Solar System Archives

December 14, 2023December 14, 2023 by Matt Williams

Voyager 1 Has Another Problem With its Computer System

For more than 46 years, the Voyager 1 probe has been traveling through space. On August 25th, 2012, it became the first spacecraft to cross the heliopause and enter interstellar space. Since then, mission controllers have maintained contact with the probe as part of an extended mission, which will last until the probe’s radioisotopic thermoelectric generators (RTGs) finally run out. Unfortunately, the Voyager 1 probe has been showing its age and signs of wear and tear, which is unavoidable when you’re the farthest spacecraft from Earth.

This includes issues with some of the probe’s subsystems, which have been a bit buggy lately. For instance, engineers at NASA recently announced that they were working to resolve an error with the probe’s flight data system (FDS). This system consists of three onboard computers responsible for communicating with another of Voyager 1’s subsystems, known as the telemetry modulation unit (TMU). As a result, while the spacecraft can receive and execute commands sent from Earth, it cannot send any science or engineering data back.

December 2, 2023December 2, 2023 by Matt Williams

Eris Could be Slushier Than Pluto

Artist’s impression shows the distant dwarf planet Eris. Credit: ESO

In 2005, astronomer Mike Brown and his colleagues Chad Trujillo and David Rabinowitz announced the discovery of a previously unknown planetoid in the Kuiper Belt beyond Neptune’s orbit. The team named this object Eris after the Greek personification of strife and discord, which was assigned by the IAU a year later. Along with Haumea and Makemake, which they similarly observed in 2004 and 2005 (respectively), this object led to the “Great Planet Debate,” which continues to this day. Meanwhile, astronomers have continued to study the Trans-Neptunian region to learn more about these objects.

While subsequent observations have allowed astronomers to get a better idea of Eris’ size and mass, there are many unresolved questions about the structure of this “dwarf planet” and how it compares to Pluto. In a recent study, Mike Brown and University of California Santa Cruz professor Francis Nimmo presented a series of models based on new mass estimates for Eris’ moon Dysnomia. According to their results, Eris is likely differentiated into a convecting icy shell and rocky core, which sets it apart from Pluto’s conductive shell.

November 29, 2023November 29, 2023 by Evan Gough

It Doesn’t Take Much to Get Tilted Planets

Earth's axial tilt (or obliquity) and its relation to the rotation axis and plane of orbit. Credit: Wikipedia Commons

Chinese and Indian astronomers were the first to measure Earth’s axial tilt accurately, and they did it about 3,000 years ago. Their measurements were remarkably accurate: in 1120 BC, Chinese astronomers pegged the Earth’s axial tilt at 24 degrees. Now we know that all of the planets in the Solar System, with the exception of Mercury, have some tilt.

While astronomers have puzzled over why our Solar System’s planets are tilted, it turns out it’s rather normal.

November 28, 2023November 28, 2023 by Mark Thompson

A Tiny Quadcopter Could Gather Rocks for China’s Sample Return Mission

Mars Ingenuity helicopter on the surface of Mars — Image of the Mars Ingenuity helicopter (Source : NASA)

Space exploration is always changing. Before February 2021 there had never been a human made craft flying around in the atmosphere of another world (other than rocket propelled landers arriving or departing). The Mars Perseverance rover changed that, carrying with it what can only be described as a drone named Ingenuity. It revolutionised planetary exploration and now, China are getting in on the act with a proposed quadcopter for a Mars sample return mission.

November 23, 2023November 23, 2023 by Matt Williams

NASA is Getting the Plutonium it Needs for Future Missions

Close-up of NASA’s Perseverance Mars rover as it looks back at its wheel tracks on March 17, 2022, the 381st Martian day, or sol, of the mission. Credit: NASA

Radioisotope Thermoelectric Generators (RTGs) have a long history of service in space exploration. Since the first was tested in space in 1961, RTGs have gone on to be used by 31 NASA missions, including the Apollo Lunar Surface Experiments Packages (ALSEPs) delivered by the Apollo astronauts to the lunar surface. RTGs have also powered the Viking 1 and 2 missions to Mars, the Ulysses mission to the Sun, Galileo mission to Jupiter, and the Pioneer, Voyager, and New Horizons missions to the outer Solar System – which are currently in (or well on their way to) interstellar space.

In recent years, RTGs have allowed the Curiosity and Perseverance rovers to continue the search for evidence of past (and maybe present) life on Mars. In the coming years, these nuclear batteries will power more astrobiology missions, like the Dragonfly mission that will explore Saturn’s largest moon, Titan. In recent years, there has been concern that NASA was running low on Plutonium-238, the key component for RTGs. Luckily, the U.S. Department of Energy (DOE) recently delivered a large shipment of plutonium oxide, putting it on track to realize its goal of regular production of the radioisotopic material.

