You're 3 billion years too late to see Mars' impressive ring system. The next one will be along in 40 million years or so

Astroboffins say Deimos's wonky orbit suggests slow-burning ring-moon cycle


Like the gas giants in the outer region of the Solar System, Mars may have been circled by a ring of debris over three billion years ago.

Astronomers from the SETI Institute and Purdue University have spotted tantalizing signs that the red, rocky planet once supported a ring system. The clues lie in its two potato-shaped moons, Deimos and Phobos.

"The fact that Deimos's orbit is not exactly in plane with Mars's equator was considered unimportant, and nobody cared to try to explain it," said Matija Ćuk, a research scientist at the SETI Institute and lead author of the research accepted at the Astrophysical Journal Letters. "But once we had a big new idea and we looked at it with new eyes, Deimos's orbital tilt revealed its big secret."

The paper is being presented at the virtual 236th Meeting of the American Astronomical Society this week.

Deimos, with a radius of just 6.2km, has a small orbital tilt of two degrees. Ćuk believes that its motion can be explained by a historic orbital resonance encounter that nudged it into a more distant and slightly wonkier orbit. Under this scenario, Mars is encircled by a ring, Deimos is being pushed into a further orbit and there's a third moon that lies beyond the ring.

The gravitational interactions between Deimos and the Martian ring system makes the satellite drift further away from its parent planet until it enters a 3:1 orbital ratio with the mystery moon. Deimos's orbit aligns with the mystery moon's three times as the more distant satellite completes one orbit.

Each time Deimos nears its neighbour, the third moon exerts a small gravitational kick that tilted Deimos's orbit. In order for this to happen, however, Mars had to have a ring of debris that was pushing Deimos out in the first place.

There's a second bit of evidence for Mars' ancient ring too. Phobos's orbit is being dragged downwards by the red planet's gravitational field. Over time, it'll drop so much that it will be ripped apart by tidal forces and all the leftover fragments will litter the Martian environment. No one is quite sure when that will happen. The best estimate is in about 40 million years or so, we're told.

Mars will capture the individual pieces and the debris will form a ring that orbits the planet. The researchers believe that the process is cyclical; larger chunks of rock will lead to a new, smaller moon that will in turn be pulled apart to create a new ring and so on and so forth.

"Since Phobos and Deimos have orbits close to the plane of Mars's equator, we think they must have formed from a flat ring and disk at some point," Ćuk told The Register. "Past work by my coauthor Dave Minton from Purdue proposed that Phobos is the latest product of the ring-moon cycle at Mars that happened several times and will happen again.

"Other people thought that Mars had a ring only at the very beginning – when the moons formed – and [will] never [have one] again. My result that a larger inner moon of Mars was moving outward requires that there was a ring and that Phobos had a larger precursor, and so I basically confirmed Dave's theory."

They hope to test their theory over the next few years. Japan's space agency, JAXA, plans to launch a spacecraft to Phobos in 2024 and bring samples back from the moon's surface. "I do theoretical calculations for a living, and they are good, but getting them tested against the real world now and then is even better," he concluded. ®

Similar topics


Other stories you might like

  • Google keeps legacy G Suite alive and free for personal use
    Phew!

    Google has quietly dropped its demand that users of its free G Suite legacy edition cough up to continue enjoying custom email domains and cloudy productivity tools.

    This story starts in 2006 with the launch of “Google Apps for Your Domain”, a bundle of services that included email, a calendar, Google Talk, and a website building tool. Beta users were offered the service at no cost, complete with the ability to use a custom domain if users let Google handle their MX record.

    The service evolved over the years and added more services, and in 2020 Google rebranded its online productivity offering as “Workspace”. Beta users got most of the updated offerings at no cost.

    Continue reading
  • GNU Compiler Collection adds support for China's LoongArch CPU family
    MIPS...ish is on the march in the Middle Kingdom

    Version 12.1 of the GNU Compiler Collection (GCC) was released this month, and among its many changes is support for China's LoongArch processor architecture.

