Solar System Archives

October 12, 2021October 12, 2021 by Evan Gough

Greenland’s Ice Sheet is Similar in Many Ways to the Solar System’s Icy Worlds and Can Teach Us How to Search for Life

Floating ice at the calving front of Greenland's Kangerdlugssuaq glacier, photographed in 2011 during Operation IceBridge (Credit: NASA/Michael Studinger)

Many regions on Earth are temperate, nutrient-rich, stable environments where life seems to thrive effortlessly. But not all of Earth. Some parts, like Greenland’s ice sheet, are inhospitable.

In our nascent search for life elsewhere in the Solar System, it stands to reason that we’ll be looking at worlds that are marginal and inhospitable. Icy worlds like Jupiter’s moon Europa and Saturn’s moon Enceladus are our most likely targets. These frozen worlds have warm oceans under layers of ice.

What can Greenland’s cryo-ecosystems tell us about searching for life on icy bodies like Europa and Enceladus?

September 30, 2021September 30, 2021 by Evan Gough

BepiColombo Meets Mercury for the First Time on October 1

New research suggests that Mercury is still contracting and shrinking. Credits: NASA/JHUAPL/Carnegie Institution of Washington/USGS/Arizona State University

BepiColombo made a quick visit to Venus in August and is on to its next rendezvous. On October 1st it’ll perform a flyby of Mercury, the spacecraft’s eventual destination. This visit is just a little flirtation—one of six—ahead of its eventual orbital link-up with Mercury in late 2025.

The quick visit will yield some scientific results, though, and they’ll be just a taste of what’s ahead in BepiColumbo’s one-year mission to Mercury.

September 28, 2021September 28, 2021 by Evan Gough

The Early Solar System was Messier and More Violent Than Previously Believed

This artwork shows a rocky planet being bombarded by comets. Image credit: NASA/JPL-Caltech

Our conventional models of planet formation may have to be updated, according to a pair of new papers.

Accretion is the keyword in current planet formation theory. The idea is that the planets formed out of the solar nebula, the material left over after the Sun formed. They did this through accretion, where small particles accumulate into more massive objects. These massive boulder-sized objects, called planetesimals, continued to merge together into larger entities, sometimes through collisions. Eventually, through repeated mergers and collisions, the inner Solar System was populated by four rocky planets.

But the new research suggests that the collisions played out much differently than thought and that objects collided with each other several times, in a series of hit and runs, before merging. This research fills some stubborn holes in our current understanding.

September 27, 2021September 27, 2021 by Evan Gough

What Happens to Interstellar Objects Captured by the Solar System?

An artist’s overview of the mission concept for the Comet Interceptor spacecraft. Credit: ESA

Now that we know that interstellar objects (ISOs) visit our Solar System, scientists are keen to understand them better. How could they be captured? If they’re captured, what happens to them? How many of them might be in our Solar System?

One team of researchers is trying to find answers.

September 23, 2021September 23, 2021 by Andy Tomaswick

A Proposed Clockwork Solar System Made out of LEGO

One of the best innovations Lego has had in the last decade is leveraging the power of the internet to help choose what kits to create. Innovative designers can buy piece parts, make their own masterpieces, carefully document how to recreate them, and then lobby Lego to release them at a kit. One of the more creative recent projects is a Clockwork Solar System designed by Chris Orchard and Brent Waller, and it is absolutely stunning.

September 20, 2021September 20, 2021 by Evan Gough

The Moon was Pummeled Even Harder by Asteroids Than it Looks

We intend to explore the Moon, use its resources, and use it as a jumping-off point for missions deeper into the Solar System. For that we need a Lunar GPS. Image Credit: NASA

The Moon’s pitted surface tells a tale of repeated impacts over a long period of time. While Earth’s active geology erases most evidence of impacts, the Moon has no mechanism that can do the same. So there it sits, stark evidence of an impact-rich past.

The visible record of lunar cratering is used to understand Earth’s formation and history since periods of frequent impacts would affect both bodies similarly. But something’s wrong in our understanding of the Moon’s history. Impact crater dating, asteroid dynamics, lunar samples, impact basin-forming simulations, and lunar evolution modelling all suggest there’s some missing evidence from the Moon’s earliest impacts.

New research says that there were even more large, basin-forming impacts than we think. Scientists think that some of those impacts left crater imprints that are nearly invisible.

September 15, 2021September 15, 2021 by Matt Williams

A 6-Year Search of the Outer Solar System Turns up 461 new Objects (but no Planet 9)

Artist's concept of the New Horizons spacecraft encountering a Kuiper Belt object, part of an extended mission after the spacecraft’s July 2015 Pluto flyby. Credits: NASA/JHUAPL/SwRI

In the near future, astronomers will benefit from the presence of next-generation telescopes like the James Webb Space Telescope (JWST) and the Nancy Grace Roman Space Telescope (RST). At the same time, improved data mining and machine learning techniques will also allow astronomers to get more out of existing instruments. In the process, they hope to finally answer some of the most burning questions about the cosmos.

For instance, the Dark Energy Survey (DES ), an international, collaborative effort to map the cosmos, recently released the results of their six-year survey of the outer Solar System. In addition to gathering data on hundreds of known objects, this survey revealed 461 previously undetected objects. The results of this study could have significant implications for our understanding of the Solar System’s formation and evolution.

September 10, 2021September 10, 2021 by Evan Gough

Why are Rubble Pile Asteroids Shaped Like Diamonds?

The asteroid Bennu from a distance of 24 km (15) miles captured by the PolyCam on OSIRIS-REx. The spacecraft has detected water on Bennu. On the bottom right in the termination line is the large boulder. The image is a mosaic constructed of 12 images. Image Credit: NASA/Goddard/University of Arizona.

Scientists are fortunate enough to have detailed, close-up views of the near-Earth asteroids Bennu and Ryugu. Both asteroids have a diamond shape, for some reason. Why? Up until now, it’s been a puzzle.

Now a team of scientists has tackled the question and may have come up with the answer.

September 10, 2021September 10, 2021 by Paul M. Sutter

There Should be More Material Left Over From Bombardment Eras. Maybe the Sun Blew it all Away?

The early solar system was an especially violent place. The terrestrial planets (Mercury, Venus, Earth, and Mars) likely formed by suffering countless collisions between planetesimals. But the material left over from all those collisions should have remained in orbit around the sun, where it would’ve eventually found itself in the asteroid belt. But the belt contains no such record of that process.

September 9, 2021September 9, 2021 by Evan Gough

Protoplanetary Disks Throw Out More Material Than Gets Turned Into Planets

A protosolar disk is the disk of material around a young stellar object that isn't yet a star. It's called a protoplanetary disk once the star has formed and begun fusion. Planetesimals are the building blocks of planets and are present in both stages of a disk's evolution. Image Credit: NASA/JPL

When a young solar system gets going it’s little more than a young star and a rotating disk of debris. Accepted thinking says that the swirling debris is swept up in planet formation. But a new study says that much of the matter in the disk could face a different fate.

It may not have the honour of becoming part of a nice stable planet, orbiting placidly and reliably around its host star. Instead, it’s simply discarded. It’s ejected out of the young, still-forming solar system to spend its existence as interstellar objects or as rogue planets.