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Saturne perd ses anneaux | ICI.Radio-Canada.ca

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Les anneaux de glace d’eau poussiéreuse de Saturne se vident peu à peu sous l’effet de la gravité et du champ magnétique de cette planète géante gazeuse, confirment de récentes analyses d’astrophysiciens de la NASA.

L’astronome James O’Donoghue et ses collègues en viennent à cette constatation après avoir analysé des informations obtenues depuis quelques années par la sonde Cassini et des télescopes terrestres.

Illustration de la sonde Cassini et des anneaux de Saturne.Illustration de la sonde Cassini et des anneaux de Saturne Photo : NASA/JPL-Caltech

En fait, les données recueillies par les sondes Voyager 1 et 2 au début des années 1980 avaient permis d’établir que des « pluies » d’eau glacée tombaient des anneaux vers la planète.

Image de Saturne captée le 18 octobre 1980 par la sonde Voyager 1.Image de Saturne captée le 18 octobre 1980 par la sonde Voyager 1. Photo : NASA/JPL-Caltech

Les présents travaux confirment que les anneaux emblématiques de la sixième planète du système solaire se vident de leur matière au rythme le plus rapide estimé dans les divers scénarios envisagés à l’époque.

Nous estimons que cette ”pluie annulaire” draine une quantité d’eau qui pourrait remplir une piscine olympique toutes les demi-heures.

James O’Donoghue

Cela représente jusqu’à 10 000 kg de matière provenant des anneaux qui prend la direction de l’atmosphère de Saturne chaque seconde.

Le saviez-vous?

  • Les anneaux de Saturne furent découverts en 1610 par Galilée. C’est toutefois l’astronome néerlandais Christiaan Huygens qui, en 1656, comprit le premier que les anneaux étaient séparés du corps de la planète.
  • L’Union astronomique internationale recense sept anneaux principaux désignés par une lettre majuscule selon un ordre alphabétique qui correspond à l’ordre chronologique de leurs découvertes. Les derniers anneaux découverts sont désignés par un nom de code (année-planète-numéro de découverte) en attendant de recevoir un nom de baptême.
  • Le système d’anneaux est composé de millions de blocs de glace et de roches glacées d’une taille variant de 1 centimètre à 10 mètres. Certains astronomes affirment que ses anneaux se seraient formés lors d’une collision avec une énorme lune de la taille de Titan.

Une disparition annoncée

Les chercheurs estimaient à partir des données des sondes Voyager que l’entièreté du système d’anneaux de Saturne aurait disparu dans 300 millions d’années.

Mais les récentes analyses réalisées par la sonde Cassini, qui a passé plus de 13 ans à étudier la planète, ses lunes et ses anneaux, laissent maintenant à penser que le système d’anneaux aura disparu dans moins de 100 millions d’années.

Cela représente une disparition relativement rapide considérant que l’âge de la planète avoisine les 4 milliards d’années.

Ces structures circulaires n’ont pas toujours existé. Elles se seraient formées il y a « à peine » 100 millions d’années, selon les astrophysiciens.

La sonde Cassini survolant l'hémisphère Nord de Saturne.La sonde Cassini survolant l’hémisphère Nord de Saturne. Photo : NASA/JPL-Caltech

Les phénomènes en présence

Le rayonnement ultraviolet du Soleil et le contact du plasma produit par les collisions entre les microastéroïdes chargent électriquement les poussières de glace qui composent majoritairement les anneaux. Elles sont alors captées par le champ magnétique de Saturne, et son champ gravitationnel les ramène vers elle. Elles terminent leurs courses vaporisées dans l’atmosphère.

Nous sommes chanceux de pouvoir observer le système d’anneaux de Saturne qui semble être en milieu de vie. Si les anneaux sont temporaires, peut-être que nous avons manqué des systèmes d’anneaux géants autour de Jupiter, Uranus et Neptune, qui n’ont plus que de petits anneaux ténus de nos jours.

James O’Donoghue

Le détail de ces travaux est publié dans la revue Icarus (en anglais)

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Canadian tech diversity and inclusion in the spotlight

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Diversity and inclusion are hot-button issues, but for all the attention they get, there’s still work to be done in the tech sector, according to a recent Gartner blog.

Citing a range of challenges that include pay inequity, lack of diversity in corporate management, and difficulty recruiting diverse talent, the blog suggests three possible remedies for organizations trying to become more diverse and inclusive: having a long-term plan but focusing on one aspect that will make the most benefit, setting targets and making leadership accountable, and committing resources.

The call for such strategies finds support in a report from the Brookfield Institute revealing that Canada’s technology sector has a disappointing track record when it comes to inclusion and equity, with women “four times less likely to be employed in the sector than men, and earning on average $7,300 less than men in technology jobs.”

The findings are just as grim in a January 2020 report funded by Canada’s Future Skills Centre. According to this document, despite corporate commitments to diversity, “decades of initiatives designed to advance women in technology have scarcely had an effect: The proportion of women in engineering and computer science in Canada has changed little in 25 years.”

