Robyn Adderly
SpaceX Falcon 9’s latest launch a success, but landing failed
After two postponed launch attempts, the latest launch of SpaceX’s Falcon 9 rocket finally successfully lifted off at Cape Canaveral on Friday and delivered the commercial communications satellite SES-9 to a geostationary transfer orbit.
While most rockets are designed to burn on re-entry, SpaceX rockets are designed not only to withstand the return, but also to land on a launch pad or ocean landing site.
Due to the unique orbit target altitude of 40,600 kilometres, an experimental landing of the Falcon 9 first stage onto a drone ship named “Of Course I Still Love You” was attempted but was not expected to be successful.
The first stage made it back to the drone ship, but, as predicted, the landing failed. SpaceX founder Elon Musk tweeted shortly afterwards: “Rocket landed hard on the droneship. Didn't expect this one to work (v hot reentry), but next flight has a good chance.”
Solar eclipse from above
This week while residents of islands and nations in the western Pacific looked up in the early morning hours to observe a total eclipse of the Sun, the Deep Space Climate Observatory (DSCOVR) looked down from space and captured the shadow of the Moon marching across Earth’s sunlit face.
“What is unique for us is that being near the Sun-Earth line, we follow the complete passage of the lunar shadow from one edge of the Earth to the other,” said Adam Szabo, NASA’s project scientist for DSCOVR.“A geosynchronous satellite would have to be lucky to have the middle of an eclipse at noon local time for it. I am not aware of anybody ever capturing the full eclipse in one set of images or video.”
Thirteen images were snapped of the event, which will be the only total solar eclipse of 2016.
Ten years of discovery by Mars Reconnaissance Orbiter
NASA's Mars Reconnaissance Orbiter (MRO) began orbiting Mars a decade ago this week. Since then, it’s described in unprecedented detail a planet that held diverse wet environments billions of years ago, and remains dynamic today.
One example of MRO's major discoveries was published last year, about the possibility of liquid water being present seasonally on present-day Mars.
"This mission has helped us appreciate how much Mars – a planet that has changed greatly over time – continues to change today," said MRO project scientist Rich Zurek of NASA's Jet Propulsion Laboratory, Pasadena, California. JPL manages the mission.
A symbiotic relationship
Warthogs living in Uganda have learntto rid themselves of annoying ticks by seeking out the grooming services of some accommodating neighbours: a group of mongooses looking for snacks.
A study of the warthogs of Queen Elizabeth National Park have learnt to lie down in the presence of banded mongooses. In response, the mongoose cleaning crew have learnt to inspect the wild pigs for ticks, going so far as to climb on top of their customers to gain access to more parasites.
The warthog-mongoose encounter is a rare example of mammals exhibiting a symbiotic relationship called mutualism, where two animal species form a partnership with benefits for both groups. The warthogs get a cleaning and the mongooses get a meal.
Other examples of mutualism include rhinos, zebras, and other animals that receive visits from parasite-eating birds called oxpeckers, and bees that feed on the nectar of flowers and deliver pollen to other plants.
The importance of newborn cells in memory encoding
Neuroscientists have described the activity of newly generated brain cells in awake mice – a process known as adult neurogenesis – and revealed the critical role these cells play in forming memories.
Research published this week in the journal Neuron also offers clues as to what happens when the memory-encoding process goes awry.
This image shows granule cells of part of the brain called the dentate gyrus in a mouse. Newborn cells are labelled in red, shown here integrating into mature granule cells' existing cellular circuitry.
"These findings reveal that adult-born granule cells are required not only to encode the memory of a new experience, but also to determine whether one experience is different from the next," said Mazen Kheirbek, one of the researchers in the study. "The merging of memories, which is what we observed when the adult-born cells were silenced, is a key feature of a wide range of psychiatric conditions – from anxiety and mood disorders to post-traumatic stress disorder."
