Canadian astronaut Chris Hadfield departed the International Space Station (ISS), landing on Tuesday with Tom Marshburn (USA) and Roman Romanenkoin (Russia) in Kazakhstan in a Soyuz capsule.

Hadfield’s rendition of David Bowie’s Space Oddity, recorded on board the ISS.

On Saturday, astronauts Chris Cassidy and Tom Marshburn performed a spacewalk to investigate and repair a potential ammonia leak on the ISS.

Chris Hadfield’s scientific efforts during his ISS mission.

A closer look at Hadfield’s popularity abord the ISS. In case you missed it, here’s his much-watched washcloth.

Still image from Google’s animated doodle for Earth Day 2013.

Monday was Earth Day! Google celebrated with an elaborate doodle. But according to Phil Plait, they got a few astronomical details wrong…

With all the debate over what is and what isn’t being taught in public school science classrooms, it’s a refreshing change to see a proposed bill to mandate the inclusion of science fiction in West Virginia middle and high school curriculums. Ray Canterbury, a legislator from the West Virginia House of Delegates, proposed the bill; he stated in an interview with Blastr that  “I’m not interested in fantasy novels about dragons, I’m primarily interested in things where advanced technology is a key component of the storyline, both in terms of the problems that it presents and the solutions that it offers.”

A new study in BJOG suggests that light drinking by pregnant women—meaning 1 or 2 drinks a week—was not harmful to their unborn children. While the links between fetal alcohol syndrome and drinking during pregnancy are clear, studies over the last few years have investigated the safety of occasional drinking, and led to discussions about mothers‘ choices during pregnancy.

An independent journalist is suing the University of Central Florida for access to records related to the publication of the debut analysis of the “New Family Structures Study” in Social Science Research last year. The journal has been criticized for the speedy publication (and timeliness) of Mark Regnerus’ paper, as well as its methodology and the political motivation of the project’s funders. Regnerus, an associate professor at the University of Texas, commented on the study’s results for Slate last year.

Publicity? A media frenzy? An interview on the Colbert Report? Most grad students don’t expect to get famous from coursework assignments, but University of Massachusetts Amherst economics Ph.D. student Thomas Herndon’s unsuccessful attempt to replicate the results of the prominent Reinhart-Rogoff “Growth in a Time of Debt” study revealed a simple coding error in the original Excel spreadsheet, leading to a publication with his professors, Michael Ash and Robert Pollin.

It’s a women’s magazine headline! No, it’s a stand-up routine! No, it’s a recent study in PLOS ONE: men can’t read women’s emotions.

Changes in the upcoming 5th edition of the DSM (Diagnostic and Statistical Manual of Mental Disorders) have been in the news this week. The best simile’s from Slate: “If we think of having a diagnosable mental illness as being under a tent, the tent seems pretty big. Huge, in fact.”

In light of the recent measles epidemic in the UK, Andrew Wakefield blames the government in a statement for The Independent. The paper quickly followed up with a damning article, with critics calling the whole episode “lunacy.”

The US Supreme Court is debating whether human genes can be patented, as Myriad Genetics defends their patents on breast cancer susceptibility genes BRCA1 and BRCA2. It may all come down to “snipping.”

I’m back from a 2-week hiatus in Quebec, where it’s still freezing. Thanks to Mike for his great job filling in last week.

Canadian scientists determined that Monarch butterflies migrate to Mexico using a built-in solar-calibrated compass, and not a “true” navigation system with positional awareness. Bonus points to CBC News author Emily Chung for including researchers’ “experimental bumps,” including uncooperative butterflies who wouldn’t migrate within the flight simulator, showcasing how the course of an experiment isn’t always smooth.  The research is forthcoming in PNAS.

Sheila Jasanoff raises questions about the accountability (and lack thereof) of science advisers in the fourth article of The Guardian’s series on science advice (read parts 1, 2, and 3).

Will Oremus at Slate reminds us that Margaret Thatcher was really a “climate hawk”: she promoted responsible, sustainable economic development and was one of the earliest world leaders who spoke about the danger of global warming.

Here’s an amazing time-lapse video from Scott Lawson’s YouTube channel demonstrating magnetism with iron oxide-infused Silly Putty. Phil Plait at Bad Astronomy explains the properties at work, as well as why science needs more cool stuff like this.

Looking for some easy money? Creationist Joseph Mastropaolo is offering $10,000 to anyone who can disprove the literal story in Genesis. Mastopaolo is a Young Earth Creationist and is proposing a legal-like court trial to decide the issue. Challengers will have to put up $10,000 of their own, winner takes all. This should be a great case study for those interested in the “public understanding of science”.

According to this article, scientists have found that the speed of light in a vacuum is not constant, because the vacuum isn’t really empty—at the quantum level particles are continually popping in and out of existence. Finding that the speed of light varies slightly in a vacuum isn’t particularly interesting; we’ve known that the vacuum isn’t really empty for a while now. What is more interesting is the scientists’ argument that the speed of light depends on the electric charges of those particles, and the average speed of light depends on the total number of particles in the universe.

The disparity between men and women in scientific and technical careers has been a continuing source of concern for many. A recent study suggests that the disparity might not be due to systemic discrimination, but because females who are good a both math and language (as measured by the SAT) are more likely that similarly talented men to choose humanistic rather than technical careers. Faye Flam takes a look at how the media has covered this potentially polarizing story.

In a reminder that the effects of global warming can be hard to predict and often counter-intuitive, scientists have observed that the melting of glacial ice in Antartica is causing the Antarctic sea ice to expand. And in another study, scientists seem to have solved the case of the missing heat, much to the consternation of those dastardly global warming deniers.

Image via Canadian Space Agency

Chris Hadfield became the first Canadian commander of the International Space Station, and spoke with Stephen Harper in a live chat. Earlier this month, Harper faced some mockery on issues of science policy after requesting questions for Hadfield on Twitter.

NASA’s Curiosity rover has discovered indications of past water, following last week’s evidence of a potentially “habitable environment.”

National Geographic, along with Revive & Restore, hosted a TEDx event on the topic of DeExtinction. The conference included reports of progress towards reviving the gastric-brooding frog. Critics worry that deextinction could undermine conservation efforts or introduce environmental problems.

This weekend, homes and businesses around the world are expected to celebrate Earth Hour. Vancouver was awarded this year’s Global Earth Hour Capital by the WWF for its innovative climate and sustainability initiatives. Earth Hour is not without critics, however; some argue that it is futile, anti-technology, and even energy-wasting, while others promote consuming more energy in protest.

NYC Mayor’s Office

New York City Mayor Bloomberg’s plan to eliminate large-sized sugary drinks begins tomorrow, opening a 3-month grace period for business owners. Reaction to the ban has been mixed, and a lawsuit by the soft-drink industry and related business groups is pending. UPDATE: As of Monday afternoon, the soda ban has been blocked by New York Supreme Court Judge Milton Tingling, who cited the regulations’ “arbitrary and capricious consequences.”  (CNBC).

The “God” particle overhyped? You don’t say! Physicists at the Moriond conference report that the Higgs boson completes the standard model but falls short of the “exotic” promises of “New Physics,” including super symmetry (The Globe and Mail).

Also “oversold”? The claim that a healthy lifestyle protects us from heart disease. In a new Lancet study, CT scans show evidence of atherosclerosis in one third of examined mummies across numerous ancient cultures, including some from hunter-gatherer societies. This suggests to some researchers that clogged arteries are not merely a symptom of modern, sedentary lifestyle.