    The announcement of the release is here; the LoongArch port was accepted as recently as March.

    China's Academy of Sciences developed a family of MIPS-compatible microprocessors in the early 2000s. In 2010 the tech was spun out into a company callled Loongson Technology which today markets silicon under the brand "Godson". The company bills itself as working to develop technology that secures China and underpins its ability to innovate, a reflection of Beijing's believe that home-grown CPU architectures are critical to the nation's future.

    Continue reading
  • China’s COVID lockdowns bite e-commerce players
    CEO of e-tail market leader JD perhaps boldly points out wider economic impact of zero-virus stance

    The CEO of China’s top e-commerce company, JD, has pointed out the economic impact of China’s current COVID-19 lockdowns - and the news is not good.

    Speaking on the company’s Q1 2022 earnings call, JD Retail CEO Lei Xu said that the first two years of the COVID-19 pandemic had brought positive effects for many Chinese e-tailers as buyer behaviour shifted to online purchases.

    But Lei said the current lengthy and strict lockdowns in Shanghai and Beijing, plus shorter restrictions in other large cities, have started to bite all online businesses as well as their real-world counterparts.

    Continue reading
  • Foxconn forms JV to build chip fab in Malaysia
    Can't say when, where, nor price tag. Has promised 40k wafers a month at between 28nm and 40nm

    Taiwanese contract manufacturer to the stars Foxconn is to build a chip fabrication plant in Malaysia.

    The planned factory will emit 12-inch wafers, with process nodes ranging from 28 to 40nm, and will have a capacity of 40,000 wafers a month. By way of comparison, semiconductor-centric analyst house IC Insights rates global wafer capacity at 21 million a month, and Taiwanese TSMC’s four “gigafabs” can each crank out 250,000 wafers a month.

    In terms of production volume and technology, this Malaysian facility will not therefore catapult Foxconn into the ranks of leading chipmakers.

    Continue reading
  • NASA's InSight doomed as Mars dust coats solar panels
    The little lander that couldn't (any longer)

    The Martian InSight lander will no longer be able to function within months as dust continues to pile up on its solar panels, starving it of energy, NASA reported on Tuesday.

    Launched from Earth in 2018, the six-metre-wide machine's mission was sent to study the Red Planet below its surface. InSight is armed with a range of instruments, including a robotic arm, seismometer, and a soil temperature sensor. Astronomers figured the data would help them understand how the rocky cores of planets in the Solar System formed and evolved over time.

    "InSight has transformed our understanding of the interiors of rocky planets and set the stage for future missions," Lori Glaze, director of NASA's Planetary Science Division, said in a statement. "We can apply what we've learned about Mars' inner structure to Earth, the Moon, Venus, and even rocky planets in other solar systems."

    Continue reading
  • The ‘substantial contributions’ Intel has promised to boost RISC-V adoption
    With the benefit of maybe revitalizing the x86 giant’s foundry business

    Analysis Here's something that would have seemed outlandish only a few years ago: to help fuel Intel's future growth, the x86 giant has vowed to do what it can to make the open-source RISC-V ISA worthy of widespread adoption.

    In a presentation, an Intel representative shared some details of how the chipmaker plans to contribute to RISC-V as part of its bet that the instruction set architecture will fuel growth for its revitalized contract chip manufacturing business.

    While Intel invested in RISC-V chip designer SiFive in 2018, the semiconductor titan's intentions with RISC-V evolved last year when it revealed that the contract manufacturing business key to its comeback, Intel Foundry Services, would be willing to make chips compatible with x86, Arm, and RISC-V ISAs. The chipmaker then announced in February it joined RISC-V International, the ISA's governing body, and launched a $1 billion innovation fund that will support chip designers, including those making RISC-V components.

    Continue reading

Biting the hand that feeds IT © 1998–2022