Solar System Archives

May 14, 2024May 14, 2024 by Matt Williams

White Dwarfs are Often Polluted With Heavier Elements. Now We Know Why

In this artist's illustration, lumps of debris from a disrupted planetesimal are irregularly spaced on a long and eccentric orbit around a white dwarf. Credit: Dr Mark Garlick/The University of Warwick

When stars exhaust their hydrogen fuel at the end of their main sequence phase, they undergo core collapse and shed their outer layers in a supernova. Whereas particularly massive stars will collapse and become black holes, stars comparable to our Sun become stellar remnants known as “white dwarfs.” These “dead stars” are extremely compact and dense, having mass comparable to a star but concentrated in a volume about the size of a planet. Despite being prevalent in our galaxy, the chemical makeup of these stellar remnants has puzzled astronomers for years.

For instance, white dwarfs consume nearby objects like comets and planetesimals, causing them to become “polluted” by trace metals and other elements. While this process is not yet well understood, it could be the key to unraveling the metal content and composition (aka. metallicity) of white dwarf stars, potentially leading to discoveries about their dynamics. In a recent paper, a team from the University of Colorado Boulder theorized that the reason white dwarf stars consume neighboring planetesimals could have to do with their formation.

May 8, 2024May 8, 2024 by Evan Gough

What Deadly Venus Can Tell Us About Life on Other Worlds

Earth and Venus. Why are they so different and what do the differences tell us about rocky exoplanet habitability? Image Credit: NASA

Even though Venus and Earth are so-called sister planets, they’re as different as heaven and hell. Earth is a natural paradise where life has persevered under its azure skies despite multiple mass extinctions. On the other hand, Venus is a blistering planet with clouds of sulphuric acid and atmospheric pressure strong enough to squash a human being.

But the sister thing won’t go away because both worlds are about the same mass and radius and are rocky planets next to one another in the inner Solar System. Why are they so different? What do the differences tell us about our search for life?

April 23, 2024April 23, 2024 by Matt Williams

Hubble Has Accidentally Discovered Over a Thousand Asteroids

Illustration of Asteroid (Artist’s Impression). Credit: N. Bartmann (ESA/Webb), ESO/M. Kornmesser and S. Brunier, N. Risinger

The venerable Hubble Space Telescope is like a gift that keeps on giving. Not only is it still making astronomical discoveries after more than thirty years in operation. It is also making discoveries by accident! Thanks to an international team of citizen scientists, with the help of astronomers from the European Space Agency (ESA) and some machine learning algorithms, a new sample of over one thousand asteroids has been identified in Hubble‘s archival data. The methods used represent a new approach for finding objects in decades-old data that could be applied to other datasets as well.

April 18, 2024April 18, 2024 by Allen Versfeld

Are Titan's Dunes Made of Comet Dust?

Two different dune fields on Titan: Belet and Fensal, as imaged by Cassini’s radar. It also shows two similar dune fields on Earth in Rub Al Khali, Saudi Arabia. CREDIT NASA/JPL–Caltech/ASI/ESA and USGS/ESA — Two different dune fields on Titan: Belet and Fensal, as imaged by Cassini’s radar. It also shows two similar dune fields on Earth in Rub Al Khali, Saudi Arabia. Credit: NASA/JPL–Caltech/ASI/ESA and USGS/ESA

A new theory suggests that Titan’s majestic dune fields may have come from outer space. Researchers had always assumed that the sand making up Titan’s dunes was locally made, through erosion or condensed from atmospheric hydrocarbons. But researchers from the University of Colorado want to know: Could it have come from comets?

April 12, 2024April 24, 2024 by Matt Williams

Formation-Flying Spacecraft Could Probe the Solar System for New Physics

A solar flare erupts on the Sun. Credit: NASA/GSFC/SDO

It’s an exciting time for the fields of astronomy, astrophysics, and cosmology. Thanks to cutting-edge observatories, instruments, and new techniques, scientists are getting closer to experimentally verifying theories that remain largely untested. These theories address some of the most pressing questions scientists have about the Universe and the physical laws governing it – like the nature of gravity, Dark Matter, and Dark Energy. For decades, scientists have postulated that either there is additional physics at work or that our predominant cosmological model needs to be revised.

While the investigation into the existence and nature of Dark Matter and Dark Energy is ongoing, there are also attempts to resolve these mysteries with the possible existence of new physics. In a recent paper, a team of NASA researchers proposed how spacecraft could search for evidence of additional physical within our Solar Systems. This search, they argue, would be assisted by the spacecraft flying in a tetrahedral formation and using interferometers. Such a mission could help resolve a cosmological mystery that has eluded scientists for over half a century.

