Using the NASA/ESA Hubble Space Telescope, for the first time [in 2003], astronomers have observed the atmosphere of an extrasolar planet evaporating off into space (shown in blue in this illustration). The planet’s outer atmosphere is extended and heated so much by the nearby star that it starts to escape the planet’s gravity. Hydrogen boils off in the planet’s upper atmosphere under the searing heat from the star. HD 209458b belongs to a type of extrasolar planet known as ‘hot Jupiters’. These planets orbit precariously close to their stars. They are giant, gaseous planets that must have formed in the cold outer reaches of the star system and then spiralled into their close orbits. This new discovery might help explain why ‘hot Jupiters’ so often orbit a few million kilometres from their parent stars. They are not usually found much closer than 7 million kilometres, as is the case for HD 209458b. Currently, the current closest distance is 5.7 million kilometres. Hot Jupiters have orbits that are as brief as 3 days, but not shorter. Perhaps the evaporation of the atmosphere plays a role in setting an inner boundary for orbits of hot Jupiters.
Oxytocin is on its way up in the world. The hormone, whose name is medical Greek for “quick birth”, has led a relatively anonymous life since its discovery early in the 20th century, then known for its ability to induce uterine contractions in pregnant women and stimulate breast feeding. But in recent years, researchers have found it to be heavily implicated in social behavior. Paul Zak is betting on it as the moral molecule. Perhaps more interestingly, it has been linked to social disorders like autism, and may cure some of its symptoms.
Lower levels of oxytocin in the blood plasma have been documented in children with autism. Mutations in the oxytocin receptor gene have been found to occur in autistic individuals. Conversely, the ability to mind-read—to infer other people’s mental states by interpreting subtle cues—has been shown to improve after administering oxytocin intranasally, both in neurotypical and autistic individuals.
Rats with defective oxytocin receptor genes exhibit a sort of social amnesia: they can’t learn to recognize the smell of their peers, but they can still learn to recognize non-social smells. This amnesia can be cured by administering oxytocin to the rats, or induced in healthy rats via an oxytocin antagonist.
Oxytocin reduces social fear. It’s released during orgasm. It’s been speculated that the feelings of empathy and closeness caused by MDMA, the active component of Ecstasy, may be due to oxytocin release caused by MDMA’s stimulation of serotonin receptors.
Oxytocin can be administered to the brain as a nasal spray, allowing it to cross the blood-brain barrier. In a few years, you could be spraying it up before a date, a job interview, or to alleviate symptoms of autistic spectrum disorders. Oxytocin release can also be stimulated by hugs, sex, or other natural forms of human contact. On the other hand, people with Williams syndrome—a syndrome characterized by, among other things, pathological trust of strangers—may learn to be less gullible with the help of an oxytocin antagonist.
We should be very careful not to reduce complex phenomena like trust, social interaction and morality to the actions of a single molecule. There is almost certainly a more complex picture here, and one that science will continue to unravel in the years to come. But right now, oxytocin is looking really good.