic radiation, and a surface of flowing liquid water. But due to Mars’s small size, the interior cooled far faster than Earth’s has cooled, leading to a loss of volcanism, near-absolute depletion of its magnetic field, and complete evaporation of all surface liquid water. But what is the interior heat of Mars like today?
-
7-stage journey reveals how falling space rocks survive air
At least once in our lives, we’ve all seen a bright streak of light briefly blaze across the sky and have quickly referred to it as an asteroid, meteor, shooting star, comet, or some other whimsical name we’ve heard others use to describe it. For those calling it a meteor, you would be correct, but we’ll touch upon this later. The time it takes for a space rock, bolide being its scientific name, to travel through Earth's atmosphere and crash into the ground literally takes only a few seconds. But what happens to a space rock during this very brief travel time, and how can scientists use this to learn about a specific space rock’s origin and the potential damage it could cause if it explodes in mid-air?
-
Gardening the Moon's Cosmic Archives
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.
-
Ancient Dust Grains Hold Magnetic Clues to the Sun's Birth
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.
-
Planets Hurry To Form Before the Protoplanetary Disk Dissipates
Planets form in protoplanetary disks, reservoirs of gas and dust around young stars. But young stars are a little hyperactive, and they emit powerful winds that can dissipate the gas. So planets, especially gas giants, are in a race against time to form. They only have a few million years before the gas is gone.
-
Scientists Melted A Diamond and Cracked a Secret of Ice Giants
Some of the strangest weather in the solar system doesn’t happen on Earth, or even Jupiter’s Great Red Spot - it happens in the interior of the Ice Giants like Neptune and Uranus. Specifically, scientists have long believed that, at certain pressure and temperatures, it literally rains diamonds inside of these planets. And for the first time, scientists have mimicked the process they believe creates that. A new paper by physicists at the Lawrence Livermore National Laboratory (LLNL), published in Nature Physics, resolves a 20 year old scientific mystery, and shows how the same physics that makes it rain diamonds inside Neptune could also help us triple our fusion energy output.
-
A Greenland Glacier Loses Another Chunk of Ice
The ESA's Sentinel satellites captured a 76 sq. km. chunk of ice breaking off from Greenland's Petermann Glacier. They watched the cracks and deformations happen in real time leading up to the calving. While calving is normal, it's happening more often, and this is another clear sign that the Arctic is rapidly changing due to the warming climate.
-
Dry Martian Meteorite Reveals Early Water in Mars's Crust
Billions of years ago, Mars was hypothesized to have been a habitable world with flowing liquid water and the potential for life. But directly studying its ancient past is currently limited to orbiters and rovers, as scientists have yet to obtain direct samples from Mars. However, meteorites have been found on Earth to have potentially originated from Mars during large impacts that flung chunks of the Red Planet into space, eventually being grabbed by Earth’s gravity and crashing into the Earth’s surface.