This week in science: Cassini's last dive and Ig Nobel Prize

This week in science is a review of the most interesting scientific news of the past week.

Farewell Cassini

As previously announced by NASA, the Cassini spacecraft finally entered Saturn’s atmosphere last Friday, September 15. At about 7:55 a.m. EDT, Cassini's last radio signals were detected here on Earth, confirming the spacecraft's expected demise by burning up after descending into the planet’s atmosphere at more than 76,000 mph (122,000 km/h).

Cassini was an international project that cost $3.9 billion and traveled 4.9 billion miles (7.9 billion kilometers) since its launch 20 years ago, in 1997. It finally arrived at Saturn back in 2004, also taking with it the module Huygens, which landed on Titan, one of Saturn’s 62 moons, in 2005. During its mission, Cassini orbited Saturn nearly 300 times, collected more than 453,000 images and 635 gigabytes of scientific data. As stated by Earl Maize, the program manager:

This has been an incredible mission, an incredible spacecraft and you're all an incredible team. I'm going to call this the end of mission.

Cassini’s Grand Finale, as called by NASA, was expected because the spacecraft was finally running out of fuel. To begin its 22 final orbits between Saturn and its rings, Cassini even took advantage of Titan’s massive gravitational push while passing close to it to gain momentum. Last Tuesday, the spacecraft had its last flyby of Titan, which mission engineers called "the goodbye kiss".

Finally, the well-planned demise of Cassini was a choice to prevent any damage to Saturn's ocean-bearing moons Titan and Enceladus. Those moons may contain some form of life and scientists wanted to keep them pristine for future exploration.

Source: Phys.org

This year's recipients of the Ig Nobel Prize

The Ig Nobel Prize is a parody of the Nobel Prize and awards scientists for the ten most unusual or trivial achievements in scientific research. It has been awarded since 1991 to “honor achievements that first make people laugh, and then make them think”.

The award ceremony took place at Harvard University last Thursday and featured real Nobel laureates presenting the ten prizes. Besides the honor, each Ig Nobel laureate received $10 trillion in virtually worthless Zimbabwean money.

The 2017 Ig Nobel Prize winners are:

• Physics Prize — Marc-Antoine Fardin, for using fluid dynamics to probe the question "Can a Cat Be Both a Solid and a Liquid?". Reference: "On the Rheology of Cats".
• Peace Prize — Milo Puhan, Alex Suarez, Christian Lo Cascio, Alfred Zahn, Markus Heitz, and Otto Braendli, for demonstrating that regular playing of a didgeridoo is an effective treatment for obstructive sleep apnea and snoring. Reference: "Didgeridoo Playing as Alternative Treatment for Obstructive Sleep Apnoea Syndrome: Randomised Controlled Trial".
• Economics Prize — Matthew Rockloff and Nancy Greer, for their experiments to see how contact with a live crocodile affects a person's willingness to gamble. Reference: "Never Smile at a Crocodile: Betting on Electronic Gaming Machines is Intensified by Reptile-Induced Arousal".
• Anatomy Prize — James Heathcote, for his medical research study "Why Do Old Men Have Big Ears?". Reference: "Why Do Old Men Have Big Ears?".
• Biology Prize — Kazunori Yoshizawa, Rodrigo Ferreira, Yoshitaka Kamimura, and Charles Lienhard, for their discovery of a female penis, and a male vagina, in a cave insect. Reference: "Female Penis, Male Vagina and Their Correlated Evolution in a Cave Insect".
• Fluid Dynamics Prize — Jiwon Han, for studying the dynamics of liquid-sloshing, to learn what happens when a person walks backwards while carrying a cup of coffee. Reference: "A Study on the Coffee Spilling Phenomena in the Low Impulse Regime".
• Nutrition Prize — Fernanda Ito, Enrico Bernard, and Rodrigo Torres, for the first scientific report of human blood in the diet of the hairy-legged vampire bat. Reference: "What is for Dinner? First Report of Human Blood in the Diet of the Hairy-Legged Vampire Bat Diphylla ecaudata".
• Medicine Prize — Jean-Pierre Royet, David Meunier, Nicolas Torquet, Anne-Marie Mouly and Tao Jiang, for using advanced brain-scanning technology to measure the extent to which some people are disgusted by cheese. Reference: "The Neural Bases of Disgust for Cheese: An fMRI Study".
• Cognition Prize — Matteo Martini, Ilaria Bufalari, Maria Antonietta Stazi, and Salvatore Maria Aglioti, for demonstrating that many identical twins cannot tell themselves apart visually. Reference: "Is That Me or My Twin? Lack of Self-Face Recognition Advantage in Identical Twins".
• Obstetrics Prize — Marisa López-Teijón, Álex García-Faura, Alberto Prats-Galino, and Luis Pallarés Aniorte, for showing that a developing human fetus responds more strongly to music that is played electromechanically inside the mother's vagina than to music that is played electromechanically on the mother's belly. References: "Fetal Facial Expression in Response to Intravaginal Music Emission" and "Fetal Acoustic Stimulation Device" (patent).

Finally, one should never forget that receieving an Ig Nobel Prize does not disqualify in any way a scientist. For example, Andre Geim was awarded the 2010 Nobel Prize in Physics, jointly with Novoselov, "for groundbreaking experiments regarding the two-dimensional material graphene". Ten years earlier, he also received an Ig Nobel Prize, this time with Michael Berry, for magnetically levitating a live frog.

Source: Improbable Research via Phys.org

To round off our weekly science wrap up, scientists have found that about one million Facebook accounts are enrolled in "collusion networks" run by spammers, which generated as many as 100 million fake "likes" between 2015 and 2016. Those networks are based on more than 50 websites that offer free, fake "likes" for user's posts in exchange for access to their accounts.