moons Archives

December 11, 2023December 11, 2023 by Evan Gough

Exomoons Defy Discovery

So far we only know of two exoplanets with candidate exomoons. But even those two may be false positives. Image Credit: NASA

For a long time, we wondered if other stars hosted planets like the Sun does. Finally, in the 1990s, we got our answer. Now, another question lingers.

Most of the planets in our Solar System have moons. Do exoplanets have exomoons?

October 26, 2023October 26, 2023 by Evan Gough

JWST Takes a Detailed Look at Jupiter’s Moon Ganymede

Juno captured this image of Ganymede in July 2022. Now the JWST is taking a look at our Solar System's largest moon. Image Credit: NASA/JPL-Caltech/SwRI/MSSS/Kevin M. Gill

Nature doesn’t conform to our ideas of neatly-contained categories. Many things in nature blur the lines we try to draw around them. That’s true of Jupiter’s moon Ganymede, the largest moon in the Solar System.

The JWST took a closer look at Ganymede, the moon that’s kind of like a planet, to understand its surface better.

October 25, 2023October 25, 2023 by Evan Gough

Io has 266 Active Volcanic Hotspots Linked by a Global Magma Ocean

NASA’s Galileo spacecraft captured this image of a volcanic eruption on Io in 1997. Image Credit:NASA, NASA-JPL, DLR

Jupiter’s Io stands apart from the Solar System’s other moons, with its numerous volcanoes and its surface dominated by lava flows. Io’s surface volcanism was confirmed in 1979 when the Voyager spacecraft imaged it, but its volcanic nature isn’t duplicated anywhere else in our system. Tidal heating is behind the moon’s eruptive nature, driven by Jupiter’s powerful gravity, and by resonance with other moons. But is there a magma ocean inside Io?

A final answer to that question has been elusive, but new research supports the idea of a magma ocean.

October 19, 2023October 19, 2023 by Evan Gough

Juno Completes its Closest Flyby of Io Yet

Not since the Galileo mission ended 20 years ago have we seen such great images of Io. NASA's Juno spacecraft captured this image with its JunoCam instrument on October 15th from less than 12,000 km altitude. Ted Stryk processed the image. Image Credit: Ted Stryk/NASA/JPL-Caltech/SwRI/MSSS/

Jupiter’s ocean moons capture most of our attention because of their potential habitability. But Io, Jupiter’s bad-boy volcanic moon, is in a class of its own. There’s nothing else like it in the Solar System, and NASA’s Juno spacecraft captured new images of the volcanic satellite during its closest approach yet.

September 28, 2023September 28, 2023 by Evan Gough

Colliding Moons Might Have Created Saturn’s Rings

Saturn's rings are arguably the most recognizable feature in our Solar System and are made mostly of ice particles. New research says a collision between icy moons may have created them in the recent past. Image Credit: NASA/JPL/Space Science Institute

If we could wind the clock back billions of years, we’d see our Solar System the way it used to be. Planetesimals and other rocky bodies were constantly colliding with each other, and new objects would coalesce out of the debris. Asteroids rained down on the planets and their moons. The gas giants were migrating and contributing to the chaos by destroying gravitational relationships and creating new ones. Even moons and moonlets would’ve been part of the cascade of collisions and impacts.

When nature crams enough objects into a small enough space, it breeds collisions. A new study says that’s what happened at Saturn and created the planet’s dramatic rings.

May 25, 2023May 25, 2023 by Evan Gough

Researchers Are Building a Simulated Moon/Mars Research Station Deep Underground

These images show the first laboratory in the Bio-SPHERE project. The medical lab is located 1 km under the surface, near one of the UK's deepest mine sites. Image Credit: Dr. Alexandra Iordachescu/University of Birmingham.

In the early days of spaceflight, just getting a satellite into Earth’s orbit was an accomplishment. In our era, landing rovers on other planets and bringing samples home from asteroids is the cutting edge. But the next frontier is rapidly approaching, when astronauts will stay for long periods of time on the Moon and hopefully Mars.

But before we can send people to those dangerous environments, the Artemis partner space agencies have to know how to keep them safe. An important part of that is simulating the conditions on the Moon and Mars.

May 23, 2023May 23, 2023 by Evan Gough

Juno Reveals Volcanoes on Io

The Juno spacecraft used its JIRAM (Jovian Infrared Auroral Mapper) instrument to capture these images of Jupiter's volcanic moon Io. It captured the four images in sequence to gain different viewing angles of the moon's volcanic activity. Image Credit: NASA/JPL-Caltech/SwRI/ASI/INAF/JIRAM

Jupiter’s moon Io is the most volcanic world in the Solar System, with over 400 volcanoes. Some of them eject plumes as high as 500 km (300 mi) above the surface. Its surface is almost entirely shaped by all this volcanic activity, with large regions covered by silicates, sulphur, and sulphur dioxide brought up from the moon’s interior. The intense volcanic activity has created over 100 mountains, and some of them are taller than Mt. Everest.

Io is unique in the Solar System, and the Juno orbiter’s JunoCam captured some new images of Io’s abundant volcanic activity.

May 15, 2023May 15, 2023 by Evan Gough

62 New Moons Found for Saturn

The Hubble Space Telescope captured this image of Saturn in February, 2023. Image Credit: STScI

Jupiter is the King, Earth is teeming with life, Venus is a weird, spacecraft-crushing hellhole, and now Saturn has the most moons. Again.

Jupiter sat atop the podium as the planet with the most moons for a while. But with the discovery of 62 more moons, Saturn has surpassed Jupiter as the planet with the most natural satellites and reclaimed the top spot.

April 26, 2023April 26, 2023 by Nancy Atkinson

New High-Resolution Photos of Deimos From the Hope Mission

The Hope spacecraft from the United Arab Emirates took this image of Mars and its moon Deimos from a distance of approximately 100 km from the moon. Credit: UAE Space Agency.

We’ve seen our share of photos of Mars from orbit and the surface, but what about its moons? The United Arab Emirates Hope orbital mission to Mars sent home new beautiful high-resolution images of the Red Planet’s moon Deimos when it flew within 100 km of the moon last month. This is the closest any spacecraft has been to Deimos in almost 50 years.

In the photos, the science team says that their images of Deimos help provide evidence that the moon wasn’t a captured asteroid but came from Mars itself during an impact in the ancient past, much like Earth’s Moon.

April 21, 2023April 23, 2023 by Laurence Tognetti

We Could Soon See Landslides on Europa and Ganymede

Image of potential flat, smooth terrain on Ganymede imaged by NASA's Galileo spacecraft in 2000 that could be indicative of landslides. (Credit: NASA/JPL/Brown University)

The European Space Agency’s (ESA) recently launched Jupiter Icy Moons Explorer (JUICE) mission and NASA’s upcoming Europa Clipper mission could allow scientists to image landslides on the icy moons of Europa and Ganymede due to potential moonquakes on these small worlds. This comes after a recent study examined fault scarps on Europa and Ganymede orbiting Jupiter and Enceladus and Dione orbiting Saturn with the goal of drawing a connection between tectonic activity (quakes) and observed mass wasting (landslides) on these surfaces. The researchers “consider whether such smooth material can be generated by mass wasting triggered from local seismic shaking”, according to the study.