Solar System Archives

November 25, 2022November 25, 2022 by Matt Williams

Mars Once had Enough Water for a Planet-Wide Ocean 300 Meters Deep

This artist’s impression shows how Mars may have looked about four billion years ago. The young planet Mars would have had enough water to cover its entire surface in a liquid layer about 140 metres deep, but it is more likely that the liquid would have pooled to form an ocean occupying almost half of Mars’s northern hemisphere, and in some regions reaching depths greater than 1.6 kilometres. Credit: ESO/M. Kornmesser

Today, Mars is colloquially known as the “Red Planet” on a count of how its dry, dusty landscape is rich in iron oxide (aka. “rust”). In addition, the atmosphere is extremely thin and cold, and no water can exist on the surface in any form other than ice. But as the Martian landscape and other lines of evidence attest, Mars was once a very different place, with a warmer, denser atmosphere and flowing water on its surface. For years, scientists have attempted to determine how long natural bodies existed on Mars and whether or not they were intermittent or persistent.

Another important question is how much water Mars once had and whether or not this was enough to support life. According to a new study by an international team of planetary scientists, Mars may have had enough water 4.5 billion years ago to cover it in a global ocean up to 300 meters (almost 1,000 feet) deep. Along with organic molecules and other elements distributed throughout the Solar System by asteroids and comets at this time, they argue, these conditions indicate that Mars may have been the first planet in the Solar System to support life.

October 24, 2022October 24, 2022 by Evan Gough

NASA Provides a Timelapse Movie Showing How the Universe Changed Over 12 Years

This mosaic is composed of images covering the entire sky, taken by the Wide-field Infrared Survey Explorer (WISE) as part of WISE’s 2012 All-Sky Data Release. By observing the entire sky, WISE can search for faint objects, like distant galaxies, or survey groups of cosmic objects. Credits: NASA/JPL-Caltech/UCLA

The Universe is over 13 billion years old, so a 12-year slice of that time might seem uneventful. But a timelapse movie from NASA shows how much can change in just over a decade. Stars pulse, asteroids follow their trajectories, and distant black holes flare as they pull gas and dust toward themselves.

October 18, 2022October 17, 2022 by Paul M. Sutter

Planet Formation Doesn’t Have to be a Rush job After all

Astronomers believe that it can take 10 million years or more to build a planet like the Earth. But studies of protoplanetary disks show that they can only last 1 to 3 million years. How can planet formation finish if the material its made from disappears so quickly? A team of astronomers have proposed a solution: it’s a simple matter of bias in our observations.

October 12, 2022October 12, 2022 by Evan Gough

The Moon Might be One Large Chunk that was Blasted Off the Earth Billions of Years Ago

A new study and supercomputer simulations present an alternative explanation for the Moon. Yes, it formed from an impact, but it may not have taken years. Image Credit: NASA Ames Research Center

Where did the Moon come from?

The widely-accepted view is that the Moon is a result of an ancient collision between the young Earth and a Mars-sized planet named Theia about 4.5 billion years ago. The impact melted Earth and Theia and sent molten material into orbit around Earth, where it formed a rotating torus of molten rock. That rock eventually coalesced into the Moon. It’s called the Giant Impact Hypothesis, and isotopic evidence from Apollo moon rocks illustrates the link between Earth and its Moon.

Case closed?

Not so fast. There’ve always been problems with this hypothesis. Can a new study answer them?

September 29, 2022September 29, 2022 by Seth Lockman

Robots Might Jump Around to Explore the Moon

LEAP (Legged Exploration of the Aristarchus Plateau) is a mission concept study, funded by ESA, to explore challenging lunar terrains using ANYmal, a four-legged robot developed at ETH Zürich and its spin-off ANYbotics. Credit: ETH Zürich/Robotics Systems Labs (RSL)

How great are wheels, really? Wheels need axles. Suspension. Power of some kind. And roads, or at least swaths of relatively flat and stable terrain. Then you need to maintain all of it. Because of their cost many civilizations across human history, who knew all about wheels and axles, didn’t bother using them for transportation. Another way to look at it – much of human technology mimics nature. Of the simple machines, levers, inclined planes, wedges, and even screws are observed in nature. Why not the wheel?