And women are not the only disadvantaged group, says the report. “The under-employment of skilled immigrants and under-representation of women and other groups in the ICT industry suggests that recruitment and retention policies and practices of the very firms complaining about this [skills] gap may be contributing to the problem.”

Until we do a better job of addressing inclusion and diversity, career opportunities will continue to be limited for women, internationally educated professionals, racialized minorities, First Nations, Inuit and Métis people. In addition to being a very human issue, this is also one that perpetuates the ICT skills gap by failing to tap into a supply of well-qualified labour.

On the bright side, there are technology companies and organizations across Canada that are truly determined to create opportunities for those who are under-represented in the digital talent pool. There is also an opportunity to recognize their efforts during Channel Innovation 2021: Adapting to the New Customer Experience, a 2.5-hour, virtual event on April 28, 2021.

A showcase for independent software vendors (ISVs) and Canadian channel innovators, the Channel Innovation 2021 celebration will take place on CIA-TV, a unique ITWC platform that allows the audience to take in the show, download related content and videos, and network in live breakout rooms. There are six award categories, including the C4 Award for Diversity and Inclusion. Nominating is simple. Whether a self- or third-party nomination, there are only two main questions to answer and an opportunity to include a supporting document or image.

Winning entries will be announced during the celebration and profiled in the Channel Daily News Magazine and in Direction Informatique, ITWC’s French-language publication devoted to the Quebec marketplace. They will also receive a digital badge for use on their websites and on social media to help gain industry-wide recognition and end-user exposure.

The media attention and recognition are reason enough to vie for this honour, and we always need things to celebrate during a global pandemic, but the real value in awards for diversity and inclusion is in setting an example for others to follow. The news is full of the ways we are falling down when it comes to equity in the IT sector. Let’s take some time to highlight the success stories and encourage other tech innovators to step up.

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Leading Canadian tech entrepreneur Saadia Muzaffar to give virtual keynote in Peterborough on March 9

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In celebration of International Women’s Day, one of Canada’s leading female tech entrepreneurs will be giving a virtual keynote for residents of Peterborough and the Kawarthas on Tuesday, March 9th at 7 p.m.

The Innovation Cluster is hosting Saadia Muzaffar as part of its ‘Electric City Talks’ series.

Muzaffar is a tech entrepreneur, author, and passionate advocate of responsible innovation, decent work for everyone, and prosperity of immigrant talent in science, technology, engineering, and mathematics (STEM). She is the founder of TechGirls Canada, a hub for Canadian women in STEM, and co-founder of Tech Reset Canada, a group of business people, technologists, and other residents advocating for innovation that is focused on the public good.

In 2017, Muzaffar was featured in Canada 150 Women, a book about 150 of the most influential and groundbreaking women in Canada. Her work has been featured in CNNMoney, BBC World, Fortune Magazine, The Globe and Mail, VICE, CBC, TVO, and Chatelaine.

Muzaffar’s March 9th talk, entitled ‘Redefining Term Sheets: Success, Solidarity, & The Future We Want’, will inspire women to achieve success in all areas of life, including in business by providing strategies for obtaining funding.

“It is impossible to explain how women only get 2.2 per cent of funding for their ventures while we constitute a majority of the population, without acknowledging long-standing structural and systemic bias,” Muzaffar says, describing her talk. “Women know these odds in our bones because we feel them in too many boardrooms, banks, media advertisements, and venture competitions — yet women are the fastest-growing demographic in new businesses.”

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ARK’s Cathie Wood joins board of Canadian tech firm mimik

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ARK Invest’s Cathie Wood is joining the board of Canadian technology company mimik.

Vancouver-based mimik is an edge computing company that effectively turns devices like phones into private cloud servers. It has already teamed up with Amazon Web Services and IBM on edge computing – two of the bigger players in the space.

The AWS partnership gives software developers access to mimik’s cloud platform. Together, edge devices including smart phones, tablets, and Internet of Things (IoT) products can act as extensions of the AWS cloud. With the IBM partnership, mimik’s technology will be included in automation and digital transformation across manufacturing, retail, IoT and healthcare.

All of mimik’s business lines fit in with Wood’s broad ‘next generation internet’ thesis, one of her big five investment themes. The company itself is private and Wood is not an investor. 

However, as Citywire noted in January, Wood has hinted in interviews that ARK is exploring the launch of a private markets strategy. 

Wood joins a relatively high profile board at mimik. Other members include  Allen Salmasi, a pioneer in mobile technology who was previously with Qualcomm, and Ori Sasson, managing director of Primera Capital, who was an investor in VMWare and other technology companies.

‘I’ve always believed in backing founders who are at the forefront of innovation,’ Wood said in a statement on her decision to join mimik. ‘At mimik, [they] have built a foundation for the next generation of cloud computing.’ 

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