Solar System Archives

January 31, 2023January 31, 2023 by Evan Gough

Don’t Bother Trying to Destroy Rubble Pile Asteroids

Detailed view of the rubble-pile asteroid 25143 Itokawa visited by the Japanese spacecraft Hayabusa in 2005. Credit: JAXA

The asteroids in our Solar System are survivors. They’ve withstood billions of years of collisions. The surviving asteroids are divided into two groups: monolithic asteroids, which are intact chunks of planetesimals, and rubble piles, which are made of up fragments of shattered primordial asteroids.

It turns out there are far more rubble pile asteroids than we thought, and that raises the difficulty of protecting Earth from asteroid strikes.

January 30, 2023February 3, 2023 by Laurence Tognetti

The Outer Solar System Supplied a Surprising Amount of Earth’s Water

Currently exploring the Kuiper Belt, New Horizons is just one of five spacecraft to reach beyond 50 astronomical units, on its way out of the solar system and, eventually, into interstellar space. (Credit: NASA/Johns Hopkins APL/Southwest Research Institute)

In a recent study published in Science, a team of researchers at Imperial College London examined 18 meteorites containing the volatile element zinc to help determine their origin, as it has been long hypothesized that Earth’s volatiles materials, including water, were derived from asteroids closer to our home planet. However, their results potentially indicate a much different origin story.

January 26, 2023January 26, 2023 by Evan Gough

Lucy Adds Another Asteroid to its Flyby List

This artist's illustration shows NASA's Lucy spacecraft close to one of its targets. NASA has added another asteroid, the eleventh, to Lucy's mission. Image Credit: NASA/SWRI/GSFC

In October 2021, NASA launched its ambitious Lucy mission. Its targets are asteroids, two in the main belt and eight Jupiter trojans, which orbit the Sun in the same path as Jupiter. The mission is named after early hominin fossils (Australopithecus afarensis,) and the name pays homage to the idea that asteroids are fossils from the Solar System’s early days of planet formation.

Visiting ten asteroids in one mission is the definition of ambitious, and now NASA is adding an eleventh.

January 4, 2023January 4, 2023 by Evan Gough

How Many Stars Formed Together With the Sun in Our Stellar Nebula?

This is a two-panel mosaic of part of the Taurus Giant Molecular Cloud, the nearest active star-forming region to Earth. The darkest regions are where stars are being born. Inside these vast clouds, complex chemicals are also forming. Image Credit: Adam Block /Steward Observatory/University of Arizona

Even though our Sun is now a solitary star, it still has siblings somewhere in the Milky Way. Stars form in massive clouds of gas called Molecular Clouds. When the Sun formed about five billion years ago, other stars would’ve formed from the same cloud, creating a star cluster.

How many other stars formed in the cluster?

December 15, 2022December 16, 2022 by Evan Gough

Earth’s Water is 4.5 Billion Years Old

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

The origin of Earth’s water has been an enduring mystery. There are different hypotheses and theories explaining how the water got here, and lots of evidence supporting them.

But water is ubiquitous in protoplanetary disks, and water’s origin may not be so mysterious after all.

December 14, 2022December 14, 2022 by Evan Gough

The Oort Cloud Could Have More Rock Than Previously Believed

This artist's concept puts Solar System distances in perspective. The scale bar is in astronomical units, with each set distance beyond 1 AU representing 10 times the previous distance (logarithmic scale.) The image shows Voyager 2's location in 2018. (It also shows where the star Ross 248 will be in 40,000 years, when it will briefly be the closest star to the Sun.) Image Credit: NASA/JPL-Caltech

The Oort Cloud is a collection of icy objects in the furthest reaches of the Solar System. It contains the most distant objects in the Solar System, and instead of orbiting on a plane like the planets or forming a ring like the Kuiper Belt, it’s a vast spherical cloud centred on the Sun. It’s where comets originate, and beyond it is interstellar space.

At least that’s what scientists think; nobody’s ever seen it.

December 13, 2022December 13, 2022 by Evan Gough

Asteroids Didn’t Create the Moon’s Largest Craters. Left-Over Planetesimals Did

The largest impact basin on the Moon is the South-Pole Aitken basin. It, and other impact basins, were created by planetesimals according to a new study. Image Credit: Moriarty et al., 2021.

The Moon’s pock-marked surface tells the story of its history. It’s marked by over 9,000 impact craters, according to the International Astronomical Union (IAU.) The largest ones are called impact basins, not craters. According to a new study, asteroids didn’t create the basins; leftover planetesimals did.

December 9, 2022December 9, 2022 by Carolyn Collins Petersen

Comets Leave Dusty Trails That Surround the Solar System

Could the solar system be enveloped in a shell of faintly glowing dust from comets? Courtesy NASA/ESA/STSci

Comets are messy things. They scatter bits of dust as they travel through the solar system. If Earth happens to encounter one of those cometary dust trails, we get to see a meteor shower.

December 6, 2022December 6, 2022 by Evan Gough

Will We Ever Go Back to Explore the Ice Giants? Yes, If We Keep the Missions Simple and Affordable

Uranus and Neptune are begging to be visited, but expensive missions to visit them may never be approved. Image Credits: (L) By NASA – http://photojournal.jpl.nasa.gov/catalog/PIA18182, Public Domain, https://commons.wikimedia.org/w/index.php?curid=121128532. (R) By Justin Cowart – https://www.flickr.com/photos/132160802@N06/29347980845/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=82476611

It’s been over 35 years since a spacecraft visited Uranus and Neptune. That was Voyager 2, and it only did flybys. Will we ever go back? There are discoveries waiting to be made on these fascinating ice giants and their moons.

But complex missions to Mars and the Moon are eating up budgets and shoving other endeavours aside.

A new paper shows how we can send spacecraft to Uranus and Neptune cheaply and quickly without cutting into Martian and Lunar missions.

November 29, 2022November 29, 2022 by Evan Gough

Baby Gas Giants Cast Shadows on Their Siblings

A computer-generated image depicting a dark protostellar disk seen edge-on at 90 degrees to jets (orange) emanating from the poles of a young star. Such disks are thought to be the precursors of planetary systems, with planets forming as the dust coalesces. RIKEN researchers may have spotted embryos of gas giant planets in one protostellar disk. Credit: Mark Garlick/Science Photo Library

A team of astronomers has caught glimpses of gas giants forming around a very young star.

The nascent giants are having a chilling effect on their potential siblings.