Neptune Archives

December 2, 2024December 2, 2024 by Brian Koberlein

What's Inside Uranus and Neptune? A New Way to Find Out

Artist expoded view of an ice giant planet similar to Uranus and Neptune. Credit: @iammoteh/Quanta magazine

In our search for exoplanets, we’ve found that many of them fall into certain types or categories, such as Hot Jupiters, Super-Earths, and Ice Giants. While we don’t have any examples of the first two in our solar system, we do have two Ice Giants: Uranus and Neptune. They are mid-size gas planets formed in the cold outer regions of the solar system. Because of this, they are rich in water and other volatile compounds, and they are very different from large gas giants such as Jupiter. We still have a great deal to learn about these worlds, but what we’ve discovered so far has been surprising, such as the nature of their magnetic fields.

November 28, 2024November 28, 2024 by Mark Thompson

Uranus’s Wobbling Moons Could Point to Oceans Under the Ice

This is an image of the planet Uranus taken by the spacecraft Voyager 2 in 1986.

Subsurface oceans of liquid water are a common feature of the moon’s of Jupiter and Saturn. Researchers are exploring whether the icy moons of Uranus and Neptune might have them as well. Their new paper suggests future missions to the outer Solar System could measure the rotation of the moons and detect any wobbles pointing to liquid oceans. Less wobble means the moons is mostly solid but large wobbles can indicate ice floating on an ocean of liquid.

September 30, 2024September 30, 2024 by Mark Thompson

Was the Moon Captured?

The general consensus is that Theia crashed into Earth billions of years ago and led to the formation of the Moon. The story doesn’t end there though since there are a few lines of evidence to suggest the Moon could have been captured by the gravitational pull of the Earth instead. The orbit of the Moon is one such observation that leads to a different conclusion for it’s in-line with the plane of the ecliptic rather than the Earth’s equator. A team of researchers have suggested capture theory was the Moon’s origin.

September 16, 2024September 16, 2024 by Andy Tomaswick

An Ambitious Mission to Neptune Could Study Both the Planet and Triton

Mission concepts to the outer solar system are relatively common, as planetary scientists are increasingly frustrated by our lack of knowledge of the farthest planets. Neptune, the farthest known planet, was last visited by Voyager 2 in the 1980s. Technologies have advanced a lot since that probe was launched in 1977. But to utilize that better technology, we first need to have a mission arrive in the system – and one such mission is being developed over a series of papers by ConEx Research and University College London.

May 18, 2024May 18, 2024 by Mark Thompson

When Uranus and Neptune Migrated, Three Icy Objects Were Crashing Into Them Every Hour!

The giant outer planets haven’t always been in their current position. Uranus and Neptune for example are thought to have wandered through the outer Solar System to their current orbital position. On the way, they accumulated icy, comet-like objects. A new piece of research suggests as many as three kilomerer-sized objects crashed into them every hour increasing their mass. Not only would it increase the mass but it would enrich their atmospheres.

February 27, 2024February 27, 2024 by Evan Gough

New Moons Found at Uranus and Neptune

The discovery image of the new Uranian moon S/2023 U1 using the Magellan telescope on November 4, 2023. Uranus is just off the field of view in the upper left, as seen by the increased scattered light. S/2023 U1 is the faint point of light in the center of the image with the yellow arrow. The trails are from background stars. Credit: Scott Sheppard.

Astronomers have found three new moons orbiting our Solar System’s ice giants. One is orbiting Uranus, and two are orbiting Neptune. It took hard work to find them, including dozens of time exposures by some of our most powerful telescopes over several years. All three are captured objects, and there are likely more moons around both planets waiting to be discovered.

November 27, 2023November 29, 2023 by Nancy Atkinson

Aerocapture is a Free Lunch in Space Exploration

Visualisation of the ExoMars Trace Gas Orbiter aerobraking at Mars. Credit: ESA/ATG medialab.

This article was updated on 11/28/23

When spacecraft return to Earth, they don’t need to shed all their velocity by firing retro-rockets. Instead, they use the atmosphere as a brake to slow down for a soft landing. Every planet in the Solar System except Mercury has enough of an atmosphere to allow aerocapture maneuvers, and could allow high-speed exploration missions. A new paper looks at the different worlds and how a spacecraft must fly to take advantage of this “free lunch” to slow down at the destination.

November 16, 2023November 16, 2023 by Evan Gough

Take a Plunge Into the Ice Giants

The unique atmospheric compositions of ‘ice giant’ planets Uranus and Neptune were recreated to simulate a plunge deep within them. These simulations are part of preparation for eventual atmospheric probes the ESA intends to send. Image Credit: University of Stuttgart’s High Enthalpy Flow Diagnostics Group

Our Solar System’s ice giants, Uranus and Neptune, have been largely left out of the planetary probe game. While all of the other planets—including even the demoted Pluto—have been the subjects of dedicated missions, the ice giants have not. In fact, the only spacecraft to ever even fly by Uranus and Neptune was Voyager 2 in the late 1980s.

August 24, 2023August 24, 2023 by Matt Williams

One of Neptune's Dark Spots Finally Seen From Earth

This image shows Neptune observed with the MUSE instrument at ESO’s Very Large Telescope (VLT). Credit: ESO/P. Irwin et al.

There’s no getting around it: our Solar System’s gas giants all have big, conspicuous spots on their faces. These include Jupiter’s Great Red Spot, Saturn’s Great White Spot, Uranus’ Great Dark Spot, and Neptune’s Great Dark Spot. Far from blemishes or features that tarnish the planets’ natural beauty, these “spots” are caused by massive storms or other processes in the planets’ atmospheres. While they are extremely large by Earth standards, they are difficult to study by anything other than robotic probes that can get close to the planet.

Neptune’s Great Dark Spot was not discovered until NASA’s Voyager 2 probe flew past the planet in 1989 on its way to the edge of the Solar System. Decades later, scientists are still unsure how this storm originated or what mechanisms drive it today. Using the ESO’s Very Large Telescope (VLT), a team of astronomers was able to observe the Great Dark Spot for the first time using a ground-based telescope. Their results provided the most detailed data on the spot to date and some interesting insights into the nature and origin of this mysterious feature.

August 24, 2023August 24, 2023 by Nancy Atkinson

Neptune's Cloud Cover is Linked to the Solar Cycle

This sequence of Hubble Space Telescope images chronicles the waxing and waning of the amount of cloud cover on Neptune. Credits: NASA, ESA, Erandi Chavez (UC Berkeley), Imke de Pater (UC Berkeley)

Whenever Neptune reaches its closest point in the sky to Earth, its portrait is taken by the Hubble Space Telescope and other ground-based observatories. Watching the planet from 1994 to 2020, astronomers have made puzzling discovery.

The clouds in Neptune’s atmosphere appear to be to be linked to the solar cycle and not the planet’s cycle of seasons. The global cloud cover seems to come and go in a cycle that apparently syncs up with the Sun’s 11-year cycle, as it shifts from solar maximum to solar minimum or vice versa. This is surprising since Neptune is so far from the Sun and receives about 0.1% of Earth’s sunlight.