September 11, 2022September 11, 2022 by Brian Koberlein

If Jupiter's Orbit got Weirder, it Would Actually Make Earth More Habitable

Io Eclipse on Jupiter from Juno Perijove 22 - NASA/JPL/Kevin Gill

Earth is not just habitable, it’s unusually habitable. It’s rather wet for a planet so close to its Sun, it’s geologically active, and it has a stable orbit, all of which are necessary for life as we know it. But there are also secondary advantages, such as not being constantly bombarded by large asteroids, and having a rotational axis that is fairly stable. This is due in part thanks to the planet Jupiter. The giant planet has helped clear the solar system of asteroid debris and may have helped stabilize the orbits of the inner planets. So life is good. But a new study shows that if Jupiter had a different orbit, life could be even better.

July 31, 2022July 31, 2022 by Brian Koberlein

Planet 9 is Running out of Places to Hide

Illustration of the hypothetical Planet 9. Credit: R. Hurt/IPAC, Caltech

We have a pretty good idea of what lurks within our solar system. We know there isn’t a Mars-sized planet orbiting between Jupiter and Saturn, nor a brown dwarf nemesis heading our way. Anything large and fairly close to the Sun would be easily spotted. But we can’t rule out a smaller, more distant world, such as the hypothetical Planet 9 (or Planet 10 if you want to throw down over Pluto). The odds against such a planet existing are fairly high, and a recent study finds it even less likely.

July 15, 2022July 15, 2022 by Evan Gough

These Ancient Microbes Give a Glimpse of What Extraterrestrial Life Might Look Like

Rhodopsins are ancient proteins evolved by some of Earth's first life forms. They turned sunlight into energy without photosynthesis. Image Credit: Sohail Wasif/University of California, Riverside.

Will we discover simple life somewhere? Maybe on Enceladus or Europa in our Solar System, or further away on an exoplanet? As we get more proficient at exploring our Solar System and studying exoplanets, the prospect of finding some simple life is moving out of the creative realm of science fiction and into concrete mission planning.

As the hopeful day of discovery draws nearer, it’s a good time to ask: what might this potential life look like?

July 15, 2022July 15, 2022 by Nancy Atkinson

JWST Also Looked Inside the Solar System, at Jupiter and its Moons

Jupiter, center, and its moon Europa, left, are seen through the James Webb Space Telescope’s NIRCam instrument 2.12 micron filter. Credits: NASA, ESA, CSA, and B. Holler and J. Stansberry (STScI)

After the ‘big reveal’ earlier this week of the James Webb Space Telescope’s first full color images and spectra of the universe, the science team has now released data from closer to home. One stunning shot includes Jupiter and its moons, and there are also data from several asteroids. These latest data are actually just engineering images, designed to test JWST’s ability to track solar system targets, as well as test out how the team can produce images from the data. The quality and detail in these test images have excited the mission scientists.

July 11, 2022July 11, 2022 by Evan Gough

A Swarm of Swimming Robots to Search for Life Under the Ice on Europa

An artist’s interpretation of liquid water on the surface of the Europa pooling beneath chaos terrain. Credit: : NASA/JPL-Caltech

When Galileo pointed his telescope at Jupiter 400 years ago, he saw three blobs of light around the giant planet, which he at first thought were fixed stars. He kept looking, and eventually, he spotted a fourth blob and noticed the blobs were moving. Galileo’s discovery of objects orbiting something other than Earth—which we call the Galilean moons in his honour—struck a blow to the Ptolemaic (geocentric) worldview of the time.

Galileo couldn’t have foreseen the age of space exploration that we’re living in now. Fast forward 400 years, and here we are. We know the Earth doesn’t occupy any central point. We’ve discovered thousands of other planets, and many of them will have their own moons. Galileo would be amazed at this.

What would he think about robotic missions to explore one of the blobs of light he spotted?