November 18, 2023November 18, 2023 by Matt Williams

Under Some Conditions, Comets Could Deliver Organic Molecules to Planets

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

Approximately 4.1 to 3.8 billion years ago, the planets of the inner Solar System experienced many impacts from comets and asteroids that originated in the outer Solar System. This is known as the Late Heavy Bombardment (LHB) period when (according to theory) the migration of the giant planets kicked asteroids and comets out of their regular orbits, sending them hurtling towards Mercury, Venus, Earth, and Mars. This bombardment is believed to have distributed water to the inner Solar System and maybe the building blocks of life itself.

According to new research from the University of Cambridge, comets must travel slowly – below 15 km/s (9.32 mi/s) – to deliver organic material onto other planets. Otherwise, the essential molecules would not survive the high speed and temperatures generated by atmospheric entry and impact. As the researchers found, such comets are only likely to occur in tightly bound systems where planets orbit closely to each other. Their results show that these systems would be a good place to look for evidence of life (biosignatures) beyond the Solar System.

October 15, 2023October 16, 2023 by Matt Williams

JWST Observes the Kuiper Belt: Sedna, Gonggong, and Quaoar

Artist's conception of Sedna, the TNO that orbits in the outer edges of the Solar System. Credit: NASA/JPL-Caltech

The Kuiper Belt, the vast region at the edge of our Solar System populated by countless icy objects, is a treasure trove of scientific discoveries. The detection and characterization of Kuiper Belt Objects (KBOs), sometimes referred to as Trans-Neptunian Objects (TNOs), has led to a new understanding of the history of the Solar System. The disposition of KBOs is an indicator of gravitational currents that have shaped the Solar System and reveal a dynamic history of planetary migrations. Since the late 20th century, scientists have been eager to get a closer look at KBOs to learn more about their orbits and composition.

Studying bodies in the outer Solar System is one of the many objectives of the James Webb Space Telescope (JWST). Using data obtained by Webb’s Near-Infrared Spectrometer (NIRSpec), an international team of astronomers observed three dwarf planets in the Kuiper Belt: Sedna, Gonggong, and Quaoar. These observations revealed several interesting things about their respective orbits and composition, including light hydrocarbons and complex organic molecules believed to be the product of methane irradiation.

October 12, 2023October 12, 2023 by Evan Gough

OSIRIS-REx Returned Carbon and Water from Asteroid Bennu

This is the outside of the OSIRIS-REx sample collector. Sample material from asteroid Bennu is on the middle right. There's evidence of carbon and water in the initial analysis of Bennu's regolith. Most of the sample is sealed inside the capsule. Photo: NASA/Erika Blumenfeld & Joseph Aebersold

Carbon and water are so common on Earth that they’re barely worth mentioning. But not if you’re a scientist. They know that carbon and water are life-enabling chemicals and are also links to the larger cosmos.

Initial results from OSIRIS-REx’s Bennu samples show the presence of both in the asteroid’s regolith. Now, eager scientists will begin to piece together how Bennu’s carbon, water, and other molecules fit into the puzzle of the Earth, the Sun, and even the entire Solar System and beyond.

September 28, 2023September 28, 2023 by Matt Williams

If Earth is Average, We Should Find Extraterrestrial Life Within 60 Light-Years

Illustration: Assortment of exoplanets — Astronomers have detected thousands of planets, including dozens that are potentially habitable. (NASA Illustration)

In 1960, while preparing for the first meeting on the Search for Extraterrestrial Intelligence (SETI), legendary astronomer and SETI pioneer Dr. Frank Drake unveiled his probabilistic equation for estimating the number of possible civilizations in our galaxy – aka. The Drake Equation. A key parameter in this equation was n_e, the number of planets in our galaxy capable of supporting life – aka. “habitable.” At the time, astronomers were not yet certain other stars had systems of planets. But thanks to missions like Kepler, 5523 exoplanets have been confirmed, and another 9,867 await confirmation!

Based on this data, astronomers have produced various estimates for the number of habitable planets in our galaxy – at least 100 billion, according to one estimate! In a recent study, Professor Piero Madau introduced a mathematical framework for calculating the population of habitable planets within 100 parsecs (326 light-years) of our Sun. Assuming Earth and the Solar System are representative of the norm, Madau calculated that this volume of space could contain as much as 11,000 Earth-sized terrestrial (aka. rocky) exoplanets that orbit within their stars’ habitable zones (HZs).

September 24, 2023September 24, 2023 by Matt Williams

The OSIRIS-REx Capsule Has Landed! Asteroid Samples Returned!

The sample return capsule from NASA’s OSIRIS-REx mission is seen shortly after touching down in the desert, Sunday, Sept. 24, 2023. Credit: NASA

The OSIRIS-REx mission has just completed NASA’s first sample-return mission from a near-Earth asteroid (NEA). The samples arrived at the Utah Test and Training Range (UTTR) near Salt Lake City, where a team of engineers arrived by helicopter to retrieve the sample capsule. The samples will be curated by NASA’s Astromaterials Research and Exploration Science Directorate (ARES) and Japan’s Extraterrestrial Sample Curation Center (ESCuC). Analysis of the rocks and dust obtained from Bennu is expected to provide new insight into the formation and evolution of the Solar System.