March 27, 2024March 27, 2024 by Matt Williams

DART Changed the Shape of Asteroid Dimorphos, not Just its Orbit

The asteroid Dimorphos was captured by NASA’s DART mission just two seconds before the spacecraft struck its surface on Sept. 26, 2022. Observations of the asteroid before and after impact suggest it is a loosely packed “rubble pile” object. Credit: NASA/JHUAPL

On September 26th, 2022, NASA’s Double Asteroid Redirection Test (DART) collided with the asteroid Dimorphos, a moonlet that orbits the larger asteroid Didymos. The purpose of this test was to evaluate a potential strategy for planetary defense. The demonstration showed that a kinetic impactor could alter the orbit of an asteroid that could potentially impact Earth someday – aka. Potentially Hazardous Asteroid (PHA). According to a new NASA-led study, the DART mission’s impact not only altered the orbit of the asteroid but also its shape!

March 13, 2024March 16, 2024 by Matt Williams

What Can We Learn Flying Through the Plumes at Enceladus?

The Cassini spacecraft captured this image of cryovolcanic plumes erupting from Enceladus' ice-capped ocean. Image Credit: NASA/JPL/CalTech

In the next decade, space agencies will expand the search for extraterrestrial life beyond Mars, where all of our astrobiology efforts are currently focused. This includes the ESA’s JUpiter ICy moon’s Explorer (JUICE) and NASA’s Europa Clipper, which will fly past Europa and Ganymede repeatedly to study their surfaces and interiors. There’s also NASA’s proposed Dragonfly mission that will fly to Titan and study its atmosphere, methane lakes, and the rich organic chemistry happening on its surface. But perhaps the most compelling destination is Enceladus and the lovely plumes emanating from its southern polar region.

Since the Cassini mission got a close-up look at these plumes, scientists have been aching to send a robotic mission there to sample them – which appear to have all the ingredients for life in them. This is not as easy as it sounds, and there’s no indication flying through plumes will yield intact samples. In a recent paper, researchers from the University of Kent examined how the velocity of a passing spacecraft (and the resulting shock of impact) could significantly affect its ability to sample water and ice within the plumes.

March 9, 2024March 17, 2024 by Matt Williams

This Hot Jupiter is Doomed to Crash Into its Star in Just Three Million Years

Artist's impression of the searing-hot gas planet WASP-12b and its star. A Princeton-led team of astrophysicists has shown that this exoplanet is spiraling in toward its host star, heading toward certain destruction in about 3 million years. Credit: NASA/JPL-Caltech

In 2008, astronomers with the SuperWASP survey spotted WASP-12b as it transited in front of its star. At the time, it was part of a new class of exoplanets (“Hot Jupiters”) discovered a little more than a decade before. However, subsequent observations revealed that WASP-12b was the first Hot Jupiter observed that orbits so closely to its parent star that it has become deformed. While several plausible scenarios have been suggested to explain these observations, a widely accepted theory is that the planet is being pulled apart as it slowly falls into its star.

Based on the observed rate of “tidal decay,” astronomers estimate that WASP-12b will fall into its parent star in about ten million years. In a recent study, astronomers with The Asiago Search for Transit Timing Variations of Exoplanets (TASTE) project presented an analysis that combines new spectral data from the Telescopio Nazionale Galileo (TNG) in La Palma with 12 years worth of unpublished transit light curves and archival data. Their results are consistent with previous observations that suggest WASP-12b is rapidly undergoing tidal dissipation and will be consumed by its star.

February 27, 2024February 27, 2024 by Laurence Tognetti

Comets: Why study them? What can they teach us about finding life beyond Earth?

Image of Comet 67P/Churyumov-Gerasimenko taken by the European Space Agency’s (ESA) Rosetta spacecraft on Jan. 31, 2015. There's a jet of material streaming from the comet as it's warmed by the Sun. (Credit: ESA/Rosetta/NAVCAM – CC BY-SA IGO 3.0)

Universe Today has explored the importance of studying impact craters, planetary surfaces, exoplanets, astrobiology, and solar physics, and what this myriad of scientific disciplines can teach scientists and the public regarding the search for life beyond Earth. Here, we will explore some of the most awe-inspiring spectacles within our solar system known as comets, including why researchers study comets, the benefits and challenges, what comets can teach us about finding life beyond Earth, and how upcoming students can pursue studying comets. So, why is it so important to study comets?

February 1, 2024February 3, 2024 by Matt Williams

Asteroid Ryugu Contained Bonus Comet Particles

Asteroid Ryugu, as imaged by the Hayabusa2 spacecraft. The red dot marks the sampling location. Image Credit: JAXA/Hayabusa2

On December 5th, 2020, Japan’s Hayabusa2 mission successfully returned samples it had collected from the Near-Earth Asteroid (NEA) 162173 Ryugu home. Since asteroids are basically leftover material from the formation of the Solar System, analysis of these samples will provide insight into what conditions were like back then. In particular, scientists are interested in determining how organic molecules were delivered throughout the Solar System shortly after its formation (ca. 4.6 billion years ago), possibly offering clues as to how (and where) life emerged.

The samples have already provided a wealth of information, including more than 20 amino acids, vitamin B3 (niacine), and interstellar dust. According to a recent study by a team of Earth scientists from Tohoku University, the Ryugu samples also showed evidence of micrometeoroid impacts that left patches of melted glass and minerals. According to their findings, these micrometeoroids likely came from other comets and contained carbonaceous materials similar to primitive organic matter typically found in ancient cometary dust.